WorldWideScience

Sample records for fidelity thermal simulators

  1. Toward Improved Fidelity of Thermal Explosion Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, A L; Becker, R; Howard, W M; Wemhoff, A

    2009-07-17

    We will present results of an effort to improve the thermal/chemical/mechanical modeling of HMX based explosive like LX04 and LX10 for thermal cook-off. The original HMX model and analysis scheme were developed by Yoh et.al. for use in the ALE3D modeling framework. The current results were built to remedy the deficiencies of that original model. We concentrated our efforts in four areas. The first area was addition of porosity to the chemical material model framework in ALE3D that is used to model the HMX explosive formulation. This is needed to handle the roughly 2% porosity in solid explosives. The second area was the improvement of the HMX reaction network, which included the inclusion of a reactive phase change model base on work by Henson et.al. The third area required adding early decomposition gas species to the CHEETAH material database to develop more accurate equations of state for gaseous intermediates and products. Finally, it was necessary to improve the implicit mechanics module in ALE3D to more naturally handle the long time scales associated with thermal cook-off. The application of the resulting framework to the analysis of the Scaled Thermal Explosion (STEX) experiments will be discussed.

  2. Fidelity in clinical simulation

    DEFF Research Database (Denmark)

    Jensen, Sanne; Nøhr, Christian; Rasmussen, Stine Loft

    2013-01-01

    Clinical simulation may be used to identify user needs for context sensitive functionalities in e-Health. The objective with this paper is to describe how user requirements and use cases in a large EHR-platform procurement may be validated by clinical simulation using a very low-fidelity prototype...... without any existing test data. Instead of using test scenarios and use cases, the healthcare professionals who are participating in the clinical simulation are generating both scenario and patient data themselves. We found that this approach allows for an imaginative discussion, not restricted by known...... functionalities and limitations, of the ideal EHR-platform. Subsequently, we discuss benefits and challenges of using an extremely low fidelity environment and discuss the degree of fidelity necessary for conducting clinical simulation....

  3. High Fidelity BWR Fuel Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Su Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    This report describes the Consortium for Advanced Simulation of Light Water Reactors (CASL) work conducted for completion of the Thermal Hydraulics Methods (THM) Level 3 milestone THM.CFD.P13.03: High Fidelity BWR Fuel Simulation. High fidelity computational fluid dynamics (CFD) simulation for Boiling Water Reactor (BWR) was conducted to investigate the applicability and robustness performance of BWR closures. As a preliminary study, a CFD model with simplified Ferrule spacer grid geometry of NUPEC BWR Full-size Fine-mesh Bundle Test (BFBT) benchmark has been implemented. Performance of multiphase segregated solver with baseline boiling closures has been evaluated. Although the mean values of void fraction and exit quality of CFD result for BFBT case 4101-61 agreed with experimental data, the local void distribution was not predicted accurately. The mesh quality was one of the critical factors to obtain converged result. The stability and robustness of the simulation was mainly affected by the mesh quality, combination of BWR closure models. In addition, the CFD modeling of fully-detailed spacer grid geometry with mixing vane is necessary for improving the accuracy of CFD simulation.

  4. Nuclear power plant training simulator fidelity assessment

    International Nuclear Information System (INIS)

    Carter, R.J.; Laughery, K.R.

    1985-01-01

    The fidelity assessment portion of a methodology for evaluating nuclear power plant simulation facilities in regard to their appropriateness for conducting the Nuclear Regulatory Commission's operating test was described. The need for fidelity assessment, data sources, and fidelity data to be collected are addressed. Fidelity data recording, collection, and analysis are discussed. The processes for drawing conclusions from the fidelity assessment and evaluating the adequacy of the simulator control-room layout were presented. 3 refs

  5. Coupled high fidelity thermal hydraulics and neutronics for reactor safety simulations

    International Nuclear Information System (INIS)

    Vincent A. Mousseau; Hongbin Zhang; Haihua Zhao

    2008-01-01

    This work is a continuation of previous work on the importance of accuracy in the simulation of nuclear reactor safety transients. This work is qualitative in nature and future work will be more quantitative. The focus of this work will be on a simplified single phase nuclear reactor primary. The transient of interest investigates the importance of accuracy related to passive (inherent) safety systems. The transient run here will be an Unprotected Loss of Flow (ULOF) transient. Here the coolant pump is turned off and the un-SCRAM-ed reactor transitions from forced to free convection (Natural circulation). Results will be presented that show the difference that the first order in time truncation physics makes on the transient. The purpose of this document is to illuminate a possible problem in traditional reactor simulation approaches. Detailed studies need to be done on each simulation code for each transient analyzed to determine if the first order truncation physics plays an important role

  6. The Numerical Nuclear Reactor for High-Fidelity Integrated Simulation of Neutronic, Thermal-Hydraulic, and Thermo-Mechanical Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. S.; Ju, H. G.; Jeon, T. H. and others

    2005-03-15

    A comprehensive high fidelity reactor core modeling capability has been developed for detailed analysis of current and advanced reactor designs as part of a US-ROK collaborative I-NERI project. High fidelity was accomplished by integrating highly refined solution modules for the coupled neutronic, thermal-hydraulic, and thermo-mechanical phenomena. Each solution module employs methods and models that are formulated faithfully to the first-principles governing the physics, real geometry, and constituents. Specifically, the critical analysis elements that are incorporated in the coupled code capability are whole-core neutron transport solution, ultra-fine-mesh computational fluid dynamics/heat transfer solution, and finite-element-based thermo-mechanics solution, all obtained with explicit (fuel pin cell level) heterogeneous representations of the components of the core. The vast computational problem resulting from such highly refined modeling is solved on massively parallel computers, and serves as the 'numerical nuclear reactor'. Relaxation of modeling parameters were also pursued to make problems run on clusters of workstations and PCs for smaller scale applications as well.

  7. The Numerical Nuclear Reactor for High-Fidelity Integrated Simulation of Neutronic, Thermal-Hydraulic, and Thermo-Mechanical Phenomena

    International Nuclear Information System (INIS)

    Kim, K. S.; Ju, H. G.; Jeon, T. H. and others

    2005-03-01

    A comprehensive high fidelity reactor core modeling capability has been developed for detailed analysis of current and advanced reactor designs as part of a US-ROK collaborative I-NERI project. High fidelity was accomplished by integrating highly refined solution modules for the coupled neutronic, thermal-hydraulic, and thermo-mechanical phenomena. Each solution module employs methods and models that are formulated faithfully to the first-principles governing the physics, real geometry, and constituents. Specifically, the critical analysis elements that are incorporated in the coupled code capability are whole-core neutron transport solution, ultra-fine-mesh computational fluid dynamics/heat transfer solution, and finite-element-based thermo-mechanics solution, all obtained with explicit (fuel pin cell level) heterogeneous representations of the components of the core. The vast computational problem resulting from such highly refined modeling is solved on massively parallel computers, and serves as the 'numerical nuclear reactor'. Relaxation of modeling parameters were also pursued to make problems run on clusters of workstations and PCs for smaller scale applications as well

  8. Status report on high fidelity reactor simulation

    International Nuclear Information System (INIS)

    Palmiotti, G.; Smith, M.; Rabiti, C.; Lewis, E.; Yang, W.; Leclere, M.; Siegel, A.; Fischer, P.; Kaushik, D.; Ragusa, J.; Lottes, J.; Smith, B.

    2006-01-01

    This report presents the effort under way at Argonne National Laboratory toward a comprehensive, integrated computational tool intended mainly for the high-fidelity simulation of sodium-cooled fast reactors. The main activities carried out involved neutronics, thermal hydraulics, coupling strategies, software architecture, and high-performance computing. A new neutronics code, UNIC, is being developed. The first phase involves the application of a spherical harmonics method to a general, unstructured three-dimensional mesh. The method also has been interfaced with a method of characteristics. The spherical harmonics equations were implemented in a stand-alone code that was then used to solve several benchmark problems. For thermal hydraulics, a computational fluid dynamics code called Nek5000, developed in the Mathematics and Computer Science Division for coupled hydrodynamics and heat transfer, has been applied to a single-pin, periodic cell in the wire-wrap geometry typical of advanced burner reactors. Numerical strategies for multiphysics coupling have been considered and higher-accuracy efficient methods proposed to finely simulate coupled neutronic/thermal-hydraulic reactor transients. Initial steps have been taken in order to couple UNIC and Nek5000, and simplified problems have been defined and solved for testing. Furthermore, we have begun developing a lightweight computational framework, based in part on carefully selected open source tools, to nonobtrusively and efficiently integrate the individual physics modules into a unified simulation tool

  9. Physiological Based Simulator Fidelity Design Guidance

    Science.gov (United States)

    Schnell, Thomas; Hamel, Nancy; Postnikov, Alex; Hoke, Jaclyn; McLean, Angus L. M. Thom, III

    2012-01-01

    The evolution of the role of flight simulation has reinforced assumptions in aviation that the degree of realism in a simulation system directly correlates to the training benefit, i.e., more fidelity is always better. The construct of fidelity has several dimensions, including physical fidelity, functional fidelity, and cognitive fidelity. Interaction of different fidelity dimensions has an impact on trainee immersion, presence, and transfer of training. This paper discusses research results of a recent study that investigated if physiological-based methods could be used to determine the required level of simulator fidelity. Pilots performed a relatively complex flight task consisting of mission task elements of various levels of difficulty in a fixed base flight simulator and a real fighter jet trainer aircraft. Flight runs were performed using one forward visual channel of 40 deg. field of view for the lowest level of fidelity, 120 deg. field of view for the middle level of fidelity, and unrestricted field of view and full dynamic acceleration in the real airplane. Neuro-cognitive and physiological measures were collected under these conditions using the Cognitive Avionics Tool Set (CATS) and nonlinear closed form models for workload prediction were generated based on these data for the various mission task elements. One finding of the work described herein is that simple heart rate is a relatively good predictor of cognitive workload, even for short tasks with dynamic changes in cognitive loading. Additionally, we found that models that used a wide range of physiological and neuro-cognitive measures can further boost the accuracy of the workload prediction.

  10. RELAP5: Applications to high fidelity simulation

    International Nuclear Information System (INIS)

    Johnsen, G.W.; Chen, Y.S.

    1988-01-01

    RELAP5 is a pressurized water reactor system transient simulation code for use in nuclear power plant safety analysis. The latest version, MOD2, may be used to simulate and study a wide variety of abnormal events, including loss-of-coolant accidents, operational transients, and transients in which the entire secondary system must be modeled. In this paper, a basic overview of the code is given, its assessment and application illustrated, and progress toward its use as a high fidelity simulator described. 7 refs., 7 figs

  11. High-Fidelity Roadway Modeling and Simulation

    Science.gov (United States)

    Wang, Jie; Papelis, Yiannis; Shen, Yuzhong; Unal, Ozhan; Cetin, Mecit

    2010-01-01

    Roads are an essential feature in our daily lives. With the advances in computing technologies, 2D and 3D road models are employed in many applications, such as computer games and virtual environments. Traditional road models were generated by professional artists manually using modeling software tools such as Maya and 3ds Max. This approach requires both highly specialized and sophisticated skills and massive manual labor. Automatic road generation based on procedural modeling can create road models using specially designed computer algorithms or procedures, reducing the tedious manual editing needed for road modeling dramatically. But most existing procedural modeling methods for road generation put emphasis on the visual effects of the generated roads, not the geometrical and architectural fidelity. This limitation seriously restricts the applicability of the generated road models. To address this problem, this paper proposes a high-fidelity roadway generation method that takes into account road design principles practiced by civil engineering professionals, and as a result, the generated roads can support not only general applications such as games and simulations in which roads are used as 3D assets, but also demanding civil engineering applications, which requires accurate geometrical models of roads. The inputs to the proposed method include road specifications, civil engineering road design rules, terrain information, and surrounding environment. Then the proposed method generates in real time 3D roads that have both high visual and geometrical fidelities. This paper discusses in details the procedures that convert 2D roads specified in shape files into 3D roads and civil engineering road design principles. The proposed method can be used in many applications that have stringent requirements on high precision 3D models, such as driving simulations and road design prototyping. Preliminary results demonstrate the effectiveness of the proposed method.

  12. High Fidelity In Situ Shoulder Dystocia Simulation

    Directory of Open Access Journals (Sweden)

    Andrew Pelikan, MD

    2018-04-01

    Full Text Available Audience: Resident physicians, emergency department (ED staff Introduction: Precipitous deliveries are high acuity, low occurrence in most emergency departments. Shoulder dystocia is a rare but potentially fatal complication of labor that can be relieved by specific maneuvers that must be implemented in a timely manner. This simulation is designed to educate resident learners on the critical management steps in a shoulder dystocia presenting to the emergency department. A special aspect of this simulation is the unique utilization of the “Noelle” model with an instructing physician at bedside maneuvering the fetus through the stations of labor and providing subtle adjustments to fetal positioning not possible though a mechanized model. A literature search of “shoulder dystocia simulation” consists primarily of obstetrics and mid-wife journals, many of which utilize various mannequin models. None of the reviewed articles utilized a bedside provider maneuvering the fetus with the Noelle model, making this method unique. While the Noelle model is equipped with a remote-controlled motor that automatically rotates and delivers the baby either to the head or to the shoulders and can produce a turtle sign and which will prevent delivery of the baby until signaled to do so by the instructor, using the bedside instructor method allows this simulation to be reproduced with less mechanistically advanced and lower cost models.1-5 Objectives: At the end of this simulation, learners will: 1 Recognize impending delivery and mobilize appropriate resources (ie, both obstetrics [OB] and NICU/pediatrics; 2 Identify risk factors for shoulder dystocia based on history and physical; 3 Recognize shoulder dystocia during delivery; 4 Demonstrate maneuvers to relieve shoulder dystocia; 5 Communicate with team members and nursing staff during resuscitation of a critically ill patient. Method: High-fidelity simulation. Topics: High fidelity, in situ, Noelle model

  13. Fidelity Witnesses for Fermionic Quantum Simulations

    Science.gov (United States)

    Gluza, M.; Kliesch, M.; Eisert, J.; Aolita, L.

    2018-05-01

    The experimental interest and developments in quantum spin-1 /2 chains has increased uninterruptedly over the past decade. In many instances, the target quantum simulation belongs to the broader class of noninteracting fermionic models, constituting an important benchmark. In spite of this class being analytically efficiently tractable, no direct certification tool has yet been reported for it. In fact, in experiments, certification has almost exclusively relied on notions of quantum state tomography scaling very unfavorably with the system size. Here, we develop experimentally friendly fidelity witnesses for all pure fermionic Gaussian target states. Their expectation value yields a tight lower bound to the fidelity and can be measured efficiently. We derive witnesses in full generality in the Majorana-fermion representation and apply them to experimentally relevant spin-1 /2 chains. Among others, we show how to efficiently certify strongly out-of-equilibrium dynamics in critical Ising chains. At the heart of the measurement scheme is a variant of importance sampling specially tailored to overlaps between covariance matrices. The method is shown to be robust against finite experimental-state infidelities.

  14. High Fidelity Simulation of Atomization in Diesel Engine Sprays

    Science.gov (United States)

    2015-09-01

    state Figure 5. Q criterion isosurface colored by streamwise velocity in the diesel spray injector as viewed from the nozzle exit. Figure 6. U contour...fidelity simulation approach was adopted to study the atom- ization physics of a diesel injector with detailed nozzle internal geometry. The nozzle flow...26; Stanford, CA 14. ABSTRACT A high fidelity numerical simulation of jet breakup and spray formation from a complex diesel fuel injector has been

  15. Fidelity of Simulation for Pilot Training

    Science.gov (United States)

    1980-12-01

    indicators of joint angles. The combination of all the pro- prioceptive senses permits subjects to perceive body accelerations based on the biomechanical ...constraints III. Controllers A. Flight controls 1. Center stick, column, side stick, collective 2. Pedals (yaw control, brakes) 3. Thrust controllers 4...the most sensitive elements in terms of fidelity require- ments. The force-generating systems associated with the stick or column and pedals are

  16. Recommendations on Model Fidelity for Wind Turbine Gearbox Simulations: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y.; Keller, J.; La Cava, W.; Austin, J.; Nejad, A. R.; Halse, C.; Bastard, L.; Helsen, J.

    2015-01-01

    This work investigates the minimum level of fidelity required to accurately simulate wind turbine gearboxes using state-of-the-art design tools. Excessive model fidelity including drivetrain complexity, gearbox complexity, excitation sources, and imperfections, significantly increases computational time, but may not provide a commensurate increase in the value of the results. Essential design parameters are evaluated, including the planetary load-sharing factor, gear tooth load distribution, and sun orbit motion. Based on the sensitivity study results, recommendations for the minimum model fidelities are provided.

  17. Interprofessional education in pharmacology using high-fidelity simulation.

    Science.gov (United States)

    Meyer, Brittney A; Seefeldt, Teresa M; Ngorsuraches, Surachat; Hendrickx, Lori D; Lubeck, Paula M; Farver, Debra K; Heins, Jodi R

    2017-11-01

    This study examined the feasibility of an interprofessional high-fidelity pharmacology simulation and its impact on pharmacy and nursing students' perceptions of interprofessionalism and pharmacology knowledge. Pharmacy and nursing students participated in a pharmacology simulation using a high-fidelity patient simulator. Faculty-facilitated debriefing included discussion of the case and collaboration. To determine the impact of the activity on students' perceptions of interprofessionalism and their ability to apply pharmacology knowledge, surveys were administered to students before and after the simulation. Attitudes Toward Health Care Teams scale (ATHCT) scores improved from 4.55 to 4.72 on a scale of 1-6 (p = 0.005). Almost all (over 90%) of the students stated their pharmacology knowledge and their ability to apply that knowledge improved following the simulation. A simulation in pharmacology is feasible and favorably affected students' interprofessionalism and pharmacology knowledge perceptions. Pharmacology is a core science course required by multiple health professions in early program curricula, making it favorable for incorporation of interprofessional learning experiences. However, reports of high-fidelity interprofessional simulation in pharmacology courses are limited. This manuscript contributes to the literature in the field of interprofessional education by demonstrating that an interprofessional simulation in pharmacology is feasible and can favorably affect students' perceptions of interprofessionalism. This manuscript provides an example of a pharmacology interprofessional simulation that faculty in other programs can use to build similar educational activities. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Hand ultrasound: a high-fidelity simulation of lung sliding.

    Science.gov (United States)

    Shokoohi, Hamid; Boniface, Keith

    2012-09-01

    Simulation training has been effectively used to integrate didactic knowledge and technical skills in emergency and critical care medicine. In this article, we introduce a novel model of simulating lung ultrasound and the features of lung sliding and pneumothorax by performing a hand ultrasound. The simulation model involves scanning the palmar aspect of the hand to create normal lung sliding in varying modes of scanning and to mimic ultrasound features of pneumothorax, including "stratosphere/barcode sign" and "lung point." The simple, reproducible, and readily available simulation model we describe demonstrates a high-fidelity simulation surrogate that can be used to rapidly illustrate the signs of normal and abnormal lung sliding at the bedside. © 2012 by the Society for Academic Emergency Medicine.

  19. High Fidelity Simulation of Primary Atomization in Diesel Engine Sprays

    Science.gov (United States)

    Ivey, Christopher; Bravo, Luis; Kim, Dokyun

    2014-11-01

    A high-fidelity numerical simulation of jet breakup and spray formation from a complex diesel fuel injector at ambient conditions has been performed. A full understanding of the primary atomization process in fuel injection of diesel has not been achieved for several reasons including the difficulties accessing the optically dense region. Due to the recent advances in numerical methods and computing resources, high fidelity simulations of atomizing flows are becoming available to provide new insights of the process. In the present study, an unstructured un-split Volume-of-Fluid (VoF) method coupled to a stochastic Lagrangian spray model is employed to simulate the atomization process. A common rail fuel injector is simulated by using a nozzle geometry available through the Engine Combustion Network. The working conditions correspond to a single orifice (90 μm) JP-8 fueled injector operating at an injection pressure of 90 bar, ambient condition at 29 bar, 300 K filled with 100% nitrogen with Rel = 16,071, Wel = 75,334 setting the spray in the full atomization mode. The experimental dataset from Army Research Lab is used for validation in terms of spray global parameters and local droplet distributions. The quantitative comparison will be presented and discussed. Supported by Oak Ridge Associated Universities and the Army Research Laboratory.

  20. Patterns of communication in high-fidelity simulation.

    Science.gov (United States)

    Anderson, Judy K; Nelson, Kimberly

    2015-01-01

    High-fidelity simulation is commonplace in nursing education. However, critical thinking, decision making, and psychomotor skills scenarios are emphasized. Scenarios involving communication occur in interprofessional or intraprofessional settings. The importance of effective nurse-patient communication is reflected in statements from the American Nurses Association and Quality and Safety Education for Nurses, and in the graduate outcomes of most nursing programs. This qualitative study examined the patterns of communication observed in video recordings of a medical-surgical scenario with 71 senior students in a baccalaureate program. Thematic analysis revealed patterns of (a) focusing on tasks, (b) communicating-in-action, and (c) being therapeutic. Additional categories under the patterns included missing opportunities, viewing the "small picture," relying on informing, speaking in "medical tongues," offering choices…okay?, feeling uncomfortable, and using therapeutic techniques. The findings suggest the importance of using high-fidelity simulation to develop expertise in communication. In addition, the findings reinforce the recommendation to prioritize communication aspects of scenarios and debriefing for all simulations. Copyright 2015, SLACK Incorporated.

  1. Importance of debriefing in high-fidelity simulations

    Directory of Open Access Journals (Sweden)

    Igor Karnjuš

    2014-04-01

    Full Text Available Debriefing has been identified as one of the most important parts of a high-fidelity simulation learning process. During debriefing, the mentor invites learners to critically assess the knowledge and skills used during the execution of a scenario. Regardless of the abundance of studies that have examined simulation-based education, debriefing is still poorly defined.The present article examines the essential features of debriefing, its phases, techniques and methods with a systematic review of recent publications. It emphasizes the mentor’s role, since the effectiveness of debriefing largely depends on the mentor’s skills to conduct it. The guidelines that allow the mentor to evaluate his performance in conducting debriefing are also presented. We underline the importance of debriefing in clinical settings as part of continuous learning process. Debriefing allows the medical teams to assess their performance and develop new strategies to achieve higher competencies.Although the debriefing is the cornerstone of high-fidelity simulation learning process, it also represents an important learning strategy in the clinical setting. Many important aspects of debriefing are still poorly explored and understood, therefore this part of the learning process should be given greater attention in the future.

  2. High fidelity simulation effectiveness in nursing students' transfer of learning.

    Science.gov (United States)

    Kirkman, Tera R

    2013-07-13

    Members of nursing faculty are utilizing interactive teaching tools to improve nursing student's clinical judgment; one method that has been found to be potentially effective is high fidelity simulation (HFS). The purpose of this time series design study was to determine whether undergraduate nursing students were able to transfer knowledge and skills learned from classroom lecture and a HFS clinical to the traditional clinical setting. Students (n=42) were observed and rated on their ability to perform a respiratory assessment. The observations and ratings took place at the bedside, prior to a respiratory lecture, following the respiratory lecture, and following simulation clinical. The findings indicated that there was a significant difference (p=0.000) in transfer of learning demonstrated over time. Transfer of learning was demonstrated and the use of HFS was found to be an effective learning and teaching method. Implications of results are discussed.

  3. Realism in paediatric emergency simulations: A prospective comparison of in situ, low fidelity and centre-based, high fidelity scenarios.

    Science.gov (United States)

    O'Leary, Fenton; Pegiazoglou, Ioannis; McGarvey, Kathryn; Novakov, Ruza; Wolfsberger, Ingrid; Peat, Jennifer

    2018-02-01

    To measure scenario participant and faculty self-reported realism, engagement and learning for the low fidelity, in situ simulations and compare this to high fidelity, centre-based simulations. A prospective survey of scenario participants and faculty completing in situ and centre-based paediatric simulations. There were 382 responses, 276 from scenario participants and 106 from faculty with 241 responses from in situ and 141 from centre-based simulations. Scenario participant responses showed significantly higher ratings for the centre-based simulations for respiratory rate (P = 0.007), pulse (P = 0.036), breath sounds (P = 0.002), heart sounds (P realism for engagement and learning. © 2017 The Authors Emergency Medicine Australasia published by John Wiley & Sons Australia, Ltd on behalf of Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  4. Teaching Palatoplasty Using a High-Fidelity Cleft Palate Simulator.

    Science.gov (United States)

    Cheng, Homan; Podolsky, Dale J; Fisher, David M; Wong, Karen W; Lorenz, H Peter; Khosla, Rohit K; Drake, James M; Forrest, Christopher R

    2018-01-01

    Cleft palate repair is a challenging procedure for cleft surgeons to teach. A novel high-fidelity cleft palate simulator has been described for surgeon training. This study evaluates the simulator's effect on surgeon procedural confidence and palatoplasty knowledge among learners. Plastic surgery trainees attended a palatoplasty workshop consisting of a didactic session on cleft palate anatomy and repair followed by a simulation session. Participants completed a procedural confidence questionnaire and palatoplasty knowledge test immediately before and after the workshop. All participants reported significantly higher procedural confidence following the workshop (p cleft palate surgery experience had higher procedural confidence before (p cleft palate experience did not have higher mean baseline test scores than those with no experience (30 percent versus 28 percent; p > 0.05), but did have significantly higher scores after the workshop (61 percent versus 35 percent; p cleft palate simulator as a training tool to teach palatoplasty. Improved procedural confidence and knowledge were observed after a single session, with benefits seen among trainees both with and without previous cleft experience.

  5. Fidelity considerations for simulation-based usability assessments of mobile ICT for hospitals

    DEFF Research Database (Denmark)

    Dahl, Yngve; Alsos, Ole A; Svanæs, Dag

    2010-01-01

    training simulation fidelity theories. Based on a review of the training simulation literature, a set of fidelity dimensions through which training simulations are often adjusted to meet specific goals are identified. It is argued that the same mechanisms can be used in usability assessments of mobile ICT...... for hospitals. Our argument is substantiated by using the identified set of fidelity dimensions in a retrospective analysis of two usability assessments. The analysis explains how the configuration of fidelity dimensions, each reflecting various degrees of realism vis-à-vis the actual performance context...

  6. Casting thermal simulation

    International Nuclear Information System (INIS)

    Shamsuddin bin Sulaiman

    1994-01-01

    The whole of this study is concerned with process simulation in casting processes. This study describes the application of the finite element method as an aid to simulating the thermal design of a high pressure die casting die by analysing the cooling transients in the casting cycle. Two types of investigation were carried out to model the linear and non-linear cooling behavior with consideration of a thermal interface effect. The simulated cooling for different stages were presented in temperature contour form. These illustrate the successful application of the Finite Element Method to model the process and they illustrate the significance of the thermal interface at low pressure

  7. The effect of high fidelity simulated learning methods on physiotherapy pre-registration education: a systematic review protocol.

    Science.gov (United States)

    Roberts, Fiona; Cooper, Kay

    2017-11-01

    The objective of this review is to identify if high fidelity simulated learning methods are effective in enhancing clinical/practical skills compared to usual, low fidelity simulated learning methods in pre-registration physiotherapy education.

  8. Cellular Scanning Strategy for Selective Laser Melting: Capturing Thermal Trends with a Low-Fidelity, Pseudo-Analytical Model

    Directory of Open Access Journals (Sweden)

    Sankhya Mohanty

    2014-01-01

    Full Text Available Simulations of additive manufacturing processes are known to be computationally expensive. The resulting large runtimes prohibit their application in secondary analysis requiring several complete simulations such as optimization studies, and sensitivity analysis. In this paper, a low-fidelity pseudo-analytical model has been introduced to enable such secondary analysis. The model has been able to mimic a finite element model and was able to capture the thermal trends associated with the process. The model has been validated and subsequently applied in a small optimization case study. The pseudo-analytical modelling technique is established as a fast tool for primary modelling investigations.

  9. Effect on High versus Low Fidelity Haptic Feedback in a Virtual Reality Baseball Simulation

    DEFF Research Database (Denmark)

    Ryge, Andreas Nicolaj; Thomsen, Lui Albæk; Berthelsen, Theis

    2017-01-01

    In this paper we present a within-subjects study (n=26) comparing participants' experience of three kinds of haptic feedback (no haptic feedback, low fidelity haptic feedback and high fidelity haptic feedback) simulating the impact between a virtual baseball bat and ball. We noticed some minor ef...

  10. High-Fidelity Simulation for Neonatal Nursing Education: An Integrative Review of the Literature.

    Science.gov (United States)

    Cooper, Allyson

    2015-01-01

    The lack of safe avenues to develop neonatal nursing competencies using human subjects leads to the notion that simulation education for neonatal nurses might be an ideal form of education. This integrative literature review compares traditional, teacher-centered education with high-fidelity simulation education for neonatal nurses. It examines the theoretical frameworks used in neonatal nursing education and outlines the advantages of this type of training, including improving communication and teamwork; providing an innovative pedagogical approach; and aiding in skill acquisition, confidence, and participant satisfaction. The importance of debriefing is also examined. High-fidelity simulation is not without disadvantages, including its significant cost, the time associated with training, the need for very complex technical equipment, and increased faculty resource requirements. Innovative uses of high-fidelity simulation in neonatal nursing education are suggested. High-fidelity simulation has great potential but requires additional research to fully prove its efficacy.

  11. High Fidelity Simulation of Littoral Environments: Applications and Coupling of Participating Models

    National Research Council Canada - National Science Library

    Allard, Richard

    2003-01-01

    The High Fidelity Simulation of Littoral Environments (HFSoLE) Challenge Project (C75) encompasses a suite of seven oceanographic models capable of exchanging information in a physically meaningful sense across the littoral environment...

  12. Advanced High and Low Fidelity HPC Simulations of FCS Concept Designs for Dynamic Systems

    National Research Council Canada - National Science Library

    Sandhu, S. S; Kanapady, R; Tamma, K. K

    2004-01-01

    ...) resources of many Army initiatives. In this paper we present a new and advanced HPC based rigid and flexible modeling and simulation technology capable of adaptive high/low fidelity modeling that is useful in the initial design concept...

  13. A Low Fidelity Simulation To Examine The Design Space For An Expendable Active Decoy

    Science.gov (United States)

    2017-12-01

    SIMULATIONS FOR ANALYSIS ................................11 C. BENEFITS OF MODELING AND SIMULATION IN THE SYSTEM ENGINEERING PROCESS ... simulation may be able to predict the performance parameters of the system of interest (SOI) accurately. The systems engineering process utilizes the low...fidelity simulation developed in this thesis during the early phases of the systems acquisition process : namely, the concept exploration, concept of

  14. Simulator fidelity and training effectiveness: a comprehensive bibliography with selected annotations

    International Nuclear Information System (INIS)

    Rankin, W.L.; Bolton, P.A.; Shikiar, R.; Saari, L.M.

    1984-05-01

    This document contains a comprehensive bibliography on the topic of simulator fidelity and training effectiveness, prepared during the preliminary phases of work on an NRC-sponsored project on the Role of Nuclear Power Plant Simulators in Operator Licensing and Training. Section A of the document is an annotated bibliography consisting of articles and reports with relevance to the psychological aspects of simulator fidelity and the effectiveness of training simulators in a variety of settings, including military. The annotated items are drawn from a more comprehensive bibliography, presented in Section B, listing documents treating the role of simulators in operator training both in the nuclear industry and elsewhere

  15. Recommendations on Model Fidelity for Wind Turbine Gearbox Simulations; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; Lacava, W.; Austin, J.; Nejad, A.; Halse, C.; Bastard, L.; Helsen, J.

    2015-02-01

    This work investigates the minimum level of fidelity required to accurately simulate wind turbine gearboxes using state-of-the-art design tools. Excessive model fidelity including drivetrain complexity, gearbox complexity, excitation sources, and imperfections, significantly increases computational time, but may not provide a commensurate increase in the value of the results. Essential designparameters are evaluated, including the planetary load-sharing factor, gear tooth load distribution, and sun orbit motion. Based on the sensitivity study results, recommendations for the minimum model fidelities are provided.

  16. A high-fidelity approach towards simulation of pool boiling

    Energy Technology Data Exchange (ETDEWEB)

    Yazdani, Miad; Radcliff, Thomas; Soteriou, Marios; Alahyari, Abbas A. [United Technologies Research Center, East Hartford, Connecticut 06108 (United States)

    2016-01-15

    A novel numerical approach is developed to simulate the multiscale problem of pool-boiling phase change. The particular focus is to develop a simulation technique that is capable of predicting the heat transfer and hydrodynamic characteristics of nucleate boiling and the transition to critical heat flux on surfaces of arbitrary shape and roughness distribution addressing a critical need to design enhanced boiling heat transfer surfaces. The macro-scale of the phase change and bubble dynamics is addressed through employing off-the-shelf Computational Fluid Dynamics (CFD) methods for interface tracking and interphase mass and energy transfer. The micro-scale of the microlayer, which forms at early stage of bubble nucleation near the wall, is resolved through asymptotic approximation of the thin-film theory which provides a closed-form solution for the distribution of the micro-layer and its influence on the evaporation process. In addition, the sub-grid surface roughness is represented stochastically through probabilistic density functions and its role in bubble nucleation and growth is then represented based on the thermodynamics of nucleation process. This combination of deterministic CFD, local approximation, and stochastic representation allows the simulation of pool boiling on any surface with known roughness and enhancement characteristics. The numerical model is validated for dynamics and hydrothermal characteristics of a single nucleated bubble on a flat surface against available literature data. In addition, the prediction of pool-boiling heat transfer coefficient is verified against experimental measurements as well as reputable correlations for various roughness distributions and different surface orientations. Finally, the model is employed to demonstrate pool-boiling phenomenon on enhanced structures with reentrance cavities and to explore the effect of enhancement feature design on thermal and hydrodynamic characteristics of these surfaces.

  17. A high-fidelity approach towards simulation of pool boiling

    International Nuclear Information System (INIS)

    Yazdani, Miad; Radcliff, Thomas; Soteriou, Marios; Alahyari, Abbas A.

    2016-01-01

    A novel numerical approach is developed to simulate the multiscale problem of pool-boiling phase change. The particular focus is to develop a simulation technique that is capable of predicting the heat transfer and hydrodynamic characteristics of nucleate boiling and the transition to critical heat flux on surfaces of arbitrary shape and roughness distribution addressing a critical need to design enhanced boiling heat transfer surfaces. The macro-scale of the phase change and bubble dynamics is addressed through employing off-the-shelf Computational Fluid Dynamics (CFD) methods for interface tracking and interphase mass and energy transfer. The micro-scale of the microlayer, which forms at early stage of bubble nucleation near the wall, is resolved through asymptotic approximation of the thin-film theory which provides a closed-form solution for the distribution of the micro-layer and its influence on the evaporation process. In addition, the sub-grid surface roughness is represented stochastically through probabilistic density functions and its role in bubble nucleation and growth is then represented based on the thermodynamics of nucleation process. This combination of deterministic CFD, local approximation, and stochastic representation allows the simulation of pool boiling on any surface with known roughness and enhancement characteristics. The numerical model is validated for dynamics and hydrothermal characteristics of a single nucleated bubble on a flat surface against available literature data. In addition, the prediction of pool-boiling heat transfer coefficient is verified against experimental measurements as well as reputable correlations for various roughness distributions and different surface orientations. Finally, the model is employed to demonstrate pool-boiling phenomenon on enhanced structures with reentrance cavities and to explore the effect of enhancement feature design on thermal and hydrodynamic characteristics of these surfaces

  18. Decoherence and Fidelity in Teleportation of Coherent Photon-Added Two-Mode Squeezed Thermal States

    Science.gov (United States)

    Li, Heng-Mei; Yuan, Hong-Chun; Wan, Zhi-Long; Wang, Zhen

    2018-04-01

    We theoretically introduce a kind of non-Gaussian entangled resources, i.e., coherent photon-added two-mode squeezed thermal states (CPA-TMSTS), by successively performing coherent photon addition operation to the two-mode squeezed thermal states. The normalization factor related to bivariate Hermite polynomials is obtained. Based upon it, the nonclassicality and decoherence process are analyzed by virtue of the Wigner function. It is shown that the coherent photon addition operation is an effective way in generating partial negative values of Wigner function, which clearly manifests the nonclassicality and non-Gaussianity of the target states. Additionally, the fidelity in teleporting coherent states using CPA-TMSTS as entangled resource is quantified both analytically and numerically. It is found that the CPA-TMSTS is an entangled resource of high-efficiency and high-fidelity in quantum teleportation.

  19. Cellular Scanning Strategy for Selective Laser Melting: Capturing Thermal Trends with a Low-Fidelity, Pseudo-Analytical Model

    DEFF Research Database (Denmark)

    Mohanty, Sankhya; Hattel, Jesper Henri

    2014-01-01

    Simulations of additivemanufacturing processes are known to be computationally expensive.The resulting large runtimes prohibit their application in secondary analysis requiring several complete simulations such as optimization studies, and sensitivity analysis. In this paper, a low-fidelity pseud...

  20. High-fidelity simulation among bachelor students in simulation groups and use of different roles.

    Science.gov (United States)

    Thidemann, Inger-Johanne; Söderhamn, Olle

    2013-12-01

    Cost limitations might challenge the use of high-fidelity simulation as a teaching-learning method. This article presents the results of a Norwegian project including two simulation studies in which simulation teaching and learning were studied among students in the second year of a three-year bachelor nursing programme. The students were organised into small simulation groups with different roles; nurse, physician, family member and observer. Based on experiences in different roles, the students evaluated the simulation design characteristics and educational practices used in the simulation. In addition, three simulation outcomes were measured; knowledge (learning), Student Satisfaction and Self-confidence in Learning. The simulation was evaluated to be a valuable teaching-learning method to develop professional understanding and insight independent of roles. Overall, the students rated the Student Satisfaction and Self-confidence in Learning as high. Knowledge about the specific patient focus increased after the simulation activity. Students can develop practical, communication and collaboration skills, through experiencing the nurse's role. Assuming the observer role, students have the potential for vicarious learning, which could increase the learning value. Both methods of learning (practical experience or vicarious learning) may bridge the gap between theory and practice and contribute to the development of skills in reflective and critical thinking. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Progress in the Utilization of High-Fidelity Simulation in Basic Science Education

    Science.gov (United States)

    Helyer, Richard; Dickens, Peter

    2016-01-01

    High-fidelity patient simulators are mainly used to teach clinical skills and remain underutilized in teaching basic sciences. This article summarizes our current views on the use of simulation in basic science education and identifies pitfalls and opportunities for progress.

  2. Degrees of reality: airway anatomy of high-fidelity human patient simulators and airway trainers.

    Science.gov (United States)

    Schebesta, Karl; Hüpfl, Michael; Rössler, Bernhard; Ringl, Helmut; Müller, Michael P; Kimberger, Oliver

    2012-06-01

    Human patient simulators and airway training manikins are widely used to train airway management skills to medical professionals. Furthermore, these patient simulators are employed as standardized "patients" to evaluate airway devices. However, little is known about how realistic these patient simulators and airway-training manikins really are. This trial aimed to evaluate the upper airway anatomy of four high-fidelity patient simulators and two airway trainers in comparison with actual patients by means of radiographic measurements. The volume of the pharyngeal airspace was the primary outcome parameter. Computed tomography scans of 20 adult trauma patients without head or neck injuries were compared with computed tomography scans of four high-fidelity patient simulators and two airway trainers. By using 14 predefined distances, two cross-sectional areas and three volume parameters of the upper airway, the manikins' similarity to a human patient was assessed. The pharyngeal airspace of all manikins differed significantly from the patients' pharyngeal airspace. The HPS Human Patient Simulator (METI®, Sarasota, FL) was the most realistic high-fidelity patient simulator (6/19 [32%] of all parameters were within the 95% CI of human airway measurements). The airway anatomy of four high-fidelity patient simulators and two airway trainers does not reflect the upper airway anatomy of actual patients. This finding may impact airway training and confound comparative airway device studies.

  3. Developing High-Fidelity Health Care Simulation Scenarios: A Guide for Educators and Professionals

    Science.gov (United States)

    Alinier, Guillaume

    2011-01-01

    The development of appropriate scenarios is critical in high-fidelity simulation training. They need to be developed to address specific learning objectives, while not preventing other learning points from emerging. Buying a patient simulator, finding a volunteer to act as the patient, or even obtaining ready-made scenarios from another simulation…

  4. High-Fidelity Simulation in Biomedical and Aerospace Engineering

    Science.gov (United States)

    Kwak, Dochan

    2005-01-01

    Contents include the following: Introduction / Background. Modeling and Simulation Challenges in Aerospace Engineering. Modeling and Simulation Challenges in Biomedical Engineering. Digital Astronaut. Project Columbia. Summary and Discussion.

  5. Technical Basis for Physical Fidelity of NRC Control Room Training Simulators for Advanced Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Minsk, Brian S.; Branch, Kristi M.; Bates, Edward K.; Mitchell, Mark R.; Gore, Bryan F.; Faris, Drury K.

    2009-10-09

    The objective of this study is to determine how simulator physical fidelity influences the effectiveness of training the regulatory personnel responsible for examination and oversight of operating personnel and inspection of technical systems at nuclear power reactors. It seeks to contribute to the U.S. Nuclear Regulatory Commission’s (NRC’s) understanding of the physical fidelity requirements of training simulators. The goal of the study is to provide an analytic framework, data, and analyses that inform NRC decisions about the physical fidelity requirements of the simulators it will need to train its staff for assignment at advanced reactors. These staff are expected to come from increasingly diverse educational and experiential backgrounds.

  6. High fidelity thermal-hydraulic analysis using CFD and massively parallel computers

    International Nuclear Information System (INIS)

    Weber, D.P.; Wei, T.Y.C.; Brewster, R.A.; Rock, Daniel T.; Rizwan-uddin

    2000-01-01

    Thermal-hydraulic analyses play an important role in design and reload analysis of nuclear power plants. These analyses have historically relied on early generation computational fluid dynamics capabilities, originally developed in the 1960s and 1970s. Over the last twenty years, however, dramatic improvements in both computational fluid dynamics codes in the commercial sector and in computing power have taken place. These developments offer the possibility of performing large scale, high fidelity, core thermal hydraulics analysis. Such analyses will allow a determination of the conservatism employed in traditional design approaches and possibly justify the operation of nuclear power systems at higher powers without compromising safety margins. The objective of this work is to demonstrate such a large scale analysis approach using a state of the art CFD code, STAR-CD, and the computing power of massively parallel computers, provided by IBM. A high fidelity representation of a current generation PWR was analyzed with the STAR-CD CFD code and the results were compared to traditional analyses based on the VIPRE code. Current design methodology typically involves a simplified representation of the assemblies, where a single average pin is used in each assembly to determine the hot assembly from a whole core analysis. After determining this assembly, increased refinement is used in the hot assembly, and possibly some of its neighbors, to refine the analysis for purposes of calculating DNBR. This latter calculation is performed with sub-channel codes such as VIPRE. The modeling simplifications that are used involve the approximate treatment of surrounding assemblies and coarse representation of the hot assembly, where the subchannel is the lowest level of discretization. In the high fidelity analysis performed in this study, both restrictions have been removed. Within the hot assembly, several hundred thousand to several million computational zones have been used, to

  7. Low vs. high fidelity: the importance of 'realism' in the simulation of a stone treatment procedure.

    Science.gov (United States)

    Sarmah, Piyush; Voss, Jim; Ho, Adrian; Veneziano, Domenico; Somani, Bhaskar

    2017-07-01

    Simulation training for stone surgery is now increasingly used as part of training curricula worldwide. A combination of low and high fidelity simulators has been used with varying degrees of 'realism' provided by them. In this review, we discuss low and high fidelity simulators used for ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) stone procedures with their advantages, disadvantages and future direction for endourological simulation surgery. The final goal will be to understand whether or not 'realism' has to be considered as a critical element in simulation for this field. There is a wide range of simulators available for URS and PCNL training ranging from basic bench-type model to advanced virtual reality and cadaveric models, all providing various levels of realism. Although basic models might be more useful to novices, advanced models allow for complex and more realistic simulation training. With a wide variety of simulators now available and given the latest novelties in modular training curriculums, combination of low and high fidelity simulators that provide a realistic and cost-effective option seems to be the way forward. It is unavoidable that simulators will play an increasing role in endourological training.

  8. The Validity and Incremental Validity of Knowledge Tests, Low-Fidelity Simulations, and High-Fidelity Simulations for Predicting Job Performance in Advanced-Level High-Stakes Selection

    Science.gov (United States)

    Lievens, Filip; Patterson, Fiona

    2011-01-01

    In high-stakes selection among candidates with considerable domain-specific knowledge and experience, investigations of whether high-fidelity simulations (assessment centers; ACs) have incremental validity over low-fidelity simulations (situational judgment tests; SJTs) are lacking. Therefore, this article integrates research on the validity of…

  9. A High-Fidelity Batch Simulation Environment for Integrated Batch and Piloted Air Combat Simulation Analysis

    Science.gov (United States)

    Goodrich, Kenneth H.; McManus, John W.; Chappell, Alan R.

    1992-01-01

    A batch air combat simulation environment known as the Tactical Maneuvering Simulator (TMS) is presented. The TMS serves as a tool for developing and evaluating tactical maneuvering logics. The environment can also be used to evaluate the tactical implications of perturbations to aircraft performance or supporting systems. The TMS is capable of simulating air combat between any number of engagement participants, with practical limits imposed by computer memory and processing power. Aircraft are modeled using equations of motion, control laws, aerodynamics and propulsive characteristics equivalent to those used in high-fidelity piloted simulation. Databases representative of a modern high-performance aircraft with and without thrust-vectoring capability are included. To simplify the task of developing and implementing maneuvering logics in the TMS, an outer-loop control system known as the Tactical Autopilot (TA) is implemented in the aircraft simulation model. The TA converts guidance commands issued by computerized maneuvering logics in the form of desired angle-of-attack and wind axis-bank angle into inputs to the inner-loop control augmentation system of the aircraft. This report describes the capabilities and operation of the TMS.

  10. Debriefing after High-Fidelity Simulation and Knowledge Retention: A Quasi-Experimental Study

    Science.gov (United States)

    Olson, Susan L.

    2013-01-01

    High-fidelity simulation (HFS) use in nursing education has been a frequent research topic in recent years. Previous research included studies on the use of HFS with nursing students, focusing on their feelings of self-confidence and anxiety. However, research focused specifically on the debriefing portion of HFS was limited. This quantitative,…

  11. Evaluating Outcomes of High Fidelity Simulation Curriculum in a Community College Nursing Program

    Science.gov (United States)

    Denlea, Gregory Richard

    2017-01-01

    This study took place at a Wake Technical Community College, a multi-campus institution in Raleigh, North Carolina. An evaluation of the return on investment in high fidelity simulation used by an associate degree of nursing program was conducted with valid and reliable instruments. The study demonstrated that comparable student outcomes are…

  12. Pharmacy Students' Learning and Satisfaction With High-Fidelity Simulation to Teach Drug-Induced Dyspepsia

    Science.gov (United States)

    2013-01-01

    Objective. To assess second-year pharmacy students’ acquisition of pharmacotherapy knowledge and clinical competence from participation in a high-fidelity simulation, and to determine the impact on the simulation experience of implementing feedback from previous students. Design. A high-fidelity simulation was used to present a patient case scenario of drug-induced dyspepsia with gastrointestinal bleeding. The simulation was revised based on feedback from a previous class of students to include a smaller group size, provision of session material to students in advance, and an improved learning environment. Assessment. Student performance on pre- and post-simulation knowledge and clinical competence tests documented significant improvements in students' knowledge of dyspepsia and associated symptoms, with the greatest improvement on questions relating to the hemodynamic effects of gastrointestinal bleeding. Students were more satisfied with the simulation experience compared to students in the earlier study. Conclusion. Participation in a high-fidelity simulation allowed pharmacy students to apply knowledge and skills learned in the classroom. Improved student satisfaction with the simulation suggests that implementing feedback obtained through student course evaluations can be an effective means of improving the curriculum. PMID:23519773

  13. High Fidelity Regolith Simulation Tool for ISRU Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has serious unmet needs for simulation tools capable of predicting the behavior of lunar regolith in proposed excavation, transport and handling systems....

  14. Specification of Training Simulator Fidelity: A Research Plan

    Science.gov (United States)

    1982-02-01

    Knowlede --Dunnette (1976) has recently reviewed the literature in the areas of human skills, abilities, and knowledges. The establishment of what types... management 6. Other than rational user responses to R&D studies and to training simulators 7. Deficiencies in training simulator design 23...proficient at managing the introduction of training innovations by applying those factors that can be controlled to influence acceptance. (p. 19) The

  15. A high fidelity model and code generator for the simulation of BOP systems

    International Nuclear Information System (INIS)

    Galen, S.; Vinay, M.

    1993-01-01

    TOPMERET represents a significant advance in the modelling fidelity of Balance of Plant systems (BOP). It is extremely flexible and can accommodate a variety of systems, including main steam, feedwater, turbine, condenser, offgas, large volumes, such as the containment, and water systems such as service water. It handles both normal and abnormal operating scenarios, including pipe break accidents. It was tested successfully on various simulators, and meets the fidelity required of BOP system models so as to successfully integrate with the high level of control automation of European designs. (Z.S.) 1 ref

  16. GNES-R: Global nuclear energy simulator for reactors task 1: High-fidelity neutron transport

    International Nuclear Information System (INIS)

    Clarno, K.; De Almeida, V.; D'Azevedo, E.; De Oliveira, C.; Hamilton, S.

    2006-01-01

    A multi-laboratory, multi-university collaboration has formed to advance the state-of-the-art in high-fidelity, coupled-physics simulation of nuclear energy systems. We are embarking on the first-phase in the development of a new suite of simulation tools dedicated to the advancement of nuclear science and engineering technologies. We seek to develop and demonstrate a new generation of multi-physics simulation tools that will explore the scientific phenomena of tightly coupled physics parameters within nuclear systems, support the design and licensing of advanced nuclear reactors, and provide benchmark quality solutions for code validation. In this paper, we have presented the general scope of the collaborative project and discuss the specific challenges of high-fidelity neutronics for nuclear reactor simulation and the inroads we have made along this path. The high-performance computing neutronics code system utilizes the latest version of SCALE to generate accurate, problem-dependent cross sections, which are used in NEWTRNX - a new 3-D, general-geometry, discrete-ordinates solver based on the Slice-Balance Approach. The Global Nuclear Energy Simulator for Reactors (GNES-R) team is embarking on a long-term simulation development project that encompasses multiple laboratories and universities for the expansion of high-fidelity coupled-physics simulation of nuclear energy systems. (authors)

  17. A study on the usefulness of high fidelity patient simulation in undergraduate medical education

    Directory of Open Access Journals (Sweden)

    Bikramjit Pal

    2018-01-01

    Full Text Available Introduction: Simulation is the imitation of the operation of a real-world process or system over time. Innovative simulation training solutions are now being used to train medical professionals in an attempt to reduce the number of safety concerns that have adverse effects on the patients. Objectives: (a To determine its usefulness as a teaching or learning tool for management of surgical emergencies, both in the short term and medium term by students’ perception. (b To plan future teaching methodology regarding hi-fidelity simulation based on the study outcomes and re-assessment of the current training modules. Methods: Quasi-experimental time series design with pretest-posttest interventional study. Quantitative data was analysed in terms of Mean, Standard Deviation and standard error of Mean. Statistical tests of significance like Repeated Measure of Analysis of Variance (ANOVA were used for comparisons. P value < 0.001 was considered to be statistically significant. Results: The students opined that the simulated sessions on high fidelity simulators had encouraged their active participation which was appropriate to their current level of learning. It helped them to think fast and the training sessions resembled a real life situation. The study showed that learning had progressively improved with each session of simulation with corresponding decrease in stress. Conclusion: Implementation of high fidelity simulation based learning in our Institute had been perceived favourably by a large number of students in enhancing their knowledge over time in management of trauma and surgical emergencies.

  18. High Fidelity Simulation of Transcritical Liquid Jet in Crossflow

    Science.gov (United States)

    Li, Xiaoyi; Soteriou, Marios

    2017-11-01

    Transcritical injection of liquid fuel occurs in many practical applications such as diesel, rocket and gas turbine engines. In these applications, the liquid fuel, with a supercritical pressure and a subcritical temperature, is introduced into an environment where both the pressure and temperature exceeds the critical point of the fuel. The convoluted physics of the transition from subcritical to supercritical conditions poses great challenges for both experimental and numerical investigations. In this work, numerical simulation of a binary system of a subcritical liquid injecting into a supercritical gaseous crossflow is performed. The spatially varying fluid thermodynamic and transport properties are evaluated using established cubic equation of state and extended corresponding state principles with established mixing rules. To efficiently account for the large spatial gradients in property variations, an adaptive mesh refinement technique is employed. The transcritical simulation results are compared with the predictions from the traditional subcritical jet atomization simulations.

  19. Self-Reflection of Video-Recorded High-Fidelity Simulations and Development of Clinical Judgment.

    Science.gov (United States)

    Bussard, Michelle E

    2016-09-01

    Nurse educators are increasingly using high-fidelity simulators to improve prelicensure nursing students' ability to develop clinical judgment. Traditionally, oral debriefing sessions have immediately followed the simulation scenarios as a method for students to connect theory to practice and therefore develop clinical judgment. Recently, video recording of the simulation scenarios is being incorporated. This qualitative, interpretive description study was conducted to identify whether self-reflection on video-recorded high-fidelity simulation (HFS) scenarios helped prelicensure nursing students to develop clinical judgment. Tanner's clinical judgment model was the framework for this study. Four themes emerged from this study: Confidence, Communication, Decision Making, and Change in Clinical Practice. This study indicated that self-reflection of video-recorded HFS scenarios is beneficial for prelicensure nursing students to develop clinical judgment. [J Nurs Educ. 2016;55(9):522-527.]. Copyright 2016, SLACK Incorporated.

  20. Simulation based medical education; teaching normal delivery on intermediate fidelity simulator to medical students.

    Science.gov (United States)

    Shah, Nighat; Baig, Lubna; Shah, Nusrat; Hussain, Riffat; Aly, Syed Moyn

    2017-10-01

    To assess the effectiveness of medium fidelity simulator in teaching normal vaginal delivery to medical students. The quasi-experimental study was conducted at the professional development centre of the Jinnah Sindh Medical University, Karachi, from June to December 2015, and comprised medical students. Third-year medical students were included. They were divided into two groups. Group A was taught normal delivery through traditional PowerPoint and group B through simulator. The instruments used for assessing knowledge were pre-test and post-test, for skills of labour/delivery checklist of performance was used, and perception forms were filled to evaluate workshops/learning environment by students. Of the 76 participants, there were 36(47.4%) in group A and 40(52.6%) in group B. The overall mean age of the participants was 20.86±0.76 years in group B and 20.60±0.95 years in group A (p=0.19). The mean grade point average of the participants was 2.89±0.47 in group A and 2.87±0.48 in group B (p=0.81).Group B performed much better in skill of delivery having a mean score of 8.91±3.20compared to group A which had mean of 5.67±1.84 (pSimulation-based skill learning showed significantly better results.

  1. Use of Low-Fidelity Simulation Laboratory Training for Teaching Radiology Residents CT-Guided Procedures.

    Science.gov (United States)

    Picard, Melissa; Nelson, Rachel; Roebel, John; Collins, Heather; Anderson, M Bret

    2016-11-01

    To determine the benefit of the addition of low-fidelity simulation-based training to the standard didactic-based training in teaching radiology residents common CT-guided procedures. This was a prospective study involving 24 radiology residents across all years in a university program. All residents underwent standard didactic lecture followed by low-fidelity simulation-based training on three common CT-guided procedures: random liver biopsy, lung nodule biopsy, and drain placement. Baseline knowledge, confidence, and performance assessments were obtained after the didactic session and before the simulation training session. Approximately 2 months later, all residents participated in a simulation-based training session covering all three of these procedures. Knowledge, confidence, and performance data were obtained afterward. These assessments covered topics related to preprocedure workup, intraprocedure steps, and postprocedure management. Knowledge data were collected based on a 15-question assessment. Confidence data were obtained based on a 5-point Likert-like scale. Performance data were obtained based on successful completion of predefined critical steps. There was significant improvement in knowledge (P = .005), confidence (P simulation-based training to the standard didactic curriculum for all procedures. This study suggests that the addition of low-fidelity simulation-based training to a standard didactic-based curriculum is beneficial in improving resident knowledge, confidence, and tested performance of common CT-guided procedures. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  2. An Investigation of the Impact of Aerodynamic Model Fidelity on Close-In Combat Effectiveness Prediction in Piloted Simulation

    Science.gov (United States)

    Persing, T. Ray; Bellish, Christine A.; Brandon, Jay; Kenney, P. Sean; Carzoo, Susan; Buttrill, Catherine; Guenther, Arlene

    2005-01-01

    Several aircraft airframe modeling approaches are currently being used in the DoD community for acquisition, threat evaluation, training, and other purposes. To date there has been no clear empirical study of the impact of airframe simulation fidelity on piloted real-time aircraft simulation study results, or when use of a particular level of fidelity is indicated. This paper documents a series of piloted simulation studies using three different levels of airframe model fidelity. This study was conducted using the NASA Langley Differential Maneuvering Simulator. Evaluations were conducted with three pilots for scenarios requiring extensive maneuvering of the airplanes during air combat. In many cases, a low-fidelity modified point-mass model may be sufficient to evaluate the combat effectiveness of the aircraft. However, in cases where high angle-of-attack flying qualities and aerodynamic performance are a factor or when precision tracking ability of the aircraft must be represented, use of high-fidelity models is indicated.

  3. Towards developing high-fidelity simulated learning environment training modules in audiology.

    Science.gov (United States)

    Dzulkarnain, A A; Rahmat, S; Mohd Puzi, N A F; Badzis, M

    2017-02-01

    This discussion paper reviews and synthesises the literature on simulated learning environment (SLE) from allied health sciences, medical and nursing in general and audiology specifically. The focus of the paper is on discussing the use of high-fidelity (HF) SLE and describing the challenges for developing a HF SLE for clinical audiology training. Through the review of the literature, this paper discusses seven questions, (i) What is SLE? (ii) What are the types of SLEs? (iii) How is SLE classified? (iv) What is HF SLE? (v) What types of SLEs are available in audiology and their level of fidelity? (vi) What are the components needed for developing HF SLE? (vii) What are the possible types of HF SLEs that are suitable for audiology training? Publications were identified by structured searches from three major databases PubMed, Web of Knowledge and PsychInfo and from the reference lists of relevant articles. The authors discussed and mapped the levels of fidelity of SLE audiology training modules from the literature and the learning domains involved in the clinical audiology courses. The discussion paper has highlighted that most of the existing SLE audiology training modules consist of either low- or medium-fidelity types of simulators. Those components needed to achieve a HF SLE for audiology training are also highlighted. Overall, this review recommends that the combined approach of different levels and types of SLE could be used to obtain a HF SLE training module in audiology training.

  4. Bioelectric Control of a 757 Class High Fidelity Aircraft Simulation

    Science.gov (United States)

    Jorgensen, Charles; Wheeler, Kevin; Stepniewski, Slawomir; Norvig, Peter (Technical Monitor)

    2000-01-01

    This paper presents results of a recent experiment in fine grain Electromyographic (EMG) signal recognition, We demonstrate bioelectric flight control of 757 class simulation aircraft landing at San Francisco International Airport. The physical instrumentality of a pilot control stick is not used. A pilot closes a fist in empty air and performs control movements which are captured by a dry electrode array on the arm, analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. A Vision Dome immersive display is used to create a VR world for the aircraft body mechanics and flight changes to pilot movements. Inner loop surfaces and differential aircraft thrust is controlled using a hybrid neural network architecture that combines a damage adaptive controller (Jorgensen 1998, Totah 1998) with a propulsion only based control system (Bull & Kaneshige 1997). Thus the 757 aircraft is not only being flown bioelectrically at the pilot level but also demonstrates damage adaptive neural network control permitting adaptation to severe changes in the physical flight characteristics of the aircraft at the inner loop level. To compensate for accident scenarios, the aircraft uses remaining control surface authority and differential thrust from the engines. To the best of our knowledge this is the first time real time bioelectric fine-grained control, differential thrust based control, and neural network damage adaptive control have been integrated into a single flight demonstration. The paper describes the EMG pattern recognition system and the bioelectric pattern recognition methodology.

  5. High-Fidelity Simulation: Preparing Dental Hygiene Students for Managing Medical Emergencies.

    Science.gov (United States)

    Bilich, Lisa A; Jackson, Sarah C; Bray, Brenda S; Willson, Megan N

    2015-09-01

    Medical emergencies can occur at any time in the dental office, so being prepared to properly manage the situation can be the difference between life and death. The entire dental team must be properly trained regarding all aspects of emergency management in the dental clinic. The aim of this study was to evaluate a new educational approach using a high-fidelity simulator to prepare dental hygiene students for medical emergencies. This study utilized high-fidelity simulation (HFS) to evaluate the abilities of junior dental hygiene students at Eastern Washington University to handle a medical emergency in the dental hygiene clinic. Students were given a medical emergency scenario requiring them to assess the emergency and implement life-saving protocols in a simulated "real-life" situation using a high-fidelity manikin. Retrospective data were collected for four years from the classes of 2010 through 2013 (N=114). The results indicated that learning with simulation was effective in helping the students identify the medical emergency in a timely manner, implement emergency procedures correctly, locate and correctly utilize contents of the emergency kit, administer appropriate intervention/treatment for a specific patient, and provide the patient with appropriate follow-up instructions. For dental hygiene programs seeking to enhance their curricula in the area of medical emergencies, this study suggests that HFS is an effective tool to prepare students to appropriately handle medical emergencies. Faculty calibration is essential to standardize simulation.

  6. High Fidelity Ion Beam Simulation of High Dose Neutron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Wirth, Brian; Motta, Athur; Morgan, Dane; Kaoumi, Djamel; Hosemann, Peter; Odette, Robert

    2018-04-30

    Project Objective: The objective of this proposal is to demonstrate the capability to predict the evolution of microstructure and properties of structural materials in-reactor and at high doses, using ion irradiation as a surrogate for reactor irradiations. “Properties” includes both physical properties (irradiated microstructure) and the mechanical properties of the material. Demonstration of the capability to predict properties has two components. One is ion irradiation of a set of alloys to yield an irradiated microstructure and corresponding mechanical behavior that are substantially the same as results from neutron exposure in the appropriate reactor environment. Second is the capability to predict the irradiated microstructure and corresponding mechanical behavior on the basis of improved models, validated against both ion and reactor irradiations and verified against ion irradiations. Taken together, achievement of these objectives will yield an enhanced capability for simulating the behavior of materials in reactor irradiations

  7. High-fidelity stack and system modeling for tubular solid oxide fuel cell system design and thermal management

    Science.gov (United States)

    Kattke, K. J.; Braun, R. J.; Colclasure, A. M.; Goldin, G.

    Effective thermal integration of system components is critical to the performance of small-scale (design and simulation tool for a highly-integrated tubular SOFC system. The SOFC is modeled using a high fidelity, one-dimensional tube model coupled to a three-dimensional computational fluid dynamics (CFD) model. Recuperative heat exchange between SOFC tail-gas and inlet cathode air and reformer air/fuel preheat processes are captured within the CFD model. Quasi one-dimensional thermal resistance models of the tail-gas combustor (TGC) and catalytic partial oxidation (CPOx) complete the balance of plant (BoP) and SOFC coupling. The simulation tool is demonstrated on a prototype 66-tube SOFC system with 650 W of nominal gross power. Stack cooling predominately occurs at the external surface of the tubes where radiation accounts for 66-92% of heat transfer. A strong relationship develops between the power output of a tube and its view factor to the relatively cold cylinder wall surrounding the bundle. The bundle geometry yields seven view factor groupings which correspond to seven power groupings with tube powers ranging from 7.6-10.8 W. Furthermore, the low effectiveness of the co-flow recuperator contributes to lower tube powers at the bundle outer periphery.

  8. First experiences of high-fidelity simulation training in junior nursing students in Korea.

    Science.gov (United States)

    Lee, Suk Jeong; Kim, Sang Suk; Park, Young-Mi

    2015-07-01

    This study was conducted to explore first experiences of high-fidelity simulation training in Korean nursing students, in order to develop and establish more effective guidelines for future simulation training in Korea. Thirty-three junior nursing students participated in high-fidelity simulation training for the first time. Using both qualitative and quantitative methods, data were collected from reflective journals and questionnaires of simulation effectiveness after simulation training. Descriptive statistics were used to analyze simulation effectiveness and content analysis was performed with the reflective journal data. Five dimensions and 31 domains, both positive and negative experiences, emerged from qualitative analysis: (i) machine-human interaction in a safe environment; (ii) perceived learning capability; (iii) observational learning; (iv) reconciling practice with theory; and (v) follow-up debriefing effect. More than 70% of students scored high on increased ability to identify changes in the patient's condition, critical thinking, decision-making, effectiveness of peer observation, and debriefing in effectiveness of simulation. This study reported both positive and negative experiences of simulation. The results of this study could be used to set the level of task difficulty in simulation. Future simulation programs can be designed by reinforcing the positive experiences and modifying the negative results. © 2014 The Authors. Japan Journal of Nursing Science © 2014 Japan Academy of Nursing Science.

  9. Quantum Fidelity and Thermal Phase Transitions in a Two-Dimensional Spin System

    International Nuclear Information System (INIS)

    Wang Bo; Kou Su-Peng; Huang Hai-Lin; Sun Zhao-Yu

    2012-01-01

    We investigate the ability of quantum fidelity in detecting the classical phase transitions (CPTs) in a two-dimensional Heisenberg—Ising mixed spin model, which has a very rich phase diagram and is exactly soluble. For a two-site subsystem of the model, the reduced fidelity (including the operator fidelity and the fidelity susceptibility) at finite temperatures is calculated, and it is found that an extreme value presents at the critical temperature, thus shows a signal for the CPTs. In some parameter region, the signal becomes blurred. We propose to use the 'normalized fidelity susceptibility' to solve this problem

  10. Evaluation of simulation motion fidelity criteria in the vertical and directional axes

    Science.gov (United States)

    Schroeder, Jeffery A.

    1993-01-01

    An evaluation of existing motion fidelity criteria was conducted on the NASA Ames Vertical Motion Simulator. Experienced test pilots flew single-axis repositioning tasks in both the vertical and the directional axes. Using a first-order approximation of a hovering helicopter, tasks were flown with variations only in the filters that attenuate the commands to the simulator motion system. These filters had second-order high-pass characteristics, and the variations were made in the filter gain and natural frequency. The variations spanned motion response characteristics from nearly full math-model motion to fixed-base. Between configurations, pilots recalibrated their motion response perception by flying the task with full motion. Pilots subjectively rated the motion fidelity of subsequent configurations relative to this full motion case, which was considered the standard for comparison. The results suggested that the existing vertical-axis criterion was accurate for combinations of gain and natural frequency changes. However, if only the gain or the natural frequency was changed, the rated motion fidelity was better than the criterion predicted. In the vertical axis, the objective and subjective results indicated that a larger gain reduction was tolerated than the existing criterion allowed. The limited data collected in the yaw axis revealed that pilots had difficulty in distinguishing among the variations in the pure yaw motion cues.

  11. Multi-fidelity uncertainty quantification in large-scale predictive simulations of turbulent flow

    Science.gov (United States)

    Geraci, Gianluca; Jofre-Cruanyes, Lluis; Iaccarino, Gianluca

    2017-11-01

    The performance characterization of complex engineering systems often relies on accurate, but computationally intensive numerical simulations. It is also well recognized that in order to obtain a reliable numerical prediction the propagation of uncertainties needs to be included. Therefore, Uncertainty Quantification (UQ) plays a fundamental role in building confidence in predictive science. Despite the great improvement in recent years, even the more advanced UQ algorithms are still limited to fairly simplified applications and only moderate parameter dimensionality. Moreover, in the case of extremely large dimensionality, sampling methods, i.e. Monte Carlo (MC) based approaches, appear to be the only viable alternative. In this talk we describe and compare a family of approaches which aim to accelerate the convergence of standard MC simulations. These methods are based on hierarchies of generalized numerical resolutions (multi-level) or model fidelities (multi-fidelity), and attempt to leverage the correlation between Low- and High-Fidelity (HF) models to obtain a more accurate statistical estimator without introducing additional HF realizations. The performance of these methods are assessed on an irradiated particle laden turbulent flow (PSAAP II solar energy receiver). This investigation was funded by the United States Department of Energy's (DoE) National Nuclear Security Administration (NNSA) under the Predicitive Science Academic Alliance Program (PSAAP) II at Stanford University.

  12. Are Simulation Stethoscopes a Useful Adjunct for Emergency Residents' Training on High-fidelity Mannequins?

    Science.gov (United States)

    Warrington, Steven J; Beeson, Michael S; Fire, Frank L

    2013-05-01

    Emergency medicine residents use simulation training for many reasons, such as gaining experience with critically ill patients and becoming familiar with disease processes. Residents frequently criticize simulation training using current high-fidelity mannequins due to the poor quality of physical exam findings present, such as auscultatory findings, as it may lead them down an alternate diagnostic or therapeutic pathway. Recently wireless remote programmed stethoscopes (simulation stethoscopes) have been developed that allow wireless transmission of any sound to a stethoscope receiver, which improves the fidelity of a physical examination and the simulation case. Following institutional review committee approval, 14 PGY1-3 emergency medicine residents were assessed during 2 simulation-based cases using pre-defined scoring anchors on multiple actions, such as communication skills and treatment decisions (Appendix 1). Each case involved a patient presenting with dyspnea requiring management based off physical examination findings. One case was a patient with exacerbation of heart failure, while the other was a patient with a tension pneumothorax. Each resident was randomized into a case associated with the simulation stethoscope. Following the cases residents were asked to fill out an evaluation questionnaire. Residents perceived the most realistic physical exam findings on those associated with the case using the simulation stethoscope (13/14, 93%). Residents also preferred the simulation stethoscope as an adjunct to the case (13/14, 93%), and they rated the simulation stethoscope case to have significantly more realistic auscultatory findings (4.4/5 vs. 3.0/5 difference of means 1.4, p=0.0007). Average scores of residents were significantly better in the simulation stethoscope-associated case (2.5/3 vs. 2.3/3 difference of means 0.2, p=0.04). There was no considerable difference in the total time taken per case. A simulation stethoscope may be a useful adjunct to

  13. Are Simulation Stethoscopes a Useful Adjunct for Emergency Residents' Training on High-Fidelity Mannequins?

    Directory of Open Access Journals (Sweden)

    Steven J Warrington

    2013-05-01

    Full Text Available Introduction: Emergency medicine residents use simulation training for many reasons, such as gaining experience with critically ill patients and becoming familiar with disease processes. Residents frequently criticize simulation training using current high-fidelity mannequins due to the poor quality of physical exam findings present, such as auscultatory findings, as it may lead them down an alternate diagnostic or therapeutic pathway. Recently wireless remote programmed stethoscopes (simulation stethoscopes have been developed that allow wireless transmission of any sound to a stethoscope receiver, which improves the fidelity of a physical examination and the simulation case. Methods: Following institutional review committee approval, 14 PGY1-3 emergency medicine residents were assessed during 2 simulation-based cases using pre-defined scoring anchors on multiple actions, such as communication skills and treatment decisions (Appendix 1. Each case involved a patient presenting with dyspnea requiring management based off physical examination findings. One case was a patient with exacerbation of heart failure, while the other was a patient with a tension pneumothorax. Each resident was randomized into a case associated with the simulation stethoscope. Following the cases residents were asked to fill out an evaluation questionnaire. Results: Residents perceived the most realistic physical exam findings on those associated with the case using the simulation stethoscope (13/14, 93%. Residents also preferred the simulation stethoscope as an adjunct to the case (13/14, 93%, and they rated the simulation stethoscope case to have significantly more realistic auscultatory findings (4.4/5 vs. 3.0/5 difference of means 1.4, P = 0.0007. Average scores of residents were significantly better in the simulation stethoscope-associated case (2.5/3 vs. 2.3/3 difference of means 0.2, P = 0.04. There was no considerable difference in the total time taken per case

  14. HIGH-FIDELITY SIMULATION-DRIVEN MODEL DEVELOPMENT FOR COARSE-GRAINED COMPUTATIONAL FLUID DYNAMICS

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, Botros N.; Dinh, Nam T.; Bolotnov, Igor A.

    2016-06-01

    Nuclear reactor safety analysis requires identifying various credible accident scenarios and determining their consequences. For a full-scale nuclear power plant system behavior, it is impossible to obtain sufficient experimental data for a broad range of risk-significant accident scenarios. In single-phase flow convective problems, Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) can provide us with high fidelity results when physical data are unavailable. However, these methods are computationally expensive and cannot be afforded for simulation of long transient scenarios in nuclear accidents despite extraordinary advances in high performance scientific computing over the past decades. The major issue is the inability to make the transient computation parallel, thus making number of time steps required in high-fidelity methods unaffordable for long transients. In this work, we propose to apply a high fidelity simulation-driven approach to model sub-grid scale (SGS) effect in Coarse Grained Computational Fluid Dynamics CG-CFD. This approach aims to develop a statistical surrogate model instead of the deterministic SGS model. We chose to start with a turbulent natural convection case with volumetric heating in a horizontal fluid layer with a rigid, insulated lower boundary and isothermal (cold) upper boundary. This scenario of unstable stratification is relevant to turbulent natural convection in a molten corium pool during a severe nuclear reactor accident, as well as in containment mixing and passive cooling. The presented approach demonstrates how to create a correction for the CG-CFD solution by modifying the energy balance equation. A global correction for the temperature equation proves to achieve a significant improvement to the prediction of steady state temperature distribution through the fluid layer.

  15. The Effect of Model Fidelity on Learning Outcomes of a Simulation-Based Education Program for Central Venous Catheter Insertion.

    Science.gov (United States)

    Diederich, Emily; Mahnken, Jonathan D; Rigler, Sally K; Williamson, Timothy L; Tarver, Stephen; Sharpe, Matthew R

    2015-12-01

    Simulation-based education for central venous catheter (CVC) insertion has been repeatedly documented to improve performance, but the impact of simulation model fidelity has not been described. The aim of this study was to examine the impact of the physical fidelity of the simulation model on learning outcomes for a simulation-based education program for CVC insertion. Forty consecutive residents rotating through the medical intensive care unit of an academic medical center completed a simulation-based education program for CVC insertion. The curriculum was designed in accordance with the principles of deliberate practice and mastery learning. Each resident underwent baseline skills testing and was then randomized to training on a commercially available CVC model with high physical fidelity (High-Fi group) or a simply constructed model with low physical fidelity (Low-Fi group) in a noninferiority trial. Upon completion of their medical intensive care unit rotation 4 weeks later, residents returned for repeat skills testing on the high-fidelity model using a 26-item checklist. The mean (SD) posttraining score on the 26-item checklist for the Low-Fi group was 23.8 (2.2) (91.5%) and was not inferior to the mean (SD) score for the High-Fi group of 22.5 (2.6) (86.5%) (P Simulation-based education using equipment with low physical fidelity can achieve learning outcomes comparable with those with high-fidelity equipment, as long as other aspects of fidelity are maintained and robust educational principles are applied during the design of the curriculum.

  16. A Review of the Literature on Training Simulators: Translators: Transfer of Training and Simulator Fidelity.

    Science.gov (United States)

    1984-04-01

    Noise is distracting especially in complex tasks that require close attention and concentration (Finkelman 1975). Improper lighting (Tinker 1943...before coping with . the entire systemi. However, the functional fidelity may be affected due to the isolation of a £ articular subsystem. Curry (1981

  17. Novel high-fidelity realistic explosion damage simulation for urban environments

    Science.gov (United States)

    Liu, Xiaoqing; Yadegar, Jacob; Zhu, Youding; Raju, Chaitanya; Bhagavathula, Jaya

    2010-04-01

    Realistic building damage simulation has a significant impact in modern modeling and simulation systems especially in diverse panoply of military and civil applications where these simulation systems are widely used for personnel training, critical mission planning, disaster management, etc. Realistic building damage simulation should incorporate accurate physics-based explosion models, rubble generation, rubble flyout, and interactions between flying rubble and their surrounding entities. However, none of the existing building damage simulation systems sufficiently faithfully realize the criteria of realism required for effective military applications. In this paper, we present a novel physics-based high-fidelity and runtime efficient explosion simulation system to realistically simulate destruction to buildings. In the proposed system, a family of novel blast models is applied to accurately and realistically simulate explosions based on static and/or dynamic detonation conditions. The system also takes account of rubble pile formation and applies a generic and scalable multi-component based object representation to describe scene entities and highly scalable agent-subsumption architecture and scheduler to schedule clusters of sequential and parallel events. The proposed system utilizes a highly efficient and scalable tetrahedral decomposition approach to realistically simulate rubble formation. Experimental results demonstrate that the proposed system has the capability to realistically simulate rubble generation, rubble flyout and their primary and secondary impacts on surrounding objects including buildings, constructions, vehicles and pedestrians in clusters of sequential and parallel damage events.

  18. Hybrid High-Fidelity Modeling of Radar Scenarios Using Atemporal, Discrete-Event, and Time-Step Simulation

    Science.gov (United States)

    2016-12-01

    10 Figure 1.8 High-efficiency and high-fidelity radar system simulation flowchart . 15 Figure 1.9...Methodology roadmaps: experimental-design flowchart showing hybrid sensor models integrated from three simulation categories, followed by overall...simulation display and output produced by Java Simkit program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Figure 4.5 Hybrid

  19. Use of simulated data sets to evaluate the fidelity of Metagenomicprocessing methods

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, Konstantinos; Ivanova, Natalia; Barry, Kerri; Shapiro, Harris; Goltsman, Eugene; McHardy, Alice C.; Rigoutsos, Isidore; Salamov, Asaf; Korzeniewski, Frank; Land, Miriam; Lapidus, Alla; Grigoriev, Igor; Richardson, Paul; Hugenholtz, Philip; Kyrpides, Nikos C.

    2006-12-01

    Metagenomics is a rapidly emerging field of research for studying microbial communities. To evaluate methods presently used to process metagenomic sequences, we constructed three simulated data sets of varying complexity by combining sequencing reads randomly selected from 113 isolate genomes. These data sets were designed to model real metagenomes in terms of complexity and phylogenetic composition. We assembled sampled reads using three commonly used genome assemblers (Phrap, Arachne and JAZZ), and predicted genes using two popular gene finding pipelines (fgenesb and CRITICA/GLIMMER). The phylogenetic origins of the assembled contigs were predicted using one sequence similarity--based (blast hit distribution) and two sequence composition--based (PhyloPythia, oligonucleotide frequencies) binning methods. We explored the effects of the simulated community structure and method combinations on the fidelity of each processing step by comparison to the corresponding isolate genomes. The simulated data sets are available online to facilitate standardized benchmarking of tools for metagenomic analysis.

  20. Collective efficacy in a high-fidelity simulation of an airline operations center

    Science.gov (United States)

    Jinkerson, Shanna

    This study investigated the relationships between collective efficacy, teamwork, and team performance. Participants were placed into teams, where they worked together in a high-fidelity simulation of an airline operations center. Each individual was assigned a different role to represent different jobs within an airline (Flight Operations Coordinator, Crew Scheduling, Maintenance, Weather, Flight Scheduling, or Flight Planning.) Participants completed a total of three simulations with an After Action Review between each. Within this setting, both team performance and teamwork behaviors were shown to be positively related to expectations for subsequent performance (collective efficacy). Additionally, teamwork and collective efficacy were not shown to be concomitantly related to subsequent team performance. A chi-square test was used to evaluate existence of performance spirals, and they were not supported. The results of this study were likely impacted by lack of power, as well as a lack of consistency across the three simulations.

  1. Use of simulated data sets to evaluate the fidelity of metagenomic processing methods

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Barry, Kerrie [U.S. Department of Energy, Joint Genome Institute; Shapiro, Harris [U.S. Department of Energy, Joint Genome Institute; Goltsman, Eugene [U.S. Department of Energy, Joint Genome Institute; McHardy, Alice C. [IBM T. J. Watson Research Center; Rigoutsos, Isidore [IBM T. J. Watson Research Center; Salamov, Asaf [U.S. Department of Energy, Joint Genome Institute; Korzeniewski, Frank [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Grigoriev, Igor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute

    2007-01-01

    Metagenomics is a rapidly emerging field of research for studying microbial communities. To evaluate methods presently used to process metagenomic sequences, we constructed three simulated data sets of varying complexity by combining sequencing reads randomly selected from 113 isolate genomes. These data sets were designed to model real metagenomes in terms of complexity and phylogenetic composition. We assembled sampled reads using three commonly used genome assemblers (Phrap, Arachne and JAZZ), and predicted genes using two popular gene-finding pipelines (fgenesb and CRITICA/GLIMMER). The phylogenetic origins of the assembled contigs were predicted using one sequence similarity-based ( blast hit distribution) and two sequence composition-based (PhyloPythia, oligonucleotide frequencies) binning methods. We explored the effects of the simulated community structure and method combinations on the fidelity of each processing step by comparison to the corresponding isolate genomes. The simulated data sets are available online to facilitate standardized benchmarking of tools for metagenomic analysis.

  2. High-Fidelity Contrast Reaction Simulation Training: Performance Comparison of Faculty, Fellows, and Residents.

    Science.gov (United States)

    Pfeifer, Kyle; Staib, Lawrence; Arango, Jennifer; Kirsch, John; Arici, Mel; Kappus, Liana; Pahade, Jay

    2016-01-01

    Reactions to contrast material are uncommon in diagnostic radiology, and vary in clinical presentation from urticaria to life-threatening anaphylaxis. Prior studies have demonstrated a high error rate in contrast reaction management, with smaller studies using simulation demonstrating variable data on effectiveness. We sought to assess the effectiveness of high-fidelity simulation in teaching contrast reaction management for residents, fellows, and attendings. A 20-question multiple-choice test assessing contrast reaction knowledge, with Likert-scale questions assessing subjective comfort levels of management of contrast reactions, was created. Three simulation scenarios that represented a moderate reaction, a severe reaction, and a contrast reaction mimic were completed in a one-hour period in a simulation laboratory. All participants completed a pretest and a posttest at one month. A six-month delayed posttest was given, but was optional for all participants. A total of 150 radiologists participated (residents = 52; fellows = 24; faculty = 74) in the pretest and posttest; and 105 participants completed the delayed posttest (residents = 31; fellows = 17; faculty = 57). A statistically significant increase was found in the one-month posttest (P < .00001) and the six-month posttest scores (P < .00001) and Likert scores (P < .001) assessing comfort level in managing all contrast reactions, compared with the pretest. Test scores and comfort level for moderate and severe reactions significantly decreased at six months, compared with the one-month posttest (P < .05). High-fidelity simulation is an effective learning tool, allowing practice of "high-acuity" situation management in a nonthreatening environment; the simulation training resulted in significant improvement in test scores, as well as an increase in subjective comfort in management of reactions, across all levels of training. A six-month refresher course is suggested, to maintain knowledge and comfort level in

  3. Using "The Burns Suite" as a Novel High Fidelity Simulation Tool for Interprofessional and Teamwork Training.

    Science.gov (United States)

    Sadideen, Hazim; Wilson, David; Moiemen, Naiem; Kneebone, Roger

    2016-01-01

    Educational theory highlights the importance of contextualized simulation for effective learning. The authors recently published the concept of "The Burns Suite" (TBS) as a novel tool to advance the delivery of burns education for residents/clinicians. Effectively, TBS represents a low-cost, high-fidelity, portable, immersive simulation environment. Recently, simulation-based team training (SBTT) has been advocated as a means to improve interprofessional practice. The authors aimed to explore the role of TBS in SBTT. A realistic pediatric burn resuscitation scenario was designed based on "advanced trauma and life support" and "emergency management of severe burns" principles, refined utilizing expert opinion through cognitive task analysis. The focus of this analysis was on nontechnical and interpersonal skills of clinicians and nurses within the scenario, mirroring what happens in real life. Five-point Likert-type questionnaires were developed for face and content validity. Cronbach's alpha was calculated for scale reliability. Semistructured interviews captured responses for qualitative thematic analysis allowing for data triangulation. Twenty-two participants completed TBS resuscitation scenario. Mean face and content validity ratings were high (4.4 and 4.7 respectively; range 4-5). The internal consistency of questions was high. Qualitative data analysis revealed two new themes. Participants reported that the experience felt particularly authentic because the simulation had high psychological and social fidelity, and there was a demand for such a facility to be made available to improve nontechnical skills and interprofessional relations. TBS provides a realistic, novel tool for SBTT, addressing both nontechnical and interprofessional team skills. Recreating clinical challenge is crucial to optimize SBTT. With a better understanding of the theories underpinning simulation and interprofessional education, future simulation scenarios can be designed to provide

  4. High-fidelity simulation in Neonatology and the Italian experience of Nina

    Directory of Open Access Journals (Sweden)

    Armando Cuttano

    2012-10-01

    Full Text Available The modern methodology of simulation was born in the aeronautical field. In medicine, anesthetists showed great attention for technological advances and simulation, closely followed by surgeons with minimally invasive surgery. In Neonatology training in simulation is actually useful in order to face unexpected dramatic events, to minimize clinical risk preventing errors and to optimize team work. Critical issues in simulation are: teachers-learners relationship, focus on technical and non-technical skills, training coordination, adequate scenarios, effective debriefing. Therefore, the quality of a simulation training center is multi-factorial and is not only related to the mannequin equipment. High-fidelity simulation is the most effective method in education. In Italy simulation for education in Medicine has been used for a few years only. In Pisa we founded Nina (that is the acronymous for the Italian name of the Center, CeNtro di FormazIone e SimulazioNe NeonAtale, the first neonatal simulation center dedicated but integrated within a Hospital Unit in Italy. This paper describes how we manage education in Nina Center, in order to offer a model for other similar experiences.

  5. Exploring the use of high-fidelity simulation training to enhance clinical skills.

    Science.gov (United States)

    Ann Kirkham, Lucy

    2018-02-07

    The use of interprofessional simulation training to enhance nursing students' performance of technical and non-technical clinical skills is becoming increasingly common. Simulation training can involve the use of role play, virtual reality or patient simulator manikins to replicate clinical scenarios and assess the nursing student's ability to, for example, undertake clinical observations or work as part of a team. Simulation training enables nursing students to practise clinical skills in a safe environment. Effective simulation training requires extensive preparation, and debriefing is necessary following a simulated training session to review any positive or negative aspects of the learning experience. This article discusses a high-fidelity simulated training session that was used to assess a group of third-year nursing students and foundation level 1 medical students. This involved the use of a patient simulator manikin in a scenario that required the collaborative management of a deteriorating patient. ©2018 RCN Publishing Company Ltd. All rights reserved. Not to be copied, transmitted or recorded in any way, in whole or part, without prior permission of the publishers.

  6. Design and Test of Advanced Thermal Simulators for an Alkali Metal-Cooled Reactor Simulator

    Science.gov (United States)

    Garber, Anne E.; Dickens, Ricky E.

    2011-01-01

    The Early Flight Fission Test Facility (EFF-TF) at NASA Marshall Space Flight Center (MSFC) has as one of its primary missions the development and testing of fission reactor simulators for space applications. A key component in these simulated reactors is the thermal simulator, designed to closely mimic the form and function of a nuclear fuel pin using electric heating. Continuing effort has been made to design simple, robust, inexpensive thermal simulators that closely match the steady-state and transient performance of a nuclear fuel pin. A series of these simulators have been designed, developed, fabricated and tested individually and in a number of simulated reactor systems at the EFF-TF. The purpose of the thermal simulators developed under the Fission Surface Power (FSP) task is to ensure that non-nuclear testing can be performed at sufficiently high fidelity to allow a cost-effective qualification and acceptance strategy to be used. Prototype thermal simulator design is founded on the baseline Fission Surface Power reactor design. Recent efforts have been focused on the design, fabrication and test of a prototype thermal simulator appropriate for use in the Technology Demonstration Unit (TDU). While designing the thermal simulators described in this paper, effort were made to improve the axial power profile matching of the thermal simulators. Simultaneously, a search was conducted for graphite materials with higher resistivities than had been employed in the past. The combination of these two efforts resulted in the creation of thermal simulators with power capacities of 2300-3300 W per unit. Six of these elements were installed in a simulated core and tested in the alkali metal-cooled Fission Surface Power Primary Test Circuit (FSP-PTC) at a variety of liquid metal flow rates and temperatures. This paper documents the design of the thermal simulators, test program, and test results.

  7. The experiences of last-year student midwives with High-Fidelity Perinatal Simulation training: A qualitative descriptive study.

    Science.gov (United States)

    Vermeulen, Joeri; Beeckman, Katrien; Turcksin, Rivka; Van Winkel, Lies; Gucciardo, Léonardo; Laubach, Monika; Peersman, Wim; Swinnen, Eva

    2017-06-01

    Simulation training is a powerful and evidence-based teaching method in healthcare. It allows students to develop essential competences that are often difficult to achieve during internships. High-Fidelity Perinatal Simulation exposes them to real-life scenarios in a safe environment. Although student midwives' experiences need to be considered to make the simulation training work, these have been overlooked so far. To explore the experiences of last-year student midwives with High-Fidelity Perinatal Simulation training. A qualitative descriptive study, using three focus group conversations with last-year student midwives (n=24). Audio tapes were transcribed and a thematic content analysis was performed. The entire data set was coded according to recurrent or common themes. To achieve investigator triangulation and confirm themes, discussions among the researchers was incorporated in the analysis. Students found High-Fidelity Perinatal Simulation training to be a positive learning method that increased both their competence and confidence. Their experiences varied over the different phases of the High-Fidelity Perinatal Simulation training. Although uncertainty, tension, confusion and disappointment were experienced throughout the simulation trajectory, they reported that this did not affect their learning and confidence-building. As High-Fidelity Perinatal Simulation training constitutes a helpful learning experience in midwifery education, it could have a positive influence on maternal and neonatal outcomes. In the long term, it could therefore enhance the midwifery profession in several ways. The present study is an important first step in opening up the debate about the pedagogical use of High-Fidelity Perinatal Simulation training within midwifery education. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  8. Evaluation of high-fidelity simulation training in radiation oncology using an outcomes logic model

    International Nuclear Information System (INIS)

    Giuliani, Meredith; Gillan, Caitlin; Wong, Olive; Harnett, Nicole; Milne, Emily; Moseley, Doug; Thompson, Robert; Catton, Pamela; Bissonnette, Jean-Pierre

    2014-01-01

    To evaluate the feasibility and educational value of high-fidelity, interprofessional team-based simulation in radiation oncology. The simulation event was conducted in a radiation oncology department during a non-clinical day. It involved 5 simulation scenarios that were run over three 105 minute timeslots in a single day. High-acuity, low-frequency clinical situations were selected and included HDR brachytherapy emergency, 4D CT artifact management, pediatric emergency clinical mark-up, electron scalp trial set-up and a cone beam CT misregistration incident. A purposive sample of a minimum of 20 trainees was required to assess recruitment feasibility. A faculty radiation oncologist (RO), medical physicist (MP) or radiation therapist (RTT), facilitated each case. Participants completed a pre event survey of demographic data and motivation for participation. A post event survey collected perceptions of familiarity with the clinical content, comfort with interprofessional practice, and event satisfaction, scored on a 1–10 scale in terms of clinical knowledge, clinical decision making, clinical skills, exposure to other trainees and interprofessional communication. Means and standard deviations were calculated. Twenty-one trainees participated including 6 ROs (29%), 6 MPs (29%), and 9 RTTs (43%). All 12 cases (100%) were completed within the allocated 105 minutes. Nine faculty facilitators, (3MP, 2 RO, 4 RTTs) were required for 405 minutes each. Additional costs associated with this event were 154 hours to build the high fidelity scenarios, 2 standardized patients (SPs) for a total of 15.5 hours, and consumables.The mean (±SD) educational value score reported by participants with respect to clinical knowledge was 8.9 (1.1), clinical decision making 8.9 (1.3), clinical skills 8.9 (1.1), exposure to other trainees 9.1 (2.3) and interprofessional communication 9.1 (1.0). Fifteen (71%) participants reported the cases were of an appropriate complexity. The importance

  9. High fidelity case-based simulation debriefing: everything you need to know.

    Science.gov (United States)

    Hart, Danielle; McNeil, Mary Ann; Griswold-Theodorson, Sharon; Bhatia, Kriti; Joing, Scott

    2012-09-01

    In this 30-minute talk, the authors take an in-depth look at how to debrief high-fidelity case-based simulation sessions, including discussion on debriefing theory, goals, approaches, and structure, as well as ways to create a supportive and safe learning environment, resulting in successful small group learning and self-reflection. Emphasis is placed on the "debriefing with good judgment" approach. Video clips of sample debriefing attempts, highlighting the "dos and don'ts" of simulation debriefing, are included. The goal of this talk is to provide you with the necessary tools and information to develop a successful and effective debriefing approach. There is a bibliography and a quick reference guide in Data Supplements S1 and S2 (available as supporting information in the online version of this paper). © 2012 by the Society for Academic Emergency Medicine.

  10. Proof-of-principle of high-fidelity coupled CRUD deposition and cycle depletion simulation

    International Nuclear Information System (INIS)

    Walter, Daniel J.; Kendrick, Brian K.; Petrov, Victor; Manera, Annalisa; Collins, Benjamin; Downar, Thomas

    2015-01-01

    A multiphysics framework for the high-fidelity simulation of CRUD deposition is developed to better understand the coupled physics and their respective feedback mechanisms. This framework includes the primary physics of lattice depletion, computational fluid dynamics, and CRUD chemistry. The three physics are coupled together via the operator-splitting technique, where predictor–corrector and fixed-point iteration schemes are utilized to converge the nonlinear solution. High-fidelity simulations may provide a means to predict and assess potential operating issues, including CRUD induced power shift and CRUD induced localized corrosion, known as CIPS and CILC, respectively. As a proof-of-principle, a coupled 500-day cycle depletion simulation of a pressurized water reactor fuel pin cell was performed using the coupled code suite; a burnup of 31 MWd/kgHM was reached. The simulation recreated the classic striped CRUD pattern often seen on pulled fuel rods containing CRUD. It is concluded that the striping is caused by the flow swirl induced by spacer grid mixing vanes. Two anti-correlated effects contribute to the striping: (1) the flow swirl yields significant azimuthal temperature variations, which impact the locations where CRUD deposits, and (2) the flow swirl is correlated to increased shear stress along the cladding surface and subsequent erosion of the CRUD layer. The CIPS condition of the core is concluded to be primarily controlled by lithium tetraborate precipitation, referred to as boron hideout, which occurs in regions experiencing subcooled nucleate boiling as soluble boron and lithium species reach their solubility limit within the CRUD layer. Subsequently, a localized reduction in power occurs due to the high neutron absorption cross section of boron-10

  11. High-Fidelity Simulation in Occupational Therapy Curriculum: Impact on Level II Fieldwork Performance

    Directory of Open Access Journals (Sweden)

    Rebecca Ozelie

    2016-10-01

    Full Text Available Simulation experiences provide experiential learning opportunities during artificially produced real-life medical situations in a safe environment. Evidence supports using simulation in health care education yet limited quantitative evidence exists in occupational therapy. This study aimed to evaluate the differences in scores on the AOTA Fieldwork Performance Evaluation for the Occupational Therapy Student of Level II occupational therapy students who received high-fidelity simulation training and students who did not. A retrospective analysis of 180 students from a private university was used. Independent samples nonparametric t tests examined mean differences between Fieldwork Performance Evaluation scores of those who did and did not receive simulation experiences in the curriculum. Mean ranks were also analyzed for subsection scores and practice settings. Results of this study found no significant difference in overall Fieldwork Performance Evaluation scores between the two groups. The students who completed simulation and had fieldwork in inpatient rehabilitation had the greatest increase in mean rank scores and increases in several subsections. The outcome measure used in this study was found to have limited discriminatory capability and may have affected the results; however, this study finds that using simulation may be a beneficial supplement to didactic coursework in occupational therapy curriculums.

  12. Prospective randomized comparison of standard didactic lecture versus high-fidelity simulation for radiology resident contrast reaction management training.

    Science.gov (United States)

    Wang, Carolyn L; Schopp, Jennifer G; Petscavage, Jonelle M; Paladin, Angelisa M; Richardson, Michael L; Bush, William H

    2011-06-01

    The objective of our study was to assess whether high-fidelity simulation-based training is more effective than traditional didactic lecture to train radiology residents in the management of contrast reactions. This was a prospective study of 44 radiology residents randomized into a simulation group versus a lecture group. All residents attended a contrast reaction didactic lecture. Four months later, baseline knowledge was assessed with a written test, which we refer to as the "pretest." After the pretest, the 21 residents in the lecture group attended a repeat didactic lecture and the 23 residents in the simulation group underwent high-fidelity simulation-based training with five contrast reaction scenarios. Next, all residents took a second written test, which we refer to as the "posttest." Two months after the posttest, both groups took a third written test, which we refer to as the "delayed posttest," and underwent performance testing with a high-fidelity severe contrast reaction scenario graded on predefined critical actions. There was no statistically significant difference between the simulation and lecture group pretest, immediate posttest, or delayed posttest scores. The simulation group performed better than the lecture group on the severe contrast reaction simulation scenario (p = 0.001). The simulation group reported improved comfort in identifying and managing contrast reactions and administering medications after the simulation training (p ≤ 0.04) and was more comfortable than the control group (p = 0.03), which reported no change in comfort level after the repeat didactic lecture. When compared with didactic lecture, high-fidelity simulation-based training of contrast reaction management shows equal results on written test scores but improved performance during a high-fidelity severe contrast reaction simulation scenario.

  13. ROSE: A realtime object oriented software environment for high fidelity replica simulation

    International Nuclear Information System (INIS)

    Abramovitch, A.

    1994-01-01

    An object oriented software environment used for the production testing and documentation of real time models for high fidelity training simulators encompasses a wide variety of software constructs including code generators for various classes of physical systems, model executive control programs, a high resolution graphics editor, as well as databases and associated access routines used to store and control information transfer among the various software entities. CAE Electronics' newly developed ROSE allows for the generation and integrated test of thermalhydraulic, analog control, digital control and electrical system models. Based on an iconical/standard subroutine representation of standard plant components along with an admittance matrix solution governed by the topology of the system under consideration, the ROSE blends together network solution algorithms and standard component models, both previously time tested via manual implementation into a single integrated automated software environment. The methodology employed to construct the ROSE, along with a synopsis of the various CASE tools integrated together to form a complete graphics based system for high fidelity real time code generation and validation is described in the presentation. (1 fig.)

  14. [Acquiring skills in malignant hyperthermia crisis management: comparison of high-fidelity simulation versus computer-based case study].

    Science.gov (United States)

    Mejía, Vilma; Gonzalez, Carlos; Delfino, Alejandro E; Altermatt, Fernando R; Corvetto, Marcia A

    The primary purpose of this study was to compare the effect of high fidelity simulation versus a computer-based case solving self-study, in skills acquisition about malignant hyperthermia on first year anesthesiology residents. After institutional ethical committee approval, 31 first year anesthesiology residents were enrolled in this prospective randomized single-blinded study. Participants were randomized to either a High Fidelity Simulation Scenario or a computer-based Case Study about malignant hyperthermia. After the intervention, all subjects' performance in was assessed through a high fidelity simulation scenario using a previously validated assessment rubric. Additionally, knowledge tests and a satisfaction survey were applied. Finally, a semi-structured interview was done to assess self-perception of reasoning process and decision-making. 28 first year residents finished successfully the study. Resident's management skill scores were globally higher in High Fidelity Simulation versus Case Study, however they were significant in 4 of the 8 performance rubric elements: recognize signs and symptoms (p = 0.025), prioritization of initial actions of management (p = 0.003), recognize complications (p = 0.025) and communication (p = 0.025). Average scores from pre- and post-test knowledge questionnaires improved from 74% to 85% in the High Fidelity Simulation group, and decreased from 78% to 75% in the Case Study group (p = 0.032). Regarding the qualitative analysis, there was no difference in factors influencing the student's process of reasoning and decision-making with both teaching strategies. Simulation-based training with a malignant hyperthermia high-fidelity scenario was superior to computer-based case study, improving knowledge and skills in malignant hyperthermia crisis management, with a very good satisfaction level in anesthesia residents. Copyright © 2018 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights

  15. Acquiring skills in malignant hyperthermia crisis management: comparison of high-fidelity simulation versus computer-based case study

    Directory of Open Access Journals (Sweden)

    Vilma Mejía

    Full Text Available Abstract Introduction: The primary purpose of this study was to compare the effect of high fidelity simulation versus a computer-based case solving self-study, in skills acquisition about malignant hyperthermia on first year anesthesiology residents. Methods: After institutional ethical committee approval, 31 first year anesthesiology residents were enrolled in this prospective randomized single-blinded study. Participants were randomized to either a High Fidelity Simulation Scenario or a computer-based Case Study about malignant hyperthermia. After the intervention, all subjects' performance in was assessed through a high fidelity simulation scenario using a previously validated assessment rubric. Additionally, knowledge tests and a satisfaction survey were applied. Finally, a semi-structured interview was done to assess self-perception of reasoning process and decision-making. Results: 28 first year residents finished successfully the study. Resident's management skill scores were globally higher in High Fidelity Simulation versus Case Study, however they were significant in 4 of the 8 performance rubric elements: recognize signs and symptoms (p = 0.025, prioritization of initial actions of management (p = 0.003, recognize complications (p = 0.025 and communication (p = 0.025. Average scores from pre- and post-test knowledge questionnaires improved from 74% to 85% in the High Fidelity Simulation group, and decreased from 78% to 75% in the Case Study group (p = 0.032. Regarding the qualitative analysis, there was no difference in factors influencing the student's process of reasoning and decision-making with both teaching strategies. Conclusion: Simulation-based training with a malignant hyperthermia high-fidelity scenario was superior to computer-based case study, improving knowledge and skills in malignant hyperthermia crisis management, with a very good satisfaction level in anesthesia residents.

  16. High-fidelity simulations for clean and efficient combustion of alternative fuels

    Energy Technology Data Exchange (ETDEWEB)

    Oefelein, J C; Chen, J H [Reacting Flow Research Department, Sandia National Laboratories, Livermore, CA 94550 (United States); Sankaran, R, E-mail: oefelei@sandia.go [National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2009-07-01

    There is an urgent and growing demand for high-fidelity simulations that capture complex turbulence-chemistry interactions in propulsion and power systems, and in particular, that capture and discriminate the effects of fuel variability. This project addresses this demand using the Large Eddy Simulation (LES) technique (led by Oefelein) and the Direct Numerical Simulation (DNS) technique (led by Chen). In particular, we are conducting research under the INCITE program that is tightly coupled with funded projects established under the DOE Basic Energy Sciences and Energy Efficiency and Renewable Energy programs that will provide the foundational science required to develop a predictive modeling capability for design of advanced engines for transportation. Application of LES provides the formal ability to treat the full range of multidimensional time and length scales that exist in turbulent reacting flows in a computationally feasible manner and thus provides a way to simulate reacting flow phenomena in complex internal-combustion engine geometries at device relevant conditions. Application of DNS provides a way to study fundamental issues related to small-scale combustion processes in canonical configurations to understand dynamics that occur over a range of reactive-diffusive scales. Here we describe the challenges and present representative examples of the types of simulations each respective tool has been used for as part of the INCITE program. We focus on recent experiences on the Oak Ridge National Laboratory (ORNL) National Center for Computational Sciences (NCCS) Cray-XT Platform (i.e., Jaguar).

  17. High-Fidelity Simulation of Pediatric Emergency Care: An Eye-Opening Experience for Baccalaureate Nursing Students.

    Science.gov (United States)

    Small, Sandra P; Colbourne, Peggy A; Murray, Cynthia L

    2018-01-01

    Background Little attention has been given to in-depth examination of what high-fidelity simulation is like for nursing students within the context of a pediatric emergency, such as a cardiopulmonary arrest. It is possible that such high-fidelity simulation could provoke in nursing students intense psychological reactions. Purpose The purpose of this study was to learn about baccalaureate nursing students' lived experience of high-fidelity simulation of pediatric cardiopulmonary arrest. Method Phenomenological methods were used. Twenty-four interviews were conducted with 12 students and were analyzed for themes. Results The essence of the experience is that it was eye-opening. The students found the simulation to be a surprisingly realistic nursing experience as reflected in their perceiving the manikin as a real patient, thinking that they were saving their patient's life, feeling like a real nurse, and feeling relief after mounting stress. It was a surprisingly valuable learning experience in that the students had an increased awareness of the art and science of nursing and increased understanding of the importance of teamwork and were feeling more prepared for clinical practice and wanting more simulation experiences. Conclusion Educators should capitalize on the benefits of high-fidelity simulation as a pedagogy, while endeavoring to provide psychologically safe learning.

  18. Embedding High-Fidelity Simulation Into a Foundations of Nursing Course.

    Science.gov (United States)

    Talbot, Megan Sary

    2015-01-01

    Delay in recognizing the need for and initiating lifesaving measures is unacceptable in health care. It is never too early to teach novice nursing students to recognize and respond to early warning signs of patient deterioration. The rapid response system was developed to expedite recognition of and response to changes in a patient's condition. Use of high-fidelity simulation by beginning nursing students to practice recognizing and responding to patient deterioration is vital to both the welfare of patients and the edification of students. Recognizing and responding quickly to patients' early warning signs of deterioration can determine a patient's outcome. This article discusses the importance of instructing beginning nursing students in identifying and reacting appropriately to early signs of patient deterioration and in following the chain of command to activate the rapid response team.

  19. Nuclear fuel cycle system simulation tool based on high-fidelity component modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ames, David E.,

    2014-02-01

    The DOE is currently directing extensive research into developing fuel cycle technologies that will enable the safe, secure, economic, and sustainable expansion of nuclear energy. The task is formidable considering the numerous fuel cycle options, the large dynamic systems that each represent, and the necessity to accurately predict their behavior. The path to successfully develop and implement an advanced fuel cycle is highly dependent on the modeling capabilities and simulation tools available for performing useful relevant analysis to assist stakeholders in decision making. Therefore a high-fidelity fuel cycle simulation tool that performs system analysis, including uncertainty quantification and optimization was developed. The resulting simulator also includes the capability to calculate environmental impact measures for individual components and the system. An integrated system method and analysis approach that provides consistent and comprehensive evaluations of advanced fuel cycles was developed. A general approach was utilized allowing for the system to be modified in order to provide analysis for other systems with similar attributes. By utilizing this approach, the framework for simulating many different fuel cycle options is provided. Two example fuel cycle configurations were developed to take advantage of used fuel recycling and transmutation capabilities in waste management scenarios leading to minimized waste inventories.

  20. Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Hong G. Im; Arnaud Trouve; Christopher J. Rutland; Jacqueline H. Chen

    2009-02-02

    The TSTC project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of our approach is direct numerical simulation (DNS) featuring highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a useful tool for development of sub-models needed in device-level simulations. The code named S3D, developed and shared with Chen and coworkers at Sandia National Laboratories, has been enhanced with new numerical algorithms and physical models to provide predictive capabilities for spray dynamics, combustion, and pollutant formation processes in turbulent combustion. Major accomplishments include improved characteristic boundary conditions, fundamental studies of auto-ignition in turbulent stratified reactant mixtures, flame-wall interaction, and turbulent flame extinction by water spray. The overarching scientific issue in our recent investigations is to characterize criticality phenomena (ignition/extinction) in turbulent combustion, thereby developing unified criteria to identify ignition and extinction conditions. The computational development under TSTC has enabled the recent large-scale 3D turbulent combustion simulations conducted at Sandia National Laboratories.

  1. Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Im, Hong G [University of Michigan; Trouve, Arnaud [University of Maryland; Rutland, Christopher J [University of Wisconsin; Chen, Jacqueline H [Sandia National Laboratories

    2012-08-13

    The TSTC project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of our approach is direct numerical simulation (DNS) featuring highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a useful tool for development of sub-models needed in device-level simulations. The code named S3D, developed and shared with Chen and coworkers at Sandia National Laboratories, has been enhanced with new numerical algorithms and physical models to provide predictive capabilities for spray dynamics, combustion, and pollutant formation processes in turbulent combustion. Major accomplishments include improved characteristic boundary conditions, fundamental studies of auto-ignition in turbulent stratified reactant mixtures, flame-wall interaction, and turbulent flame extinction by water spray. The overarching scientific issue in our recent investigations is to characterize criticality phenomena (ignition/extinction) in turbulent combustion, thereby developing unified criteria to identify ignition and extinction conditions. The computational development under TSTC has enabled the recent large-scale 3D turbulent combustion simulations conducted at Sandia National Laboratories.

  2. On the Fidelity of Semi-distributed Hydrologic Model Simulations for Large Scale Catchment Applications

    Science.gov (United States)

    Ajami, H.; Sharma, A.; Lakshmi, V.

    2017-12-01

    Application of semi-distributed hydrologic modeling frameworks is a viable alternative to fully distributed hyper-resolution hydrologic models due to computational efficiency and resolving fine-scale spatial structure of hydrologic fluxes and states. However, fidelity of semi-distributed model simulations is impacted by (1) formulation of hydrologic response units (HRUs), and (2) aggregation of catchment properties for formulating simulation elements. Here, we evaluate the performance of a recently developed Soil Moisture and Runoff simulation Toolkit (SMART) for large catchment scale simulations. In SMART, topologically connected HRUs are delineated using thresholds obtained from topographic and geomorphic analysis of a catchment, and simulation elements are equivalent cross sections (ECS) representative of a hillslope in first order sub-basins. Earlier investigations have shown that formulation of ECSs at the scale of a first order sub-basin reduces computational time significantly without compromising simulation accuracy. However, the implementation of this approach has not been fully explored for catchment scale simulations. To assess SMART performance, we set-up the model over the Little Washita watershed in Oklahoma. Model evaluations using in-situ soil moisture observations show satisfactory model performance. In addition, we evaluated the performance of a number of soil moisture disaggregation schemes recently developed to provide spatially explicit soil moisture outputs at fine scale resolution. Our results illustrate that the statistical disaggregation scheme performs significantly better than the methods based on topographic data. Future work is focused on assessing the performance of SMART using remotely sensed soil moisture observations using spatially based model evaluation metrics.

  3. A comparison of color fidelity metrics for light sources using simulation of color samples under lighting conditions

    Science.gov (United States)

    Kwon, Hyeokjun; Kang, Yoojin; Jang, Junwoo

    2017-09-01

    Color fidelity has been used as one of indices to evaluate the performance of light sources. Since the Color Rendering Index (CRI) was proposed at CIE, many color fidelity metrics have been proposed to increase the accuracy of the metric. This paper focuses on a comparison of the color fidelity metrics in an aspect of accuracy with human visual assessments. To visually evaluate the color fidelity of light sources, we made a simulator that reproduces the color samples under lighting conditions. In this paper, eighteen color samples of the Macbeth color checker under test light sources and reference illuminant for each of them are simulated and displayed on a well-characterized monitor. With only a spectrum set of the test light source and reference illuminant, color samples under any lighting condition can be reproduced. In this paper, the spectrums of the two LED and two OLED light sources that have similar values of CRI are used for the visual assessment. In addition, the results of the visual assessment are compared with the two color fidelity metrics that include CRI and IES TM-30-15 (Rf), proposed by Illuminating Engineering Society (IES) in 2015. Experimental results indicate that Rf outperforms CRI in terms of the correlation with visual assessment.

  4. High-fidelity haptic and visual rendering for patient-specific simulation of temporal bone surgery.

    Science.gov (United States)

    Chan, Sonny; Li, Peter; Locketz, Garrett; Salisbury, Kenneth; Blevins, Nikolas H

    2016-12-01

    Medical imaging techniques provide a wealth of information for surgical preparation, but it is still often the case that surgeons are examining three-dimensional pre-operative image data as a series of two-dimensional images. With recent advances in visual computing and interactive technologies, there is much opportunity to provide surgeons an ability to actively manipulate and interpret digital image data in a surgically meaningful way. This article describes the design and initial evaluation of a virtual surgical environment that supports patient-specific simulation of temporal bone surgery using pre-operative medical image data. Computational methods are presented that enable six degree-of-freedom haptic feedback during manipulation, and that simulate virtual dissection according to the mechanical principles of orthogonal cutting and abrasive wear. A highly efficient direct volume renderer simultaneously provides high-fidelity visual feedback during surgical manipulation of the virtual anatomy. The resulting virtual surgical environment was assessed by evaluating its ability to replicate findings in the operating room, using pre-operative imaging of the same patient. Correspondences between surgical exposure, anatomical features, and the locations of pathology were readily observed when comparing intra-operative video with the simulation, indicating the predictive ability of the virtual surgical environment.

  5. Barriers and enablers to the use of high-fidelity patient simulation manikins in nurse education: an integrative review.

    Science.gov (United States)

    Al-Ghareeb, Amal Z; Cooper, Simon J

    2016-01-01

    This integrative review identified, critically appraised and synthesised the existing evidence on the barriers and enablers to using high-fidelity human patient simulator manikins (HPSMs) in undergraduate nursing education. In nursing education, specifically at the undergraduate level, a range of low to high-fidelity simulations have been used as teaching aids. However, nursing educators encounter challenges when introducing new teaching methods or technology, despite the prevalence of high-fidelity HPSMs in nursing education. An integrative review adapted a systematic approach. Medline, CINAHL plus, ERIC, PsychINFO, EMBASE, SCOPUS, Science Direct, Cochrane database, Joanna Brigge Institute, ProQuest, California Simulation Alliance, Simulation Innovative Recourses Center and the search engine Google Scholar were searched. Keywords were selected and specific inclusion/exclusion criteria were applied. The review included all research designs for papers published between 2000 and 2015 that identified the barriers and enablers to using high-fidelity HPSMs in undergraduate nursing education. Studies were appraised using the Critical Appraisal Skills Programme criteria. Thematic analysis was undertaken and emergent themes were extracted. Twenty-one studies were included in the review. These studies adopted quasi-experimental, prospective non-experimental and descriptive designs. Ten barriers were identified, including "lack of time," "fear of technology" and "workload issues." Seven enablers were identified, including "faculty training," "administrative support" and a "dedicated simulation coordinator." Barriers to simulation relate specifically to the complex technologies inherent in high-fidelity HPSMs approaches. Strategic approaches that support up-skilling and provide dedicated technological support may overcome these barriers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The Effect of High-Fidelity Cardiopulmonary Resuscitation (CPR) Simulation on Athletic Training Student Knowledge, Confidence, Emotions, and Experiences

    Science.gov (United States)

    Tivener, Kristin Ann; Gloe, Donna Sue

    2015-01-01

    Context: High-fidelity simulation is widely used in healthcare for the training and professional education of students though literature of its application to athletic training education remains sparse. Objective: This research attempts to address a wide-range of data. This includes athletic training student knowledge acquisition from…

  7. The Effects of Moderate- and High-Fidelity Patient Simulator Use on Critical Thinking in Associate Degree Nursing Students

    Science.gov (United States)

    Vieck, Jana

    2013-01-01

    The purpose of this study was to examine the impact of moderate- and high-fidelity patient simulator use on the critical thinking skills of associate degree nursing students. This quantitative study used a quasi-experimental design and the Health Sciences Reasoning Test (HSRT) to evaluate the critical thinking skills of third semester nursing…

  8. A New Coupled CFD/Neutron Kinetics System for High Fidelity Simulations of LWR Core Phenomena: Proof of Concept

    Directory of Open Access Journals (Sweden)

    Jorge Pérez Mañes

    2014-01-01

    Full Text Available The Institute for Neutron Physics and Reactor Technology (INR at the Karlsruhe Institute of Technology (KIT is investigating the application of the meso- and microscale analysis for the prediction of local safety parameters for light water reactors (LWR. By applying codes like CFD (computational fluid dynamics and SP3 (simplified transport reactor dynamics it is possible to describe the underlying phenomena in a more accurate manner than by the nodal/coarse 1D thermal hydraulic coupled codes. By coupling the transport (SP3 based neutron kinetics (NK code DYN3D with NEPTUNE-CFD, within a parallel MPI-environment, the NHESDYN platform is created. The newly developed system will allow high fidelity simulations of LWR fuel assemblies and cores. In NHESDYN, a heat conduction solver, SYRTHES, is coupled to NEPTUNE-CFD. The driver module of NHESDYN controls the sequence of execution of the solvers as well as the communication between the solvers based on MPI. In this paper, the main features of NHESDYN are discussed and the proof of the concept is done by solving a single pin problem. The prediction capability of NHESDYN is demonstrated by a code-to-code comparison with the DYNSUB code. Finally, the future developments and validation efforts are highlighted.

  9. Bridging burn care education with modern technology, an integration with high fidelity human patient simulation.

    Science.gov (United States)

    Reeves, Patrick T; Borgman, Matthew A; Caldwell, Nicole W; Patel, Leela; Aden, James; Duggan, John P; Serio-Melvin, Maria L; Mann-Salinas, Elizabeth A

    2018-08-01

    The Advanced Burn Life Support (ABLS) program is a burn-education curriculum nearly 30 years in the making, focusing on the unique challenges of the first 24h of care after burn injury. Our team applied high fidelity human patient simulation (HFHPS) to the established ABLS curriculum. Our hypothesis was that HFHPS would be a feasible, easily replicable, and valuable adjunct to the current curriculum that would enhance learner experience. This prospective, evidenced-based practice project was conducted in a single simulation center employing the American Burn Association's ABLS curriculum using HFHPS. Participants managed 7 separate simulated polytrauma and burn scenarios with resultant clinical complications. After training, participants completed written and practical examinations as well as satisfaction surveys. From 2012 to 2013, 71 students participated in this training. Simulation (ABLS-Sim) participants demonstrated a 2.5% increase in written post-test scores compared to traditional ABLS Provider Course (ABLS Live) (p=0.0016). There was no difference in the practical examination when comparing ABLS-Sim versus ABLS Live. Subjectively, 60 (85%) participants completed surveys. The Educational Practice Questionnaire showed best practices rating of 4.5±0.7; with importance of learning rated at 4.4±0.8. The Simulation Design Scale rating for design was 4.6±0.6 with an importance rating of 4.4±0.8. Overall Satisfaction and Self-Confidence with Learning were 4.4±0.7 and 4.5±0.7, respectfully. Integrating HFHPS with the current ABLS curriculum led to higher written exam scores, high levels of confidence, satisfaction, and active learning, and presented an evidenced-based model for education that is easily employable for other facilities nationwide. Copyright © 2018 Elsevier Ltd and ISBI. All rights reserved.

  10. Embedding Microethical Dilemmas in High-Fidelity Simulation Scenarios: Preparing Nursing Students for Ethical Practice.

    Science.gov (United States)

    Krautscheid, Lorretta C

    2017-01-01

    Despite the inclusion of ethics education in the formal curriculum, students felt ill-prepared to manage ethical issues and protect patients' health and well-being. Nursing students reported knowing what should be done to promote optimal patient care; however, they also reported an inability to act on their convictions due to fear of reprisal, powerlessness, and low confidence. Bloom's Taxonomy guided the development and implementation of experiential-applied ethics education via microethical dilemmas embedded in existing high-fidelity simulation (HFS) scenarios. Students were unaware that ethical dilemmas would be presented, replicating complex and spontaneous practice environments. Students reported that the educational strategy was powerful, increasing ethical decision-making confidence, empowering effective advocacy, and building courage to overcome fears and defend ethical practice. Simulation extends ethics education beyond the cognitive domain, ensuring the purposeful integration of affective and psychomotor learning, which promotes congruence between knowing what to do and acting on one's convictions. [J Nurs Educ. 2017;56(1):55-58.]. Copyright 2017, SLACK Incorporated.

  11. A cost effective and high fidelity fluoroscopy simulator using the Image-Guided Surgery Toolkit (IGSTK)

    Science.gov (United States)

    Gong, Ren Hui; Jenkins, Brad; Sze, Raymond W.; Yaniv, Ziv

    2014-03-01

    The skills required for obtaining informative x-ray fluoroscopy images are currently acquired while trainees provide clinical care. As a consequence, trainees and patients are exposed to higher doses of radiation. Use of simulation has the potential to reduce this radiation exposure by enabling trainees to improve their skills in a safe environment prior to treating patients. We describe a low cost, high fidelity, fluoroscopy simulation system. Our system enables operators to practice their skills using the clinical device and simulated x-rays of a virtual patient. The patient is represented using a set of temporal Computed Tomography (CT) images, corresponding to the underlying dynamic processes. Simulated x-ray images, digitally reconstructed radiographs (DRRs), are generated from the CTs using ray-casting with customizable machine specific imaging parameters. To establish the spatial relationship between the CT and the fluoroscopy device, the CT is virtually attached to a patient phantom and a web camera is used to track the phantom's pose. The camera is mounted on the fluoroscope's intensifier and the relationship between it and the x-ray source is obtained via calibration. To control image acquisition the operator moves the fluoroscope as in normal operation mode. Control of zoom, collimation and image save is done using a keypad mounted alongside the device's control panel. Implementation is based on the Image-Guided Surgery Toolkit (IGSTK), and the use of the graphics processing unit (GPU) for accelerated image generation. Our system was evaluated by 11 clinicians and was found to be sufficiently realistic for training purposes.

  12. Evaluating Multiple Levels of an Interaction Fidelity Continuum on Performance and Learning in Near-Field Training Simulations.

    Science.gov (United States)

    Bhargava, Ayush; Bertrand, Jeffrey W; Gramopadhye, Anand K; Madathil, Kapil C; Babu, Sabarish V

    2018-04-01

    With costs of head-mounted displays (HMDs) and tracking technology decreasing rapidly, various virtual reality applications are being widely adopted for education and training. Hardware advancements have enabled replication of real-world interactions in virtual environments to a large extent, paving the way for commercial grade applications that provide a safe and risk-free training environment at a fraction of the cost. But this also mandates the need to develop more intrinsic interaction techniques and to empirically evaluate them in a more comprehensive manner. Although there exists a body of previous research that examines the benefits of selected levels of interaction fidelity on performance, few studies have investigated the constituent components of fidelity in a Interaction Fidelity Continuum (IFC) with several system instances and their respective effects on performance and learning in the context of a real-world skills training application. Our work describes a large between-subjects investigation conducted over several years that utilizes bimanual interaction metaphors at six discrete levels of interaction fidelity to teach basic precision metrology concepts in a near-field spatial interaction task in VR. A combined analysis performed on the data compares and contrasts the six different conditions and their overall effects on performance and learning outcomes, eliciting patterns in the results between the discrete application points on the IFC. With respect to some performance variables, results indicate that simpler restrictive interaction metaphors and highest fidelity metaphors perform better than medium fidelity interaction metaphors. In light of these results, a set of general guidelines are created for developers of spatial interaction metaphors in immersive virtual environments for precise fine-motor skills training simulations.

  13. Time to unravel the conceptual confusion of authenticity and fidelity and their contribution to learning within simulation-based nurse education. A discussion paper.

    Science.gov (United States)

    Bland, Andrew J; Topping, Annie; Tobbell, Jane

    2014-07-01

    High-fidelity patient simulation is a method of education increasingly utilised by educators of nursing to provide authentic learning experiences. Fidelity and authenticity, however, are not conceptually equivalent. Whilst fidelity is important when striving to replicate a life experience such as clinical practice, authenticity can be produced with low fidelity. A challenge for educators of undergraduate nursing is to ensure authentic representation of the clinical situation which is a core component for potential success. What is less clear is the relationship between fidelity and authenticity in the context of simulation based learning. Authenticity does not automatically follow fidelity and as a result, educators of nursing cannot assume that embracing the latest technology-based educational tools will in isolation provide a learning environment perceived authentic by the learner. As nursing education programmes increasingly adopt simulators that offer the possibility of representing authentic real world situations, there is an urgency to better articulate and understand the terms fidelity and authenticity. Without such understanding there is a real danger that simulation as a teaching and learning resource in nurse education will never reach its potential and be misunderstood, creating a potential barrier to learning. This paper examines current literature to promote discussion within nurse education, concluding that authenticity in the context of simulation-based learning is complex, relying on far more than engineered fidelity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. High fidelity computational characterization of the mechanical response of thermally aged polycarbonate

    Science.gov (United States)

    Zhang, Zesheng; Zhang, Lili; Jasa, John; Li, Wenlong; Gazonas, George; Negahban, Mehrdad

    2017-07-01

    A representative all-atom molecular dynamics (MD) system of polycarbonate (PC) is built and conditioned to capture and predict the behaviours of PC in response to a broad range of thermo-mechanical loadings for various thermal aging. The PC system is constructed to have a distribution of molecular weights comparable to a widely used commercial PC (LEXAN 9034), and thermally conditioned to produce models for aged and unaged PC. The MD responses of these models are evaluated through comparisons to existing experimental results carried out at much lower loading rates, but done over a broad range of temperatures and loading modes. These experiments include monotonic extension/compression/shear, unilaterally and bilaterally confined compression, and load-reversal during shear. It is shown that the MD simulations show both qualitative and quantitative similarity with the experimental response. The quantitative similarity is evaluated by comparing the dilatational response under bilaterally confined compression, the shear flow viscosity and the equivalent yield stress. The consistency of the in silico response to real laboratory experiments strongly suggests that the current PC models are physically and mechanically relevant and potentially can be used to investigate thermo-mechanical response to loading conditions that would not easily be possible. These MD models may provide valuable insight into the molecular sources of certain observations, and could possibly offer new perspectives on how to develop constitutive models that are based on better understanding the response of PC under complex loadings. To this latter end, the models are used to predict the response of PC to complex loading modes that would normally be difficult to do or that include characteristics that would be difficult to measure. These include the responses of unaged and aged PC to unilaterally confined extension/compression, cyclic uniaxial/shear loadings, and saw-tooth extension/compression/shear.

  15. An information theoretic approach to use high-fidelity codes to calibrate low-fidelity codes

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Allison, E-mail: lewis.allison10@gmail.com [Department of Mathematics, North Carolina State University, Raleigh, NC 27695 (United States); Smith, Ralph [Department of Mathematics, North Carolina State University, Raleigh, NC 27695 (United States); Williams, Brian [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Figueroa, Victor [Sandia National Laboratories, Albuquerque, NM 87185 (United States)

    2016-11-01

    For many simulation models, it can be prohibitively expensive or physically infeasible to obtain a complete set of experimental data to calibrate model parameters. In such cases, one can alternatively employ validated higher-fidelity codes to generate simulated data, which can be used to calibrate the lower-fidelity code. In this paper, we employ an information-theoretic framework to determine the reduction in parameter uncertainty that is obtained by evaluating the high-fidelity code at a specific set of design conditions. These conditions are chosen sequentially, based on the amount of information that they contribute to the low-fidelity model parameters. The goal is to employ Bayesian experimental design techniques to minimize the number of high-fidelity code evaluations required to accurately calibrate the low-fidelity model. We illustrate the performance of this framework using heat and diffusion examples, a 1-D kinetic neutron diffusion equation, and a particle transport model, and include initial results from the integration of the high-fidelity thermal-hydraulics code Hydra-TH with a low-fidelity exponential model for the friction correlation factor.

  16. Advancing interprofessional education through the use of high fidelity human patient simulators

    Directory of Open Access Journals (Sweden)

    Kane-Gill SL

    2013-06-01

    Full Text Available Background: Modern medical care increasingly requires coordinated teamwork and communication between healthcare professionals of different disciplines. Unfortunately, healthcare professional students are rarely afforded the opportunity to learn effective methods of interprofessional (IP communication and teamwork strategies during their education. The question of how to best incorporate IP interactions in the curricula of the schools of health professions remains unanswered.Objective: We aim to solve the lack of IP education in the pharmacy curricula through the use of high fidelity simulation (HFS to allow teams of medical, pharmacy, nursing, physician assistant, and social work students to work together in a controlled environment to solve cases of complex medical and social issues.Methods: Once weekly for a 4-week time period, students worked together to complete complex simulation scenarios in small IP teams consisting of pharmacy, medical, nursing, social work, and physician assistant students. Student perception of the use of HFS was evaluated by a survey given at the conclusion of the HFS sessions. Team communication was evaluated through the use of Communication and Teamwork Skills (CATS Assessment by 2 independent evaluators external to the project.Results: The CATS scores improved from the HFS sessions 1 to 2 (p = 0.01, 2 to 3 (p = 0.035, and overall from 1 to 4 (p = 0.001. The inter-rater reliability between evaluators was high (0.85, 95% CI 0.71, 0.99. Students perceived the HFS improved: their ability to communicate with other professionals (median =4; confidence in patient care in an IP team (median=4. It also stimulated student interest in IP work (median=4.5, and was an efficient use of student time (median=4.5Conclusion: The use of HFS improved student teamwork and communication and was an accepted teaching modality. This method of exposing students of the health sciences to IP care should be incorporated throughout the

  17. Analysis of precipitation teleconnections in CMIP models as a measure of model fidelity in simulating precipitation

    Science.gov (United States)

    Langenbrunner, B.; Neelin, J.; Meyerson, J.

    2011-12-01

    The accurate representation of precipitation is a recurring issue in global climate models, especially in the tropics. Poor skill in modeling the variability and climate teleconnections associated with El Niño/Southern Oscillation (ENSO) also persisted in the latest Climate Model Intercomparison Project (CMIP) campaigns. Observed ENSO precipitation teleconnections provide a standard by which we can judge a given model's ability to reproduce precipitation and dynamic feedback processes originating in the tropical Pacific. Using CMIP3 Atmospheric Model Intercomparison Project (AMIP) runs as a baseline, we compare precipitation teleconnections between models and observations, and we evaluate these results against available CMIP5 historical and AMIP runs. Using AMIP simulations restricts evaluation to the atmospheric response, as sea surface temperatures (SSTs) in AMIP are prescribed by observations. We use a rank correlation between ENSO SST indices and precipitation to define teleconnections, since this method is robust to outliers and appropriate for non-Gaussian data. Spatial correlations of the modeled and observed teleconnections are then evaluated. We look at these correlations in regions of strong precipitation teleconnections, including equatorial S. America, the "horseshoe" region in the western tropical Pacific, and southern N. America. For each region and season, we create a "normalized projection" of a given model's teleconnection pattern onto that of the observations, a metric that assesses the quality of regional pattern simulations while rewarding signals of correct sign over the region. Comparing this to an area-averaged (i.e., more generous) metric suggests models do better when restrictions on exact spatial dependence are loosened and conservation constraints apply. Model fidelity in regional measures remains far from perfect, suggesting intrinsic issues with the models' regional sensitivities in moist processes.

  18. Prospective randomized study of contrast reaction management curricula: Computer-based interactive simulation versus high-fidelity hands-on simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Carolyn L., E-mail: wangcl@uw.edu [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States); Schopp, Jennifer G.; Kani, Kimia [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States); Petscavage-Thomas, Jonelle M. [Penn State Hershey Medical Center, Department of Radiology, 500 University Drive, Hershey, PA 17033 (United States); Zaidi, Sadaf; Hippe, Dan S.; Paladin, Angelisa M.; Bush, William H. [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States)

    2013-12-01

    Purpose: We developed a computer-based interactive simulation program for teaching contrast reaction management to radiology trainees and compared its effectiveness to high-fidelity hands-on simulation training. Materials and methods: IRB approved HIPAA compliant prospective study of 44 radiology residents, fellows and faculty who were randomized into either the high-fidelity hands-on simulation group or computer-based simulation group. All participants took separate written tests prior to and immediately after their intervention. Four months later participants took a delayed written test and a hands-on high-fidelity severe contrast reaction scenario performance test graded on predefined critical actions. Results: There was no statistically significant difference between the computer and hands-on groups’ written pretest, immediate post-test, or delayed post-test scores (p > 0.6 for all). Both groups’ scores improved immediately following the intervention (p < 0.001). The delayed test scores 4 months later were still significantly higher than the pre-test scores (p ≤ 0.02). The computer group's performance was similar to the hands-on group on the severe contrast reaction simulation scenario test (p = 0.7). There were also no significant differences between the computer and hands-on groups in performance on the individual core competencies of contrast reaction management during the contrast reaction scenario. Conclusion: It is feasible to develop a computer-based interactive simulation program to teach contrast reaction management. Trainees that underwent computer-based simulation training scored similarly on written tests and on a hands-on high-fidelity severe contrast reaction scenario performance test as those trained with hands-on high-fidelity simulation.

  19. Prospective randomized study of contrast reaction management curricula: Computer-based interactive simulation versus high-fidelity hands-on simulation

    International Nuclear Information System (INIS)

    Wang, Carolyn L.; Schopp, Jennifer G.; Kani, Kimia; Petscavage-Thomas, Jonelle M.; Zaidi, Sadaf; Hippe, Dan S.; Paladin, Angelisa M.; Bush, William H.

    2013-01-01

    Purpose: We developed a computer-based interactive simulation program for teaching contrast reaction management to radiology trainees and compared its effectiveness to high-fidelity hands-on simulation training. Materials and methods: IRB approved HIPAA compliant prospective study of 44 radiology residents, fellows and faculty who were randomized into either the high-fidelity hands-on simulation group or computer-based simulation group. All participants took separate written tests prior to and immediately after their intervention. Four months later participants took a delayed written test and a hands-on high-fidelity severe contrast reaction scenario performance test graded on predefined critical actions. Results: There was no statistically significant difference between the computer and hands-on groups’ written pretest, immediate post-test, or delayed post-test scores (p > 0.6 for all). Both groups’ scores improved immediately following the intervention (p < 0.001). The delayed test scores 4 months later were still significantly higher than the pre-test scores (p ≤ 0.02). The computer group's performance was similar to the hands-on group on the severe contrast reaction simulation scenario test (p = 0.7). There were also no significant differences between the computer and hands-on groups in performance on the individual core competencies of contrast reaction management during the contrast reaction scenario. Conclusion: It is feasible to develop a computer-based interactive simulation program to teach contrast reaction management. Trainees that underwent computer-based simulation training scored similarly on written tests and on a hands-on high-fidelity severe contrast reaction scenario performance test as those trained with hands-on high-fidelity simulation

  20. Features and uses of high-fidelity medical simulations that lead to effective learning: a BEME systematic review.

    Science.gov (United States)

    Issenberg, S Barry; McGaghie, William C; Petrusa, Emil R; Lee Gordon, David; Scalese, Ross J

    2005-01-01

    1969 to 2003, 34 years. Simulations are now in widespread use in medical education and medical personnel evaluation. Outcomes research on the use and effectiveness of simulation technology in medical education is scattered, inconsistent and varies widely in methodological rigor and substantive focus. Review and synthesize existing evidence in educational science that addresses the question, 'What are the features and uses of high-fidelity medical simulations that lead to most effective learning?'. The search covered five literature databases (ERIC, MEDLINE, PsycINFO, Web of Science and Timelit) and employed 91 single search terms and concepts and their Boolean combinations. Hand searching, Internet searches and attention to the 'grey literature' were also used. The aim was to perform the most thorough literature search possible of peer-reviewed publications and reports in the unpublished literature that have been judged for academic quality. Four screening criteria were used to reduce the initial pool of 670 journal articles to a focused set of 109 studies: (a) elimination of review articles in favor of empirical studies; (b) use of a simulator as an educational assessment or intervention with learner outcomes measured quantitatively; (c) comparative research, either experimental or quasi-experimental; and (d) research that involves simulation as an educational intervention. Data were extracted systematically from the 109 eligible journal articles by independent coders. Each coder used a standardized data extraction protocol. Qualitative data synthesis and tabular presentation of research methods and outcomes were used. Heterogeneity of research designs, educational interventions, outcome measures and timeframe precluded data synthesis using meta-analysis. Coding accuracy for features of the journal articles is high. The extant quality of the published research is generally weak. The weight of the best available evidence suggests that high-fidelity medical

  1. Simulation Learning: PC-Screen Based (PCSB) versus High Fidelity Simulation (HFS)

    Science.gov (United States)

    2013-08-01

    1.00 (0.00) Score Change (mean change and sd) Assemble Equipment (Yes/No) 1. Water soluble lubricant 2. Suction equipment 3. Selecting correct...0.92 (0.25) 0.64 (0.31) 0.86 (0.22) 0.98 (0.07) Mean score change and sd Procedural Steps (Yes/No) 1. Lubricate tube with water -soluble...w., Johnson, C., Hsu, E. and  Wasser , T. (2006). Using innovative  simulation modalities for civilian based, chemical, biological, radiological

  2. A survey of modelling methods for high-fidelity wind farm simulations using large eddy simulation

    DEFF Research Database (Denmark)

    Breton, Simon-Philippe; Sumner, J.; Sørensen, Jens Nørkær

    2017-01-01

    surveys the most common schemes available to model the rotor, atmospheric conditions and terrain effects within current state-of-the-art LES codes, of which an overview is provided. A summary of the experimental research data available for validation of LES codes within the context of single and multiple......Large eddy simulations (LES) of wind farms have the capability to provide valuable and detailed information about the dynamics of wind turbine wakes. For this reason, their use within the wind energy research community is on the rise, spurring the development of new models and methods. This review...

  3. Improving the fidelity of electrically heated nuclear systems testing using simulated neutronic feedback

    International Nuclear Information System (INIS)

    Bragg-Sitton, Shannon M.; Godfroy, Thomas J.; Webster, Kenny

    2010-01-01

    Nonnuclear test platforms and methodologies can be employed to reduce the overall cost, risk and complexity of testing nuclear systems while allowing one to evaluate the operation of an integrated nuclear system within a reasonable timeframe, providing valuable input to the overall system design. In a nonnuclear test bed, electric heaters are used to simulate the heat from nuclear fuel. Standard electric test techniques allow one to fully assess thermal, heat transfer, and stress related attributes of a given system, but these approaches fail to demonstrate the dynamic response that would be present in an integrated, fueled reactor system. The integration of thermal hydraulic hardware tests with simulated neutronic response provides a bridge between electrically heated testing and testing with nuclear fuel elements installed. By implementing a neutronic response model to simulate the dynamic response that would be expected in a fueled reactor system, one can better understand system integration issues, characterize integrated system response times and response characteristics, and assess potential design improvements at a relatively small fiscal investment. This paper summarizes the results of initial system dynamic response testing for two electrically heated reactor concepts: a heat pipe-cooled reactor simulator with integrated heat exchanger and a gas-cooled reactor simulator with integrated Brayton power conversion system. Initial applications apply a simplified reactor kinetics model with either a single or an averaged measured state point. Preliminary results demonstrate the applicability of the dynamic test methodology to any reactor type, elucidating the variation in system response characteristics in different reactor concepts. These results suggest a need to further enhance the dynamic test approach by incorporating a more accurate model of the reactor dynamics and improved hardware instrumentation for better state estimation in application of the

  4. High fidelity medical simulation in the difficult environment of a helicopter: feasibility, self-efficacy and cost

    Directory of Open Access Journals (Sweden)

    Holland Carolyn

    2006-10-01

    Full Text Available Abstract Background This study assessed the feasibility, self-efficacy and cost of providing a high fidelity medical simulation experience in the difficult environment of an air ambulance helicopter. Methods Seven of 12 EM residents in their first postgraduate year participated in an EMS flight simulation as the flight physician. The simulation used the Laerdal SimMan™ to present a cardiac and a trauma case in an EMS helicopter while running at flight idle. Before and after the simulation, subjects completed visual analog scales and a semi-structured interview to measure their self-efficacy, i.e. comfort with their ability to treat patients in the helicopter, and recognition of obstacles to care in the helicopter environment. After all 12 residents had completed their first non-simulated flight as the flight physician; they were surveyed about self-assessed comfort and perceived value of the simulation. Continuous data were compared between pre- and post-simulation using a paired samples t-test, and between residents participating in the simulation and those who did not using an independent samples t-test. Categorical data were compared using Fisher's exact test. Cost data for the simulation experience were estimated by the investigators. Results The simulations functioned correctly 5 out of 7 times; suggesting some refinement is necessary. Cost data indicated a monetary cost of $440 and a time cost of 22 hours of skilled instructor time. The simulation and non-simulation groups were similar in their demographics and pre-hospital experiences. The simulation did not improve residents' self-assessed comfort prior to their first flight (p > 0.234, but did improve understanding of the obstacles to patient care in the helicopter (p = 0.029. Every resident undertaking the simulation agreed it was educational and it should be included in their training. Qualitative data suggested residents would benefit from high fidelity simulation in other

  5. A practical discrete-adjoint method for high-fidelity compressible turbulence simulations

    International Nuclear Information System (INIS)

    Vishnampet, Ramanathan; Bodony, Daniel J.; Freund, Jonathan B.

    2015-01-01

    Methods and computing hardware advances have enabled accurate predictions of complex compressible turbulence phenomena, such as the generation of jet noise that motivates the present effort. However, limited understanding of underlying physical mechanisms restricts the utility of such predictions since they do not, by themselves, indicate a route to design improvements. Gradient-based optimization using adjoints can circumvent the flow complexity to guide designs, though this is predicated on the availability of a sufficiently accurate solution of the forward and adjoint systems. These are challenging to obtain, since both the chaotic character of the turbulence and the typical use of discretizations near their resolution limits in order to efficiently represent its smaller scales will amplify any approximation errors made in the adjoint formulation. Formulating a practical exact adjoint that avoids such errors is especially challenging if it is to be compatible with state-of-the-art simulation methods used for the turbulent flow itself. Automatic differentiation (AD) can provide code to calculate a nominally exact adjoint, but existing general-purpose AD codes are inefficient to the point of being prohibitive for large-scale turbulence simulations. Here, we analyze the compressible flow equations as discretized using the same high-order workhorse methods used for many high-fidelity compressible turbulence simulations, and formulate a practical space–time discrete-adjoint method without changing the basic discretization. A key step is the definition of a particular discrete analog of the continuous norm that defines our cost functional; our selection leads directly to an efficient Runge–Kutta-like scheme, though it would be just first-order accurate if used outside the adjoint formulation for time integration, with finite-difference spatial operators for the adjoint system. Its computational cost only modestly exceeds that of the flow equations. We confirm that

  6. A High Fidelity Approach to Data Simulation for Space Situational Awareness Missions

    Science.gov (United States)

    Hagerty, S.; Ellis, H., Jr.

    2016-09-01

    Space Situational Awareness (SSA) is vital to maintaining our Space Superiority. A high fidelity, time-based simulation tool, PROXOR™ (Proximity Operations and Rendering), supports SSA by generating realistic mission scenarios including sensor frame data with corresponding truth. This is a unique and critical tool for supporting mission architecture studies, new capability (algorithm) development, current/future capability performance analysis, and mission performance prediction. PROXOR™ provides a flexible architecture for sensor and resident space object (RSO) orbital motion and attitude control that simulates SSA, rendezvous and proximity operations scenarios. The major elements of interest are based on the ability to accurately simulate all aspects of the RSO model, viewing geometry, imaging optics, sensor detector, and environmental conditions. These capabilities enhance the realism of mission scenario models and generated mission image data. As an input, PROXOR™ uses a library of 3-D satellite models containing 10+ satellites, including low-earth orbit (e.g., DMSP) and geostationary (e.g., Intelsat) spacecraft, where the spacecraft surface properties are those of actual materials and include Phong and Maxwell-Beard bidirectional reflectance distribution function (BRDF) coefficients for accurate radiometric modeling. We calculate the inertial attitude, the changing solar and Earth illumination angles of the satellite, and the viewing angles from the sensor as we propagate the RSO in its orbit. The synthetic satellite image is rendered at high resolution and aggregated to the focal plane resolution resulting in accurate radiometry even when the RSO is a point source. The sensor model includes optical effects from the imaging system [point spread function (PSF) includes aberrations, obscurations, support structures, defocus], detector effects (CCD blooming, left/right bias, fixed pattern noise, image persistence, shot noise, read noise, and quantization

  7. Teaching childbirth with high-fidelity simulation. Is it better observing the scenario during the briefing session?

    Science.gov (United States)

    Cuerva, Marcos J; Piñel, Carlos S; Martin, Lourdes; Espinosa, Jose A; Corral, Octavio J; Mendoza, Nicolás

    2018-02-12

    The design of optimal courses for obstetric undergraduate teaching is a relevant question. This study evaluates two different designs of simulator-based learning activity on childbirth with regard to respect to the patient, obstetric manoeuvres, interpretation of cardiotocography tracings (CTG) and infection prevention. This randomised experimental study which differs in the content of their briefing sessions consisted of two groups of undergraduate students, who performed two simulator-based learning activities on childbirth. The first briefing session included the observations of a properly performed scenario according to Spanish clinical practice guidelines on care in normal childbirth by the teachers whereas the second group did not include the observations of a properly performed scenario, and the students observed it only after the simulation process. The group that observed a properly performed scenario after the simulation obtained worse grades during the simulation, but better grades during the debriefing and evaluation. Simulator use in childbirth may be more fruitful when the medical students observe correct performance at the completion of the scenario compared to that at the start of the scenario. Impact statement What is already known on this subject? There is a scarcity of literature about the design of optimal high-fidelity simulation training in childbirth. It is known that preparing simulator-based learning activities is a complex process. Simulator-based learning includes the following steps: briefing, simulation, debriefing and evaluation. The most important part of high-fidelity simulations is the debriefing. A good briefing and simulation are of high relevance in order to have a fruitful debriefing session. What do the results of this study add? Our study describes a full simulator-based learning activity on childbirth that can be reproduced in similar facilities. The findings of this study add that high-fidelity simulation training in

  8. Cognitive load, emotion, and performance in high-fidelity simulation among beginning nursing students: a pilot study.

    Science.gov (United States)

    Schlairet, Maura C; Schlairet, Timothy James; Sauls, Denise H; Bellflowers, Lois

    2015-03-01

    Establishing the impact of the high-fidelity simulation environment on student performance, as well as identifying factors that could predict learning, would refine simulation outcome expectations among educators. The purpose of this quasi-experimental pilot study was to explore the impact of simulation on emotion and cognitive load among beginning nursing students. Forty baccalaureate nursing students participated in teaching simulations, rated their emotional state and cognitive load, and completed evaluation simulations. Two principal components of emotion were identified representing the pleasant activation and pleasant deactivation components of affect. Mean rating of cognitive load following simulation was high. Linear regression identiffed slight but statistically nonsignificant positive associations between principal components of emotion and cognitive load. Logistic regression identified a negative but statistically nonsignificant effect of cognitive load on assessment performance. Among lower ability students, a more pronounced effect of cognitive load on assessment performance was observed; this also was statistically non-significant. Copyright 2015, SLACK Incorporated.

  9. The effect of high-fidelity patient simulation on the critical thinking and clinical decision-making skills of new graduate nurses.

    Science.gov (United States)

    Maneval, Rhonda; Fowler, Kimberly A; Kays, John A; Boyd, Tiffany M; Shuey, Jennifer; Harne-Britner, Sarah; Mastrine, Cynthia

    2012-03-01

    This study was conducted to determine whether the addition of high-fidelity patient simulation to new nurse orientation enhanced critical thinking and clinical decision-making skills. A pretest-posttest design was used to assess critical thinking and clinical decision-making skills in two groups of graduate nurses. Compared with the control group, the high-fidelity patient simulation group did not show significant improvement in mean critical thinking or clinical decision-making scores. When mean scores were analyzed, both groups showed an increase in critical thinking scores from pretest to posttest, with the high-fidelity patient simulation group showing greater gains in overall scores. However, neither group showed a statistically significant increase in mean test scores. The effect of high-fidelity patient simulation on critical thinking and clinical decision-making skills remains unclear. Copyright 2012, SLACK Incorporated.

  10. Development of High-Fidelity Material Response Modeling for Resin-Infused Woven Thermal Protection Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — For future space exploration missions, it is essential for the thermal protection system (TPS) found on hypersonic vehicles or atmospheric entry probes to be...

  11. High-fidelity hybrid simulation of allergic emergencies demonstrates improved preparedness for office emergencies in pediatric allergy clinics.

    Science.gov (United States)

    Kennedy, Joshua L; Jones, Stacie M; Porter, Nicholas; White, Marjorie L; Gephardt, Grace; Hill, Travis; Cantrell, Mary; Nick, Todd G; Melguizo, Maria; Smith, Chris; Boateng, Beatrice A; Perry, Tamara T; Scurlock, Amy M; Thompson, Tonya M

    2013-01-01

    Simulation models that used high-fidelity mannequins have shown promise in medical education, particularly for cases in which the event is uncommon. Allergy physicians encounter emergencies in their offices, and these can be the source of much trepidation. To determine if case-based simulations with high-fidelity mannequins are effective in teaching and retention of emergency management team skills. Allergy clinics were invited to Arkansas Children's Hospital Pediatric Understanding and Learning through Simulation Education center for a 1-day workshop to evaluate skills concerning the management of allergic emergencies. A Clinical Emergency Preparedness Team Performance Evaluation was developed to evaluate the competence of teams in several areas: leadership and/or role clarity, closed-loop communication, team support, situational awareness, and scenario-specific skills. Four cases, which focus on common allergic emergencies, were simulated by using high-fidelity mannequins and standardized patients. Teams were evaluated by multiple reviewers by using video recording and standardized scoring. Ten to 12 months after initial training, an unannounced in situ case was performed to determine retention of the skills training. Clinics showed significant improvements for role clarity, teamwork, situational awareness, and scenario-specific skills during the 1-day workshop (all P clinics (all P ≤ .004). Clinical Emergency Preparedness Team Performance Evaluation scores demonstrated improved team management skills with simulation training in office emergencies. Significant recall of team emergency management skills was demonstrated months after the initial training. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  12. Benefits of a Unified LaSRS++ Simulation for NAS-Wide and High-Fidelity Modeling

    Science.gov (United States)

    Glaab, Patricia; Madden, Michael

    2014-01-01

    The LaSRS++ high-fidelity vehicle simulation was extended in 2012 to support a NAS-wide simulation mode. Since the initial proof-of-concept, the LaSRS++ NAS-wide simulation is maturing into a research-ready tool. A primary benefit of this new capability is the consolidation of the two modeling paradigms under a single framework to save cost, facilitate iterative concept testing between the two tools, and to promote communication and model sharing between user communities at Langley. Specific benefits of each type of modeling are discussed along with the expected benefits of the unified framework. Current capability details of the LaSRS++ NAS-wide simulations are provided, including the visualization tool, live data interface, trajectory generators, terminal routing for arrivals and departures, maneuvering, re-routing, navigation, winds, and turbulence. The plan for future development is also described.

  13. Assessing Technical Performance and Determining the Learning Curve in Cleft Palate Surgery Using a High-Fidelity Cleft Palate Simulator.

    Science.gov (United States)

    Podolsky, Dale J; Fisher, David M; Wong Riff, Karen W; Szasz, Peter; Looi, Thomas; Drake, James M; Forrest, Christopher R

    2018-06-01

    This study assessed technical performance in cleft palate repair using a newly developed assessment tool and high-fidelity cleft palate simulator through a longitudinal simulation training exercise. Three residents performed five and one resident performed nine consecutive endoscopically recorded cleft palate repairs using a cleft palate simulator. Two fellows in pediatric plastic surgery and two expert cleft surgeons also performed recorded simulated repairs. The Cleft Palate Objective Structured Assessment of Technical Skill (CLOSATS) and end-product scales were developed to assess performance. Two blinded cleft surgeons assessed the recordings and the final repairs using the CLOSATS, end-product scale, and a previously developed global rating scale. The average procedure-specific (CLOSATS), global rating, and end-product scores increased logarithmically after each successive simulation session for the residents. Reliability of the CLOSATS (average item intraclass correlation coefficient (ICC), 0.85 ± 0.093) and global ratings (average item ICC, 0.91 ± 0.02) among the raters was high. Reliability of the end-product assessments was lower (average item ICC, 0.66 ± 0.15). Standard setting linear regression using an overall cutoff score of 7 of 10 corresponded to a pass score for the CLOSATS and the global score of 44 (maximum, 60) and 23 (maximum, 30), respectively. Using logarithmic best-fit curves, 6.3 simulation sessions are required to reach the minimum standard. A high-fidelity cleft palate simulator has been developed that improves technical performance in cleft palate repair. The simulator and technical assessment scores can be used to determine performance before operating on patients.

  14. Improvement of the NSSS T/H Module for Enhancing the Simulation Fidelity of KNPEC-2 Simulator

    International Nuclear Information System (INIS)

    Kim, Kyung Doo; Lee, Seung Wook; Jeong, Jae Jun; Lee, Myung Soo

    2005-01-01

    KEPRI(Korea Electric Power Research Institute) and KAERI (Korea Atomic Energy Research Institute) jointly developed and supplied a realistic NSSS (Nuclear Steam Supply System) T/H (Thermal-Hydraulic) module (named ARTS) based on the best-estimate code RETRAN-3D for the improvement of the KNPEC-2 full-scope simulator in 2001. Although ARTS can simulate the most transients in real-time, and its robustness is ensured, real-time calculation and robustness can fail for largebreak (LB) loss-of-coolant accident (LOCA) and longterm, two-phase transients. In order to improve its robustness, ARTS equipped with the backup calculation module to be used whenever a regular ARTS module fails to calculate. When the symptom for the failure of T/H module is detected, the main ARTS module is replaced with the backup module for the calculation of primary and secondary reactor system although most failures of ARTS occur in the calculation of the primary system especially for LB LOCA simulation. The sudden transition from the main ARTS module to the backup module can exhibit the discontinuity of simulation of secondary system on rare occasions. To mitigate the simulation discontinuity, we have improved the backup module of ARTS. The performance of a new approach has been illustrated by the non-integrated standalone test. The improved ARTS module will be incorporated into KNPEC-2 simulator and evaluated its performance in the real simulator environment. This paper presents the brief description of a new backup calculation strategy and the simulation results of LOCA to evaluate the performance of a new backup strategy in standalone test environment

  15. High-fidelity simulations of moving and flexible airfoils at low Reynolds numbers

    Energy Technology Data Exchange (ETDEWEB)

    Visbal, Miguel R.; Gordnier, Raymond E.; Galbraith, Marshall C. [Air Force Research Laboratory, Computational Sciences Branch, Air Vehicles Directorate, Wright-Patterson AFB, OH (United States)

    2009-05-15

    The present paper highlights results derived from the application of a high-fidelity simulation technique to the analysis of low-Reynolds-number transitional flows over moving and flexible canonical configurations motivated by small natural and man-made flyers. This effort addresses three separate fluid dynamic phenomena relevant to small fliers, including: laminar separation and transition over a stationary airfoil, transition effects on the dynamic stall vortex generated by a plunging airfoil, and the effect of flexibility on the flow structure above a membrane airfoil. The specific cases were also selected to permit comparison with available experimental measurements. First, the process of transition on a stationary SD7003 airfoil section over a range of Reynolds numbers and angles of attack is considered. Prior to stall, the flow exhibits a separated shear layer which rolls up into spanwise vortices. These vortices subsequently undergo spanwise instabilities, and ultimately breakdown into fine-scale turbulent structures as the boundary layer reattaches to the airfoil surface. In a time-averaged sense, the flow displays a closed laminar separation bubble which moves upstream and contracts in size with increasing angle of attack for a fixed Reynolds number. For a fixed angle of attack, as the Reynolds number decreases, the laminar separation bubble grows in vertical extent producing a significant increase in drag. For the lowest Reynolds number considered (Re{sub c} = 10 {sup 4}), transition does not occur over the airfoil at moderate angles of attack prior to stall. Next, the impact of a prescribed high-frequency small-amplitude plunging motion on the transitional flow over the SD7003 airfoil is investigated. The motion-induced high angle of attack results in unsteady separation in the leading edge and in the formation of dynamic-stall-like vortices which convect downstream close to the airfoil. At the lowest value of Reynolds number (Re{sub c}=10 {sup 4

  16. An Immersed Boundary - Adaptive Mesh Refinement solver (IB-AMR) for high fidelity fully resolved wind turbine simulations

    Science.gov (United States)

    Angelidis, Dionysios; Sotiropoulos, Fotis

    2015-11-01

    The geometrical details of wind turbines determine the structure of the turbulence in the near and far wake and should be taken in account when performing high fidelity calculations. Multi-resolution simulations coupled with an immersed boundary method constitutes a powerful framework for high-fidelity calculations past wind farms located over complex terrains. We develop a 3D Immersed-Boundary Adaptive Mesh Refinement flow solver (IB-AMR) which enables turbine-resolving LES of wind turbines. The idea of using a hybrid staggered/non-staggered grid layout adopted in the Curvilinear Immersed Boundary Method (CURVIB) has been successfully incorporated on unstructured meshes and the fractional step method has been employed. The overall performance and robustness of the second order accurate, parallel, unstructured solver is evaluated by comparing the numerical simulations against conforming grid calculations and experimental measurements of laminar and turbulent flows over complex geometries. We also present turbine-resolving multi-scale LES considering all the details affecting the induced flow field; including the geometry of the tower, the nacelle and especially the rotor blades of a wind tunnel scale turbine. This material is based upon work supported by the Department of Energy under Award Number DE-EE0005482 and the Sandia National Laboratories.

  17. High Fidelity, “Faster than Real-Time” Simulator for Predicting Power System Dynamic Behavior - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Flueck, Alex [Illinois Inst. of Technology, Chicago, IL (United States)

    2017-07-14

    The “High Fidelity, Faster than Real­Time Simulator for Predicting Power System Dynamic Behavior” was designed and developed by Illinois Institute of Technology with critical contributions from Electrocon International, Argonne National Laboratory, Alstom Grid and McCoy Energy. Also essential to the project were our two utility partners: Commonwealth Edison and AltaLink. The project was a success due to several major breakthroughs in the area of large­scale power system dynamics simulation, including (1) a validated faster than real­ time simulation of both stable and unstable transient dynamics in a large­scale positive sequence transmission grid model, (2) a three­phase unbalanced simulation platform for modeling new grid devices, such as independently controlled single­phase static var compensators (SVCs), (3) the world’s first high fidelity three­phase unbalanced dynamics and protection simulator based on Electrocon’s CAPE program, and (4) a first­of­its­ kind implementation of a single­phase induction motor model with stall capability. The simulator results will aid power grid operators in their true time of need, when there is a significant risk of cascading outages. The simulator will accelerate performance and enhance accuracy of dynamics simulations, enabling operators to maintain reliability and steer clear of blackouts. In the long­term, the simulator will form the backbone of the newly conceived hybrid real­time protection and control architecture that will coordinate local controls, wide­area measurements, wide­area controls and advanced real­time prediction capabilities. The nation’s citizens will benefit in several ways, including (1) less down time from power outages due to the faster­than­real­time simulator’s predictive capability, (2) higher levels of reliability due to the detailed dynamics plus protection simulation capability, and (3) more resiliency due to the three­ phase unbalanced simulator’s ability to

  18. Use of high fidelity operating room simulation to assess and teach communication, teamwork and laparoscopic skills: initial experience.

    Science.gov (United States)

    Gettman, Matthew T; Pereira, Claudio W; Lipsky, Katja; Wilson, Torrence; Arnold, Jacqueline J; Leibovich, Bradley C; Karnes, R Jeffrey; Dong, Yue

    2009-03-01

    Structured opportunities for learning communication, teamwork and laparoscopic principles are limited for urology residents. We evaluated and taught teamwork, communication and laparoscopic skills to urology residents in a simulated operating room. Scenarios related to laparoscopy (insufflator failure, carbon dioxide embolism) were developed using mannequins, urology residents and nurses. These scenarios were developed based on Accreditation Council for Graduate Medical Education core competencies and performed in a simulation center. Between the pretest scenario (insufflation failure) and the posttest scenario (carbon dioxide embolism) instruction was given on teamwork, communication and laparoscopic skills. A total of 19 urology residents participated in the training that involved participation in at least 2 scenarios. Performance was evaluated using validated teamwork instruments, questionnaires and videotape analysis. Significant improvement was noted on validated teamwork instruments between scenarios based on resident (pretest 24, posttest 27, p = 0.01) and expert (pretest 16, posttest 25, p = 0.008) evaluation. Increased teamwork and team performance were also noted between scenarios on videotape analysis with significant improvement for adherence to best practice (p = 0.01) and maintenance of positive rapport among team members (p = 0.02). Significant improvement in the setup of the laparoscopic procedure was observed (p = 0.01). Favorable face and content validity was noted for both scenarios. Teamwork, intraoperative communication and laparoscopic skills of urology residents improved during the high fidelity simulation course. Face and content validity of the individual sessions was favorable. In this study high fidelity simulation was effective for assessing and teaching Accreditation Council for Graduate Medical Education core competencies related to intraoperative communication, teamwork and laparoscopic skills.

  19. Investigation of the impact of high liquid viscosity on jet atomization in crossflow via high-fidelity simulations

    Science.gov (United States)

    Li, Xiaoyi; Gao, Hui; Soteriou, Marios C.

    2017-08-01

    Atomization of extremely high viscosity liquid can be of interest for many applications in aerospace, automotive, pharmaceutical, and food industries. While detailed atomization measurements usually face grand challenges, high-fidelity numerical simulations offer the advantage to comprehensively explore the atomization details. In this work, a previously validated high-fidelity first-principle simulation code HiMIST is utilized to simulate high-viscosity liquid jet atomization in crossflow. The code is used to perform a parametric study of the atomization process in a wide range of Ohnesorge numbers (Oh = 0.004-2) and Weber numbers (We = 10-160). Direct comparisons between the present study and previously published low-viscosity jet in crossflow results are performed. The effects of viscous damping and slowing on jet penetration, liquid surface instabilities, ligament formation/breakup, and subsequent droplet formation are investigated. Complex variations in near-field and far-field jet penetrations with increasing Oh at different We are observed and linked with the underlying jet deformation and breakup physics. Transition in breakup regimes and increase in droplet size with increasing Oh are observed, mostly consistent with the literature reports. The detailed simulations elucidate a distinctive edge-ligament-breakup dominated process with long surviving ligaments for the higher Oh cases, as opposed to a two-stage edge-stripping/column-fracture process for the lower Oh counterparts. The trend of decreasing column deflection with increasing We is reversed as Oh increases. A predominantly unimodal droplet size distribution is predicted at higher Oh, in contrast to the bimodal distribution at lower Oh. It has been found that both Rayleigh-Taylor and Kelvin-Helmholtz linear stability theories cannot be easily applied to interpret the distinct edge breakup process and further study of the underlying physics is needed.

  20. Implementation and outcome evaluation of high-fidelity simulation scenarios to integrate cognitive and psychomotor skills for Korean nursing students.

    Science.gov (United States)

    Ahn, Heejung; Kim, Hyun-Young

    2015-05-01

    This study is involved in designing high-fidelity simulations reflecting the Korean nursing education environment. In addition, it evaluated the simulations by nursing students' learning outcomes and perceptions of the simulation design features. A quantitative design was used in two separate phases. For the first phase, five nursing experts participated in verifying the appropriateness of two simulation scenarios that reflected the intended learning objectives. For the second phase, 69 nursing students in the third year of a bachelor's degree at a nursing school participated in evaluating the simulations and were randomized according to their previous course grades. The first phase verified the two simulation scenarios using a questionnaire. The second phase evaluated students' perceptions of the simulation design, self-confidence, and critical thinking skills using a quasi-experimental post-test design. ANCOVA was used to compare the experimental and control groups, and correlation coefficient analysis was used to determine the correlation among them. We created 2 simulation scenarios to integrate cognitive and psychomotor skills according to the learning objectives and clinical environment in Korea. The experimental group had significantly higher scores on self-confidence in the first scenario. The positive correlations between perceptions of the simulation design features, self-confidence, and critical thinking skill scores were statistically significant. Students with a more positive perception of the design features of the simulations had better learning outcomes. Based on this result, simulations need to be designed and implemented with more differentiation in order to be perceived more appropriately by students. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Progress Toward Affordable High Fidelity Combustion Simulations Using Filtered Density Functions for Hypersonic Flows in Complex Geometries

    Science.gov (United States)

    Drozda, Tomasz G.; Quinlan, Jesse R.; Pisciuneri, Patrick H.; Yilmaz, S. Levent

    2012-01-01

    Significant progress has been made in the development of subgrid scale (SGS) closures based on a filtered density function (FDF) for large eddy simulations (LES) of turbulent reacting flows. The FDF is the counterpart of the probability density function (PDF) method, which has proven effective in Reynolds averaged simulations (RAS). However, while systematic progress is being made advancing the FDF models for relatively simple flows and lab-scale flames, the application of these methods in complex geometries and high speed, wall-bounded flows with shocks remains a challenge. The key difficulties are the significant computational cost associated with solving the FDF transport equation and numerically stiff finite rate chemistry. For LES/FDF methods to make a more significant impact in practical applications a pragmatic approach must be taken that significantly reduces the computational cost while maintaining high modeling fidelity. An example of one such ongoing effort is at the NASA Langley Research Center, where the first generation FDF models, namely the scalar filtered mass density function (SFMDF) are being implemented into VULCAN, a production-quality RAS and LES solver widely used for design of high speed propulsion flowpaths. This effort leverages internal and external collaborations to reduce the overall computational cost of high fidelity simulations in VULCAN by: implementing high order methods that allow reduction in the total number of computational cells without loss in accuracy; implementing first generation of high fidelity scalar PDF/FDF models applicable to high-speed compressible flows; coupling RAS/PDF and LES/FDF into a hybrid framework to efficiently and accurately model the effects of combustion in the vicinity of the walls; developing efficient Lagrangian particle tracking algorithms to support robust solutions of the FDF equations for high speed flows; and utilizing finite rate chemistry parametrization, such as flamelet models, to reduce

  2. High Fidelity Simulations for Unsteady Flow Through the Orbiter LH2 Feedline Flowliner

    Science.gov (United States)

    Kiris, Cetin C.; Kwak, Dochan; Chan, William; Housman, Jeffrey

    2005-01-01

    High fidelity computations were carried out to analyze the orbiter M2 feedline flowliner. Various computational models were used to characterize the unsteady flow features in the turbopump, including the orbiter Low-Pressure-Fuel-Turbopump (LPFTP) inducer, the orbiter manifold and a test article used to represent the manifold. Unsteady flow originating from the orbiter LPFTP inducer is one of the major contributors to the high frequency cyclic loading that results in high cycle fatigue damage to the gimbal flowliners just upstream of the LPFTP. The flow fields for the orbiter manifold and representative test article are computed and analyzed for similarities and differences. An incompressible Navier-Stokes flow solver INS3D, based on the artificial compressibility method, was used to compute the flow of liquid hydrogen in each test article.

  3. Simulation-based optimization of thermal systems

    International Nuclear Information System (INIS)

    Jaluria, Yogesh

    2009-01-01

    This paper considers the design and optimization of thermal systems on the basis of the mathematical and numerical modeling of the system. Many complexities are often encountered in practical thermal processes and systems, making the modeling challenging and involved. These include property variations, complicated regions, combined transport mechanisms, chemical reactions, and intricate boundary conditions. The paper briefly presents approaches that may be used to accurately simulate these systems. Validation of the numerical model is a particularly critical aspect and is discussed. It is important to couple the modeling with the system performance, design, control and optimization. This aspect, which has often been ignored in the literature, is considered in this paper. Design of thermal systems based on concurrent simulation and experimentation is also discussed in terms of dynamic data-driven optimization methods. Optimization of the system and of the operating conditions is needed to minimize costs and improve product quality and system performance. Different optimization strategies that are currently used for thermal systems are outlined, focusing on new and emerging strategies. Of particular interest is multi-objective optimization, since most thermal systems involve several important objective functions, such as heat transfer rate and pressure in electronic cooling systems. A few practical thermal systems are considered in greater detail to illustrate these approaches and to present typical simulation, design and optimization results

  4. A high-fidelity, six-degree-of-freedom batch simulation environment for tactical guidance research and evaluation

    Science.gov (United States)

    Goodrich, Kenneth H.

    1993-01-01

    A batch air combat simulation environment, the tactical maneuvering simulator (TMS), is presented. The TMS is a tool for developing and evaluating tactical maneuvering logics, but it can also be used to evaluate the tactical implications of perturbations to aircraft performance or supporting systems. The TMS can simulate air combat between any number of engagement participants, with practical limits imposed by computer memory and processing power. Aircraft are modeled using equations of motion, control laws, aerodynamics, and propulsive characteristics equivalent to those used in high-fidelity piloted simulations. Data bases representative of a modern high-performance aircraft with and without thrust-vectoring capability are included. To simplify the task of developing and implementing maneuvering logics in the TMS, an outer-loop control system, the tactical autopilot (TA), is implemented in the aircraft simulation model. The TA converts guidance commands by computerized maneuvering logics from desired angle of attack and wind-axis bank-angle inputs to the inner loop control augmentation system of the aircraft. The capabilities and operation of the TMS and the TA are described.

  5. Development of a High-Fidelity Simulation Environment for Shadow-Mode Assessments of Air Traffic Concepts

    Science.gov (United States)

    Robinson, John E., III; Lee, Alan; Lai, Chok Fung

    2017-01-01

    This paper describes the Shadow-Mode Assessment Using Realistic Technologies for the National Airspace System (SMART-NAS) Test Bed. The SMART-NAS Test Bed is an air traffic simulation platform being developed by the National Aeronautics and Space Administration (NASA). The SMART-NAS Test Bed's core purpose is to conduct high-fidelity, real-time, human-in-the-loop and automation-in-the-loop simulations of current and proposed future air traffic concepts for the United States' Next Generation Air Transportation System called NextGen. The setup, configuration, coordination, and execution of realtime, human-in-the-loop air traffic management simulations are complex, tedious, time intensive, and expensive. The SMART-NAS Test Bed framework is an alternative to the current approach and will provide services throughout the simulation workflow pipeline to help alleviate these shortcomings. The principle concepts to be simulated include advanced gate-to-gate, trajectory-based operations, widespread integration of novel aircraft such as unmanned vehicles, and real-time safety assurance technologies to enable autonomous operations. To make this possible, SNTB will utilize Web-based technologies, cloud resources, and real-time, scalable, communication middleware. This paper describes the SMART-NAS Test Bed's vision, purpose, its concept of use, and the potential benefits, key capabilities, high-level requirements, architecture, software design, and usage.

  6. Computer simulation of thermal plant operations

    CERN Document Server

    O'Kelly, Peter

    2012-01-01

    This book describes thermal plant simulation, that is, dynamic simulation of plants which produce, exchange and otherwise utilize heat as their working medium. Directed at chemical, mechanical and control engineers involved with operations, control and optimization and operator training, the book gives the mathematical formulation and use of simulation models of the equipment and systems typically found in these industries. The author has adopted a fundamental approach to the subject. The initial chapters provide an overview of simulation concepts and describe a suitable computer environment.

  7. Utilizing Three-Dimensional Printing Technology to Assess the Feasibility of High-Fidelity Synthetic Ventricular Septal Defect Models for Simulation in Medical Education.

    Science.gov (United States)

    Costello, John P; Olivieri, Laura J; Krieger, Axel; Thabit, Omar; Marshall, M Blair; Yoo, Shi-Joon; Kim, Peter C; Jonas, Richard A; Nath, Dilip S

    2014-07-01

    The current educational approach for teaching congenital heart disease (CHD) anatomy to students involves instructional tools and techniques that have significant limitations. This study sought to assess the feasibility of utilizing present-day three-dimensional (3D) printing technology to create high-fidelity synthetic heart models with ventricular septal defect (VSD) lesions and applying these models to a novel, simulation-based educational curriculum for premedical and medical students. Archived, de-identified magnetic resonance images of five common VSD subtypes were obtained. These cardiac images were then segmented and built into 3D computer-aided design models using Mimics Innovation Suite software. An Objet500 Connex 3D printer was subsequently utilized to print a high-fidelity heart model for each VSD subtype. Next, a simulation-based educational curriculum using these heart models was developed and implemented in the instruction of 29 premedical and medical students. Assessment of this curriculum was undertaken with Likert-type questionnaires. High-fidelity VSD models were successfully created utilizing magnetic resonance imaging data and 3D printing. Following instruction with these high-fidelity models, all students reported significant improvement in knowledge acquisition (P 3D printing technology to create high-fidelity heart models with complex intracardiac defects. Furthermore, this tool forms the foundation for an innovative, simulation-based educational approach to teach students about CHD and creates a novel opportunity to stimulate their interest in this field. © The Author(s) 2014.

  8. Acquiring skills in malignant hyperthermia crisis management: comparison of high-fidelity simulation versus computer-based case study

    Directory of Open Access Journals (Sweden)

    Vilma Mejía

    2018-05-01

    Full Text Available Introduction: The primary purpose of this study was to compare the effect of high fidelity simulation versus a computer-based case solving self-study, in skills acquisition about malignant hyperthermia on first year anesthesiology residents. Methods: After institutional ethical committee approval, 31 first year anesthesiology residents were enrolled in this prospective randomized single-blinded study. Participants were randomized to either a High Fidelity Simulation Scenario or a computer-based Case Study about malignant hyperthermia. After the intervention, all subjects’ performance in was assessed through a high fidelity simulation scenario using a previously validated assessment rubric. Additionally, knowledge tests and a satisfaction survey were applied. Finally, a semi-structured interview was done to assess self-perception of reasoning process and decision-making. Results: 28 first year residents finished successfully the study. Resident's management skill scores were globally higher in High Fidelity Simulation versus Case Study, however they were significant in 4 of the 8 performance rubric elements: recognize signs and symptoms (p = 0.025, prioritization of initial actions of management (p = 0.003, recognize complications (p = 0.025 and communication (p = 0.025. Average scores from pre- and post-test knowledge questionnaires improved from 74% to 85% in the High Fidelity Simulation group, and decreased from 78% to 75% in the Case Study group (p = 0.032. Regarding the qualitative analysis, there was no difference in factors influencing the student's process of reasoning and decision-making with both teaching strategies. Conclusion: Simulation-based training with a malignant hyperthermia high-fidelity scenario was superior to computer-based case study, improving knowledge and skills in malignant hyperthermia crisis management, with a very good satisfaction level in anesthesia residents. Resumo: Introdução: O objetivo prim

  9. Effects of simulation fidelity on user experience in virtual fear of public speaking training - an experimental study.

    Science.gov (United States)

    Poeschl, Sandra; Doering, Nicola

    2014-01-01

    Realistic models in virtual reality training applications are considered to positively influence presence and performance. The experimental study presented, analyzed the effect of simulation fidelity (static vs. animated audience) on presence as a prerequisite for performance in a prototype virtual fear of public speaking application with a sample of N = 40 academic non-phobic users. Contrary to the state of research, no influence was shown on virtual presence and perceived realism, but an animated audience led to significantly higher effects in anxiety during giving a talk. Although these findings could be explained by an application that might not have been realistic enough, they still question the role of presence as a mediating factor in virtual exposure applications.

  10. Getting a head start: high-fidelity, simulation-based operating room team training of interprofessional students.

    Science.gov (United States)

    Paige, John T; Garbee, Deborah D; Kozmenko, Valeriy; Yu, Qingzhao; Kozmenko, Lyubov; Yang, Tong; Bonanno, Laura; Swartz, William

    2014-01-01

    Effective teamwork in the operating room (OR) is often undermined by the "silo mentality" of the differing professions. Such thinking is formed early in one's professional experience and is fostered by undergraduate medical and nursing curricula lacking interprofessional education. We investigated the immediate impact of conducting interprofessional student OR team training using high-fidelity simulation (HFS) on students' team-related attitudes and behaviors. Ten HFS OR interprofessional student team training sessions were conducted involving 2 standardized HFS scenarios, each of which was followed by a structured debriefing that targeted team-based competencies. Pre- and post-session mean scores were calculated and analyzed for 15 Likert-type items measuring self-efficacy in teamwork competencies using the t-test. Additionally, mean scores of observer ratings of team performance after each scenario and participant ratings after the second scenario for an 11-item Likert-type teamwork scale were calculated and analyzed using one-way ANOVA and t-test. Eighteen nursing students, 20 nurse anesthetist students, and 28 medical students participated in the training. Statistically significant gains from mean pre- to post-training scores occurred on 11 of the 15 self-efficacy items. Statistically significant gains in mean observer performance scores were present on all 3 subscales of the teamwork scale from the first scenario to the second. A statistically significant difference was found in comparisons of mean observer scores with mean participant scores for the team-based behaviors subscale. High-fidelity simulation OR interprofessional student team training improves students' team-based attitudes and behaviors. Students tend to overestimate their team-based behaviors. Copyright © 2014 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Impact of high-fidelity simulation on the development of clinical judgment and motivation among Lebanese nursing students.

    Science.gov (United States)

    Fawaz, Mirna A; Hamdan-Mansour, Ayman M

    2016-11-01

    High-fidelity simulation (HFS) offers a strategy to facilitate cognitive, affective, and psychomotor outcomes and motivate the new generation of students. The purpose of this study was to examine the impact of using high-fidelity simulation on the development of clinical judgment and motivation among Lebanese nursing students. A post-test, quasi-experimental design was used. Two private universities in Lebanon were targeted to implement the intervention. A convenience sample of 56 nursing students from two private universities in Lebanon were recruited. Data were collected using the Lasater Clinical Judgment Rubric and the Motivated Strategies for Learning questionnaires. Nursing students exhibited significant improvement in clinical judgment and motivation due to exposure to HFS. There was a significant difference post HFS between the intervention group and the control group in clinical judgment intervention (t=5.23, pmotivation for academic achievement (t=-6.71, pstudents had higher mean scores of motivation (198.6, SD=10.5) in the intervention group than in the control group (161.6, SD=20). The analysis related to differences between the intervention and control groups in motivation and clinical judgment; controlling for previous experience in health care services, the analysis showed no significant difference (Wilk's lambda =0.77, F=1.09, p=0.374). There is a need for nursing educators to implement HFS in nursing curricula, where its integration can bridge the gap between theoretical knowledge and nursing practice and enhance critical thinking and motivation among nursing students. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Implementation of a novel synchronous multi-site all day high-fidelity simulation.

    Science.gov (United States)

    Abraham, Paul; Verdonk, Franck; Buleon, Clement; Tesniere, Antoine; Lilot, Marc

    2018-01-01

    Integration of simulation in educational curricula for anesthesia and intensive care residents is a hot topic. There is a great interest for simulation centers to share their experiences through multi-site synchronous simulation sessions. The present study results from an experience conducted at three sites in France (Paris, Lyon, and Caen), which involved 16 instructors and 25 residents facing the same scenario across 1 day. Synchronous simulations were performed at each site with local and shared debriefing via teleconference. This innovative approach to simulation was found to be feasible, although certain difficulties were encountered with connectivity.

  13. Ventilator caregiver education through the use of high-fidelity pediatric simulators: a pilot study.

    Science.gov (United States)

    Tofil, Nancy M; Rutledge, Chrystal; Zinkan, J Lynn; Youngblood, Amber Q; Stone, Julie; Peterson, Dawn Taylor; Slayton, Donna; Makris, Chris; Magruder, Terri; White, Marjorie Lee

    2013-11-01

    Introduction. Home ventilator programs (HVP) have been developed to train parents of critically ill children. Simulators are used in health care, but not often for parents. We added simulation to our HVP and assessed parents' response. Methods. In July 2008, the HVP at Children's of Alabama added simulation to parent training. Debriefing was provided after the training session to reinforce correct skills and critical thinking. Follow-up surveys were completed after training. Results. Fifteen families participated. All parents were confident in changing tracheostomies, knowing signs of breathing difficulties, and responding to alarms. 71% strongly agree that simulation resulted in feeling better prepared to care for their child. 86% felt simulation improved their confidence in taking care of their child. Conclusion. Simulators provide a crucial transition between learned skills and application. This novel use of simulation-based education improves parents' confidence in emergencies and may lead to shortened training resulting in cost savings.

  14. Thermal simulation of the magnesium thermal of metallic uranium reduction

    International Nuclear Information System (INIS)

    Borges, W.A.; Saliba-Silva, A.M.

    2008-01-01

    Metallic uranium production is vital to fabricate fuel elements for nuclear research reactors and to produce radioisotopes and radiopharmaceuticals. Metallic uranium is got via magnesiothermal reduction of UF 4 . This reaction is carried out inside a closed graphite crucible inserted in a metallic reactor adequately sealed without any outside contact. The assembled set is gradually heated up inside a pit furnace up to reach the reaction ignition temperature (between 600-650 deg C). The optimization of the reactive system depends on the mathematical modeling using simulation by finite elements and computational calculation with specialized programs. In this way, the reactants' thermal behavior is forecast until they reach the ignition temperature. The optimization of the uranium production reaction is based on minimization of thermal losses using better the exo thermal reaction heat. As lower the thermal losses, as higher would be the heat amount to raise the temperature of reaction products. This promotes the adequate melting of uranium and slag, so allowing better metal/slag separation with higher metallic yield. This work shows how the mathematical simulation is made and supplies some preliminary results. (author)

  15. Quantification of Uncertainty in Thermal Building Simulation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Haghighat, F.; Frier, Christian

    In order to quantify uncertainty in thermal building simulation stochastic modelling is applied on a building model. An application of stochastic differential equations is presented in Part 1 comprising a general heat balance for an arbitrary number of loads and zones in a building to determine...

  16. Thermal simulation and validation of 8W LED lamp

    NARCIS (Netherlands)

    Jakovenko, J.; Werkhoven, R.J.; Formánek, J.; Kunen, J.M.G.; Bolt, P.J.; Kulha, P.

    2011-01-01

    This work deals with thermal simulation and characterization of solid state lightening (SSL) LED Lamp in order to get precise 3D thermal models for further lamp thermal optimization. Simulations are performed with ANSYS-CFX and CoventorWare software tools. The simulated thermal distribution has been

  17. High-Fidelity Space-Time Adaptive Multiphysics Simulations in Nuclear Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Solin, Pavel [Univ. of Reno, NV (United States); Ragusa, Jean [Texas A & M Univ., College Station, TX (United States)

    2014-03-09

    We delivered a series of fundamentally new computational technologies that have the potential to significantly advance the state-of-the-art of computer simulations of transient multiphysics nuclear reactor processes. These methods were implemented in the form of a C++ library, and applied to a number of multiphysics coupled problems relevant to nuclear reactor simulations.

  18. High-Fidelity Space-Time Adaptive Multiphysics Simulations in Nuclear Engineering

    International Nuclear Information System (INIS)

    Solin, Pavel; Ragusa, Jean

    2014-01-01

    We delivered a series of fundamentally new computational technologies that have the potential to significantly advance the state-of-the-art of computer simulations of transient multiphysics nuclear reactor processes. These methods were implemented in the form of a C++ library, and applied to a number of multiphysics coupled problems relevant to nuclear reactor simulations.

  19. Virtual reality simulation training in a high-fidelity procedure suite

    DEFF Research Database (Denmark)

    Lönn, Lars; Edmond, John J; Marco, Jean

    2012-01-01

    To assess the face and content validity of a novel, full physics, full procedural, virtual reality simulation housed in a hybrid procedure suite.......To assess the face and content validity of a novel, full physics, full procedural, virtual reality simulation housed in a hybrid procedure suite....

  20. Web-Based versus High-Fidelity Simulation Training for Certified Registered Nurse Anesthetists in the Management of High Risk/Low Occurrence Anesthesia Events

    Science.gov (United States)

    Kimemia, Judy

    2017-01-01

    Purpose: The purpose of this project was to compare web-based to high-fidelity simulation training in the management of high risk/low occurrence anesthesia related events, to enhance knowledge acquisition for Certified Registered Nurse Anesthetists (CRNAs). This project was designed to answer the question: Is web-based training as effective as…

  1. [High fidelity simulation : a new tool for learning and research in pediatrics].

    Science.gov (United States)

    Bragard, I; Farhat, N; Seghaye, M-C; Schumacher, K

    2016-10-01

    Caring for a sick child represents a high risk activity that requires technical and non-technical skills related to several factors such as the rarity of certain events or the stress of caring for a child. As regard these conditions, medi¬cal simulation provides a learning environment without risk, the control of variables, the reproducibility of situations, and the confrontation with rare events. In this article, we des¬cribe the steps of a simulation session and outline the current knowledge of the use of simulation in paediatrics. A session of simulation includes seven phases following the model of Peter Dieckmann, particularly the scenario and the debriefing that form the heart of the learning experience. Several studies have shown the advantages of simulation for paediatric trai¬ning in terms of changes in attitudes, skills and knowledge. Some studies have demonstrated a beneficial transfer to prac¬tice. In conclusion, simulation provides great potential for training and research in paediatrics. The establishment of a collaborative research program by the whole simulation com¬munity would help ensure that this type of training improves the quality of care.

  2. Comparison of fresh-frozen cadaver and high-fidelity virtual reality simulator as methods of laparoscopic training.

    Science.gov (United States)

    Sharma, Mitesh; Horgan, Alan

    2012-08-01

    The aim of this study was to compare fresh-frozen cadavers (FFC) with a high-fidelity virtual reality simulator (VRS) as training tools in minimal access surgery for complex and relatively simple procedures. A prospective comparative face validity study between FFC and VRS (LAP Mentor(™)) was performed. Surgeons were recruited to perform tasks on both FFC and VRS appropriately paired to their experience level. Group A (senior) performed a laparoscopic sigmoid colectomy, Group B (intermediate) performed a laparoscopic incisional hernia repair, and Group C (junior) performed basic laparoscopic tasks (BLT) (camera manipulation, hand-eye coordination, tissue dissection and hand-transferring skills). Each subject completed a 5-point Likert-type questionnaire rating the training modalities in nine domains. Data were analysed using nonparametric tests. Forty-five surgeons were recruited to participate (15 per skill group). Median scores for subjects in Group A were significantly higher for evaluation of FFC in all nine domains compared to VRS (p < 0.01). Group B scored FFC significantly better (p < 0.05) in all domains except task replication (p = 0.06). Group C scored FFC significantly better (p < 0.01) in eight domains but not on performance feedback (p = 0.09). When compared across groups, juniors accepted VRS as a training model more than did intermediate and senior groups on most domains (p < 0.01) except team work. Fresh-frozen cadaver is perceived as a significantly overall better model for laparoscopic training than the high-fidelity VRS by all training grades, irrespective of the complexity of the operative procedure performed. VRS is still useful when training junior trainees in BLT.

  3. Real-Time and High-Fidelity Simulation Environment for Autonomous Ground Vehicle Dynamics

    Science.gov (United States)

    Cameron, Jonathan; Myint, Steven; Kuo, Calvin; Jain, Abhi; Grip, Havard; Jayakumar, Paramsothy; Overholt, Jim

    2013-01-01

    This paper reports on a collaborative project between U.S. Army TARDEC and Jet Propulsion Laboratory (JPL) to develop a unmanned ground vehicle (UGV) simulation model using the ROAMS vehicle modeling framework. Besides modeling the physical suspension of the vehicle, the sensing and navigation of the HMMWV vehicle are simulated. Using models of urban and off-road environments, the HMMWV simulation was tested in several ways, including navigation in an urban environment with obstacle avoidance and the performance of a lane change maneuver.

  4. Dynamic Flight Simulation Utilizing High Fidelity CFD-Based Nonlinear Reduced Order Model, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nonlinear Dynamic Flight Simulation (NL-DFS) system will be developed in the Phase II project by combining the classical nonlinear rigid-body flight dynamics...

  5. High Fidelity Multi-Scale Regolith Simulation Tool for ISRU, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has serious unmet needs for simulation tools capable of predicting the behavior of lunar regolith in proposed excavation, transport and handling systems....

  6. The effects of model composition design choices on high-fidelity simulations of motoneuron recruitment and firing behaviors

    Science.gov (United States)

    Allen, John M.; Elbasiouny, Sherif M.

    2018-06-01

    Objective. Computational models often require tradeoffs, such as balancing detail with efficiency; yet optimal balance should incorporate sound design features that do not bias the results of the specific scientific question under investigation. The present study examines how model design choices impact simulation results. Approach. We developed a rigorously-validated high-fidelity computational model of the spinal motoneuron pool to study three long-standing model design practices which have yet to be examined for their impact on motoneuron recruitment, firing rate, and force simulations. The practices examined were the use of: (1) generic cell models to simulate different motoneuron types, (2) discrete property ranges for different motoneuron types, and (3) biological homogeneity of cell properties within motoneuron types. Main results. Our results show that each of these practices accentuates conditions of motoneuron recruitment based on the size principle, and minimizes conditions of mixed and reversed recruitment orders, which have been observed in animal and human recordings. Specifically, strict motoneuron orderly size recruitment occurs, but in a compressed range, after which mixed and reverse motoneuron recruitment occurs due to the overlap in electrical properties of different motoneuron types. Additionally, these practices underestimate the motoneuron firing rates and force data simulated by existing models. Significance. Our results indicate that current modeling practices increase conditions of motoneuron recruitment based on the size principle, and decrease conditions of mixed and reversed recruitment order, which, in turn, impacts the predictions made by existing models on motoneuron recruitment, firing rate, and force. Additionally, mixed and reverse motoneuron recruitment generated higher muscle force than orderly size motoneuron recruitment in these simulations and represents one potential scheme to increase muscle efficiency. The examined model

  7. Error correction in multi-fidelity molecular dynamics simulations using functional uncertainty quantification

    Energy Technology Data Exchange (ETDEWEB)

    Reeve, Samuel Temple; Strachan, Alejandro, E-mail: strachan@purdue.edu

    2017-04-01

    We use functional, Fréchet, derivatives to quantify how thermodynamic outputs of a molecular dynamics (MD) simulation depend on the potential used to compute atomic interactions. Our approach quantifies the sensitivity of the quantities of interest with respect to the input functions as opposed to its parameters as is done in typical uncertainty quantification methods. We show that the functional sensitivity of the average potential energy and pressure in isothermal, isochoric MD simulations using Lennard–Jones two-body interactions can be used to accurately predict those properties for other interatomic potentials (with different functional forms) without re-running the simulations. This is demonstrated under three different thermodynamic conditions, namely a crystal at room temperature, a liquid at ambient pressure, and a high pressure liquid. The method provides accurate predictions as long as the change in potential can be reasonably described to first order and does not significantly affect the region in phase space explored by the simulation. The functional uncertainty quantification approach can be used to estimate the uncertainties associated with constitutive models used in the simulation and to correct predictions if a more accurate representation becomes available.

  8. High-Fidelity Simulations of Electrically-Charged Atomizing Diesel-Type Jets

    Science.gov (United States)

    Gaillard, Benoit; Owkes, Mark; van Poppel, Bret

    2015-11-01

    Combustion of liquid fuels accounts for over a third of the energy usage today. Improving efficiency of combustion systems is critical to meet the energy needs while limiting environmental impacts. Additionally, a shift away from traditional fossil fuels to bio-derived alternatives requires fuel injection systems that can atomize fuels with a wide range of properties. In this work, the potential benefits of electrically-charged atomization is investigated using numerical simulations. Particularly, the electrostatic forces on the hydrodynamic jet are quantified and the impact of the forces is analyzed by comparing simulations of Diesel-type jets at realistic flow conditions. The simulations are performed using a state-of-the-art numerical framework that globally conserves mass, momentum, and the electric charge density even at the gas-liquid interface where discontinuities exist.

  9. Pulse contour analysis of arterial waveform in a high fidelity human patient simulator.

    Science.gov (United States)

    Persona, Paolo; Saraceni, Elisabetta; Facchin, Francesca; Petranzan, Enrico; Parotto, Matteo; Baratto, Fabio; Ori, Carlo; Rossi, Sandra

    2017-10-03

    The measurement of cardiac output (CO) may be useful to improve the assessment of hemodynamics during simulated scenarios. The purpose of this study was to evaluate the feasibility of introducing an uncalibrated pulse contour device (MostCare, Vytech, Vygon, Padova, Italy) into the simulation environment. MostCare device was plugged to a clinical monitor and connected to the METI human patient simulator (HPS) to obtain a continuous arterial waveform analysis and CO calculation. In six different simulated clinical scenarios (baseline, ventricular failure, vasoplegic shock, hypertensive crisis, hypovolemic shock and aortic stenosis), the HPS-CO and the MostCare-CO were simultaneously recorded. The level of concordance between the two methods was assessed by the Bland and Altman analysis. 150-paired CO values were obtained. The HPS-CO values ranged from 2.3 to 6.6 L min -1 and the MostCare-CO values from 2.8 to 6.4 L min -1 . The mean difference between HPS-CO and MostCare-CO was - 0.3 L min -1 and the limits of agreement were - 1.5 and 0.9 L min -1 . The percentage of error was 23%. A good correlation between HPS-CO and MostCare-CO was observed in each scenario of the study (r = 0.88). Although MostCare-CO tended to underestimate the CO over the study period, good agreements were found between the two methods. Therefore, a pulse contour device can be integrated into the simulation environment, offering the opportunity to create new simulated clinical settings.

  10. High-fidelity large eddy simulation for supersonic jet noise prediction

    Science.gov (United States)

    Aikens, Kurt M.

    The problem of intense sound radiation from supersonic jets is a concern for both civil and military applications. As a result, many experimental and computational efforts are focused at evaluating possible noise suppression techniques. Large-eddy simulation (LES) is utilized in many computational studies to simulate the turbulent jet flowfield. Integral methods such as the Ffowcs Williams-Hawkings (FWH) method are then used for propagation of the sound waves to the farfield. Improving the accuracy of this two-step methodology and evaluating beveled converging-diverging nozzles for noise suppression are the main tasks of this work. First, a series of numerical experiments are undertaken to ensure adequate numerical accuracy of the FWH methodology. This includes an analysis of different treatments for the downstream integration surface: with or without including an end-cap, averaging over multiple end-caps, and including an approximate surface integral correction term. Secondly, shock-capturing methods based on characteristic filtering and adaptive spatial filtering are used to extend a highly-parallelizable multiblock subsonic LES code to enable simulations of supersonic jets. The code is based on high-order numerical methods for accurate prediction of the acoustic sources and propagation of the sound waves. Furthermore, this new code is more efficient than the legacy version, allows cylindrical multiblock topologies, and is capable of simulating nozzles with resolved turbulent boundary layers when coupled with an approximate turbulent inflow boundary condition. Even though such wall-resolved simulations are more physically accurate, their expense is often prohibitive. To make simulations more economical, a wall model is developed and implemented. The wall modeling methodology is validated for turbulent quasi-incompressible and compressible zero pressure gradient flat plate boundary layers, and for subsonic and supersonic jets. The supersonic code additions and the

  11. Simulation of Thermal Transients using CSMP

    International Nuclear Information System (INIS)

    Konuk, A.A.

    1981-01-01

    A mathematical model has been developed to simulate thermal transientes for the Hellum Loop of the 'Instituto de Pesquisas Energeticas e Nuleares', Sao Paulo. The model is based on the energy equation applied to the various components of the loop. The non-linear system of first order ordinary differential equation and algebraic equations has been solved using IBM'S 'System/360-Continuous System Modeling Program-CSMP'. The model has been tested satisfactory with experimental results. (Author) [pt

  12. High-fidelity meshes from tissue samples for diffusion MRI simulations.

    Science.gov (United States)

    Panagiotaki, Eleftheria; Hall, Matt G; Zhang, Hui; Siow, Bernard; Lythgoe, Mark F; Alexander, Daniel C

    2010-01-01

    This paper presents a method for constructing detailed geometric models of tissue microstructure for synthesizing realistic diffusion MRI data. We construct three-dimensional mesh models from confocal microscopy image stacks using the marching cubes algorithm. Random-walk simulations within the resulting meshes provide synthetic diffusion MRI measurements. Experiments optimise simulation parameters and complexity of the meshes to achieve accuracy and reproducibility while minimizing computation time. Finally we assess the quality of the synthesized data from the mesh models by comparison with scanner data as well as synthetic data from simple geometric models and simplified meshes that vary only in two dimensions. The results support the extra complexity of the three-dimensional mesh compared to simpler models although sensitivity to the mesh resolution is quite robust.

  13. Severe Trauma Stress Inoculation Training for Combat Medics using High Fidelity Simulation

    Science.gov (United States)

    2013-12-01

    expressions; and improved sensors and communication systems for current medical training simulators. He has prior experience in software development for DoD...the "look and feel" of such injuries by providing the highly realistic visual, auditory, and haptic (touch) stimuli necessary to elicit stress...addressed during development included the following: • Microcontroller-based control system for monitoring sensors and automating the actions of the

  14. Design and Optimization of Large Accelerator Systems through High-Fidelity Electromagnetic Simulations

    International Nuclear Information System (INIS)

    Ng, Cho; Akcelik, Volkan; Candel, Arno; Chen, Sheng; Ge, Lixin; Kabel, Andreas; Lee, Lie-Quan; Li, Zenghai; Prudencio, Ernesto; Schussman, Greg; Uplenchwar1, Ravi; Xiao1, Liling; Ko1, Kwok; Austin, T.; Cary, J.R.; Ovtchinnikov, S.; Smith, D.N.; Werner, G.R.; Bellantoni, L.; TechX Corp.; Fermilab

    2008-01-01

    SciDAC1, with its support for the 'Advanced Computing for 21st Century Accelerator Science and Technology' (AST) project, witnessed dramatic advances in electromagnetic (EM) simulations for the design and optimization of important accelerators across the Office of Science. In SciDAC2, EM simulations continue to play an important role in the 'Community Petascale Project for Accelerator Science and Simulation' (ComPASS), through close collaborations with SciDAC CETs/Institutes in computational science. Existing codes will be improved and new multi-physics tools will be developed to model large accelerator systems with unprecedented realism and high accuracy using computing resources at petascale. These tools aim at targeting the most challenging problems facing the ComPASS project. Supported by advances in computational science research, they have been successfully applied to the International Linear Collider (ILC) and the Large Hadron Collider (LHC) in High Energy Physics (HEP), the JLab 12-GeV Upgrade in Nuclear Physics (NP), as well as the Spallation Neutron Source (SNS) and the Linac Coherent Light Source (LCLS) in Basic Energy Sciences (BES)

  15. Enhancing nurse and physician collaboration in clinical decision making through high-fidelity interdisciplinary simulation training.

    Science.gov (United States)

    Maxson, Pamela M; Dozois, Eric J; Holubar, Stefan D; Wrobleski, Diane M; Dube, Joyce A Overman; Klipfel, Janee M; Arnold, Jacqueline J

    2011-01-01

    To determine whether interdisciplinary simulation team training can positively affect registered nurse and/or physician perceptions of collaboration in clinical decision making. Between March 1 and April 21, 2009, a convenience sample of volunteer nurses and physicians was recruited to undergo simulation training consisting of a team response to 3 clinical scenarios. Participants completed the Collaboration and Satisfaction About Care Decisions (CSACD) survey before training and at 2 weeks and 2 months after training. Differences in CSACD summary scores between the time points were assessed with paired t tests. Twenty-eight health care professionals (19 nurses, 9 physicians) underwent simulation training. Nurses were of similar age to physicians (27.3 vs 34.5 years; p = .82), were more likely to be women (95.0% vs 12.5%; p nurses and physicians (p = .04) and that both medical and nursing concerns influence the decision-making process (p = .02). Pretest CSACD analysis revealed that most participants were dissatisfied with the decision-making process. The CSACD summary score showed significant improvement from baseline to 2 weeks (4.2 to 5.1; p nurses and physicians and enhanced the patient care decision-making process.

  16. Design and optimization of large accelerator systems through high-fidelity electromagnetic simulations

    International Nuclear Information System (INIS)

    Ng, C; Akcelik, V; Candel, A; Chen, S; Ge, L; Kabel, A; Lee, Lie-Quan; Li, Z; Prudencio, E; Schussman, G; Uplenchwar, R; Xiao, L; Ko, K; Austin, T; Cary, J R; Ovtchinnikov, S; Smith, D N; Werner, G R; Bellantoni, L

    2008-01-01

    SciDAC-1, with its support for the 'Advanced Computing for 21st Century Accelerator Science and Technology' project, witnessed dramatic advances in electromagnetic (EM) simulations for the design and optimization of important accelerators across the Office of Science. In SciDAC2, EM simulations continue to play an important role in the 'Community Petascale Project for Accelerator Science and Simulation' (ComPASS), through close collaborations with SciDAC Centers and Insitutes in computational science. Existing codes will be improved and new multi-physics tools will be developed to model large accelerator systems with unprecedented realism and high accuracy using computing resources at petascale. These tools aim at targeting the most challenging problems facing the ComPASS project. Supported by advances in computational science research, they have been successfully applied to the International Linear Collider and the Large Hadron Collider in high energy physics, the JLab 12-GeV Upgrade in nuclear physics, and the Spallation Neutron Source and the Linac Coherent Light Source in basic energy sciences

  17. An Evaluation of Navy En Route Care Training Using a High-Fidelity Medical Simulation Scenario of Interfacility Patient Transport.

    Science.gov (United States)

    DeForest, Christine A; Blackman, Virginia; Alex, John E; Reeves, Lauren; Mora, Alejandra; Perez, Crystal; Maddry, Joseph; Selby, Domenique; Walrath, Benjamin

    2018-03-14

    Military prehospital and en route care (ERC) directly impacts patient morbidity and mortality. Provider knowledge and skills are critical variables in the effectiveness of ERC. No Navy doctrine defines provider choice for patient transport or requires standardized provider training. Frequently, Search and Rescue Medical Technicians (SMTs) and Navy Nurses (ERC RNs) are tasked with this mission though physicians have also been used. Navy ERC provider training varies greatly by professional role. Historically, evaluations of ERC and patient outcomes have been based on retrospective analyses of incomplete data sets that provide limited insight on ERC practices. Little evidence exists to determine if current training is adequate to care for the most common injuries seen in combat trauma patients. Simulation technology facilitates a standardized patient encounter to enable complete, prospective data collection while studying provider type as the independent variable. Information acquired through skill performance observation can be used to make evidence-based recommendations to improve ERC training. This IRB approved multi-center study funded through a Congressionally Directed Medical Research Program grant from the Combat Casualty Care Intramural Research Joint En Route Care portfolio evaluated Navy ERC providers. The study evaluated 84 SMT, ERC RN, and physician participants in the performance of critical and secondary actions during an immersive, high-fidelity, patient transport simulation scenario focused on the care during an interfacility transfer. Simulation evaluators with military ERC expertise, blinded to participant training and background, graded each participant's performance. Inter-rater reliability was calculated using Cohen's Kappa to evaluate concordance between evaluator assessments. Categorical data were reported as frequencies and percentages. Performance attempt and accuracy rates were compared with likelihood ratio chi-square or Fisher's exact test

  18. Implementation of high fidelity models for the conditions of operation in stop in PWR simulators

    International Nuclear Information System (INIS)

    Gonzalez Sevillano, I.; Jimenez Bogarin, R.; Ortega Pascual, F.

    2014-01-01

    The operation in stop cold conditions and in particular the States of operation with reduced inventory, the call of half loop or half nozzle, is becoming increasingly more important. These States of operation are characterized by having the coolant level approximately on the generatrix of the branches, so that any deviation in the level or malfunction of the system for the disposal of waste heat could lead to compromising situations. The importance of this type of situation is reflected in the APS in other modes (APSOM), which show that the risk in these conditions may be comparable to the power. Hence the importance that the simulator training programmes include scenarios that cover these States of operation. The article describes on the one hand, the difficulties encountered in the simulation of situations characterized by low pressure and presence of Non-Condensable and, on the other hand, its implementation, not only in the field of training of plant personnel, but also in the field of review/validation of operating procedures. (Author)

  19. Multi-fidelity numerical simulations of shock/turbulent-boundary layer interaction with uncertainty quantification

    Science.gov (United States)

    Bermejo-Moreno, Ivan; Campo, Laura; Larsson, Johan; Emory, Mike; Bodart, Julien; Palacios, Francisco; Iaccarino, Gianluca; Eaton, John

    2013-11-01

    We study the interaction between an oblique shock wave and the turbulent boundary layers inside a nearly-square duct by combining wall-modeled LES, 2D and 3D RANS simulations, targeting the experiment of Campo, Helmer & Eaton, 2012 (nominal conditions: M = 2 . 05 , Reθ = 6 , 500). A primary objective is to quantify the effect of aleatory and epistemic uncertainties on the STBLI. Aleatory uncertainties considered include the inflow conditions (Mach number of the incoming air stream and thickness of the boundary layers) and perturbations of the duct geometry upstream of the interaction. The epistemic uncertainty under consideration focuses on the RANS turbulence model form by injecting perturbations in the Reynolds stress anisotropy in regions of the flow where the model assumptions (in particular, the Boussinesq eddy-viscosity hypothesis) may be invalid. These perturbations are then propagated through the flow solver into the solution. The uncertainty quantification (UQ) analysis is done through 2D and 3D RANS simulations, assessing the importance of the three-dimensional effects imposed by the nearly-square duct geometry. Wall-modeled LES are used to verify elements of the UQ methodology and to explore the flow features and physics of the STBLI for multiple shock strengths. Financial support from the United States Department of Energy under the PSAAP program is gratefully acknowledged.

  20. Incomplete adherence to the ASA difficult airway algorithm is unchanged after a high-fidelity simulation session.

    Science.gov (United States)

    Borges, Bruno C R; Boet, Sylvain; Siu, Lyndon W; Bruppacher, Heinz R; Naik, Viren N; Riem, Nicole; Joo, Hwan S

    2010-07-01

    Although guidelines for difficult airway management have been published, the extent to which consultant anesthesiologists follow these guidelines has not been determined. The purpose of this study is to observe how consultant anesthesiologists manage a "cannot intubate, cannot ventilate" (CICV) scenario in a high-fidelity simulator and to evaluate whether a simulation teaching session improves their adherence to the American Society of Anesthesiologists (ASA) difficult airway algorithm. With Ethics Board approval and informed consent, all staff anesthesiologists in a single tertiary care institution were invited to enrol in this study where they managed a simulated unanticipated CICV scenario in a high-fidelity simulator. The scenario involved a patient with a difficult airway whose trachea could not be intubated and where it was impossible to ventilate the patient's lungs. Airway management options, including laryngeal mask airway, a fibreoptic bronchoscope, and a Glidescope were available for use but scripted to fail. A percutaneous cricothyroidotomy was required to re-establish adequate ventilation. Following the scenario, there was a personalized one-hour video-assisted expert debriefing focusing on the ASA difficult airway guidelines and "hands-on" cricothyroidotomy teaching. The second scenario followed immediately with an identical CICV scenario. The content to either scenario was not revealed beforehand. Outcome measures included: 1) major deviations from the ASA difficult airway guidelines; 2) time to start cricothyroidotomy; and 3) time to achieve ventilation. Thirty-eight anesthesiologists agreed to participate. The number of major deviations from the ASA algorithm was similar in the first and second sessions. These deviations included: multiple laryngoscopies (0 vs 2 pre-post; P = 0.49), use of fibreoptic bronchoscope (8 vs 7 pre-post; P = 1.0), bypass of laryngeal mask airway attempt (7 vs 13 pre-post; P = 0.19), and failure to call for anesthetic help

  1. Effects of the Use of High-Fidelity Human Simulation in Nursing Education: A Meta-Analysis.

    Science.gov (United States)

    Lee, Jin; Oh, Pok-Ja

    2015-09-01

    This study was conducted to evaluate the effects of high-fidelity human simulation (HFHS) on cognitive, affective, and psychomotor outcomes of learning. PubMed, Cochrane Library, EMBASE, CINAHL, and Korean databases were searched. The RevMan program was used for analysis. A meta-analysis was conducted of 26 controlled trials, with a total of 2,031 nursing students. The use of HFHS tended to have beneficial effects on cognitive and psychomotor domains of learning. In analysis of cognitive outcomes, the weighted average effect size across studies was -0.97 for problem-solving competency, -0.67 for critical thinking, and -2.15 for clinical judgment. The effect size for clinical competence of the psychomotor domain was -0.81. Use of HFHS might positively impact a high level of cognitive skill and clinical skill acquisition. Further research is required to determine the effectiveness of use of HFHS as an educational strategy to improve knowledge acquisition and communication skills. Copyright 2015, SLACK Incorporated.

  2. Developing and Testing a High-Fidelity Simulation Scenario for an Uncommon Life-Threatening Disease: Severe Malaria

    Directory of Open Access Journals (Sweden)

    Andrew Kestler

    2011-01-01

    Full Text Available Background. Severe malaria is prevalent globally, yet it is an uncommon disease posing a challenge to education in nonendemic countries. High-fidelity simulation (sim may be well suited to teaching its management. Objective. To develop and evaluate a teaching tool for severe malaria, using sim. Methods. A severe malaria sim scenario was developed based on 5 learning objectives. Sim sessions, conducted at an academic center, utilized METI ECS mannequin. After sim, participants received standardized debriefing and completed a test assessing learning and a survey assessing views on sim efficacy. Results. 29 participants included 3rd year medical students (65%, 3rd year EM residents (28%, and EM nurses (7%. Participants scored average 85% on questions related to learning objectives. 93% felt that sim was effective or very effective in teaching severe malaria, and 83% rated it most effective. All respondents felt that sim increased their knowledge on malaria. Conclusion. Sim is an effective tool for teaching severe malaria in and may be superior to other modalities.

  3. Using a high-fidelity patient simulator with first-year medical students to facilitate learning of cardiovascular function curves.

    Science.gov (United States)

    Harris, David M; Ryan, Kathleen; Rabuck, Cynthia

    2012-09-01

    Students are relying on technology for learning more than ever, and educators need to adapt to facilitate student learning. High-fidelity patient simulators (HFPS) are usually reserved for the clinical years of medical education and are geared to improve clinical decision skills, teamwork, and patient safety. Finding ways to incorporate HFPS into preclinical medical education represents more of a challenge, and there is limited literature regarding its implementation. The main objective of this study was to implement a HFPS activity into a problem-based curriculum to enhance the learning of basic sciences. More specifically, the focus was to aid in student learning of cardiovascular function curves and help students develop heart failure treatment strategies based on basic cardiovascular physiology concepts. Pretests and posttests, along with student surveys, were used to determine student knowledge and perception of learning in two first-year medical school classes. There was an increase of 21% and 22% in the percentage of students achieving correct answers on a posttest compared with their pretest score. The median number of correct questions increased from pretest scores of 2 and 2.5 to posttest scores of 4 and 5 of a possible total of 6 in each respective year. Student survey data showed agreement that the activity aided in learning. This study suggests that a HFPS activity can be implemented during the preclinical years of medical education to address basic science concepts. Additionally, it suggests that student learning of cardiovascular function curves and heart failure strategies are facilitated.

  4. Large-Scale Testing and High-Fidelity Simulation Capabilities at Sandia National Laboratories to Support Space Power and Propulsion

    International Nuclear Information System (INIS)

    Dobranich, Dean; Blanchat, Thomas K.

    2008-01-01

    Sandia National Laboratories, as a Department of Energy, National Nuclear Security Agency, has major responsibility to ensure the safety and security needs of nuclear weapons. As such, with an experienced research staff, Sandia maintains a spectrum of modeling and simulation capabilities integrated with experimental and large-scale test capabilities. This expertise and these capabilities offer considerable resources for addressing issues of interest to the space power and propulsion communities. This paper presents Sandia's capability to perform thermal qualification (analysis, test, modeling and simulation) using a representative weapon system as an example demonstrating the potential to support NASA's Lunar Reactor System

  5. Characterization of a novel, highly integrated tubular solid oxide fuel cell system using high-fidelity simulation tools

    Science.gov (United States)

    Kattke, K. J.; Braun, R. J.

    2011-08-01

    A novel, highly integrated tubular SOFC system intended for small-scale power is characterized through a series of sensitivity analyses and parametric studies using a previously developed high-fidelity simulation tool. The high-fidelity tubular SOFC system modeling tool is utilized to simulate system-wide performance and capture the thermofluidic coupling between system components. Stack performance prediction is based on 66 anode-supported tubular cells individually evaluated with a 1-D electrochemical cell model coupled to a 3-D computational fluid dynamics model of the cell surroundings. Radiation is the dominate stack cooling mechanism accounting for 66-92% of total heat loss at the outer surface of all cells at baseline conditions. An average temperature difference of nearly 125 °C provides a large driving force for radiation heat transfer from the stack to the cylindrical enclosure surrounding the tube bundle. Consequently, cell power and voltage disparities within the stack are largely a function of the radiation view factor from an individual tube to the surrounding stack can wall. The cells which are connected in electrical series, vary in power from 7.6 to 10.8 W (with a standard deviation, σ = 1.2 W) and cell voltage varies from 0.52 to 0.73 V (with σ = 81 mV) at the simulation baseline conditions. It is observed that high cell voltage and power outputs directly correspond to tubular cells with the smallest radiation view factor to the enclosure wall, and vice versa for tubes exhibiting low performance. Results also reveal effective control variables and operating strategies along with an improved understanding of the effect that design modifications have on system performance. By decreasing the air flowrate into the system by 10%, the stack can wall temperature increases by about 6% which increases the minimum cell voltage to 0.62 V and reduces deviations in cell power and voltage by 31%. A low baseline fuel utilization is increased by decreasing the

  6. Self vs expert assessment of technical and non-technical skills in high fidelity simulation.

    Science.gov (United States)

    Arora, Sonal; Miskovic, Danilo; Hull, Louise; Moorthy, Krishna; Aggarwal, Rajesh; Johannsson, Helgi; Gautama, Sanjay; Kneebone, Roger; Sevdalis, Nick

    2011-10-01

    Accurate assessment is imperative for learning, feedback and progression. The aim of this study was to examine whether surgeons can accurately self-assess their technical and nontechnical skills compared with expert faculty members' assessments. Twenty-five surgeons performed a laparoscopic cholecystectomy (LC) in a simulated operating room. Technical and nontechnical performance was assessed by participants and faculty members using the validated Objective Structured Assessment of Technical Skills (OSATS) and the Non-Technical Skills for Surgeons scale (NOTSS). Assessment of technical performance correlated between self and faculty members' ratings for experienced (median score, 30.0 vs 31.0; ρ = .831; P = .001) and inexperienced (median score, 22.0 vs 28.0; ρ = .761; P = .003) surgeons. Assessment of nontechnical skills between self and faculty members did not correlate for experienced surgeons (median score, 8.0 vs 10.5; ρ = -.375; P = .229) or their more inexperienced counterparts (median score, 9.0 vs 7.0; ρ = -.018; P = .953). Surgeons can accurately self-assess their technical skills in virtual reality LC. Conversely, formal assessment with faculty members' input is required for nontechnical skills, for which surgeons lack insight into their behaviours. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Nursing leadership competencies: low-fidelity simulation as a teaching strategy.

    Science.gov (United States)

    Pollard, Cheryl L; Wild, Carol

    2014-11-01

    Nurses must demonstrate leadership and followership competencies within complex adaptive team environments to ensure patient and staff safety, effective use of resources, and an adaptive health care system. These competencies are demonstrated through the use of communication strategies that are embedded within a relational practice. Health care professionals, regardless of formal position, need to assert their opinions and perspectives using a communication style that demonstrates value of all team members in open discussions about quality patient care, appropriate access, and stewardship. Challenges to effective communication and relational practice are the individual and organizational patterns of behavior, and the subsequent impact that these behaviors have on others. Students articulate situational awareness when they conduct a critical analysis of individual, team, and organizational functioning, and then use this information and evidence gained from a critical literature review to develop recommendations to improve individual, team, and/or organizational performance. Leadership and followership simulation exercises, inclusive of public feedback and debriefing, are used as a pedagogical/andragogical strategy in a nursing baccalaureate senior leadership course to facilitate learning of team communication skills and improve situational awareness. We view this strategy as an alternative to traditional classroom learning activities which provide little opportunity for recursive learning. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Assessment of a high-fidelity mobile simulator for intrauterine contraception training in ambulatory reproductive health centres

    Directory of Open Access Journals (Sweden)

    Laura E. Dodge

    2016-02-01

    Full Text Available Objectives. Little is known about the utility of simulation-based training in office gynaecology. The objective of this cross-sectional study was to evaluate the self-reported effectiveness and acceptability of the PelvicSim™ (VirtaMed, a high-fidelity mobile simulator, to train clinicians in intrauterine device (IUD insertion. Methods. Clinicians at ambulatory healthcare centres participated in a PelvicSim IUD training programme and completed a self-administered survey. The survey assessed prior experience with IUD insertion, pre- and post-training competency and comfort and opinions regarding the acceptability of the PelvicSim. Results. The 237 participants were primarily female (97.5% nurse practitioners (71.3%. Most had experience inserting the levonorgestrel LNG20 IUD and the copper T380A device, but only 4.1% had ever inserted the LNG14 IUD. For all three devices, participants felt more competent following training, with the most striking change reported for insertion of the LNG14 IUD. The majority of participants reported increased comfort with uterine sounding (57.7%, IUD insertion on a live patient (69.8%, and minimizing patient pain (72.8% following training. Of the respondents, 89.6% reported the PelvicSim IUD insertion activities as “valuable” or “very valuable.” All participants would recommend the PelvicSim for IUD training, and nearly all (97.2% reported that the PelvicSim was a better method to teach IUD insertion than the simple plastic models supplied by IUD manufacturers. Conclusions. These findings support the use of the PelvicSim for IUD training, though whether it is superior to traditional methods and improves patient outcomes requires evaluation.

  9. Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

    International Nuclear Information System (INIS)

    Emrich, William J. Jr.

    2008-01-01

    To support a potential future development of a nuclear thermal rocket engine, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The test device simulates the environmental conditions (minus the radiation) to which nuclear rocket fuel components could be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner as to accurately reproduce the temperatures and heat fluxes normally expected to occur as a result of nuclear fission while at the same time being exposed to flowing hydrogen. This project is referred to as the Nuclear Thermal Rocket Element Environment Simulator or NTREES. The NTREES device is located at the Marshall Space flight Center in a laboratory which has been modified to accommodate the high powers required to heat the test articles to the required temperatures and to handle the gaseous hydrogen flow required for the tests. Other modifications to the laboratory include the installation of a nitrogen gas supply system and a cooling water supply system. During the design and construction of the facility, every effort was made to comply with all pertinent regulations to provide assurance that the facility could be operated in a safe and efficient manner. The NTREES system can currently supply up to 50 kW of inductive heating to the fuel test articles, although the facility has been sized to eventually allow test article heating levels of up to several megawatts

  10. Simulation-based rhomboid flap skills training during medical education: comparing low- and high-fidelity bench models.

    Science.gov (United States)

    Denadai, Rafael; Saad-Hossne, Rogerio; Raposo-Amaral, Cassio Eduardo

    2014-11-01

    To assess if the bench model fidelity interferes in the acquisition of rhomboid flap skills by medical students. Sixty novice medical students were randomly assigned to 5 practice conditions with instructor-directed Limberg rhomboid flap skills training: didactic materials (control group 1), low-fidelity rubberized line (group 2) or ethylene-vinyl acetate (group 3) bench models; high-fidelity chicken leg skin (group 4) or pig foot skin (group 5) bench models. Pretests and posttests were applied, and Global Rating Scale, effect size, and self-perceived confidence were used to evaluate all flap performances. Medical students from groups 2 to 5 showed better flap performances based on the Global Rating Scale (all P 0.05). The magnitude of the effect was considered large (>0.80) in all measurements. There was acquisition of rhomboid flap skills regardless of bench model fidelity.

  11. Thermal Simulations, Open Boundary Conditions and Switches

    Science.gov (United States)

    Burnier, Yannis; Florio, Adrien; Kaczmarek, Olaf; Mazur, Lukas

    2018-03-01

    SU(N) gauge theories on compact spaces have a non-trivial vacuum structure characterized by a countable set of topological sectors and their topological charge. In lattice simulations, every topological sector needs to be explored a number of times which reflects its weight in the path integral. Current lattice simulations are impeded by the so-called freezing of the topological charge problem. As the continuum is approached, energy barriers between topological sectors become well defined and the simulations get trapped in a given sector. A possible way out was introduced by Lüscher and Schaefer using open boundary condition in the time extent. However, this solution cannot be used for thermal simulations, where the time direction is required to be periodic. In this proceedings, we present results obtained using open boundary conditions in space, at non-zero temperature. With these conditions, the topological charge is not quantized and the topological barriers are lifted. A downside of this method are the strong finite-size effects introduced by the boundary conditions. We also present some exploratory results which show how these conditions could be used on an algorithmic level to reshuffle the system and generate periodic configurations with non-zero topological charge.

  12. Thermal Simulations, Open Boundary Conditions and Switches

    Directory of Open Access Journals (Sweden)

    Burnier Yannis

    2018-01-01

    Full Text Available SU(N gauge theories on compact spaces have a non-trivial vacuum structure characterized by a countable set of topological sectors and their topological charge. In lattice simulations, every topological sector needs to be explored a number of times which reflects its weight in the path integral. Current lattice simulations are impeded by the so-called freezing of the topological charge problem. As the continuum is approached, energy barriers between topological sectors become well defined and the simulations get trapped in a given sector. A possible way out was introduced by Lüscher and Schaefer using open boundary condition in the time extent. However, this solution cannot be used for thermal simulations, where the time direction is required to be periodic. In this proceedings, we present results obtained using open boundary conditions in space, at non-zero temperature. With these conditions, the topological charge is not quantized and the topological barriers are lifted. A downside of this method are the strong finite-size effects introduced by the boundary conditions. We also present some exploratory results which show how these conditions could be used on an algorithmic level to reshuffle the system and generate periodic configurations with non-zero topological charge.

  13. The effects of using high-fidelity simulators and standardized patients on the thorax, lung, and cardiac examination skills of undergraduate nursing students.

    Science.gov (United States)

    Tuzer, Hilal; Dinc, Leyla; Elcin, Melih

    2016-10-01

    Existing research literature indicates that the use of various simulation techniques in the training of physical examination skills develops students' cognitive and psychomotor abilities in a realistic learning environment while improving patient safety. The study aimed to compare the effects of the use of a high-fidelity simulator and standardized patients on the knowledge and skills of students conducting thorax-lungs and cardiac examinations, and to explore the students' views and learning experiences. A mixed-method explanatory sequential design. The study was conducted in the Simulation Laboratory of a Nursing School, the Training Center at the Faculty of Medicine, and in the inpatient clinics of the Education and Research Hospital. Fifty-two fourth-year nursing students. Students were randomly assigned to Group I and Group II. The students in Group 1 attended the thorax-lungs and cardiac examination training using a high-fidelity simulator, while the students in Group 2 using standardized patients. After the training sessions, all students practiced their skills on real patients in the clinical setting under the supervision of the investigator. Knowledge and performance scores of all students increased following the simulation activities; however, the students that worked with standardized patients achieved significantly higher knowledge scores than those that worked with the high-fidelity simulator; however, there was no significant difference in performance scores between the groups. The mean performance scores of students on real patients were significantly higher compared to the post-simulation assessment scores (psimulator in increasing the knowledge scores of students on thorax-lungs and cardiac examinations; however, practice on real patients increased performance scores of all students without any significant difference in two groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Perceived Barriers to the Use of High-Fidelity Hands-On Simulation Training for Contrast Reaction Management: Why Programs are Not Using It.

    Science.gov (United States)

    Chinnugounder, Sankar; Hippe, Daniel S; Maximin, Suresh; O'Malley, Ryan B; Wang, Carolyn L

    2015-01-01

    Although subjective and objective benefits of high-fidelity simulation have been reported in medicine, there has been slow adoption in radiology. The purpose of our study was to identify the perceived barriers in the use of high-fidelity hands-on simulation for contrast reaction management training. An IRB exempt 32 questions online web survey was sent to 179 non-military radiology residency program directors listed in the Fellowship and Residency Electronic Interactive Database Access system (FREIDA). Survey questions included the type of contrast reaction management training, cost, time commitment of residents and faculty, and the reasons for not using simulation training. Responses from the survey were summarized as count (percentage), mean ± standard deviation (SD), or median (range). 84 (47%) of 179 programs responded, of which 88% offered CRM training. Most (72%) conducted the CRM training annually while only 4% conducted it more frequently. Didactic lecture was the most frequently used training modality (97%), followed by HFS (30%) and computer-based simulation (CBS) (19%); 5.5% used both HFS and CBS. Of the 51 programs that offer CRM training but do not use HFS, the most common reason reported was insufficient availability (41%). Other reported reasons included cost (33%), no access to simulation centers (33%), lack of trained faculty (27%) and time constraints (27%). Although high-fidelity hands-on simulation training is the best way to reproduce real-life contrast reaction scenarios, many institutions do not provide this training due to constraints such as cost, lack of access or insufficient availability of simulation labs, and lack of trained faculty. As a specialty, radiology needs to better address these barriers at both an institutional and national level. Copyright © 2015 Mosby, Inc. All rights reserved.

  15. High fidelity simulation and analysis of liquid jet atomization in a gaseous crossflow at intermediate Weber numbers

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaoyi, E-mail: lixy2@utrc.utc.com; Soteriou, Marios C. [United Technologies Research Center, East Hartford, Connecticut 06108 (United States)

    2016-08-15

    Recent advances in numerical methods coupled with the substantial enhancements in computing power and the advent of high performance computing have presented first principle, high fidelity simulation as a viable tool in the prediction and analysis of spray atomization processes. The credibility and potential impact of such simulations, however, has been hampered by the relative absence of detailed validation against experimental evidence. The numerical stability and accuracy challenges arising from the need to simulate the high liquid-gas density ratio across the sharp interfaces encountered in these flows are key reasons for this. In this work we challenge this status quo by presenting a numerical model able to deal with these challenges, employing it in simulations of liquid jet in crossflow atomization and performing extensive validation of its results against a carefully executed experiment with detailed measurements in the atomization region. We then proceed to the detailed analysis of the flow physics. The computational model employs the coupled level set and volume of fluid approach to directly capture the spatiotemporal evolution of the liquid-gas interface and the sharp-interface ghost fluid method to stably handle high liquid-air density ratio. Adaptive mesh refinement and Lagrangian droplet models are shown to be viable options for computational cost reduction. Moreover, high performance computing is leveraged to manage the computational cost. The experiment selected for validation eliminates the impact of inlet liquid and gas turbulence and focuses on the impact of the crossflow aerodynamic forces on the atomization physics. Validation is demonstrated by comparing column surface wavelengths, deformation, breakup locations, column trajectories and droplet sizes, velocities, and mass rates for a range of intermediate Weber numbers. Analysis of the physics is performed in terms of the instability and breakup characteristics and the features of downstream

  16. Impact of High-Fidelity Simulation and Pharmacist-Specific Didactic Lectures in Addition to ACLS Provider Certification on Pharmacy Resident ACLS Performance.

    Science.gov (United States)

    Bartel, Billie J

    2014-08-01

    This pilot study explored the use of multidisciplinary high-fidelity simulation and additional pharmacist-focused training methods in training postgraduate year 1 (PGY1) pharmacy residents to provide Advanced Cardiovascular Life Support (ACLS) care. Pharmacy resident confidence and comfort level were assessed after completing these training requirements. The ACLS training requirements for pharmacy residents were revised to include didactic instruction on ACLS pharmacology and rhythm recognition and participation in multidisciplinary high-fidelity simulation ACLS experiences in addition to ACLS provider certification. Surveys were administered to participating residents to assess the impact of this additional education on resident confidence and comfort level in cardiopulmonary arrest situations. The new ACLS didactic and simulation training requirements resulted in increased resident confidence and comfort level in all assessed functions. Residents felt more confident in all areas except providing recommendations for dosing and administration of medications and rhythm recognition after completing the simulation scenarios than with ACLS certification training and the didactic components alone. All residents felt the addition of lectures and simulation experiences better prepared them to function as a pharmacist in the ACLS team. Additional ACLS training requirements for pharmacy residents increased overall awareness of pharmacist roles and responsibilities and greatly improved resident confidence and comfort level in performing most essential pharmacist functions during ACLS situations. © The Author(s) 2013.

  17. Effect of High-Fidelity Simulation on Medical Students' Knowledge about Advanced Life Support: A Randomized Study.

    Directory of Open Access Journals (Sweden)

    Andrea Cortegiani

    Full Text Available High-fidelity simulation (HFS is a learning method which has proven effective in medical education for technical and non-technical skills. However, its effectiveness for knowledge acquisition is less validated. We performed a randomized study with the primary aim of investigating whether HFS, in association with frontal lessons, would improve knowledge about advanced life support (ALS, in comparison to frontal lessons only among medical students. The secondary aims were to evaluate the effect of HFS on knowledge acquisition of different sections of ALS and personal knowledge perception. Participants answered a pre-test questionnaire consisting of a subjective (evaluating personal perception of knowledge and an objective section (measuring level of knowledge containing 100 questions about algorithms, technical skills, team working/early warning scores/communication strategies according to ALS guidelines. All students participated in 3 frontal lessons before being randomized in group S, undergoing a HFS session, and group C, receiving no further interventions. After 10 days from the end of each intervention, both groups answered a questionnaire (post-test with the same subjective section but a different objective one. The overall number of correct answers of the post-test was significantly higher in group S (mean 74.1, SD 11.2 than in group C (mean 65.5, SD 14.3, p = 0.0017, 95% C.I. 3.34 - 13.9. A significantly higher number of correct answers was reported in group S than in group C for questions investigating knowledge of algorithms (p = 0.0001; 95% C.I 2.22-5.99 and team working/early warning scores/communication strategies (p = 0.0060; 95% C.I 1.13-6.53. Students in group S showed a significantly higher score in the post-test subjective section (p = 0.0074. A lower proportion of students in group S confirmed their perception of knowledge compared to group C (p = 0.0079. HFS showed a beneficial effect on knowledge of ALS among medical students

  18. High fidelity simulation based team training in urology: a preliminary interdisciplinary study of technical and nontechnical skills in laparoscopic complications management.

    Science.gov (United States)

    Lee, Jason Y; Mucksavage, Phillip; Canales, Cecilia; McDougall, Elspeth M; Lin, Sharon

    2012-04-01

    Simulation based team training provides an opportunity to develop interdisciplinary communication skills and address potential medical errors in a high fidelity, low stakes environment. We evaluated the implementation of a novel simulation based team training scenario and assessed the technical and nontechnical performance of urology and anesthesiology residents. Urology residents were randomly paired with anesthesiology residents to participate in a simulation based team training scenario involving the management of 2 scripted critical events during laparoscopic radical nephrectomy, including the vasovagal response to pneumoperitoneum and renal vein injury during hilar dissection. A novel kidney surgical model and a high fidelity mannequin simulator were used for the simulation. A debriefing session followed each simulation based team training scenario. Assessments of technical and nontechnical performance were made using task specific checklists and global rating scales. A total of 16 residents participated, of whom 94% rated the simulation based team training scenario as useful for communication skill training. Also, 88% of urology residents believed that the kidney surgical model was useful for technical skill training. Urology resident training level correlated with technical performance (p=0.004) and blood loss during renal vein injury management (p=0.022) but not with nontechnical performance. Anesthesia resident training level correlated with nontechnical performance (p=0.036). Urology residents consistently rated themselves higher on nontechnical performance than did faculty (p=0.033). Anesthesia residents did not differ in the self-assessment of nontechnical performance compared to faculty assessments. Residents rated the simulation based team training scenario as useful for interdisciplinary communication skill training. Urology resident training level correlated with technical performance but not with nontechnical performance. Urology residents

  19. Recent developments in numerical simulation techniques of thermal recovery processes

    Energy Technology Data Exchange (ETDEWEB)

    Tamim, M. [Bangladesh University of Engineering and Technology, Bangladesh (Bangladesh); Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, Al-Ain 17555 (United Arab Emirates); Farouq Ali, S.M. [University of Alberta, Alberta (Canada)

    2000-05-01

    Numerical simulation of thermal processes (steam flooding, steam stimulation, SAGD, in-situ combustion, electrical heating, etc.) is an integral part of a thermal project design. The general tendency in the last 10 years has been to use commercial simulators. During the last decade, only a few new models have been reported in the literature. More work has been done to modify and refine solutions to existing problems to improve the efficiency of simulators. The paper discusses some of the recent developments in simulation techniques of thermal processes such as grid refinement, grid orientation, effect of temperature on relative permeability, mathematical models, and solution methods. The various aspects of simulation discussed here promote better understanding of the problems encountered in the simulation of thermal processes and will be of value to both simulator users and developers.

  20. Modelling and simulation of thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Eborn, J.

    1998-02-01

    Mathematical modelling and simulation are important tools when dealing with engineering systems that today are becoming increasingly more complex. Integrated production and recycling of materials are trends that give rise to heterogenous systems, which are difficult to handle within one area of expertise. Model libraries are an excellent way to package engineering knowledge of systems and units to be reused by those who are not experts in modelling. Many commercial packages provide good model libraries, but they are usually domain-specific and closed. Heterogenous, multi-domain systems requires open model libraries written in general purpose modelling languages. This thesis describes a model database for thermal power plants written in the object-oriented modelling language OMOLA. The models are based on first principles. Subunits describe volumes with pressure and enthalpy dynamics and flows of heat or different media. The subunits are used to build basic units such as pumps, valves and heat exchangers which can be used to build system models. Several applications are described; a heat recovery steam generator, equipment for juice blending, steam generation in a sulphuric acid plant and a condensing steam plate heat exchanger. Model libraries for industrial use must be validated against measured data. The thesis describes how parameter estimation methods can be used for model validation. Results from a case-study on parameter optimization of a non-linear drum boiler model show how the technique can be used 32 refs, 21 figs

  1. Nuclear Thermal Rocket Simulation in NPSS

    Science.gov (United States)

    Belair, Michael L.; Sarmiento, Charles J.; Lavelle, Thomas M.

    2013-01-01

    Four nuclear thermal rocket (NTR) models have been created in the Numerical Propulsion System Simulation (NPSS) framework. The models are divided into two categories. One set is based upon the ZrC-graphite composite fuel element and tie tube-style reactor developed during the Nuclear Engine for Rocket Vehicle Application (NERVA) project in the late 1960s and early 1970s. The other reactor set is based upon a W-UO2 ceramic-metallic (CERMET) fuel element. Within each category, a small and a large thrust engine are modeled. The small engine models utilize RL-10 turbomachinery performance maps and have a thrust of approximately 33.4 kN (7,500 lbf ). The large engine models utilize scaled RL-60 turbomachinery performance maps and have a thrust of approximately 111.2 kN (25,000 lbf ). Power deposition profiles for each reactor were obtained from a detailed Monte Carlo N-Particle (MCNP5) model of the reactor cores. Performance factors such as thermodynamic state points, thrust, specific impulse, reactor power level, and maximum fuel temperature are analyzed for each engine design.

  2. Molecular dynamics simulation of thermal conductivities of superlattice nanowires

    Institute of Scientific and Technical Information of China (English)

    YANG; Juekuan(杨决宽); CHEN; Yunfei(陈云飞); YAN; Jingping(颜景平)

    2003-01-01

    Nonequilibrium molecular dynamics simulations were carried out to investigate heat transfer in superlattice nanowires. Results show that for fixed period length superlattice nanowires, the ratio of the total interfacial thermal resistance to the total thermal resistance and the effective thermal conductivities are invariant with the changes in interface numbers. Increasing the period length leads to an increase in the average interfacial thermal resistance, which indicates that the interfacial thermal resistance depends not only on the materials that constitute the alternating segments of superlattice nanowires, but also on the lattice strain throughout the segments. The modification of the lattice structure due to the lattice mismatch should be taken into account in the acoustic mismatch model. Simulation results also demonstrated the size confinement effect on the thermal conductivities for low dimensional structures, i.e. the thermal conductivities and the interfacial thermal resistance increase as the nanowire cross-sectional area increases.

  3. Thermal expansion of UO2 and simulated DUPIC fuel

    International Nuclear Information System (INIS)

    Ho Kang, Kweon; Jin Ryu, Ho; Chan Song, Kee; Seung Yang, Myung

    2002-01-01

    The lattice parameters of simulated DUPIC fuel and UO 2 were measured from room temperature to 1273 K using neutron diffraction to investigate the thermal expansion and density variation with temperature. The lattice parameter of simulated DUPIC fuel is lower than that of UO 2 , and the linear thermal expansion of simulated DUPIC fuel is higher than that of UO 2 . For the temperature range from 298 to 1273 K, the average linear thermal expansion coefficients for UO 2 and simulated DUPIC fuel are 10.471x10 -6 and 10.751x10 -6 K -1 , respectively

  4. Thermal expansion study of simulated DUPIC fuel using neutron diffraction

    International Nuclear Information System (INIS)

    Kang, Kweon Ho; Ryu, H. J.; Bae, J. H.; Kim, H. S.; Song, K. C.; Yang, M. S.; Choi, Y. N.; Han, Y. S.; Oh, H. S.

    2001-07-01

    The lattice parameters of simulated DUPIC fuel and UO2 were measured from room temperature to 1273 K using neutron diffraction to investigate the thermal expansion and density variation with temperature. The lattice parameter of simulated DUPIC fuel is lower than that of UO2 and the linear thermal expansion of simulated DUPIC fuel is higher than that of UO2. For the temperature range from 298 to 1273 K, the average linear thermal expansion coefficients for UO2 and simulated DUPIC fuel are 10.471 ''10-6 and 10.751 ''10-6 K-1, respectively

  5. Status report on multigroup cross section generation code development for high-fidelity deterministic neutronics simulation system

    International Nuclear Information System (INIS)

    Yang, W.S.; Lee, C.H.

    2008-01-01

    Under the fast reactor simulation program launched in April 2007, development of an advanced multigroup cross section generation code was initiated in July 2007, in conjunction with the development of the high-fidelity deterministic neutron transport code UNIC. The general objectives are to simplify the existing multi-step schemes and to improve the resolved and unresolved resonance treatments. Based on the review results of current methods and the fact that they have been applied successfully to fast critical experiment analyses and fast reactor designs for last three decades, the methodologies of the ETOE-2/MC 2 -2/SDX code system were selected as the starting set of methodologies for multigroup cross section generation for fast reactor analysis. As the first step for coupling with the UNIC code and use in a parallel computing environment, the MC 2 -2 code was updated by modernizing the memory structure and replacing old data management package subroutines and functions with FORTRAN 90 based routines. Various modifications were also made in the ETOE-2 and MC 2 -2 codes to process the ENDF/B-VII.0 data properly. Using the updated ETOE-2/MC 2 -2 code system, the ENDF/B-VII.0 data was successfully processed for major heavy and intermediate nuclides employed in sodium-cooled fast reactors. Initial verification tests of the MC 2 -2 libraries generated from ENDF/B-VII.0 data were performed by inter-comparison of twenty-one group infinite dilute total cross sections obtained from MC 2 -2, VIM, and NJOY. For almost all nuclides considered, MC 2 -2 cross sections agreed very well with those from VIM and NJOY. Preliminary validation tests of the ENDF/B-VII.0 libraries of MC 2 -2 were also performed using a set of sixteen fast critical benchmark problems. The deterministic results based on MC 2 -2/TWODANT calculations were in good agreement with MCNP solutions within ∼0.25% Δρ, except a few small LANL fast assemblies. Relative to the MCNP solution, the MC 2 -2/TWODANT

  6. Status report on multigroup cross section generation code development for high-fidelity deterministic neutronics simulation system.

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W. S.; Lee, C. H. (Nuclear Engineering Division)

    2008-05-16

    Under the fast reactor simulation program launched in April 2007, development of an advanced multigroup cross section generation code was initiated in July 2007, in conjunction with the development of the high-fidelity deterministic neutron transport code UNIC. The general objectives are to simplify the existing multi-step schemes and to improve the resolved and unresolved resonance treatments. Based on the review results of current methods and the fact that they have been applied successfully to fast critical experiment analyses and fast reactor designs for last three decades, the methodologies of the ETOE-2/MC{sup 2}-2/SDX code system were selected as the starting set of methodologies for multigroup cross section generation for fast reactor analysis. As the first step for coupling with the UNIC code and use in a parallel computing environment, the MC{sup 2}-2 code was updated by modernizing the memory structure and replacing old data management package subroutines and functions with FORTRAN 90 based routines. Various modifications were also made in the ETOE-2 and MC{sup 2}-2 codes to process the ENDF/B-VII.0 data properly. Using the updated ETOE-2/MC{sup 2}-2 code system, the ENDF/B-VII.0 data was successfully processed for major heavy and intermediate nuclides employed in sodium-cooled fast reactors. Initial verification tests of the MC{sup 2}-2 libraries generated from ENDF/B-VII.0 data were performed by inter-comparison of twenty-one group infinite dilute total cross sections obtained from MC{sup 2}-2, VIM, and NJOY. For almost all nuclides considered, MC{sup 2}-2 cross sections agreed very well with those from VIM and NJOY. Preliminary validation tests of the ENDF/B-VII.0 libraries of MC{sup 2}-2 were also performed using a set of sixteen fast critical benchmark problems. The deterministic results based on MC{sup 2}-2/TWODANT calculations were in good agreement with MCNP solutions within {approx}0.25% {Delta}{rho}, except a few small LANL fast assemblies

  7. Developing a High Fidelity Martian Soil Simulant Based on MSL Measurements: Applications for Habitability, Exploration, and In-Situ Resource Utilization

    Science.gov (United States)

    Cannon, K.; Britt, D. T.; Smith, T. M.; Fritsche, R. F.; Covey, S. D.; Batcheldor, D.; Watson, B.

    2017-12-01

    Powerful instruments, that include CheMin and SAM on the MSL Curiosity rover, have provided an unprecedented look into the mineral, chemical, and volatile composition of Martian soils. Interestingly, the bulk chemistry of the Rocknest windblown soil is a close match to similar measurements from the Spirit and Opportunity rovers, suggesting the presence of a global basaltic soil component. The Martian regolith is likely composed of this global soil mixed with locally to regionally derived components that include alteration products and evolved volcanic compositions. Without returned soil samples, researchers have relied on terrestrial simulants to address fundamental Mars science, habitability, in-situ resource utilization, and hardware for future exploration. However, these past simulants have low fidelity compared to actual Martian soils: JSC Mars-1a is an amorphous palagonitic material with spectral similarities to Martian dust, not soil, and Mojave Mars is simply a ground up terrestrial basalt chosen for its convenient location. Based on our experience creating asteroid regolith simulants, we are developing a high fidelity Martian soil simulant (Mars Global) designed ab initio to match the mineralogy, chemistry, and volatile contents of the global basaltic soil on Mars. The crystalline portion of the simulant is based on CheMin measurements of Rocknest and includes plagioclase, two pyroxenes, olivine, hematite, magnetite, anhydrite, and quartz. The amorphous portion is less well constrained, but we are re-creating it with basaltic glass, synthetic ferrihydrite, ferric sulfate, and carbonates. We also include perchlorate and nitrate salts based on evolved gas analyses from the SAM instrument. Analysis and testing of Mars Global will include physical properties (shear strength, density, internal friction angle), spectral properties, magnetic properties, and volatile release patterns. The simulant is initially being designed for NASA agricultural studies, but

  8. Thermal Properties of Lunar Regolith Simulants

    Science.gov (United States)

    Street, Kenneth; Ray, Chandra; Rickman, Doug

    2010-01-01

    Various high temperature chemical processes have been developed to extract oxygen and metals from lunar regolith. These processes are tested using terrestrial analogues of the regolith. But all practical terrestrial analogs contain H2O and/or OH-, the presence of which has substantial impact on important system behaviors. We have undertaken studies of lunar regolith simulants to determine the limits of the simulants to validate key components for human survivability during sustained presence on the moon. Differential Thermal Analysis (DTA) yields information on phase transitions and melting temperatures. Themo-Gravimetric Analysis (TGA) with mass spectrometric (MS) determination of evolved gas species yields chemical information on various oxygenated volatiles (water, carbon dioxide, sulfur oxides, nitrogen oxides and phosphorus oxides) and their evolution temperature profiles. The DTA and TGAMS studies included JSC-1A fine, NU-LHT-2M and its proposed feed stocks: anorthosite; dunite; HQ (high quality) glass and the norite from which HQ glass is produced. Fig 1 is a data profile for anorthosite. The DTA (Fig 1a) indicates exothermic transitions at 355 and 490 C and endothermic transitions at 970 and 1235 C. Below the 355 C transition, water (Molecular Weight, MW, 18 in Fig 1c) is lost accounting for approximately 0.1% mass loss due to water removal (Fig 1b). Just above 490 C a second type of water is lost, presumably bound in lattices of secondary minerals. Between 490 and the 970 transition other volatile oxides are lost including those of hydrogen (third water type), carbon (MW = 44), sulfur (MW = 64 and 80), nitrogen (MW 30 and 46) and possibly phosphorus (MW = 79, 95 or 142). Peaks at MW = 35 and 19 may be attributable to loss of chlorine and fluorine respectively. Negative peaks in the NO (MW = 30) and oxygen (MW = 32) MS profiles may indicate the production of NO2 (MW = 46). Because so many compounds are volatilized in this temperature range quantification of

  9. Improvement of the NSSS T/H Module ARTS for Enhancing the Simulation Fidelity of YGN no 1/2 Simulator

    International Nuclear Information System (INIS)

    Seo, In Yong; Lee, Myung Soo; Lee, Yong Kwan; Suh, Jae Seung; Jeun, Gyoo Dong

    2006-01-01

    KEPRI(Korea Electric Power Research Institute) and KAERI(Korea Atomic Energy Research Institute) developed a NSSS (Nuclear Steam Supply System) T/H (Thermal-Hydraulic) module (named ARTS) based on the best-estimate code RETRAN-3D for the KNPEC-2 full-scope simulator in 2001. Although ARTS can simulate the most transients in real-time, and its robustness is ensured, real-time calculation and robustness can fail for large break loss-of-coolant accident (LBLOCA) and long term, two-phase transients. In order to improve its robustness, ARTS equipped with the backup calculation module to be used whenever a regular ARTS module fails to calculate. When the symptom for the failure of T/H module is detected, the main ARTS module is replaced with the backup module for the calculation of primary and secondary reactor system although most failures of ARTS occur in the calculation of the primary system especially for LBLOCA simulation. The sudden transition from the main ARTS module to the backup module can exhibit the discontinuity of simulation of secondary system on rare occasions. To mitigate the simulation discontinuity, we have improved the backup module of ARTS. The performance of a new approach has been illustrated by the non-integrated standalone test. The improved ARTS module will be incorporated into YGN no. 1/2 simulator and evaluated its performance in the real simulator environment. This paper presents the brief description of a new backup calculation strategy and the simulation results of LOCA to evaluate the performance of a new backup strategy in standalone test environment

  10. An exploration of the relationship between knowledge and performance-related variables in high-fidelity simulation: designing instruction that promotes expertise in practice.

    Science.gov (United States)

    Hauber, Roxanne P; Cormier, Eileen; Whyte, James

    2010-01-01

    Increasingly, high-fidelity patient simulation (HFPS) is becoming essential to nursing education. Much remains unknown about how classroom learning is connected to student decision-making in simulation scenarios and the degree to which transference takes place between the classroom setting and actual practice. The present study was part of a larger pilot study aimed at determining the relationship between nursing students' clinical ability to prioritize their actions and the associated cognitions and physiologic outcomes of care using HFPS. In an effort to better explain the knowledge base being used by nursing students in HFPS, the investigators explored the relationship between common measures of knowledge and performance-related variables. Findings are discussed within the context of the expert performance approach and concepts from cognitive psychology, such as cognitive architecture, cognitive load, memory, and transference.

  11. Haptization of molecular dynamics simulation with thermal display

    International Nuclear Information System (INIS)

    Tamura, Yuichi; Fujiwara, Susumu; Nakamura, Hiroaki

    2010-01-01

    Thermal display, which is a type of haptic display, is effective in providing intuitive information of temperature. However, in many studies, the user has assumed a sitting position during the use of these devices. In contrast, the user generally watches 3D objects while standing and walking around in large-scale virtual reality system, In addition, in scientific visualization, the response time is very important for observing physical phenomena, especially for dynamic numerical simulation. One solution is to provide two types of thermal information: information about the rate of thermal change and information about the actual temperature. We propose a thermal display with two Peltier elements which can show above two pairs of information and the result (for example energy and temperature, as thermal information) of numerical simulation. Finally, we represent an example of visualizing and haptizing the result of molecular dynamics simulation. (author)

  12. Contact Thermal Analysis and Wear Simulation of a Brake Block

    Directory of Open Access Journals (Sweden)

    Nándor Békési

    2013-01-01

    Full Text Available The present paper describes an experimental test and a coupled contact-thermal-wear analysis of a railway wheel/brake block system through the braking process. During the test, the friction, the generated heat, and the wear were evaluated. It was found that the contact between the brake block and the wheel occurs in relatively small and slowly moving hot spots, caused by the wear and the thermal effects. A coupled simulation method was developed including numerical frictional contact, transient thermal and incremental wear calculations. In the 3D simulation, the effects of the friction, the thermal expansion, the wear, and the temperature-dependent material properties were also considered. A good agreement was found between the results of the test and the calculations, both for the thermal and wear results. The proposed method is suitable for modelling the slowly oscillating wear caused by the thermal expansions in the contact area.

  13. Electrical power system integrated thermal/electrical system simulation

    International Nuclear Information System (INIS)

    Freeman, W.E.

    1992-01-01

    This paper adds thermal properties to previously developed electrical Saber templates and incorporates these templates into a functional Electrical Power Subsystem (EPS) simulation. These combined electrical and thermal templates enable the complete and realistic simulation of a vehicle EPS on-orbit. Applications include on-orbit energy balance determinations for system load changes, initial array and battery EPS sizing for new EPS development, and array and battery technology trade studies. This effort proves the versatility of the Saber simulation program in handling varied and complex simulations accurately and in a reasonable amount of computer time. 9 refs

  14. Thermal simulation of storage in TSS-Galleries

    International Nuclear Information System (INIS)

    Lain Huerta, R.; Martinez Santiago, T.; Ramirez Oyangueren, P.

    1993-01-01

    This report describes the experiment ''thermal simulation of storage in TSS-galleries'' what is been developed in salt mine of Asse, Germany. The report has 3 part: 1) Analysis of objectives and general description of boundary layers. 2) Geomechanics parameters of salt mine. 3) Thermal modelization, thermomechanics modelization and data acquisition

  15. Computer Simulation in Problems of Thermal Strength

    Directory of Open Access Journals (Sweden)

    Olga I. Chelyapina

    2012-05-01

    Full Text Available This article discusses informative technology of using graphical programming environment LabVIEW 2009 when calculating and predicting the thermal strength of materials with an inhomogeneous structure. Algorithm for processing the experimental data was developed as part of the problem.

  16. Micromagnetic simulation of thermally activated switching in fine particles

    International Nuclear Information System (INIS)

    Scholz, Werner; Schrefl, Thomas; Fidler, J.

    2001-01-01

    Effects of thermal activation are included in micromagnetic simulations by adding a random thermal field to the effective magnetic field. As a result, the Landau-Lifshitz equation is converted into a stochastic differential equation of Langevin type with multiplicative noise. The Stratonovich interpretation of the stochastic Landau-Lifshitz equation leads to the correct thermal equilibrium properties. The proper generalization of Taylor expansions to stochastic calculus gives suitable time integration schemes. For a single rigid magnetic moment the thermal equilibrium properties are investigated. It is found, that the Heun scheme is a good compromise between numerical stability and computational complexity. Small cubic and spherical ferromagnetic particles are studied

  17. Finding the Needles in the Haystacks: High-Fidelity Models of the Modern and Archean Solar System for Simulating Exoplanet Observations

    Science.gov (United States)

    Roberge, Aki; Rizzo, Maxime J.; Lincowski, Andrew P.; Arney, Giada N.; Stark, Christopher C.; Robinson, Tyler D.; Snyder, Gregory F.; Pueyo, Laurent; Zimmerman, Neil T.; Jansen, Tiffany; hide

    2017-01-01

    We present two state-of-the-art models of the solar system, one corresponding to the present day and one to the Archean Eon 3.5 billion years ago. Each model contains spatial and spectral information for the star, the planets, and the interplanetary dust, extending to 50 au from the Sun and covering the wavelength range 0.3-2.5 micron. In addition, we created a spectral image cube representative of the astronomical backgrounds that will be seen behind deep observations of extrasolar planetary systems, including galaxies and Milky Way stars. These models are intended as inputs to high-fidelity simulations of direct observations of exoplanetary systems using telescopes equipped with high-contrast capability. They will help improve the realism of observation and instrument parameters that are required inputs to statistical observatory yield calculations, as well as guide development of post-processing algorithms for telescopes capable of directly imaging Earth-like planets.

  18. New insights into transcription fidelity: thermal stability of non-canonical structures in template DNA regulates transcriptional arrest, pause, and slippage.

    Science.gov (United States)

    Tateishi-Karimata, Hisae; Isono, Noburu; Sugimoto, Naoki

    2014-01-01

    The thermal stability and topology of non-canonical structures of G-quadruplexes and hairpins in template DNA were investigated, and the effect of non-canonical structures on transcription fidelity was evaluated quantitatively. We designed ten template DNAs: A linear sequence that does not have significant higher-order structure, three sequences that form hairpin structures, and six sequences that form G-quadruplex structures with different stabilities. Templates with non-canonical structures induced the production of an arrested, a slipped, and a full-length transcript, whereas the linear sequence produced only a full-length transcript. The efficiency of production for run-off transcripts (full-length and slipped transcripts) from templates that formed the non-canonical structures was lower than that from the linear. G-quadruplex structures were more effective inhibitors of full-length product formation than were hairpin structure even when the stability of the G-quadruplex in an aqueous solution was the same as that of the hairpin. We considered that intra-polymerase conditions may differentially affect the stability of non-canonical structures. The values of transcription efficiencies of run-off or arrest transcripts were correlated with stabilities of non-canonical structures in the intra-polymerase condition mimicked by 20 wt% polyethylene glycol (PEG). Transcriptional arrest was induced when the stability of the G-quadruplex structure (-ΔG°37) in the presence of 20 wt% PEG was more than 8.2 kcal mol(-1). Thus, values of stability in the presence of 20 wt% PEG are an important indicator of transcription perturbation. Our results further our understanding of the impact of template structure on the transcription process and may guide logical design of transcription-regulating drugs.

  19. RADYN Simulations of Non-thermal and Thermal Models of Ellerman Bombs

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jie; Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210023 (China); Carlsson, Mats, E-mail: dmd@nju.edu.cn [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway)

    2017-08-20

    Ellerman bombs (EBs) are brightenings in the H α line wings that are believed to be caused by magnetic reconnection in the lower atmosphere. To study the response and evolution of the chromospheric line profiles, we perform radiative hydrodynamic simulations of EBs using both non-thermal and thermal models. Overall, these models can generate line profiles that are similar to observations. However, in non-thermal models we find dimming in the H α line wings and continuum when the heating begins, while for the thermal models dimming occurs only in the H α line core, and with a longer lifetime. This difference in line profiles can be used to determine whether an EB is dominated by non-thermal heating or thermal heating. In our simulations, if a higher heating rate is applied, then the H α line will be unrealistically strong and there are still no clear UV burst signatures.

  20. RADYN Simulations of Non-thermal and Thermal Models of Ellerman Bombs

    Science.gov (United States)

    Hong, Jie; Carlsson, Mats; Ding, M. D.

    2017-08-01

    Ellerman bombs (EBs) are brightenings in the Hα line wings that are believed to be caused by magnetic reconnection in the lower atmosphere. To study the response and evolution of the chromospheric line profiles, we perform radiative hydrodynamic simulations of EBs using both non-thermal and thermal models. Overall, these models can generate line profiles that are similar to observations. However, in non-thermal models we find dimming in the Hα line wings and continuum when the heating begins, while for the thermal models dimming occurs only in the Hα line core, and with a longer lifetime. This difference in line profiles can be used to determine whether an EB is dominated by non-thermal heating or thermal heating. In our simulations, if a higher heating rate is applied, then the Hα line will be unrealistically strong and there are still no clear UV burst signatures.

  1. Low-Fidelity Haptic Simulation Versus Mental Imagery Training for Epidural Anesthesia Technical Achievement in Novice Anesthesiology Residents: A Randomized Comparative Study.

    Science.gov (United States)

    Lim, Grace; Krohner, Robert G; Metro, David G; Rosario, Bedda L; Jeong, Jong-Hyeon; Sakai, Tetsuro

    2016-05-01

    There are many teaching methods for epidural anesthesia skill acquisition. Previous work suggests that there is no difference in skill acquisition whether novice learners engage in low-fidelity (LF) versus high-fidelity haptic simulation for epidural anesthesia. No study, however, has compared the effect of LF haptic simulation for epidural anesthesia versus mental imagery (MI) training in which no physical practice is attempted. We tested the hypothesis that MI training is superior to LF haptic simulation training for epidural anesthesia skill acquisition. Twenty Post-Graduate Year 2 (PGY-2) anesthesiology residents were tested at the beginning of the training year. After a didactic lecture on epidural anesthesia, they were randomized into 2 groups. Group LF had LF simulation training for epidural anesthesia using a previously described banana simulation technique. Group MI had guided, scripted MI training in which they initially were oriented to the epidural kit components and epidural anesthesia was described stepwise in detail, followed by individual mental rehearsal; no physical practice was undertaken. Each resident then individually performed epidural anesthesia on a partial-human task trainer on 3 consecutive occasions under the direct observation of skilled evaluators who were blinded to group assignment. Technical achievement was assessed with the use of a modified validated skills checklist. Scores (0-21) and duration to task completion (minutes) were recorded. A linear mixed-effects model analysis was performed to determine the differences in scores and duration between groups and over time. There was no statistical difference between the 2 groups for scores and duration to task completion. Both groups showed similarly significant increases (P = 0.0015) in scores over time (estimated mean score [SE]: group MI, 15.9 [0.55] to 17.4 [0.55] to 18.6 [0.55]; group LF, 16.2 [0.55] to 17.7 [0.55] to 18.9 [0.55]). Time to complete the procedure decreased

  2. Undergraduate nursing students' performance in recognising and responding to sudden patient deterioration in high psychological fidelity simulated environments: an Australian multi-centre study.

    Science.gov (United States)

    Bogossian, Fiona; Cooper, Simon; Cant, Robyn; Beauchamp, Alison; Porter, Joanne; Kain, Victoria; Bucknall, Tracey; Phillips, Nicole M

    2014-05-01

    Early recognition and situation awareness of sudden patient deterioration, a timely appropriate clinical response, and teamwork are critical to patient outcomes. High fidelity simulated environments provide the opportunity for undergraduate nursing students to develop and refine recognition and response skills. This paper reports the quantitative findings of the first phase of a larger program of ongoing research: Feedback Incorporating Review and Simulation Techniques to Act on Clinical Trends (FIRST2ACTTM). It specifically aims to identify the characteristics that may predict primary outcome measures of clinical performance, teamwork and situation awareness in the management of deteriorating patients. Mixed-method multi-centre study. High fidelity simulated acute clinical environment in three Australian universities. A convenience sample of 97 final year nursing students enrolled in an undergraduate Bachelor of Nursing or combined Bachelor of Nursing degree were included in the study. In groups of three, participants proceeded through three phases: (i) pre-briefing and completion of a multi-choice question test, (ii) three video-recorded simulated clinical scenarios where actors substituted real patients with deteriorating conditions, and (iii) post-scenario debriefing. Clinical performance, teamwork and situation awareness were evaluated, using a validated standard checklist (OSCE), Team Emergency Assessment Measure (TEAM) score sheet and Situation Awareness Global Assessment Technique (SAGAT). A Modified Angoff technique was used to establish cut points for clinical performance. Student teams engaged in 97 simulation experiences across the three scenarios and achieved a level of clinical performance consistent with the experts' identified pass level point in only 9 (1%) of the simulation experiences. Knowledge was significantly associated with overall teamwork (p=.034), overall situation awareness (p=.05) and clinical performance in two of the three scenarios

  3. The effectiveness of and satisfaction with high-fidelity simulation to teach cardiac surgical resuscitation skills to nurses.

    Science.gov (United States)

    McRae, Marion E; Chan, Alice; Hulett, Renee; Lee, Ai Jin; Coleman, Bernice

    2017-06-01

    There are few reports of the effectiveness or satisfaction with simulation to learn cardiac surgical resuscitation skills. To test the effect of simulation on the self-confidence of nurses to perform cardiac surgical resuscitation simulation and nurses' satisfaction with the simulation experience. A convenience sample of sixty nurses rated their self-confidence to perform cardiac surgical resuscitation skills before and after two simulations. Simulation performance was assessed. Subjects completed the Satisfaction with Simulation Experience scale and demographics. Self-confidence scores to perform all cardiac surgical skills as measured by paired t-tests were significantly increased after the simulation (d=-0.50 to 1.78). Self-confidence and cardiac surgical work experience were not correlated with time to performance. Total satisfaction scores were high (mean 80.2, SD 1.06) indicating satisfaction with the simulation. There was no correlation of the satisfaction scores with cardiac surgical work experience (τ=-0.05, ns). Self-confidence scores to perform cardiac surgical resuscitation procedures were higher after the simulation. Nurses were highly satisfied with the simulation experience. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Equipping simulators with an advanced thermal hydraulics model EDF's experience

    International Nuclear Information System (INIS)

    Soldermann, R.; Poizat, F.; Sekri, A.; Faydide, B.; Dumas, J.M.

    1997-01-01

    The development of an accelerated version of the advanced CATHARe-1 thermal hydraulics code designed for EDF training simulators (CATHARE-SIMU) was successfully completed as early as 1991. Its successful integration as the principal model of the SIPA Post-Accident Simulator meant that its use could be extended to full-scale simulators as part of the renovation of the stock of existing simulators. In order to further extend the field of application to accidents occurring in shutdown states requiring action and to catch up with developments in respect of the CATHARE code, EDF initiated the SCAR Project designed to adapt CATHARE-2 to simulator requirements (acceleration, parallelization of the computation and extension of the simulation range). In other respects, the installation of SIPA on workstations means that the authors can envisage the application of this remarkable training facility to the understanding of thermal hydraulics accident phenomena

  5. Strangeness by Thermal Model Simulation at RHIC

    Institute of Scientific and Technical Information of China (English)

    SHI Xing-Hua; MA Yu-Gang; CAI Xiang-Zhou; CHEN Jin-Hui; MA Guo-Liang; ZHONG Chen

    2009-01-01

    The local temperature effect on strangeness enhancement in relativistic heavy ion collisions is discussed in the framework of the thermal model in which the K+ /h+ ratio becomes smaller with increasing freeze-out temperature.Considering that most strangeness particles of final-state particles are from the kaon meson,the temperature effect may play a role in strangeness production in hot dense matter where a slightly different temperature distribution in different areas could be produced by jet energy loss.This phenomenon is predicted by thermal model calculation at RHIC energy.The Ε-/φ ratio in central Au+Au collisions at 200 GeV from the thermal model depends on the freeze-out temperature obviously when γs is different.It should be one of the reasons why strangeness enhancements of Ε and φ are different though they include two strange quarks.These results indicate that thermodynamics is an important factor for strangeness production and the strangeness enhancement phenomenon.

  6. Tutorial: Determination of thermal boundary resistance by molecular dynamics simulations

    Science.gov (United States)

    Liang, Zhi; Hu, Ming

    2018-05-01

    Due to the high surface-to-volume ratio of nanostructured components in microelectronics and other advanced devices, the thermal resistance at material interfaces can strongly affect the overall thermal behavior in these devices. Therefore, the thermal boundary resistance, R, must be taken into account in the thermal analysis of nanoscale structures and devices. This article is a tutorial on the determination of R and the analysis of interfacial thermal transport via molecular dynamics (MD) simulations. In addition to reviewing the commonly used equilibrium and non-equilibrium MD models for the determination of R, we also discuss several MD simulation methods which can be used to understand interfacial thermal transport behavior. To illustrate how these MD models work for various interfaces, we will show several examples of MD simulation results on thermal transport across solid-solid, solid-liquid, and solid-gas interfaces. The advantages and drawbacks of a few other MD models such as approach-to-equilibrium MD and first-principles MD are also discussed.

  7. DNA - A Thermal Energy System Simulator

    DEFF Research Database (Denmark)

    2008-01-01

    DNA is a general energy system simulator for both steady-state and dynamic simulation. The program includes a * component model library * thermodynamic state models for fluids and solid fuels and * standard numerical solvers for differential and algebraic equation systems and is free and portable...... (open source, open use, standard FORTRAN77). DNA is text-based using whichever editor, you like best. It has been integerated with the emacs editor. This is usually available on unix-like systems. for windows we recommend the Installation instructions for windows: First install emacs and then run...... the DNA installer...

  8. Adaptive implicit method for thermal compositional reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, A.; Tchelepi, H.A. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Stanford Univ., Palo Alto (United States)

    2008-10-15

    As the global demand for oil increases, thermal enhanced oil recovery techniques are becoming increasingly important. Numerical reservoir simulation of thermal methods such as steam assisted gravity drainage (SAGD) is complex and requires a solution of nonlinear mass and energy conservation equations on a fine reservoir grid. The most currently used technique for solving these equations is the fully IMplicit (FIM) method which is unconditionally stable, allowing for large timesteps in simulation. However, it is computationally expensive. On the other hand, the method known as IMplicit pressure explicit saturations, temperature and compositions (IMPEST) is computationally inexpensive, but it is only conditionally stable and restricts the timestep size. To improve the balance between the timestep size and computational cost, the thermal adaptive IMplicit (TAIM) method uses stability criteria and a switching algorithm, where some simulation variables such as pressure, saturations, temperature, compositions are treated implicitly while others are treated with explicit schemes. This presentation described ongoing research on TAIM with particular reference to thermal displacement processes such as the stability criteria that dictate the maximum allowed timestep size for simulation based on the von Neumann linear stability analysis method; the switching algorithm that adapts labeling of reservoir variables as implicit or explicit as a function of space and time; and, complex physical behaviors such as heat and fluid convection, thermal conduction and compressibility. Key numerical results obtained by enhancing Stanford's General Purpose Research Simulator (GPRS) were also presented along with a list of research challenges. 14 refs., 2 tabs., 11 figs., 1 appendix.

  9. Effects of Low- Versus High-Fidelity Simulations on the Cognitive Burden and Performance of Entry-Level Paramedicine Students: A Mixed-Methods Comparison Trial Using Eye-Tracking, Continuous Heart Rate, Difficulty Rating Scales, Video Observation and Interviews.

    Science.gov (United States)

    Mills, Brennen W; Carter, Owen B-J; Rudd, Cobie J; Claxton, Louise A; Ross, Nathan P; Strobel, Natalie A

    2016-02-01

    High-fidelity simulation-based training is often avoided for early-stage students because of the assumption that while practicing newly learned skills, they are ill suited to processing multiple demands, which can lead to "cognitive overload" and poorer learning outcomes. We tested this assumption using a mixed-methods experimental design manipulating psychological immersion. Thirty-nine randomly assigned first-year paramedicine students completed low- or high-environmental fidelity simulations [low-environmental fidelity simulations (LF(en)S) vs. high-environmental fidelity simulation (HF(en)S)] involving a manikin with obstructed airway (SimMan3G). Psychological immersion and cognitive burden were determined via continuous heart rate, eye tracking, self-report questionnaire (National Aeronautics and Space Administration Task Load Index), independent observation, and postsimulation interviews. Performance was assessed by successful location of obstruction and time-to-termination. Eye tracking confirmed that students attended to multiple, concurrent stimuli in HF(en)S and interviews consistently suggested that they experienced greater psychological immersion and cognitive burden than their LF(en)S counterparts. This was confirmed by significantly higher mean heart rate (P cognitive burden but this has considerable educational merit.

  10. Evaluation of uranium dioxide thermal conductivity using molecular dynamics simulations

    International Nuclear Information System (INIS)

    Kim, Woongkee; Kaviany, Massoud; Shim, J. H.

    2014-01-01

    It can be extended to larger space, time scale and even real reactor situation with fission product as multi-scale formalism. Uranium dioxide is a fluorite structure with Fm3m space group. Since it is insulator, dominant heat carrier is phonon, rather than electrons. So, using equilibrium molecular dynamics (MD) simulation, we present the appropriate calculation parameters in MD simulation by calculating thermal conductivity and application of it to the thermal conductivity of polycrystal. In this work, we investigate thermal conductivity of uranium dioxide and optimize the parameters related to its process. In this process, called Green Kubo formula, there are two parameters i.e correlation length and sampling interval, which effect on ensemble integration in order to obtain thermal conductivity. Through several comparisons, long correlation length and short sampling interval give better results. Using this strategy, thermal conductivity of poly crystal is obtained and comparison with that of pure crystal is made. Thermal conductivity of poly crystal show lower value that that of pure crystal. In further study, we broaden the study to transport coefficient of radiation damaged structures using molecular dynamics. Although molecular dynamics is tools for treating microscopic scale, most macroscopic issues related to nuclear materials such as voids in fuel materials and weakened mechanical properties by radiation are based on microscopic basis. Thus, research on microscopic scale would be expanded in this field and many hidden mechanism in atomic scales will be revealed via both atomic scale simulations and experiments

  11. The simulation of transients in thermal plant. Part II: Applications

    International Nuclear Information System (INIS)

    Morini, G.L.; Piva, S.

    2008-01-01

    This paper deals with the simulation of the transients of thermal plant with control systems. In the companion paper forming part I of this article [G.L. Morini, S. Piva, The simulation of transients in thermal plant. Part I: Mathematical model, Applied Thermal Engineering 27 (2007) 2138-2144] it has been described how a 'thermal-library' of customised blocks can be built and used, in an intuitive way, to study the transients of any kind of thermal plant. Each component of plant such as valves, boilers, and pumps, is represented by a single block. In this paper, the 'thermal-library' approach is demonstrated by the analysis of the dynamic behaviour of a central heating plant of a typical apartment house during a sinusoidal variation of the external temperature. A comparison of the behaviour of such a plant with three way valve working either in flow rate or in temperature control, is presented and discussed. Finally, the results show the delaying effect of the thermal capacity of the building on the performance of the control system

  12. Electro-Thermal-Mechanical Simulation Capability Final Report

    International Nuclear Information System (INIS)

    White, D

    2008-01-01

    This is the Final Report for LDRD 04-ERD-086, 'Electro-Thermal-Mechanical Simulation Capability'. The accomplishments are well documented in five peer-reviewed publications and six conference presentations and hence will not be detailed here. The purpose of this LDRD was to research and develop numerical algorithms for three-dimensional (3D) Electro-Thermal-Mechanical simulations. LLNL has long been a world leader in the area of computational mechanics, and recently several mechanics codes have become 'multiphysics' codes with the addition of fluid dynamics, heat transfer, and chemistry. However, these multiphysics codes do not incorporate the electromagnetics that is required for a coupled Electro-Thermal-Mechanical (ETM) simulation. There are numerous applications for an ETM simulation capability, such as explosively-driven magnetic flux compressors, electromagnetic launchers, inductive heating and mixing of metals, and MEMS. A robust ETM simulation capability will enable LLNL physicists and engineers to better support current DOE programs, and will prepare LLNL for some very exciting long-term DoD opportunities. We define a coupled Electro-Thermal-Mechanical (ETM) simulation as a simulation that solves, in a self-consistent manner, the equations of electromagnetics (primarily statics and diffusion), heat transfer (primarily conduction), and non-linear mechanics (elastic-plastic deformation, and contact with friction). There is no existing parallel 3D code for simulating ETM systems at LLNL or elsewhere. While there are numerous magnetohydrodynamic codes, these codes are designed for astrophysics, magnetic fusion energy, laser-plasma interaction, etc. and do not attempt to accurately model electromagnetically driven solid mechanics. This project responds to the Engineering R and D Focus Areas of Simulation and Energy Manipulation, and addresses the specific problem of Electro-Thermal-Mechanical simulation for design and analysis of energy manipulation systems

  13. Developing a tool for observing group critical thinking skills in first-year medical students: a pilot study using physiology-based, high-fidelity patient simulations.

    Science.gov (United States)

    Nguyen, Khoa; Ben Khallouq, Bertha; Schuster, Amanda; Beevers, Christopher; Dil, Nyla; Kay, Denise; Kibble, Jonathan D; Harris, David M

    2017-12-01

    Most assessments of physiology in medical school use multiple choice tests that may not provide information about a student's critical thinking (CT) process. There are limited performance assessments, but high-fidelity patient simulations (HFPS) may be a feasible platform. The purpose of this pilot study was to determine whether a group's CT process could be observed over a series of HFPS. An instrument [Critical Thinking Skills Rating Instrument CTSRI)] was designed with the IDEAS framework. Fifteen groups of students participated in three HFPS that consisted of a basic knowledge quiz and introduction, HFPS session, and debriefing. HFPS were video recorded, and two raters reviewed and scored all HFPS encounters with the CTSRI independently. Interrater analysis suggested good reliability. There was a correlation between basic knowledge scores and three of the six observations on the CTSRI providing support for construct validity. The median CT ratings significantly increased for all observations between the groups' first and last simulation. However, there were still large percentages of video ratings that indicated students needed substantial prompting during the HFPS. The data from this pilot study suggest that it is feasible to observe CT skills in HFPS using the CTSRI. Based on the findings from this study, we strongly recommend that first-year medical students be competent in basic knowledge of the relevant physiology of the HFPS before participating, to minimize the risk of a poor learning experience. Copyright © 2017 the American Physiological Society.

  14. Designing solar thermal experiments based on simulation

    International Nuclear Information System (INIS)

    Huleihil, Mahmoud; Mazor, Gedalya

    2013-01-01

    In this study three different models to describe the temperature distribution inside a cylindrical solid body subjected to high solar irradiation were examined, beginning with the simpler approach, which is the single dimension lump system (time), progressing through the two-dimensional distributed system approach (time and vertical direction), and ending with the three-dimensional distributed system approach with azimuthally symmetry (time, vertical direction, and radial direction). The three models were introduced and solved analytically and numerically. The importance of the models and their solution was addressed. The simulations based on them might be considered as a powerful tool in designing experiments, as they make it possible to estimate the different effects of the parameters involved in these models

  15. Randomized Crossover Study of Training Benefits of High Fidelity ECMO Simulation versus Porcine Animal Model An Interim Report

    Science.gov (United States)

    2017-02-25

    59 MDW/SGVU SUBJECT: Professional Presentation Approval 24 FEB 2017 1. Your paper, entitled Randomized C rossover Study of T raining Benefits of...have been the gold -standard for ECMO training due to their ability to replicate complex physiology and anatomic variation . Recently ECMO simulation

  16. Effect of high-fidelity shoulder dystocia simulation on emergency obstetric skills and crew resource management skills among residents.

    Science.gov (United States)

    Mannella, Paolo; Palla, Giulia; Cuttano, Armando; Boldrini, Antonio; Simoncini, Tommaso

    2016-12-01

    To determine the effect of a simulation training program for residents in obstetrics and gynecology in terms of technical and nontechnical skills for the management of shoulder dystocia. A prospective study was performed at a center in Italy in April-May 2015. Thirty-two obstetrics and gynecology residents were divided into two groups. Residents in the control group were immediately exposed to an emergency shoulder dystocia scenario, whereas those in the simulation group completed a 2-hour training session with the simulator before being exposed to the scenario. After 8weeks, the residents were again exposed to the shoulder dystocia scenario and reassessed. Participants were scored on their demonstration of technical and nontechnical skills. In the first set of scenarios, the mean score was higher in the simulation group than the control group in terms of both technical skills (P=0.008) and nontechnical skills (Pdystocia. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  17. Weldability investigation steel P 91 by weld thermal cycle simulation

    Directory of Open Access Journals (Sweden)

    M. Dunđer

    2015-07-01

    Full Text Available This paper elaborates results of hardness and impact energy of thermal cycle simulated specimens of high-alloy steel P 91 and their dependence on cooling time from 800 to 500 °C. Results were obtained by measuring hardness HV 1 and by experimental testing of Charpy notched specimens. Metallographic analysis of samples was performed on scanning electronic microscope.

  18. Numerical simulation of thermal fracture in functionally graded

    Indian Academy of Sciences (India)

    Numerical simulation of thermal fracture in functionally graded materials using element-free ... Initially, the temperature distribution over the domain is obtained by solving the heat transfer problem. ... Department of Mechanical Engineering, National Institute of Technology, Hamirpur 177005, India ... Contact | Site index.

  19. Optical and thermal simulation chain for LED package

    NARCIS (Netherlands)

    Tapaninen, O.; Myohanen, P.; Majanen, M.; Sitomaniemi, A.; Olkkonen, J.; Hildenbrand, V.; Gielen, A.W.J.; Mackenzie, F.V.; Barink, M.; Smilauer, V.; Patzak, B.

    2016-01-01

    This paper presents a test case for coupling two physical aspects of an LED, optical and thermal, using specific simulation models coupled through an open source platform for distributed multi-physics modelling. The glue code for coupling is written with Python programming language including

  20. High-fidelity simulation of lung isolation with double-lumen endotracheal tubes and bronchial blockers in anesthesiology resident training.

    Science.gov (United States)

    Failor, Erin; Bowdle, Andrew; Jelacic, Srdjan; Togashi, Kei

    2014-08-01

    Demonstrate the feasibility of using the AirSim Bronchi airway simulator to teach residents how to manage lung isolation with double-lumen endotracheal tubes and bronchial blockers and evaluate their performance with a detailed checklist. Prospective observational study. University anesthesiology residency training program. Anesthesiology residents taking a cardiothoracic anesthesiology rotation. Residents were instructed in 7 tasks using the AirSim Bronchi: The use of the fiberoptic bronchoscope, methods for placing left and right double-lumen endotracheal tubes and 3 bronchial blockers (Univent, Arndt, and Cohen), and application of continuous positive airway pressure (CPAP) to the unventilated lung. Two to 3 weeks later, checklists and a detailed scoring system were used to assess performance. Residents rated the curriculum and their own confidence in performing the tasks using a 5-point Likert scale. Thirteen residents completed the curriculum. Their median Likert scale ratings of the curriculum based on a questionnaire with 6 items ranged from 4 to 5 of 5. Resident confidence scores for each lung isolation technique improved after the simulation training, with the median gain ranging from 0.5 to 1.5 Likert levels depending on the task. The largest improvement occurred with the bronchial blockers (psimulator in a novel simulation curriculum to teach lung-isolation techniques to anesthesiology residents and evaluated performance using a detailed checklist scoring system. This curriculum is a promising educational tool. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Advancements in reactor physics modelling methodology of Monte Carlo Burnup Code MCB dedicated to higher simulation fidelity of HTR cores

    International Nuclear Information System (INIS)

    Cetnar, Jerzy

    2014-01-01

    The recent development of MCB - Monte Carlo Continuous Energy Burn-up code is directed towards advanced description of modern reactors, including double heterogeneity structures that exist in HTR-s. In this, we exploit the advantages of MCB methodology in integrated approach, where physics, neutronics, burnup, reprocessing, non-stationary process modeling (control rod operation) and refined spatial modeling are carried in a single flow. This approach allows for implementations of advanced statistical options like analysis of error propagation, perturbation in time domain, sensitivity and source convergence analyses. It includes statistical analysis of burnup process, emitted particle collection, thermal-hydraulic coupling, automatic power profile calculations, advanced procedures of burnup step normalization and enhanced post processing capabilities. (author)

  2. Thermal shale fracturing simulation using the Cohesive Zone Method (CZM)

    KAUST Repository

    Enayatpour, Saeid; van Oort, Eric; Patzek, Tadeusz

    2018-01-01

    Extensive research has been conducted over the past two decades to improve hydraulic fracturing methods used for hydrocarbon recovery from tight reservoir rocks such as shales. Our focus in this paper is on thermal fracturing of such tight rocks to enhance hydraulic fracturing efficiency. Thermal fracturing is effective in generating small fractures in the near-wellbore zone - or in the vicinity of natural or induced fractures - that may act as initiation points for larger fractures. Previous analytical and numerical results indicate that thermal fracturing in tight rock significantly enhances rock permeability, thereby enhancing hydrocarbon recovery. Here, we present a more powerful way of simulating the initiation and propagation of thermally induced fractures in tight formations using the Cohesive Zone Method (CZM). The advantages of CZM are: 1) CZM simulation is fast compared to similar models which are based on the spring-mass particle method or Discrete Element Method (DEM); 2) unlike DEM, rock material complexities such as scale-dependent failure behavior can be incorporated in a CZM simulation; 3) CZM is capable of predicting the extent of fracture propagation in rock, which is more difficult to determine in a classic finite element approach. We demonstrate that CZM delivers results for the challenging fracture propagation problem of similar accuracy to the eXtended Finite Element Method (XFEM) while reducing complexity and computational effort. Simulation results for thermal fracturing in the near-wellbore zone show the effect of stress anisotropy in fracture propagation in the direction of the maximum horizontal stress. It is shown that CZM can be used to readily obtain the extent and the pattern of induced thermal fractures.

  3. Thermal shale fracturing simulation using the Cohesive Zone Method (CZM)

    KAUST Repository

    Enayatpour, Saeid

    2018-05-17

    Extensive research has been conducted over the past two decades to improve hydraulic fracturing methods used for hydrocarbon recovery from tight reservoir rocks such as shales. Our focus in this paper is on thermal fracturing of such tight rocks to enhance hydraulic fracturing efficiency. Thermal fracturing is effective in generating small fractures in the near-wellbore zone - or in the vicinity of natural or induced fractures - that may act as initiation points for larger fractures. Previous analytical and numerical results indicate that thermal fracturing in tight rock significantly enhances rock permeability, thereby enhancing hydrocarbon recovery. Here, we present a more powerful way of simulating the initiation and propagation of thermally induced fractures in tight formations using the Cohesive Zone Method (CZM). The advantages of CZM are: 1) CZM simulation is fast compared to similar models which are based on the spring-mass particle method or Discrete Element Method (DEM); 2) unlike DEM, rock material complexities such as scale-dependent failure behavior can be incorporated in a CZM simulation; 3) CZM is capable of predicting the extent of fracture propagation in rock, which is more difficult to determine in a classic finite element approach. We demonstrate that CZM delivers results for the challenging fracture propagation problem of similar accuracy to the eXtended Finite Element Method (XFEM) while reducing complexity and computational effort. Simulation results for thermal fracturing in the near-wellbore zone show the effect of stress anisotropy in fracture propagation in the direction of the maximum horizontal stress. It is shown that CZM can be used to readily obtain the extent and the pattern of induced thermal fractures.

  4. MHD simulations of coronal dark downflows considering thermal conduction

    Science.gov (United States)

    Zurbriggen, E.; Costa, A.; Esquivel, A.; Schneiter, M.; Cécere, M.

    2017-10-01

    While several scenarios have been proposed to explain supra-arcade downflows (SADs) observed descending through turbulent hot regions, none of them have systematically addressed the consideration of thermal conduction. The SADs are known to be voided cavities. Our model assumes that SADs are triggered by bursty localized reconnection events that produce non-linear waves generating the voided cavity. These subdense cavities are sustained in time because they are hotter than their surrounding medium. Due to the low density and large temperature values of the plasma we expect the thermal conduction to be an important process. Our main aim here is to study if it is possible to generate SADs in the framework of our model considering thermal conduction. We carry on 2D MHD simulations including anisotropic thermal conduction, and find that if the magnetic lines envelope the cavities, they can be isolated from the hot environment and be identified as SADs.

  5. Thermal transport in semicrystalline polyethylene by molecular dynamics simulation

    Science.gov (United States)

    Lu, Tingyu; Kim, Kyunghoon; Li, Xiaobo; Zhou, Jun; Chen, Gang; Liu, Jun

    2018-01-01

    Recent research has highlighted the potential to achieve high-thermal-conductivity polymers by aligning their molecular chains. Combined with other merits, such as low-cost, corrosion resistance, and light weight, such polymers are attractive for heat transfer applications. Due to their quasi-one-dimensional structural nature, the understanding on the thermal transport in those ultra-drawn semicrystalline polymer fibers or films is still lacking. In this paper, we built the ideal repeating units of semicrystalline polyethylene and studied their dependence of thermal conductivity on different crystallinity and interlamellar topology using the molecular dynamics simulations. We found that the conventional models, such as the Choy-Young's model, the series model, and Takayanagi's model, cannot accurately predict the thermal conductivity of the quasi-one-dimensional semicrystalline polyethylene. A modified Takayanagi's model was proposed to explain the dependence of thermal conductivity on the bridge number at intermediate and high crystallinity. We also analyzed the heat transfer pathways and demonstrated the substantial role of interlamellar bridges in the thermal transport in the semicrystalline polyethylene. Our work could contribute to the understanding of the structure-property relationship in semicrystalline polymers and shed some light on the development of plastic heat sinks and thermal management in flexible electronics.

  6. GOTHIC code simulation of thermal stratification in POOLEX facility

    International Nuclear Information System (INIS)

    Li, H.; Kudinov, P.

    2009-07-01

    Pressure suppression pool is an important element of BWR containment. It serves as a heat sink and steam condenser to prevent containment pressure buildup during loss of coolant accident or safety relief valve opening during normal operations of a BWR. Insufficient mixing in the pool, in case of low mass flow rate of steam, can cause development of thermal stratification and reduction of pressure suppression pool capacity. For reliable prediction of mixing and stratification phenomena validation of simulation tools has to be performed. Data produced in POOLEX/PPOOLEX facility at Lappeenranta University of Technology about development of thermal stratification in a large scale model of a pressure suppression pool is used for GOTHIC lumped and distributed parameter validation. Sensitivity of GOTHIC solution to different boundary conditions and grid convergence study for 2D simulations of POOLEX STB-20 experiment are performed in the present study. CFD simulation was carried out with FLUENT code in order to get additional insights into physics of stratification phenomena. In order to support development of experimental procedures for new tests in the PPOOLEX facility lumped parameter pre-test GOTHIC simulations were performed. Simulations show that drywell and wetwell pressures can be kept within safety margins during a long transient necessary for development of thermal stratification. (au)

  7. GOTHIC code simulation of thermal stratification in POOLEX facility

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Kudinov, P. (Royal Institute of Technology (KTH) (Sweden))

    2009-07-15

    Pressure suppression pool is an important element of BWR containment. It serves as a heat sink and steam condenser to prevent containment pressure buildup during loss of coolant accident or safety relief valve opening during normal operations of a BWR. Insufficient mixing in the pool, in case of low mass flow rate of steam, can cause development of thermal stratification and reduction of pressure suppression pool capacity. For reliable prediction of mixing and stratification phenomena validation of simulation tools has to be performed. Data produced in POOLEX/PPOOLEX facility at Lappeenranta University of Technology about development of thermal stratification in a large scale model of a pressure suppression pool is used for GOTHIC lumped and distributed parameter validation. Sensitivity of GOTHIC solution to different boundary conditions and grid convergence study for 2D simulations of POOLEX STB-20 experiment are performed in the present study. CFD simulation was carried out with FLUENT code in order to get additional insights into physics of stratification phenomena. In order to support development of experimental procedures for new tests in the PPOOLEX facility lumped parameter pre-test GOTHIC simulations were performed. Simulations show that drywell and wetwell pressures can be kept within safety margins during a long transient necessary for development of thermal stratification. (au)

  8. A study on the thermal expansion characteristics of simulated spent fuel and simulated DUPIC fuel

    International Nuclear Information System (INIS)

    Kang, Kweon Ho; Ryu, H. J.; Kim, H. S.; Song, K. C.; Yang, M. S.

    2001-10-01

    Thermal expansions of simulated spent PWR fuel and simulated DUPIC fuel were studied using a dilatometer in the temperature range from 298 to 1900 K. The densities of simulated spent PWR fuel and simulated DUPIC fuel used in the measurement were 10.28 g/cm3 (95.35 % of TD) and 10.26 g/cm3 (95.14 % of TD), respectively. Their linear thermal expansions of simulated fuels are higher than that of UO2, and the difference between these fuels and UO2 increases progressively as temperature increases. However, the difference between simulated spent PWR fuel and simulated DUPIC fuel can hardly be observed. For the temperature range from 298 to 1900 K, the values of the average linear thermal expansion coefficients for simulated spent PWR fuel and simulated DUPIC fuel are 1.391 10-5 and 1.393 10-5 K-1, respectively. As temperature increases to 1900 K, the relative densities of simulated spent PWR fuel and simulated DUPIC fuel decrease to 93.81 and 93.76 % of initial densities at 298 K, respectively

  9. Engineering-Based Thermal CFD Simulations on Massive Parallel Systems

    KAUST Repository

    Frisch, Jérôme

    2015-05-22

    The development of parallel Computational Fluid Dynamics (CFD) codes is a challenging task that entails efficient parallelization concepts and strategies in order to achieve good scalability values when running those codes on modern supercomputers with several thousands to millions of cores. In this paper, we present a hierarchical data structure for massive parallel computations that supports the coupling of a Navier–Stokes-based fluid flow code with the Boussinesq approximation in order to address complex thermal scenarios for energy-related assessments. The newly designed data structure is specifically designed with the idea of interactive data exploration and visualization during runtime of the simulation code; a major shortcoming of traditional high-performance computing (HPC) simulation codes. We further show and discuss speed-up values obtained on one of Germany’s top-ranked supercomputers with up to 140,000 processes and present simulation results for different engineering-based thermal problems.

  10. Nuclear Thermal Rocket Element Environmental Simulator (NTREES) Upgrade Activities

    Science.gov (United States)

    Emrich, William J. Jr.; Moran, Robert P.; Pearson, J. Boise

    2012-01-01

    To support the on-going nuclear thermal propulsion effort, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The facility to perform this testing is referred to as the Nuclear Thermal Rocket Element Environment Simulator (NTREES). This device can simulate the environmental conditions (minus the radiation) to which nuclear rocket fuel components will be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner so as to accurately reproduce the temperatures and heat fluxes which would normally occur as a result of nuclear fission and would be exposed to flowing hydrogen. Initial testing of a somewhat prototypical fuel element has been successfully performed in NTREES and the facility has now been shutdown to allow for an extensive reconfiguration of the facility which will result in a significant upgrade in its capabilities

  11. Semiclassical approach to fidelity amplitude

    International Nuclear Information System (INIS)

    García-Mata, Ignacio; Vallejos, Raúl O; Wisniacki, Diego A

    2011-01-01

    The fidelity amplitude (FA) is a quantity of paramount importance in echo-type experiments. We use semiclassical theory to study the average FA for quantum chaotic systems under external perturbation. We explain analytically two extreme cases: the random dynamics limit - attained approximately by strongly chaotic systems - and the random perturbation limit, which shows a Lyapunov decay. Numerical simulations help us to bridge the gap between both the extreme cases. (paper)

  12. Thermal Fluctuations in Smooth Dissipative Particle Dynamics simulation of mesoscopic thermal systems

    Science.gov (United States)

    Gatsonis, Nikolaos; Yang, Jun

    2013-11-01

    The SDPD-DV is implemented in our work for arbitrary 3D wall bounded geometries. The particle position and momentum equations are integrated with a velocity-Verlet algorithm and the entropy equation is integrated with a Runge-Kutta algorithm. Simulations of nitrogen gas are performed to evaluate the effects of timestep and particle scale on temperature, self-diffusion coefficient and shear viscosity. The hydrodynamic fluctuations in temperature, density, pressure and velocity from the SDPD-DV simulations are evaluated and compared with theoretical predictions. Steady planar thermal Couette flows are simulated and compared with analytical solutions. Simulations cover the hydrodynamic and mesocopic regime and show thermal fluctuations and their dependence on particle size.

  13. Thermal-Hydraulic Simulations of Single Pin and Assembly Sector for IVG- 1M Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Garner, P. [Argonne National Lab. (ANL), Argonne, IL (United States); Hanan, N. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-15

    Thermal-hydraulic simulations have been performed using computational fluid dynamics (CFD) for the highly-enriched uranium (HEU) design of the IVG.1M reactor at the Institute of Atomic Energy (IAE) at the National Nuclear Center (NNC) in the Republic of Kazakhstan. Steady-state simulations were performed for both types of fuel assembly (FA), i.e. the FA in rows 1 & 2 and the FA in row 3, as well as for single pins in those FA (600 mm and 800 mm pins). Both single pin calculations and bundle sectors have been simulated for the most conservative operating conditions corresponding to the 10 MW output power, which corresponds to a pin unit cell Reynolds number of only about 7500. Simulations were performed using the commercial code STAR-CCM+ for the actual twisted pin geometry as well as a straight-pin approximation. Various Reynolds-Averaged Navier-Stokes (RANS) turbulence models gave different results, and so some validation runs with a higher-fidelity Large Eddy Simulation (LES) code were performed given the lack of experimental data. These singled out the Realizable Two-Layer k-ε as the most accurate turbulence model for estimating surface temperature. Single-pin results for the twisted case, based on the average flow rate per pin and peak pin power, were conservative for peak clad surface temperature compared to the bundle results. Also the straight-pin calculations were conservative as compared to the twisted pin simulations, as expected, but the single-pin straight case was not always conservative with regard to the straight-pin bundle. This was due to the straight-pin temperature distribution being strongly influenced by the pin orientation, particularly near the outer boundary. The straight-pin case also predicted the peak temperature to be in a different location than the twisted-pin case. This is a limitation of the straight-pin approach. The peak temperature pin was in a different location from the peak power pin in every case simulated, and occurred at an

  14. Assessment of synthetic image fidelity

    Science.gov (United States)

    Mitchell, Kevin D.; Moorhead, Ian R.; Gilmore, Marilyn A.; Watson, Graham H.; Thomson, Mitch; Yates, T.; Troscianko, Tomasz; Tolhurst, David J.

    2000-07-01

    Computer generated imagery is increasingly used for a wide variety of purposes ranging from computer games to flight simulators to camouflage and sensor assessment. The fidelity required for this imagery is dependent on the anticipated use - for example when used for camouflage design it must be physically correct spectrally and spatially. The rendering techniques used will also depend upon the waveband being simulated, spatial resolution of the sensor and the required frame rate. Rendering of natural outdoor scenes is particularly demanding, because of the statistical variation in materials and illumination, atmospheric effects and the complex geometric structures of objects such as trees. The accuracy of the simulated imagery has tended to be assessed subjectively in the past. First and second order statistics do not capture many of the essential characteristics of natural scenes. Direct pixel comparison would impose an unachievable demand on the synthetic imagery. For many applications, such as camouflage design, it is important that nay metrics used will work in both visible and infrared wavebands. We are investigating a variety of different methods of comparing real and synthetic imagery and comparing synthetic imagery rendered to different levels of fidelity. These techniques will include neural networks (ICA), higher order statistics and models of human contrast perception. This paper will present an overview of the analyses we have carried out and some initial results along with some preliminary conclusions regarding the fidelity of synthetic imagery.

  15. Solar thermal power plants simulation using the TRNSYS software

    Energy Technology Data Exchange (ETDEWEB)

    Popel, O.S.; Frid, S.E.; Shpilrain, E.E. [Institute for High Temperatures, Russian Academy of Sciences (IVTAN), Moscow (Russian Federation)

    1999-03-01

    The paper describes activity directed on the TRNSYS software application for mathematical simulation of solar thermal power plants. First stage of developments has been devoted to simulation and thermodynamic analysis of the Hybrid Solar-Fuel Thermal Power Plants (HSFTPP) with gas turbine installations. Three schemes of HSFTPP, namely: Gas Turbine Regenerative Cycle, Brayton Cycle with Steam Injection and Combined Brayton-Rankine Cycle,- have been assembled and tested under the TRNSYS. For this purpose 18 new models of the schemes components (gas and steam turbines, compressor, heat-exchangers, steam generator, solar receiver, condenser, controllers, etc) have been elaborated and incorporated into the TRNSYS library of 'standard' components. The authors do expect that this initiative and received results will stimulate experts involved in the mathematical simulation of solar thermal power plants to join the described activity to contribute to acceleration of development and expansion of 'Solar Thermal Power Plants' branch of the TRNSYS. The proposed approach could provide an appropriate basis for standardization of analysis, models and assumptions for well-founded comparison of different schemes of advanced solar power plants. (authors)

  16. Internal multi-scale multi-physics coupled system for high fidelity simulation of light water reactors

    International Nuclear Information System (INIS)

    Ivanov, A.; Sanchez, V.; Stieglitz, R.; Ivanov, K.

    2014-01-01

    Highlights: • The current paper focuses on a optimized method for performing coupled Monte-Carlo/thermal–hydraulics calculations. • Innovative on-the-fly method for supplying the temperature and density distributions is presented. • Convergence acceleration method is presented. It is proven applicable by generalizing the Robbins-Monro theorem. • Tallying is optimized by using collision probability estimator for the power profile estimation. - Abstract: In order to increase the accuracy and the degree of spatial and energy resolution of core design studies, coupled 3D neutronic (multi-group deterministic and continuous energy Monte-Carlo) and 3D thermal–hydraulic (CFD and subchannel) codes are being developed worldwide. At KIT, both deterministic and Monte-Carlo codes were coupled with subchannel codes and applied to predict the safety-related design parameters such as minimal critical power ratio (MCPR), maximal cladding and fuel temperature, departure from nuclide boiling ratio (DNBR). These coupling approaches were revised and considerably improved. Innovative method of internal on-the-fly thermal feedback interchange between the codes was implemented. It no longer relies on explicit material definitions and allows the modeling of temperature and density distributions based on the cell coordinates. In contrast to all existing coupled schemes, this method uses only standard MCNP geometry input and requires only proper definition of the geometrical dimensions. The initial material definition is arbitrary and is determined on-the-fly during the neutron transport by the thermal–hydraulic feedback. Another key issue addressed is the optimal application of parallel computing and the implementation of less time consuming tally estimators. Using multi-processor computer architectures and implementing collision density flux estimator, it is possible to reduce the Monte-Carlo running time and obtain converged results within reasonable time limit. The coupled

  17. Fidelity imaging for atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ghosal, Sayan, E-mail: ghos0087@umn.edu; Salapaka, Murti, E-mail: murtis@umn.edu [Nanodynamics Systems Laboratory, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2015-01-05

    Atomic force microscopy is widely employed for imaging material at the nanoscale. However, real-time measures on image reliability are lacking in contemporary atomic force microscopy literature. In this article, we present a real-time technique that provides an image of fidelity for a high bandwidth dynamic mode imaging scheme. The fidelity images define channels that allow the user to have additional authority over the choice of decision threshold that facilitates where the emphasis is desired, on discovering most true features on the sample with the possible detection of high number of false features, or emphasizing minimizing instances of false detections. Simulation and experimental results demonstrate the effectiveness of fidelity imaging.

  18. TO THE QUESTION ABOUT THE SIMULATION OF TURBULENT THERMAL FLOWS

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The main purpose of this work was the simulation of turbulent thermal flows, which is aimed at improving the visualization and the modeling of the flow fields of wind flows, which are necessary for aviation. The physical-mathematical model of gas flow in thermal is proposed on the basis of thermodynamic model and dynamic model under the assumption that the condensation energy, when the movement of the thermal is upward, becomes the turbulent fluctuations. A thermal is an air mass, which goes up and is capable to intermix with ambient air. In the work the thermodynamic model of thermal is presented, the equations and the system of equations are derived, that describe the main characteristics of wind flow, which are required for the modeling of airflows. The generation of vertical turbulent gust with von Karman spectrum is shown. The basic assumption in the construction of the dynamic model of generation was that the energy, which is stood out in the thermal due to the condensation of steam, is converted into the energy of turbulent pulsations. Some examples of numerical simulation are given in the article. The visualizations of the generation of the vertical velocity of random wind gust are given depending on the size of the considered space and depending on the pitch of cell partition. The analysis and comparison of the obtained results of the calculation are presented. The conducted studies are aimed at the simulation of the atmospheric background and atmospheric processes and, in the final result, at the increasing of flight safety.

  19. Advances in Integrated Vehicle Thermal Management and Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-10-01

    Full Text Available With the increasing demands for vehicle dynamic performance, economy, safety and comfort, and with ever stricter laws concerning energy conservation and emissions, vehicle power systems are becoming much more complex. To pursue high efficiency and light weight in automobile design, the power system and its vehicle integrated thermal management (VITM system have attracted widespread attention as the major components of modern vehicle technology. Regarding the internal combustion engine vehicle (ICEV, its integrated thermal management (ITM mainly contains internal combustion engine (ICE cooling, turbo-charged cooling, exhaust gas recirculation (EGR cooling, lubrication cooling and air conditioning (AC or heat pump (HP. As for electric vehicles (EVs, the ITM mainly includes battery cooling/preheating, electric machines (EM cooling and AC or HP. With the rational effective and comprehensive control over the mentioned dynamic devices and thermal components, the modern VITM can realize collaborative optimization of multiple thermodynamic processes from the aspect of system integration. Furthermore, the computer-aided calculation and numerical simulation have been the significant design methods, especially for complex VITM. The 1D programming can correlate multi-thermal components and the 3D simulating can develop structuralized and modularized design. Additionally, co-simulations can virtualize simulation of various thermo-hydraulic behaviors under the vehicle transient operational conditions. This article reviews relevant researching work and current advances in the ever broadening field of modern vehicle thermal management (VTM. Based on the systematic summaries of the design methods and applications of ITM, future tasks and proposals are presented. This article aims to promote innovation of ITM, strengthen the precise control and the performance predictable ability, furthermore, to enhance the level of research and development (R&D.

  20. Thermal Simulation of the Component Rework Profile Temperature

    OpenAIRE

    Nurminen, Janne

    2015-01-01

    The aim of this study was to clarify the possibilities and feasibility of the ther-mal simulation for the modeling of the rework process. The rework process modeling could enable an easy and fast access to the component and PWB level thermally critical effects like over and under heating of the component during the rework process. The modeling could also be used as a help of the real rework profile definition at an early phase of the electrical device development. The work includes a...

  1. Integrated Variable-Fidelity Tool Set For Modeling and Simulation of Aeroservothermoelasticity -Propulsion (ASTE-P) Effects For Aerospace Vehicles Ranging From Subsonic to Hypersonic Flight, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research program aims at developing a variable-fidelity software tool set for aeroservothermoelastic-propulsive (ASTE-P) modeling that can be routinely...

  2. The thermal pressure distribution of a simulated cold neutral medium

    Energy Technology Data Exchange (ETDEWEB)

    Gazol, Adriana, E-mail: a.gazol@crya.unam.mx [Centro de Radioastronomía y Astrofísica, UNAM, A. P. 3-72, c.p. 58089 Morelia, Michoacán (Mexico)

    2014-07-01

    We numerically study the thermal pressure distribution in a gas with thermal properties similar to those of the cold neutral interstellar gas by analyzing three-dimensional hydrodynamic models in boxes with sides of 100 pc with turbulent compressible forcing at 50 pc and different Mach numbers. We find that at high pressures and for large Mach numbers, both the volume-weighted and the density-weighted distributions can be appropriately described by a log-normal distribution, whereas for small Mach numbers they are better described by a power law. Thermal pressure distributions resulting from similar simulations but with self-gravity differ only for low Mach numbers; in this case, they develop a high pressure tail.

  3. Thermal unit availability modeling in a regional simulation model

    International Nuclear Information System (INIS)

    Yamayee, Z.A.; Port, J.; Robinett, W.

    1983-01-01

    The System Analysis Model (SAM) developed under the umbrella of PNUCC's System Analysis Committee is capable of simulating the operation of a given load/resource scenario. This model employs a Monte-Carlo simulation to incorporate uncertainties. Among uncertainties modeled is thermal unit availability both for energy simulation (seasonal) and capacity simulations (hourly). This paper presents the availability modeling in the capacity and energy models. The use of regional and national data in deriving the two availability models, the interaction between the two and modifications made to the capacity model in order to reflect regional practices is presented. A sample problem is presented to show the modification process. Results for modeling a nuclear unit using NERC-GADS is presented

  4. Simulation of Thermal Hydraulic at Supercritical Pressures with APROS

    Energy Technology Data Exchange (ETDEWEB)

    Kurki, Joona [VTT Technical Research Centre of Finland, P.O. Box 1000, FI02044 VTT (Finland)

    2008-07-01

    The proposed concepts for the fourth generation of nuclear reactors include a reactor operating with water at thermodynamically supercritical state, the Supercritical Water Reactor (SCWR). For the design and safety demonstrations of such a reactor, the possibility to accurately simulate the thermal hydraulics of the supercritical coolant is an absolute prerequisite. For this purpose, the one-dimensional two-phase thermal hydraulics solution of APROS process simulation software was developed to function at the supercritical pressure region. Software modifications included the redefinition of some parameters that have physical significance only at the subcritical pressures, improvement of the steam tables, and addition of heat transfer and friction correlations suitable for the supercritical pressure region. (author)

  5. Thermal properties of graphene from path-integral simulations

    Science.gov (United States)

    Herrero, Carlos P.; Ramírez, Rafael

    2018-03-01

    Thermal properties of graphene monolayers are studied by path-integral molecular dynamics simulations, which take into account the quantization of vibrational modes in the crystalline membrane and allow one to consider anharmonic effects in these properties. This system was studied at temperatures in the range from 12 to 2000 K and zero external stress, by describing the interatomic interactions through the LCBOPII effective potential. We analyze the internal energy and specific heat and compare the results derived from the simulations with those yielded by a harmonic approximation for the vibrational modes. This approximation turns out to be rather precise up to temperatures of about 400 K. At higher temperatures, we observe an influence of the elastic energy due to the thermal expansion of the graphene sheet. Zero-point and thermal effects on the in-plane and "real" surface of graphene are discussed. The thermal expansion coefficient α of the real area is found to be positive at all temperatures, in contrast to the expansion coefficient αp of the in-plane area, which is negative at low temperatures and becomes positive for T ≳ 1000 K.

  6. Modeling and simulation of thermally actuated bilayer plates

    Science.gov (United States)

    Bartels, Sören; Bonito, Andrea; Muliana, Anastasia H.; Nochetto, Ricardo H.

    2018-02-01

    We present a mathematical model of polymer bilayers that undergo large bending deformations when actuated by non-mechanical stimuli such as thermal effects. The simple model captures a large class of nonlinear bending effects and can be discretized with standard plate elements. We devise a fully practical iterative scheme and apply it to the simulation of folding of several practically useful compliant structures comprising of thin elastic layers.

  7. thermal characteristics of a simulated non-radioactive agricultural waste

    International Nuclear Information System (INIS)

    Ahmed, A.Z.; Soliman, H.M.; Abdelmoniem, M.

    2004-01-01

    characterization of thermal degradation of a mixture of a simulated non radioactive contaminated almond shell and cotton straw is important to check possibility of its safe treatment by pyrolysis. thermal analysis of the mixture was carried out using thermal gravimetric analysis (TGA) under inert atmosphere. thermal degradation of almond shell and cotton straw mixture takes place in two stages namely, volatilization stage and decarbonization stage. kinetics of the thermal degradation was studied to determine the reaction rate, activation energy, entropy change, enthalpy change and free energy for both stages. during pyrolysis, 5.8% water Vapor, 46.4% condensed gases, 29.2% condensed gases, and 18.6% pyrolysis coke residue by weight were obtained . analysis of pyrolysis condensed gases showed that it contained 24.2% N 2 ,7.1% CO, 14% H 2 and 17.3 CO 2 by weight. in addition, results revealed that the heavy elements are concentrated in the coke residue. it was found that the rate constant of the reacion increases by the increase in the temperature for both sages. more above, results revealed that the activation energy for volatilization stage is higher than decarbonization stage

  8. Practical considerations in developing numerical simulators for thermal recovery

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, Al-Ain (United Arab Emirates)

    1996-08-15

    Numerical simulation of steam injection and in-situ combustion-based oil recovery processes is of great importance in project design. Development of such numerical simulators is an on-going process, with improvements made as the process description becomes more complete, and also as better methods are devised to resolve certain numerical difficulties. This paper addresses some of the latter, and based on the author`s experience gives useful guidelines for developing more efficient numerical simulators of steam injection and in-situ combustion. The paper takes up a series of questions related to simulating thermal processes. Included are: the elimination of constraint equations at the matrix level, phase change, steam injection rate, alternative treatments of heat loss, relative permeabilities and importance of hysteresis effects, improved solutions to the grid orientation problem and other simulation problems such as potential inversion, grid block size, time-step size control and induced fractures. The points discussed in the paper should be of use to both simulator developers and users alike, and will lead to a better understanding of simulation results

  9. Can Telemedicine Improve Adherence to Resuscitation Guidelines for Critically Ill Children at Community Hospitals? A Randomized Controlled Trial Using High-Fidelity Simulation.

    Science.gov (United States)

    Yang, Chris P; Hunt, Elizabeth A; Shilkofski, Nicole; Dudas, Robert; Egbuta, Chinyere; Schwartz, Jamie M

    2017-07-01

    Children transferred from community hospitals lacking specialized pediatric care are more seriously ill than those presenting to pediatric centers. Pediatric consultation and adherence to management guidelines improve outcomes. The aims of the study were (1) to assess whether telemedicine consultation in critical situations is feasible and (2) to compare the impact of pediatric critical care medicine (PCCM) consultation via telemedicine versus telephone on community hospital adherence to resuscitation guidelines through a randomized controlled telemedicine trial. In situ, high-fidelity simulation scenarios of critically ill children presenting to a community hospital and progressing to cardiopulmonary arrest were performed. Scenarios were randomized to PCCM consultation via telephone (control) or telemedicine (intervention). Primary outcome measure was proportion of teams who successfully defibrillated in 180 seconds or less from presentation of pulseless ventricular tachycardia. The following 30 scenarios were completed: 15 control and 15 intervention. Only 11 (37%) of 30 teams, defibrillated in 180 seconds or less from presentation of pulseless ventricular tachycardia; control: 6 (40%) of 15 versus intervention: 5 (33%) of 15, P = 0.7. Request for or use of backboard during cardiopulmonary resuscitation occurred in 24 (80%) of 30 scenarios; control: 9 (60%) of 15 versus intervention: 15 (100%) of 15, P = 0.006. Request for or use of stepstool during cardiopulmonary resuscitation occurred in 6 (20%) of 30 scenarios; control: 1 (7%) of 15 versus intervention: 5 (33%) of 15, P = 0.07. This study demonstrates the feasibility of using telemedicine to support acute management of children who present to community hospitals. Neither study arm adhered to current resuscitation guidelines and telemedicine consultation with PCCM experts was not associated with improvement. However, further research on optimizing telemedicine impact on the quality of pediatric care at

  10. Minerve: thermal-hydraulic phenomena simulation and virtual reality

    International Nuclear Information System (INIS)

    Laffont, A.; Pentori, B.

    2003-01-01

    MINERVE is a 3D interactive application representing the thermal-hydraulic phenomena happening in a nuclear plant. Therefore, the 3D geometric model of the French 900 MW PWR installations has been built. The users can interact in real time with this model to see at each step of the simulation what happens in the pipes. The thermal-hydraulic simulation is made by CATHARE-2, which calculates at every time step data on about one thousand meshes (the whole primary circuit, a part of the second circuit, and the Residual Heat Removal System). The simulation covers incidental and accidental cases on these systems. There are two main innovations in MINERVE: In the domain of nuclear plant's visualization, it is to introduce interactive 3D software mechanisms to visualize results of a physical simulation. In the domain of real-time 3D, it is to visualize fluids in a pipe, while they can have several configurations, like bubbles or single liquid phase. These mechanisms enable better comprehension and better visual representation of the possible phenomena. This paper describes the functionalities of MINERVE, and the difficulties to represent fluids with several characteristics like speed, configuration,..., in 3D. On the end, we talk about the future of MINERVE, and more widely of the possible futures of such an application in scientific visualization. (authors)

  11. Minerve: thermal-hydraulic phenomena simulation and virtual reality

    Energy Technology Data Exchange (ETDEWEB)

    Laffont, A.; Pentori, B. [EDF R and D, EDF SEPTEN Electricity of France - Research and Development, Department SINETICS, 92 - Clamart (France)

    2003-07-01

    MINERVE is a 3D interactive application representing the thermal-hydraulic phenomena happening in a nuclear plant. Therefore, the 3D geometric model of the French 900 MW PWR installations has been built. The users can interact in real time with this model to see at each step of the simulation what happens in the pipes. The thermal-hydraulic simulation is made by CATHARE-2, which calculates at every time step data on about one thousand meshes (the whole primary circuit, a part of the second circuit, and the Residual Heat Removal System). The simulation covers incidental and accidental cases on these systems. There are two main innovations in MINERVE: In the domain of nuclear plant's visualization, it is to introduce interactive 3D software mechanisms to visualize results of a physical simulation. In the domain of real-time 3D, it is to visualize fluids in a pipe, while they can have several configurations, like bubbles or single liquid phase. These mechanisms enable better comprehension and better visual representation of the possible phenomena. This paper describes the functionalities of MINERVE, and the difficulties to represent fluids with several characteristics like speed, configuration,..., in 3D. On the end, we talk about the future of MINERVE, and more widely of the possible futures of such an application in scientific visualization. (authors)

  12. Development of the McGill simulator for endoscopic sinus surgery: a new high-fidelity virtual reality simulator for endoscopic sinus surgery.

    Science.gov (United States)

    Varshney, Rickul; Frenkiel, Saul; Nguyen, Lily H P; Young, Meredith; Del Maestro, Rolando; Zeitouni, Anthony; Tewfik, Marc A

    2014-01-01

    The technical challenges of endoscopic sinus surgery (ESS) and the high risk of complications support the development of alternative modalities to train residents in these procedures. Virtual reality simulation is becoming a useful tool for training the skills necessary for minimally invasive surgery; however, there are currently no ESS virtual reality simulators available with valid evidence supporting their use in resident education. Our aim was to develop a new rhinology simulator, as well as to define potential performance metrics for trainee assessment. The McGill simulator for endoscopic sinus surgery (MSESS), a new sinus surgery virtual reality simulator with haptic feedback, was developed (a collaboration between the McGill University Department of Otolaryngology-Head and Neck Surgery, the Montreal Neurologic Institute Simulation Lab, and the National Research Council of Canada). A panel of experts in education, performance assessment, rhinology, and skull base surgery convened to identify core technical abilities that would need to be taught by the simulator, as well as performance metrics to be developed and captured. The MSESS allows the user to perform basic sinus surgery skills, such as an ethmoidectomy and sphenoidotomy, through the use of endoscopic tools in a virtual nasal model. The performance metrics were developed by an expert panel and include measurements of safety, quality, and efficiency of the procedure. The MSESS incorporates novel technological advancements to create a realistic platform for trainees. To our knowledge, this is the first simulator to combine novel tools such as the endonasal wash and elaborate anatomic deformity with advanced performance metrics for ESS.

  13. Simulation, optimization and control of a thermal cracking furnace

    International Nuclear Information System (INIS)

    Masoumi, M.E.; Sadrameli, S.M.; Towfighi, J.; Niaei, A.

    2006-01-01

    The ethylene production process is one of the most important aspect of a petrochemical plant and the cracking furnace is the heart of the process. Since, ethylene is one of the raw materials in the chemical industry and the market situation of not only the feed and the product, but also the utility is rapidly changing, the optimal operation and control of the plant is important. A mathematical model, which describes the static and dynamic operations of a pilot plant furnace, was developed. The static simulation was used to predict the steady-state profiles of temperature, pressure and products yield. The dynamic simulation of the process was used to predict the transient behavior of thermal cracking reactor. Using a dynamic programming technique, an optimal temperature profile was developed along the reactor. Performances of temperature control loop were tested for different controller parameters and disturbances. The results of the simulation were tested experimentally in a computer control pilot plant

  14. Simulator Fidelity: A Concept Paper

    Science.gov (United States)

    1980-11-01

    training programs, it should be possible to screen out those trainees who do not possess the required abilities to benefit from a given training program...PTZ!L-CAC-IM I USACAC ýITN:Z ArIL-CA(.-IA I IJSAC&%CUA ArrIN’ AT?D.--CAC-A 1 UiSA i.LICTHONIC WAqFAHk LAd CHILI INTLLLIGENCE MAYER nEVEL SUPP OFF I

  15. High-fidelity simulation-based team training in urology: evaluation of technical and nontechnical skills of urology residents during laparoscopic partial nephrectomy.

    Science.gov (United States)

    Abdelshehid, Corollos S; Quach, Stephen; Nelson, Corey; Graversen, Joseph; Lusch, Achim; Zarraga, Jerome; Alipanah, Reza; Landman, Jaime; McDougall, Elspeth M

    2013-01-01

    The use of low-risk simulation training for resident education is rapidly expanding as teaching centers integrate simulation-based team training (SBTT) sessions into their education curriculum. SBTT is a valuable tool in technical and communication skills training and assessment for residents. We created a unique SBTT scenario for urology residents involving a laparoscopic partial nephrectomy procedure. Urology residents were randomly paired with a certified registered nurse anesthetists or an anesthesia resident. The scenario incorporated a laparoscopic right partial nephrectomy utilizing a unique polyvinyl alcohol kidney model with an embedded 3cm lower pole exophytic tumor and the high-fidelity SimMan3G mannequin. The Urology residents were instructed to pay particular attention to the patient's identifying information provided at the beginning of the case. Two scripted events occurred, the patient had an anaphylactic reaction to a drug and, after tumor specimen was sent for a frozen section, the confederate pathologist called into the operating room (OR) twice, first with the wrong patient name and subsequently with the wrong specimen. After the scenario was complete, technical performance and nontechnical performance were evaluated and assessed. A debriefing session followed the scenario to discuss and assess technical performance and interdisciplinary nontechnical communication between the team. All Urology residents (n = 9) rated the SBTT scenario as a useful tool in developing communication skills among the OR team and 88% rated the model as useful for technical skills training. Despite cuing to note patient identification, only 3 of 9 (33%) participants identified that the wrong patient information was presented when the confederate "pathologist" called in to report pathology results. All urology residents rated SBTT sessions as useful for the development of communication skills between different team members and making residents aware of unlikely but

  16. MATLAB Simulation of Photovoltaic and Photovoltaic/Thermal Systems Performance

    Science.gov (United States)

    Nasir, Farah H. M.; Husaini, Yusnira

    2018-03-01

    The efficiency of the photovoltaic reduces when the photovoltaic cell temperature increased due to solar irradiance. One solution is come up with the cooling system photovoltaic system. This combination is forming the photovoltaic-thermal (PV/T) system. Not only will it generate electricity also heat at the same time. The aim of this research is to focus on the modeling and simulation of photovoltaic (PV) and photovoltaic-thermal (PV/T) electrical performance by using single-diode equivalent circuit model. Both PV and PV/T models are developed in Matlab/Simulink. By providing the cooling system in PV/T, the efficiency of the system can be increased by decreasing the PV cell temperature. The maximum thermal, electrical and total efficiency values of PV/T in the present research are 35.18%, 15.56% and 50.74% at solar irradiance of 400 W/m2, mass flow rate of 0.05kgs-1 and inlet temperature of 25 °C respectively has been obtained. The photovoltaic-thermal shows that the higher efficiency performance compared to the photovoltaic system.

  17. Simulation and test of the thermal behavior of pressure switch

    Science.gov (United States)

    Liu, Yifang; Chen, Daner; Zhang, Yao; Dai, Tingting

    2018-04-01

    Little, lightweight, low-power microelectromechanical system (MEMS) pressure switches offer a good development prospect for small, ultra-long, simple atmosphere environments. In order to realize MEMS pressure switch, it is necessary to solve one of the key technologies such as thermal robust optimization. The finite element simulation software is used to analyze the thermal behavior of the pressure switch and the deformation law of the pressure switch film under different temperature. The thermal stress releasing schemes are studied by changing the structure of fixed form and changing the thickness of the substrate, respectively. Finally, the design of the glass substrate thickness of 2.5 mm is used to ensure that the maximum equivalent stress is reduced to a quarter of the original value, only 154 MPa when the structure is in extreme temperature (80∘C). The test results show that after the pressure switch is thermally optimized, the upper and lower electrodes can be reliably contacted to accommodate different operating temperature environments.

  18. Thermal System Upgrade of the Space Environment Simulation Test Chamber

    Science.gov (United States)

    Desai, Ashok B.

    1997-01-01

    The paper deals with the refurbishing and upgrade of the thermal system for the existing thermal vacuum test facility, the Space Environment Simulator, at NASA's Goddard Space Flight Center. The chamber is the largest such facility at the center. This upgrade is the third phase of the long range upgrade of the chamber that has been underway for last few years. The first phase dealt with its vacuum system, the second phase involved the GHe subsystem. The paper describes the considerations of design philosophy options for the thermal system; approaches taken and methodology applied, in the evaluation of the remaining "life" in the chamber shrouds and related equipment by conducting special tests and studies; feasibility and extent of automation, using computer interfaces and Programmable Logic Controllers in the control system and finally, matching the old components to the new ones into an integrated, highly reliable and cost effective thermal system for the facility. This is a multi-year project just started and the paper deals mainly with the plans and approaches to implement the project successfully within schedule and costs.

  19. Large Eddy Simulation of a thermal mixing tee in order to assess the thermal fatigue

    International Nuclear Information System (INIS)

    Galpin, J.; Simoneau, J.P.

    2011-01-01

    Highlights: → In this study, we perform a Large Eddy Simulation of a mixing tee, for which experimental thermal statistics are available. → A special methodology has been set up for comparing properly the fluctuations with the experiment. → A comparison between the Smagorinsky and the structure-function sub-grid scale model is achieved out. → Slight better predictions are obtained with the structure-function model. → The possibility to reduce the computational domain by prescribing synthetic turbulence at the inlet is tested. First results are encouraging and underline the advantage of considering this technique instead of a standard noise at the entrance of the domain. - Abstract: The present paper deals with thermal fatigue phenomenon, and more particularly with the numerical simulation using Large Eddy Simulation technique of a mixing tee, for which experimental thermal statistics are available. The sensitivity to the sub-grid scale closure is first evaluated by comparing the experimental statistics with the numerical results obtained via both the Smagorinsky and the structure-function models. Because of a difference of temporal resolution between the experiment and the simulation, the direct comparison of the fluctuations is not possible. Therefore, a methodology based on filtering the numerical results is proposed in order to achieve a proper comparison. The comparison of the numerical results with the experiment suggests that slight better predictions are obtained with the structure-function model even if the dependency of the results to the sub-grid scale model is low. Then, the possibility to reduce the fluid computational domain by prescribing synthetic turbulence at the inlet is tested. First results are encouraging and underline the advantage of considering this technique instead of a standard noise at the entrance of the domain. All the simulations are conducted with the commercial CFD code STAR-CD.

  20. Simulation of electron thermal transport in H-mode discharges

    International Nuclear Information System (INIS)

    Rafiq, T.; Pankin, A. Y.; Bateman, G.; Kritz, A. H.; Halpern, F. D.

    2009-01-01

    Electron thermal transport in DIII-D H-mode tokamak plasmas [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] is investigated by comparing predictive simulation results for the evolution of electron temperature profiles with experimental data. The comparison includes the entire profile from the magnetic axis to the bottom of the pedestal. In the simulations, carried out using the automated system for transport analysis (ASTRA) integrated modeling code, different combinations of electron thermal transport models are considered. The combinations include models for electron temperature gradient (ETG) anomalous transport and trapped electron mode (TEM) anomalous transport, as well as a model for paleoclassical transport [J. D. Callen, Nucl. Fusion 45, 1120 (2005)]. It is found that the electromagnetic limit of the Horton ETG model [W. Horton et al., Phys. Fluids 31, 2971 (1988)] provides an important contribution near the magnetic axis, which is a region where the ETG mode in the GLF23 model [R. E. Waltz et al., Phys. Plasmas 4, 2482 (1997)] is below threshold. In simulations of DIII-D discharges, the observed shape of the H-mode edge pedestal is produced when transport associated with the TEM component of the GLF23 model is suppressed and transport given by the paleoclassical model is included. In a study involving 15 DIII-D H-mode discharges, it is found that with a particular combination of electron thermal transport models, the average rms deviation of the predicted electron temperature profile from the experimental profile is reduced to 9% and the offset to -4%.

  1. Development of a Reduced-Order Three-Dimensional Flow Model for Thermal Mixing and Stratification Simulation during Reactor Transients

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Rui

    2017-09-03

    Mixing, thermal-stratification, and mass transport phenomena in large pools or enclosures play major roles for the safety of reactor systems. Depending on the fidelity requirement and computational resources, various modeling methods, from the 0-D perfect mixing model to 3-D Computational Fluid Dynamics (CFD) models, are available. Each is associated with its own advantages and shortcomings. It is very desirable to develop an advanced and efficient thermal mixing and stratification modeling capability embedded in a modern system analysis code to improve the accuracy of reactor safety analyses and to reduce modeling uncertainties. An advanced system analysis tool, SAM, is being developed at Argonne National Laboratory for advanced non-LWR reactor safety analysis. While SAM is being developed as a system-level modeling and simulation tool, a reduced-order three-dimensional module is under development to model the multi-dimensional flow and thermal mixing and stratification in large enclosures of reactor systems. This paper provides an overview of the three-dimensional finite element flow model in SAM, including the governing equations, stabilization scheme, and solution methods. Additionally, several verification and validation tests are presented, including lid-driven cavity flow, natural convection inside a cavity, laminar flow in a channel of parallel plates. Based on the comparisons with the analytical solutions and experimental results, it is demonstrated that the developed 3-D fluid model can perform very well for a wide range of flow problems.

  2. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC): gap analysis for high fidelity and performance assessment code development

    International Nuclear Information System (INIS)

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-01-01

    needed for repository modeling are severely lacking. In addition, most of existing reactive transport codes were developed for non-radioactive contaminants, and they need to be adapted to account for radionuclide decay and in-growth. The accessibility to the source codes is generally limited. Because the problems of interest for the Waste IPSC are likely to result in relatively large computational models, a compact memory-usage footprint and a fast/robust solution procedure will be needed. A robust massively parallel processing (MPP) capability will also be required to provide reasonable turnaround times on the analyses that will be performed with the code. A performance assessment (PA) calculation for a waste disposal system generally requires a large number (hundreds to thousands) of model simulations to quantify the effect of model parameter uncertainties on the predicted repository performance. A set of codes for a PA calculation must be sufficiently robust and fast in terms of code execution. A PA system as a whole must be able to provide multiple alternative models for a specific set of physical/chemical processes, so that the users can choose various levels of modeling complexity based on their modeling needs. This requires PA codes, preferably, to be highly modularized. Most of the existing codes have difficulties meeting these requirements. Based on the gap analysis results, we have made the following recommendations for the code selection and code development for the NEAMS waste IPSC: (1) build fully coupled high-fidelity THCMBR codes using the existing SIERRA codes (e.g., ARIA and ADAGIO) and platform, (2) use DAKOTA to build an enhanced performance assessment system (EPAS), and build a modular code architecture and key code modules for performance assessments. The key chemical calculation modules will be built by expanding the existing CANTERA capabilities as well as by extracting useful components from other existing codes.

  3. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    needed for repository modeling are severely lacking. In addition, most of existing reactive transport codes were developed for non-radioactive contaminants, and they need to be adapted to account for radionuclide decay and in-growth. The accessibility to the source codes is generally limited. Because the problems of interest for the Waste IPSC are likely to result in relatively large computational models, a compact memory-usage footprint and a fast/robust solution procedure will be needed. A robust massively parallel processing (MPP) capability will also be required to provide reasonable turnaround times on the analyses that will be performed with the code. A performance assessment (PA) calculation for a waste disposal system generally requires a large number (hundreds to thousands) of model simulations to quantify the effect of model parameter uncertainties on the predicted repository performance. A set of codes for a PA calculation must be sufficiently robust and fast in terms of code execution. A PA system as a whole must be able to provide multiple alternative models for a specific set of physical/chemical processes, so that the users can choose various levels of modeling complexity based on their modeling needs. This requires PA codes, preferably, to be highly modularized. Most of the existing codes have difficulties meeting these requirements. Based on the gap analysis results, we have made the following recommendations for the code selection and code development for the NEAMS waste IPSC: (1) build fully coupled high-fidelity THCMBR codes using the existing SIERRA codes (e.g., ARIA and ADAGIO) and platform, (2) use DAKOTA to build an enhanced performance assessment system (EPAS), and build a modular code architecture and key code modules for performance assessments. The key chemical calculation modules will be built by expanding the existing CANTERA capabilities as well as by extracting useful components from other existing codes.

  4. Fidelity deviation in quantum teleportation

    OpenAIRE

    Bang, Jeongho; Ryu, Junghee; Kaszlikowski, Dagomir

    2018-01-01

    We analyze the performance of quantum teleportation in terms of average fidelity and fidelity deviation. The average fidelity is defined as the average value of the fidelities over all possible input states and the fidelity deviation is their standard deviation, which is referred to as a concept of fluctuation or universality. In the analysis, we find the condition to optimize both measures under a noisy quantum channel---we here consider the so-called Werner channel. To characterize our resu...

  5. Thermal lattice Boltzmann simulation for multispecies fluid equilibration

    International Nuclear Information System (INIS)

    Vahala, Linda; Wah, Darren; Vahala, George; Carter, Jonathan; Pavlo, Pavol

    2000-01-01

    The equilibration rate for multispecies fluids is examined using thermal lattice Boltzmann simulations. Two-dimensional free-decay simulations are performed for effects of velocity shear layer turbulence on sharp temperature profiles. In particular, parameters are so chosen that the lighter species is turbulent while the heavier species is laminar--and so its vorticity layers would simply decay and diffuse in time. With species coupling, however, there is velocity equilibration followed by the final relaxation to one large co- and one large counter-rotating vortex. The temperature equilibration proceeds on a slower time scale and is in good agreement with the theoretical order of magnitude estimate of Morse [Phys. Fluids 6, 1420 (1963)]. (c) 2000 The American Physical Society

  6. Thermal lattice Boltzmann simulation for multispecies fluid equilibration

    Energy Technology Data Exchange (ETDEWEB)

    Vahala, Linda [Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States); Wah, Darren [Department of Physics, William and Mary College, Williamsburg, Virginia 23187 (United States); Vahala, George [Department of Physics, William and Mary College, Williamsburg, Virginia 23187 (United States); Carter, Jonathan [NERSC, Lawrence Berkeley Laboratory, Berkeley, California 97320 (United States); Pavlo, Pavol [Institute of Plasma Physics, Czech Academy of Science, Praha 8, (Czech Republic)

    2000-07-01

    The equilibration rate for multispecies fluids is examined using thermal lattice Boltzmann simulations. Two-dimensional free-decay simulations are performed for effects of velocity shear layer turbulence on sharp temperature profiles. In particular, parameters are so chosen that the lighter species is turbulent while the heavier species is laminar--and so its vorticity layers would simply decay and diffuse in time. With species coupling, however, there is velocity equilibration followed by the final relaxation to one large co- and one large counter-rotating vortex. The temperature equilibration proceeds on a slower time scale and is in good agreement with the theoretical order of magnitude estimate of Morse [Phys. Fluids 6, 1420 (1963)]. (c) 2000 The American Physical Society.

  7. CFD simulation of a cabin thermal environment with and without human body - thermal comfort evaluation

    Science.gov (United States)

    Danca, Paul; Bode, Florin; Nastase, Ilinca; Meslem, Amina

    2018-02-01

    Nowadays, thermal comfort became one of the criteria in choosing a vehicle. In last decades time spent by people in vehicles had risen substantially. During each trip, thermal comfort must to be ensured for a good psychological and physical state of the passengers. Also, a comfortable environment leads to a higher power concentration of the driver thereby to a safe trip for vehicle occupants and for all traffic participants. The present study numerically investigated the effect of human body sited in the driver's place, over the air velocity distribution and over the thermal comfort in a passenger compartment. CFD simulations were made with different angles of the left inlet grill, in both cases, with and without driver presence. In majority of the actual vehicles environment studies, are made without consideration of human body geometry, in this case, the results precision can be affected. The results show that the presence of human body, lead to global changing of the whole flow pattern inside the vehicular cabin. Also, the locations of the maximum velocities are changing with the angle of the guiding vanes. The thermal comfort PMV/PPD indexes were calculated for each case. The presence of human body leads to a more comfortable environment.

  8. Numerical Simulation of Non-Thermal Food Preservation

    Science.gov (United States)

    Rauh, C.; Krauss, J.; Ertunc, Ö.; Delgado, a.

    2010-09-01

    Food preservation is an important process step in food technology regarding product safety and product quality. Novel preservation techniques are currently developed, that aim at improved sensory and nutritional value but comparable safety than in conventional thermal preservation techniques. These novel non-thermal food preservation techniques are based for example on high pressures up to one GPa or pulsed electric fields. in literature studies the high potential of high pressures (HP) and of pulsed electric fields (PEF) is shown due to their high retention of valuable food components as vitamins and flavour and selective inactivation of spoiling enzymes and microorganisms. for the design of preservation processes based on the non-thermal techniques it is crucial to predict the effect of high pressure and pulsed electric fields on the food components and on the spoiling enzymes and microorganisms locally and time-dependent in the treated product. Homogenous process conditions (especially of temperature fields in HP and PEF processing and of electric fields in PEF) are aimed at to avoid the need of over-processing and the connected quality loss and to minimize safety risks due to under-processing. the present contribution presents numerical simulations of thermofluiddynamical phenomena inside of high pressure autoclaves and pulsed electric field treatment chambers. in PEF processing additionally the electric fields are considered. Implementing kinetics of occurring (bio-) chemical reactions in the numerical simulations of the temperature, flow and electric fields enables the evaluation of the process homogeneity and efficiency connected to different process parameters of the preservation techniques. Suggestions to achieve safe and high quality products are concluded out of the numerical results.

  9. Fidelity of quantum interferometers

    International Nuclear Information System (INIS)

    Bahder, Thomas B.; Lopata, Paul A.

    2006-01-01

    For a generic interferometer, the conditional probability density distribution p(φ|m), for the phase φ given measurement outcome m will generally have multiple peaks. Therefore, the phase sensitivity of an interferometer cannot be adequately characterized by the standard deviation, such as Δφ∼1/√(N) (the standard limit), or Δφ∼1/N (the Heisenberg limit). We propose an alternative measure of phase sensitivity--the fidelity of an interferometer--defined as the Shannon mutual information between the phase shift φ and the measurement outcomes m. As an example application of interferometer fidelity, we consider a generic optical Mach-Zehnder interferometer, used as a sensor of a classical field. For the case where there exists no a priori information on the phase shift, we find the surprising result that maximally entangled state input leads to a lower fidelity than Fock state input, for the same photon number

  10. Simulation and parametric optimisation of thermal power plant cycles

    Directory of Open Access Journals (Sweden)

    P. Ravindra Kumar

    2016-09-01

    Full Text Available The objective of the paper is to analyse parametric studies and optimum steam extraction pressures of three different (subcritical, supercritical and ultra-supercritical coal fired power plant cycles at a particular main steam temperature of 600 °C by keeping the reheat temperature at 537 °C and condenser pressure at 0.09 bar as constant. In order to maximize the heat rate gain possible with supercritical and ultra-supercritical steam conditions, eight stages of feed water heater arrangement with single reheater is considered. The system is optimized in such a way that the percentage exergetic losses are reduced for the increase of the exergetic efficiency and higher fuel utilization. The plant cycles are simulated and optimized by using Cycle Tempo 5.0 simulation software tool. From the simulation study, it is observed that the thermal efficiency of the three different power plant cycles obtained as 41.40, 42.48 and 43.03%, respectively. The specific coal consumption for three different power plant cycles are 0.56, 0.55 and 0.54 Tonnes/MWh. The improvement in feed water temperatures at the inlet of steam generator of respective cycles are 291, 305 and 316 °C.

  11. A Temperature-Dependent Thermal Model of IGBT Modules Suitable for Circuit-Level Simulations

    DEFF Research Database (Denmark)

    Wu, Rui; Wang, Huai; Pedersen, Kristian Bonderup

    2016-01-01

    A basic challenge in the IGBT transient simulation study is to obtain the realistic junction temperature, which demands not only accurate electrical simulations but also precise thermal impedance. This paper proposed a transient thermal model for IGBT junction temperature simulations during short...

  12. Initial Operation of the Nuclear Thermal Rocket Element Environmental Simulator

    Science.gov (United States)

    Emrich, William J., Jr.; Pearson, J. Boise; Schoenfeld, Michael P.

    2015-01-01

    The Nuclear Thermal Rocket Element Environmental Simulator (NTREES) facility is designed to perform realistic non-nuclear testing of nuclear thermal rocket (NTR) fuel elements and fuel materials. Although the NTREES facility cannot mimic the neutron and gamma environment of an operating NTR, it can simulate the thermal hydraulic environment within an NTR fuel element to provide critical information on material performance and compatibility. The NTREES facility has recently been upgraded such that the power capabilities of the facility have been increased significantly. At its present 1.2 MW power level, more prototypical fuel element temperatures nay now be reached. The new 1.2 MW induction heater consists of three physical units consisting of a transformer, rectifier, and inverter. This multiunit arrangement facilitated increasing the flexibility of the induction heater by more easily allowing variable frequency operation. Frequency ranges between 20 and 60 kHz can accommodated in the new induction heater allowing more representative power distributions to be generated within the test elements. The water cooling system was also upgraded to so as to be capable of removing 100% of the heat generated during testing In this new higher power configuration, NTREES will be capable of testing fuel elements and fuel materials at near-prototypic power densities. As checkout testing progressed and as higher power levels were achieved, several design deficiencies were discovered and fixed. Most of these design deficiencies were related to stray RF energy causing various components to encounter unexpected heating. Copper shielding around these components largely eliminated these problems. Other problems encountered involved unexpected movement in the coil due to electromagnetic forces and electrical arcing between the coil and a dummy test article. The coil movement and arcing which were encountered during the checkout testing effectively destroyed the induction coil in use at

  13. Mathematical modeling and simulation of a thermal system

    Science.gov (United States)

    Toropoc, Mirela; Gavrila, Camelia; Frunzulica, Rodica; Toma, Petrica D.

    2016-12-01

    The aim of the present paper is the conception of a mathematical model and simulation of a system formed by a heatexchanger for domestic hot water preparation, a storage tank for hot water and a radiator, starting from the mathematical equations describing this system and developed using Scilab-Xcos program. The model helps to determine the evolution in time for the hot water temperature, for the return temperature in the primary circuit of the heat exchanger, for the supply temperature in the secondary circuit, the thermal power for heating and for hot water preparation to the consumer respectively. In heating systems, heat-exchangers have an important role and their performances influence the energy efficiency of the systems. In the meantime, it is very important to follow the behavior of such systems in dynamic regimes. Scilab-Xcos program can be utilized to follow the important parameters of the systems in different functioning scenarios.

  14. Computer aided analysis, simulation and optimisation of thermal sterilisation processes.

    Science.gov (United States)

    Narayanan, C M; Banerjee, Arindam

    2013-04-01

    Although thermal sterilisation is a widely employed industrial process, little work is reported in the available literature including patents on the mathematical analysis and simulation of these processes. In the present work, software packages have been developed for computer aided optimum design of thermal sterilisation processes. Systems involving steam sparging, jacketed heating/cooling, helical coils submerged in agitated vessels and systems that employ external heat exchangers (double pipe, shell and tube and plate exchangers) have been considered. Both batch and continuous operations have been analysed and simulated. The dependence of del factor on system / operating parameters such as mass or volume of substrate to be sterilised per batch, speed of agitation, helix diameter, substrate to steam ratio, rate of substrate circulation through heat exchanger and that through holding tube have been analysed separately for each mode of sterilisation. Axial dispersion in the holding tube has also been adequately accounted for through an appropriately defined axial dispersion coefficient. The effect of exchanger characteristics/specifications on the system performance has also been analysed. The multiparameter computer aided design (CAD) software packages prepared are thus highly versatile in nature and they permit to make the most optimum choice of operating variables for the processes selected. The computed results have been compared with extensive data collected from a number of industries (distilleries, food processing and pharmaceutical industries) and pilot plants and satisfactory agreement has been observed between the two, thereby ascertaining the accuracy of the CAD softwares developed. No simplifying assumptions have been made during the analysis and the design of associated heating / cooling equipment has been performed utilising the most updated design correlations and computer softwares.

  15. Neutronic/Thermal-hydraulic Coupling Technigues for Sodium Cooled Fast Reactor Simulations

    International Nuclear Information System (INIS)

    Ragusa, Jean; Siegel, Andrew; Ruggieri, Jean-Michel

    2010-01-01

    The objective of this project was to test new coupling algorithms and enable efficient and scalable multi-physics simulations of advanced nuclear reactors, with considerations regarding the implementation of such algorithms in massively parallel environments. Numerical tests were carried out to verify the proposed approach and the examples included some reactor transients. The project was directly related to the Sodium Fast Reactor program element of the Generation IV Nuclear Energy Systems Initiative and the Advanced Fuel cycle Initiative, and, supported the requirement of high-fidelity simulation as a mean of achieving the goals of the presidential Global Nuclear Energy Partnership (GNEP) vision.

  16. Comparison of High-Fidelity Simulation Versus Didactic Instruction as a Reinforcement Intervention in a Comprehensive Curriculum for Radiology Trainees in Learning Contrast Reaction Management: Does It Matter How We Refresh?

    Science.gov (United States)

    Picard, Melissa; Curry, Nancy; Collins, Heather; Soma, LaShonda; Hill, Jeanne

    2015-10-01

    Simulation-based training has been shown to be a useful adjunct to standard didactic lecture in teaching residents appropriate management of adverse contrast reactions. In addition, it has been suggested that a biannual refresher is needed; however, the type of refresher education has not been assessed. This was a prospective study involving 31 radiology residents across all years in a university program. All residents underwent standard didactic lecture followed by high-fidelity simulation-based training. At approximately 6 months, residents were randomized into a didactic versus simulation group for a refresher. At approximately 9 months, all residents returned to the simulation center for performance testing. Knowledge and confidence assessments were obtained from all participants before and after each phase. Performance testing was obtained at each simulation session and scored based on predefined critical actions. There was significant improvement in knowledge (P didactic and simulation-based training. There was no statistical difference between the simulation and didactic groups in knowledge or confidence at any phase of the study. There was no significant difference in tested performance between the groups in either performance testing session. This study suggests that a curriculum consisting of an annual didactic lecture combined with simulation-based training followed by a didactic refresher at 6 months is an effective and efficient (both cost-effective and time-effective) method of educating radiology residents in the management of adverse contrast reactions. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  17. High performance thermal stress analysis on the earth simulator

    International Nuclear Information System (INIS)

    Noriyuki, Kushida; Hiroshi, Okuda; Genki, Yagawa

    2003-01-01

    In this study, the thermal stress finite element analysis code optimized for the earth simulator was developed. A processor node of which of the earth simulator is the 8-way vector processor, and each processor can communicate using the message passing interface. Thus, there are two ways to parallelize the finite element method on the earth simulator. The first method is to assign one processor for one sub-domain, and the second method is to assign one node (=8 processors) for one sub-domain considering the shared memory type parallelization. Considering that the preconditioned conjugate gradient (PCG) method, which is one of the suitable linear equation solvers for the large-scale parallel finite element methods, shows the better convergence behavior if the number of domains is the smaller, we have determined to employ PCG and the hybrid parallelization, which is based on the shared and distributed memory type parallelization. It has been said that it is hard to obtain the good parallel or vector performance, since the finite element method is based on unstructured grids. In such situation, the reordering is inevitable to improve the computational performance [2]. In this study, we used three reordering methods, i.e. Reverse Cuthil-McKee (RCM), cyclic multicolor (CM) and diagonal jagged descending storage (DJDS)[3]. RCM provides the good convergence of the incomplete lower-upper (ILU) PCG, but causes the load imbalance. On the other hand, CM provides the good load balance, but worsens the convergence of ILU PCG if the vector length is so long. Therefore, we used the combined-method of RCM and CM. DJDS is the method to store the sparse matrices such that longer vector length can be obtained. For attaining the efficient inter-node parallelization, such partitioning methods as the recursive coordinate bisection (RCM) or MeTIS have been used. Computational performance of the practical large-scale engineering problems will be shown at the meeting. (author)

  18. Multi-fidelity stochastic collocation method for computation of statistical moments

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xueyu, E-mail: xueyu-zhu@uiowa.edu [Department of Mathematics, University of Iowa, Iowa City, IA 52242 (United States); Linebarger, Erin M., E-mail: aerinline@sci.utah.edu [Department of Mathematics, University of Utah, Salt Lake City, UT 84112 (United States); Xiu, Dongbin, E-mail: xiu.16@osu.edu [Department of Mathematics, The Ohio State University, Columbus, OH 43210 (United States)

    2017-07-15

    We present an efficient numerical algorithm to approximate the statistical moments of stochastic problems, in the presence of models with different fidelities. The method extends the multi-fidelity approximation method developed in . By combining the efficiency of low-fidelity models and the accuracy of high-fidelity models, our method exhibits fast convergence with a limited number of high-fidelity simulations. We establish an error bound of the method and present several numerical examples to demonstrate the efficiency and applicability of the multi-fidelity algorithm.

  19. Effects of deformability and thermal motion of lipid membrane on electroporation: By molecular dynamics simulations

    KAUST Repository

    Sun, Sheng; Yin, Guangyao; Lee, Yi-Kuen; Wong, Joseph T.Y.; Zhang, Tong-Yi

    2011-01-01

    Effects of mechanical properties and thermal motion of POPE lipid membrane on electroporation were studied by molecular dynamics simulations. Among simulations in which specific atoms of lipids were artificially constrained at their equilibrium

  20. Simulation of the diffusion of implanted impurities in silicon structures at the rapid thermal annealing

    International Nuclear Information System (INIS)

    Komarov, F.F.; Komarov, A.F.; Mironov, A.M.; Makarevich, Yu.V.; Miskevich, S.A.; Zayats, G.M.

    2011-01-01

    Physical and mathematical models and numerical simulation of the diffusion of implanted impurities during rapid thermal treatment of silicon structures are discussed. The calculation results correspond to the experimental results with a sufficient accuracy. A simulation software system has been developed that is integrated into ATHENA simulation system developed by Silvaco Inc. This program can simulate processes of the low-energy implantation of B, BF 2 , P, As, Sb, C ions into the silicon structures and subsequent rapid thermal annealing. (authors)

  1. Thermal-Hydraulic Results for the Boiling Water Reactor Dry Cask Simulator.

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Samuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lindgren, Eric R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    The thermal performance of commercial nuclear spent fuel dry storage casks is evaluated through detailed numerical analysis. These modeling efforts are completed by the vendor to demonstrate performance and regulatory compliance. The calculations are then independently verified by the Nuclear Regulatory Commission (NRC). Carefully measured data sets generated from testing of full sized casks or smaller cask analogs are widely recognized as vital for validating these models. Recent advances in dry storage cask designs have significantly increased the maximum thermal load allowed in a cask in part by increasing the efficiency of internal conduction pathways and by increasing the internal convection through greater canister helium pressure. These same canistered cask systems rely on ventilation between the canister and the overpack to convect heat away from the canister to the environment for both aboveground and belowground configurations. While several testing programs have been previously conducted, these earlier validation attempts did not capture the effects of elevated helium pressures or accurately portray the external convection of aboveground and belowground canistered dry cask systems. The purpose of this investigation was to produce validation-quality data that can be used to test the validity of the modeling presently used to determine cladding temperatures in modern vertical dry casks. These cladding temperatures are critical to evaluate cladding integrity throughout the storage cycle. To produce these data sets under well-controlled boundary conditions, the dry cask simulator (DCS) was built to study the thermal-hydraulic response of fuel under a variety of heat loads, internal vessel pressures, and external configurations. An existing electrically heated but otherwise prototypic BWR Incoloy-clad test assembly was deployed inside of a representative storage basket and cylindrical pressure vessel that represents a vertical canister system. The symmetric

  2. Molecular Dynamic Simulation of High Thermal Conductivity Synthetic Spider Silk for Thermal Management in Space

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal management is crucial to space technology. Because electronic and other thermally sensitive materials will be located in an essentially airless environment,...

  3. Thermal comfort in residential buildings: Comfort values and scales for building energy simulation

    NARCIS (Netherlands)

    Peeters, L.F.R.; Dear, de R.; Hensen, J.L.M.; D'Haeseleer, W.

    2009-01-01

    Building Energy Simulation (BES) programmes often use conventional thermal comfort theories to make decisions, whilst recent research in the field of thermal comfort clearly shows that important effects are not incorporated. The conventional theories of thermal comfort were set up based on steady

  4. Weldability prediction of high strength steel S960QL after weld thermal cycle simulation

    Directory of Open Access Journals (Sweden)

    M. Dunđer

    2014-10-01

    Full Text Available This paper presents weld thermal cycle simulation of high strength steel S960QL, and describes influence of cooling time t8/5 on hardness and impact toughness of weld thermal cycle simulated specimens. Furthermore, it presents analysis of characteristic fractions done by electron scanning microscope which can contribute to determination of welding parameters for S960QL steel.

  5. Geosynthetic clay liners shrinkage under simulated daily thermal cycles.

    Science.gov (United States)

    Sarabadani, Hamid; Rayhani, Mohammad T

    2014-06-01

    Geosynthetic clay liners are used as part of composite liner systems in municipal solid waste landfills and other applications to restrict the escape of contaminants into the surrounding environment. This is attainable provided that the geosynthetic clay liner panels continuously cover the subsoil. Previous case histories, however, have shown that some geosynthetic clay liner panels are prone to significant shrinkage and separation when an overlying geomembrane is exposed to solar radiation. Experimental models were initiated to evaluate the potential shrinkage of different geosynthetic clay liner products placed over sand and clay subsoils, subjected to simulated daily thermal cycles (60°C for 8 hours and 22°C for 16 hours) modelling field conditions in which the liner is exposed to solar radiation. The variation of geosynthetic clay liner shrinkage was evaluated at specified times by a photogrammetry technique. The manufacturing techniques, the initial moisture content, and the aspect ratio (ratio of length to width) of the geosynthetic clay liner were found to considerably affect the shrinkage of geosynthetic clay liners. The particle size distribution of the subsoil and the associated suction at the geosynthetic clay liner-subsoil interface was also found to have significant effects on the shrinkage of the geosynthetic clay liner. © The Author(s) 2014.

  6. Mechanical-Electrochemical-Thermal Simulation of Lithium-Ion Cells

    Energy Technology Data Exchange (ETDEWEB)

    Santhanagopalan, Shriram; Zhang, Chao; Sprague, Michael A.; Pesaran, Ahmad

    2016-06-01

    Models capture the force response for single-cell and cell-string levels to within 15%-20% accuracy and predict the location for the origin of failure based on the deformation data from the experiments. At the module level, there is some discrepancy due to poor mechanical characterization of the packaging material between the cells. The thermal response (location and value of maximum temperature) agrees qualitatively with experimental data. In general, the X-plane results agree with model predictions to within 20% (pending faulty thermocouples, etc.); the Z-plane results show a bigger variability both between the models and test-results, as well as among multiple repeats of the tests. The models are able to capture the timing and sequence in voltage drop observed in the multi-cell experiments; the shapes of the current and temperature profiles need more work to better characterize propagation. The cells within packaging experience about 60% less force under identical impact test conditions, so the packaging on the test articles is robust. However, under slow-crush simulations, the maximum deformation of the cell strings with packaging is about twice that of cell strings without packaging.

  7. Nuclear Thermal Rocket Element Environmental Simulator (NTREES) Upgrade Activities

    Science.gov (United States)

    Emrich, William J., Jr.

    2014-01-01

    Over the past year the Nuclear Thermal Rocket Element Environmental Simulator (NTREES) has been undergoing a significant upgrade beyond its initial configuration. The NTREES facility is designed to perform realistic non-nuclear testing of nuclear thermal rocket (NTR) fuel elements and fuel materials. Although the NTREES facility cannot mimic the neutron and gamma environment of an operating NTR, it can simulate the thermal hydraulic environment within an NTR fuel element to provide critical information on material performance and compatibility. The first phase of the upgrade activities which was completed in 2012 in part consisted of an extensive modification to the hydrogen system to permit computer controlled operations outside the building through the use of pneumatically operated variable position valves. This setup also allows the hydrogen flow rate to be increased to over 200 g/sec and reduced the operation complexity of the system. The second stage of modifications to NTREES which has just been completed expands the capabilities of the facility significantly. In particular, the previous 50 kW induction power supply has been replaced with a 1.2 MW unit which should allow more prototypical fuel element temperatures to be reached. The water cooling system was also upgraded to so as to be capable of removing 100% of the heat generated during. This new setup required that the NTREES vessel be raised onto a platform along with most of its associated gas and vent lines. In this arrangement, the induction heater and water systems are now located underneath the platform. In this new configuration, the 1.2 MW NTREES induction heater will be capable of testing fuel elements and fuel materials in flowing hydrogen at pressures up to 1000 psi at temperatures up to and beyond 3000 K and at near-prototypic reactor channel power densities. NTREES is also capable of testing potential fuel elements with a variety of propellants, including hydrogen with additives to inhibit

  8. Design and simulation of a low concentrating photovoltaic/thermal system

    International Nuclear Information System (INIS)

    Rosell, J.I.; Vallverdu, X.; Lechon, M.A.; Ibanez, M.

    2005-01-01

    The advantages of photovoltaic/thermal (PV/T) collectors and low solar concentration technologies are combined into a photovoltaic/thermal system to increase the solar energy conversion efficiency. This paper presents a prototype 11X concentration rate and two axis tracking system. The main novelty is the coupling of a linear Fresnel concentrator with a channel photovoltaic/thermal collector. An analytical model to simulate the thermal behaviour of the prototype is proposed and validated. Measured thermal performance of the solar system gives values above 60%. Theoretical analysis confirms that thermal conduction between the PV cells and the absorber plate is a critical parameter

  9. Analytical tools for thermal infrared engineerig: a thermal sensor simulation package

    Science.gov (United States)

    Jaggi, Sandeep

    1992-09-01

    The Advanced Sensor Development Laboratory (ASDL) at the Stennis Space Center develops, maintains and calibrates remote sensing instruments for the National Aeronautics & Space Administration. To perform system design trade-offs, analysis, and establish system parameters, ASDL has developed a software package for analytical simulation of sensor systems. This package called 'Analytical Tools for Thermal InfraRed Engineering'--ATTIRE, simulates the various components of a sensor system. The software allows each subsystem of the sensor to be analyzed independently for its performance. These performance parameters are then integrated to obtain system level information such as SNR, NER, NETD etc. This paper describes the uses of the package and the physics that were used to derive the performance parameters. In addition, ATTIRE can be used as a tutorial for understanding the distribution of thermal flux or solar irradiance over selected bandwidths of the spectrum. This spectrally distributed incident flux can then be analyzed as it propagates through the subsystems that constitute the entire sensor. ATTIRE provides a variety of functions ranging from plotting black-body curves for varying bandwidths and computing the integral flux, to performing transfer function analysis of the sensor system. The package runs from a menu- driven interface in a PC-DOS environment. Each sub-system of the sensor is represented by windows and icons. A user-friendly mouse-controlled point-and-click interface allows the user to simulate various aspects of a sensor. The package can simulate a theoretical sensor system. Trade-off studies can be easily done by changing the appropriate parameters and monitoring the effect of the system performance. The package can provide plots of system performance versus any system parameter. A parameter (such as the entrance aperture of the optics) could be varied and its effect on another parameter (e.g., NETD) can be plotted. A third parameter (e.g., the

  10. Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module

    Science.gov (United States)

    2015-02-01

    executed with SolidWorks Flow Simulation , a computational fluid-dynamics code. The graph in Fig. 2 shows the timing and amplitudes of power pulses...defined a convective flow of air perpendicular to the bottom surface of the mounting plate, with a velocity of 10 ft/s. The thermal simulations were...Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module by Gregory K Ovrebo ARL-TR-7210

  11. Thermal phase stability of some simulated Defense waste glasses

    International Nuclear Information System (INIS)

    May, R.P.

    1981-04-01

    Three simulated defense waste glass compositions developed by Savannah River Laboratories were studied to determine viscosity and compositional effects on the comparative thermal phase stabilities of these glasses. The glass compositions are similar except that the 411 glasses are high in lithium and low in sodium compared to the 211 glass, and the T glasses are high in iron and low in aluminum compared to the C glass. Specimens of these glasses were heat treated using isothermal anneals as short as 10 min and up to 15 days over the temperature range of 450 0 C to 1100 0 C. Additionally, a specimen of each glass was cooled at a constant cooling rate of 7 0 C/hour from an 1100 0 C melt down to 500 0 C where it was removed from the furnace. The following were observed. The slow cooling rate of 7 0 C/hour is possible as a canister centerline cooling rate for large canisters. Accordingly, it is important to note that a short range diffusion mechanism like cooperative growth phenomena can result in extensive devitrification at lower temperatures and higher yields than a long-range diffusion mechanism can; and can do it without the growth of large crystals that can fracture the glass. Refractory oxides like CeO 2 and (Ni, Mn, Fe) 2 O 4 form very rapidly at higher temperatures than silicates and significant yields can be obtained at sufficiently high temperatures that settling of these dense phases becomes a major microstructural feature during slow cooling of some glasses. These annealing studies further show that below 500 0 C there is but little devitrification occurring implying that glass canisters stored at 300 0 C may be kinetically stable despite not being thermodynamically so

  12. Thermal phase stability of some simulated Defense waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    May, R.P.

    1981-04-01

    Three simulated defense waste glass compositions developed by Savannah River Laboratories were studied to determine viscosity and compositional effects on the comparative thermal phase stabilities of these glasses. The glass compositions are similar except that the 411 glasses are high in lithium and low in sodium compared to the 211 glass, and the T glasses are high in iron and low in aluminum compared to the C glass. Specimens of these glasses were heat treated using isothermal anneals as short as 10 min and up to 15 days over the temperature range of 450/sup 0/C to 1100/sup 0/C. Additionally, a specimen of each glass was cooled at a constant cooling rate of 7/sup 0/C/hour from an 1100/sup 0/C melt down to 500/sup 0/C where it was removed from the furnace. The following were observed. The slow cooling rate of 7/sup 0/C/hour is possible as a canister centerline cooling rate for large canisters. Accordingly, it is important to note that a short range diffusion mechanism like cooperative growth phenomena can result in extensive devitrification at lower temperatures and higher yields than a long-range diffusion mechanism can; and can do it without the growth of large crystals that can fracture the glass. Refractory oxides like CeO/sub 2/ and (Ni, Mn, Fe)/sub 2/O/sub 4/ form very rapidly at higher temperatures than silicates and significant yields can be obtained at sufficiently high temperatures that settling of these dense phases becomes a major microstructural feature during slow cooling of some glasses. These annealing studies further show that below 500/sup 0/C there is but little devitrification occurring implying that glass canisters stored at 300/sup 0/C may be kinetically stable despite not being thermodynamically so.

  13. Thermal dynamic simulation of wall for building energy efficiency under varied climate environment

    Science.gov (United States)

    Wang, Xuejin; Zhang, Yujin; Hong, Jing

    2017-08-01

    Aiming at different kind of walls in five cities of different zoning for thermal design, using thermal instantaneous response factors method, the author develops software to calculation air conditioning cooling load temperature, thermal response factors, and periodic response factors. On the basis of the data, the author gives the net work analysis about the influence of dynamic thermal of wall on air-conditioning load and thermal environment in building of different zoning for thermal design regional, and put forward the strategy how to design thermal insulation and heat preservation wall base on dynamic thermal characteristic of wall under different zoning for thermal design regional. And then provide the theory basis and the technical references for the further study on the heat preservation with the insulation are in the service of energy saving wall design. All-year thermal dynamic load simulating and energy consumption analysis for new energy-saving building is very important in building environment. This software will provide the referable scientific foundation for all-year new thermal dynamic load simulation, energy consumption analysis, building environment systems control, carrying through farther research on thermal particularity and general particularity evaluation for new energy -saving walls building. Based on which, we will not only expediently design system of building energy, but also analyze building energy consumption and carry through scientific energy management. The study will provide the referable scientific foundation for carrying through farther research on thermal particularity and general particularity evaluation for new energy saving walls building.

  14. Simulation of thermo-Elastics Properties of Thermal Barrier Coatings ...

    African Journals Online (AJOL)

    Thermal barrier coatings are used to protect different parts in compressors and turbines from heat. They are generally composed of two layers, one metallic layer providing resistance to heat corrosion and oxidation, and one thermally insulating ceramic layer. Two different techniques are industrially used. Plasma spray ...

  15. Improved numerical algorithm and experimental validation of a system thermal-hydraulic/CFD coupling method for multi-scale transient simulations of pool-type reactors

    International Nuclear Information System (INIS)

    Toti, A.; Vierendeels, J.; Belloni, F.

    2017-01-01

    Highlights: • A system thermal-hydraulic/CFD coupling methodology is proposed for high-fidelity transient flow analyses. • The method is based on domain decomposition and implicit numerical scheme. • A novel interface Quasi-Newton algorithm is implemented to improve stability and convergence rate. • Preliminary validation analyses on the TALL-3D experiment. - Abstract: The paper describes the development and validation of a coupling methodology between the best-estimate system thermal-hydraulic code RELAP5-3D and the CFD code FLUENT, conceived for high fidelity plant-scale safety analyses of pool-type reactors. The computational tool is developed to assess the impact of three-dimensional phenomena occurring in accidental transients such as loss of flow (LOF) in the research reactor MYRRHA, currently in the design phase at the Belgian Nuclear Research Centre, SCK• CEN. A partitioned, implicit domain decomposition coupling algorithm is implemented, in which the coupled domains exchange thermal-hydraulics variables at coupling boundary interfaces. Numerical stability and interface convergence rates are improved by a novel interface Quasi-Newton algorithm, which is compared in this paper with previously tested numerical schemes. The developed computational method has been assessed for validation purposes against the experiment performed at the test facility TALL-3D, operated by the Royal Institute of Technology (KTH) in Sweden. This paper details the results of the simulation of a loss of forced convection test, showing the capability of the developed methodology to predict transients influenced by local three-dimensional phenomena.

  16. Note: Local thermal conductivities from boundary driven non-equilibrium molecular dynamics simulations

    International Nuclear Information System (INIS)

    Bresme, F.; Armstrong, J.

    2014-01-01

    We report non-equilibrium molecular dynamics simulations of heat transport in models of molecular fluids. We show that the “local” thermal conductivities obtained from non-equilibrium molecular dynamics simulations agree within numerical accuracy with equilibrium Green-Kubo computations. Our results support the local equilibrium hypothesis for transport properties. We show how to use the local dependence of the thermal gradients to quantify the thermal conductivity of molecular fluids for a wide range of thermodynamic states using a single simulation

  17. Simulation and experimental study of thermal performance of a ...

    Indian Academy of Sciences (India)

    of a building roof with a phase change material (PCM) .... ware model of concrete roof without cylindrical holes and PRO-E software model concrete roof .... John Kosnya, Kaushik Biswas, William Miller and Scott Kriner 2012 Field thermal ...

  18. Coupled Aeroheating and Ablative Thermal Response Simulation Tool

    Data.gov (United States)

    National Aeronautics and Space Administration — The thermal protection system (TPS) performance requirements for atmospheric entry vehicles on current and future NASA missions preclude the use of heritage reusable...

  19. Communication: Minimum in the thermal conductivity of supercooled water: A computer simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Bresme, F., E-mail: f.bresme@imperial.ac.uk [Chemical Physics Section, Department of Chemistry, Imperial College, London SW7 2AZ, United Kingdom and Department of Chemistry, Norwegian University of Science and Technology, Trondheim 7491 (Norway); Biddle, J. W.; Sengers, J. V.; Anisimov, M. A. [Institute for Physical Science and Technology, and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2014-04-28

    We report the results of a computer simulation study of the thermodynamic properties and the thermal conductivity of supercooled water as a function of pressure and temperature using the TIP4P-2005 water model. The thermodynamic properties can be represented by a two-structure equation of state consistent with the presence of a liquid-liquid critical point in the supercooled region. Our simulations confirm the presence of a minimum in the thermal conductivity, not only at atmospheric pressure, as previously found for the TIP5P water model, but also at elevated pressures. This anomalous behavior of the thermal conductivity of supercooled water appears to be related to the maximum of the isothermal compressibility or the minimum of the speed of sound. However, the magnitudes of the simulated thermal conductivities are sensitive to the water model adopted and appear to be significantly larger than the experimental thermal conductivities of real water at low temperatures.

  20. Communication: Minimum in the thermal conductivity of supercooled water: A computer simulation study

    International Nuclear Information System (INIS)

    Bresme, F.; Biddle, J. W.; Sengers, J. V.; Anisimov, M. A.

    2014-01-01

    We report the results of a computer simulation study of the thermodynamic properties and the thermal conductivity of supercooled water as a function of pressure and temperature using the TIP4P-2005 water model. The thermodynamic properties can be represented by a two-structure equation of state consistent with the presence of a liquid-liquid critical point in the supercooled region. Our simulations confirm the presence of a minimum in the thermal conductivity, not only at atmospheric pressure, as previously found for the TIP5P water model, but also at elevated pressures. This anomalous behavior of the thermal conductivity of supercooled water appears to be related to the maximum of the isothermal compressibility or the minimum of the speed of sound. However, the magnitudes of the simulated thermal conductivities are sensitive to the water model adopted and appear to be significantly larger than the experimental thermal conductivities of real water at low temperatures

  1. PCB-level Electro thermal Coupling Simulation Analysis

    Science.gov (United States)

    Zhou, Runjing; Shao, Xuchen

    2017-10-01

    Power transmission network needs to transmit more current with the increase of the power density. The problem of temperature rise and the reliability is becoming more and more serious. In order to accurately design the power supply system, we must consider the influence of the power supply system including Joule heat, air convection and other factors. Therefore, this paper analyzes the relationship between the electric circuit and the thermal circuit on the basis of the theory of electric circuit and thermal circuit.

  2. Main factors of thermal fatigue failure induced by thermal striping and total simulation of thermal hydraulic and structural behaviors (research report)

    International Nuclear Information System (INIS)

    Kasahara, Naoto; Muramatsu, Toshiharu

    1999-01-01

    At incomplete mixing area of high temperature and low temperature fluids near the surface of structures, temperature fluctuation of fluid gives thermal fatigue damage to wall structures. This phenomenon is called thermal striping, which becomes sometimes a critical problem in LMFR plants. Since thermal striping phenomenon is characterized by the complex thermohydraulic and thermomechanical coupled problem, conventional evaluation procedures require mock-up experiments. In order to replace them by simulation-base methods, the authors have developed numerical simulation codes and applied them to analyze a tee junction of the PHENIX secondary circuit due to thermal striping phenomenon, in the framework of the IAEA coordinated research program (CRP). Through this analysis, thermohydraulic and thermomechanical mechanism of thermal striping phenomenon was clarified, and main factors on structural integrity was extracted in each stage of thermal striping phenomenon. Furthermore, simulation base evaluation methods were proposed taking above factors of structural integrity into account. Finally, R and D problems were investigated for future development of design evaluation methods. (author)

  3. A Thermal Runaway Simulation on a Lithium Titanate Battery and the Battery Module

    Directory of Open Access Journals (Sweden)

    Man Chen

    2015-01-01

    Full Text Available Based on the electrochemical and thermal model, a coupled electro-thermal runaway model was developed and implemented using finite element methods. The thermal decomposition reactions when the battery temperature exceeds the material decomposition temperature were embedded into the model. The temperature variations of a lithium titanate battery during a series of charge-discharge cycles under different current rates were simulated. The results of temperature and heat generation rate demonstrate that the greater the current, the faster the battery temperature is rising. Furthermore, the thermal influence of the overheated cell on surrounding batteries in the module was simulated, and the variation of temperature and heat generation during thermal runaway was obtained. It was found that the overheated cell can induce thermal runaway in other adjacent cells within 3 mm distance in the battery module if the accumulated heat is not dissipated rapidly.

  4. Fidelity deviation in quantum teleportation

    Science.gov (United States)

    Bang, Jeongho; Ryu, Junghee; Kaszlikowski, Dagomir

    2018-04-01

    We analyze the performance of quantum teleportation in terms of average fidelity and fidelity deviation. The average fidelity is defined as the average value of the fidelities over all possible input states and the fidelity deviation is their standard deviation, which is referred to as a concept of fluctuation or universality. In the analysis, we find the condition to optimize both measures under a noisy quantum channel—we here consider the so-called Werner channel. To characterize our results, we introduce a 2D space defined by the aforementioned measures, in which the performance of the teleportation is represented as a point with the channel noise parameter. Through further analysis, we specify some regions drawn for different channel conditions, establishing the connection to the dissimilar contributions of the entanglement to the teleportation and the Bell inequality violation.

  5. The Modeling and Simulation of Thermal Analysis at Hydro Generator Stator Winding Insulation

    Directory of Open Access Journals (Sweden)

    Mihaela Raduca

    2006-10-01

    Full Text Available This paper presents the modelling and simulation of thermal analysis at hydro generator stator winding. The winding stator is supplied at high voltage of 11 kV for high power hydro generator. To present the thermal analysis for stator winding is presented at supply of coil by 11 kV, when coil is heat and thermal transfer in insulation at ambient temperature.

  6. Multiscale development of a fission gas thermal conductivity model: Coupling atomic, meso and continuum level simulations

    International Nuclear Information System (INIS)

    Tonks, Michael R.; Millett, Paul C.; Nerikar, Pankaj; Du, Shiyu; Andersson, David; Stanek, Christopher R.; Gaston, Derek; Andrs, David; Williamson, Richard

    2013-01-01

    Fission gas production and evolution significantly impact the fuel performance, causing swelling, a reduction in the thermal conductivity and fission gas release. However, typical empirical models of fuel properties treat each of these effects separately and uncoupled. Here, we couple a fission gas release model to a model of the impact of fission gas on the fuel thermal conductivity. To quantify the specific impact of grain boundary (GB) bubbles on the thermal conductivity, we use atomistic and mesoscale simulations. Atomistic molecular dynamic simulations were employed to determine the GB thermal resistance. These values were then used in mesoscale heat conduction simulations to develop a mechanistic expression for the effective GB thermal resistance of a GB containing gas bubbles, as a function of the percentage of the GB covered by fission gas. The coupled fission gas release and thermal conductivity model was implemented in Idaho National Laboratory’s BISON fuel performance code to model the behavior of a 10-pellet LWR fuel rodlet, showing how the fission gas impacts the UO 2 thermal conductivity. Furthermore, additional BISON simulations were conducted to demonstrate the impact of average grain size on both the fuel thermal conductivity and the fission gas release

  7. Advanced Physical Models and Numerical Algorithms to Enable High-Fidelity Aerothermodynamic Simulations of Planetary Entry Vehicles on Emerging Distributed Heterogeneous Computing Architectures

    Data.gov (United States)

    National Aeronautics and Space Administration — The design and qualification of entry systems for planetary exploration largely rely on computational simulations. However, state-of-the-art modeling capabilities...

  8. Micromagnetic simulations with thermal noise: Physical and numerical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E. [Dept. de Ingenieria Electromecanica, Universidad de Burgos, Plaza Misael Banuelos, s/n, E-09001, Burgos (Spain)]. E-mail: emvecino@ubu.es; Lopez-Diaz, L. [Dept. de Fisica Aplicada, Universidad Salamanca, Plaza de la Merced s/n, Salamanca E-37008 (Spain); Torres, L. [Dept. de Fisica Aplicada, Universidad Salamanca, Plaza de la Merced s/n, Salamanca E-37008 (Spain); Garcia-Cervera, C.J. [Department of Mathematics, University of California, Santa Barbara, CA 93106 (United States)

    2007-09-15

    Langevin dynamics treats finite temperature effects in micromagnetics framework by adding a thermal fluctuation field to the local effective field. Several works have addressed that the numerical results depend on the cell size used to split the ferromagnetic samples on the nanoscale regime. In this short paper, we analyze a thermally perturbed micromagnetic problem by using an implicit unconditionally stable numerical scheme to integrate the Langevin equation at room temperature. The obtained micromagnetic results for several cell sizes inside the validity range of the micromagnetic formalism, indicate that the addressed cell size dependence could be associated to numerical limitations of the commonly used numerical schemes.

  9. Micromagnetic simulations with thermal noise: Physical and numerical aspects

    International Nuclear Information System (INIS)

    Martinez, E.; Lopez-Diaz, L.; Torres, L.; Garcia-Cervera, C.J.

    2007-01-01

    Langevin dynamics treats finite temperature effects in micromagnetics framework by adding a thermal fluctuation field to the local effective field. Several works have addressed that the numerical results depend on the cell size used to split the ferromagnetic samples on the nanoscale regime. In this short paper, we analyze a thermally perturbed micromagnetic problem by using an implicit unconditionally stable numerical scheme to integrate the Langevin equation at room temperature. The obtained micromagnetic results for several cell sizes inside the validity range of the micromagnetic formalism, indicate that the addressed cell size dependence could be associated to numerical limitations of the commonly used numerical schemes

  10. Combined simulation of energy and thermal management for an electric vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Mohrmann, Bjoern; Jeck, Peter [Institut fuer Kraftfahrzeuge Aachen (Germany); Simon, Carsten [fortiss GmbH, Muenchen (Germany); Ungermann, Jochen [Audi AG, Ingolstadt (Germany)

    2012-11-01

    The project eperformance, which is funded by the BMBF, is conducted by project partners from RWTH Aachen, Audi, Bosch Engineering and fortiss GmbH, in order to demonstrate the concept of an electric vehicle on the basis of a holistic development approach. To support this, several simulation platforms come into use, i.e. CFD Simulation for cooling concepts, electromagnetic simulations for electric machine design, physical simulation of cooling circuits as well as vehicle mechanics and controller design. To develop an energy efficient vehicle management, some of these simulation domains have to be combined, to simulate interdependencies between for example usage of high-voltage batteries, their thermal response and the impact for controller strategies. Within the project it was decided to use the Tool TISC (TLK Inter Software Connector) to combine as well a physical model, based on Modelica/Dymola to simulate thermal behaviours of components with a longitudinal vehicle model and a controller model, both based in MATLAB/Simulink. Advantages of such a coupled simulation are the re-usability of existing models in both tools with their tool-specific benefits as well as the possibility to cluster the models on different computers. The article will explain how the combined simulation is set up and parameterized, and will show two use cases: the thermal management of the two independent battery systems of the demonstrator vehicle and the torque distribution on the three electric machines in the vehicle, depending on the drive situation and the thermal state of the machines. (orig)

  11. Experimental Study of Turbine Fuel Thermal Stability in an Aircraft Fuel System Simulator

    Science.gov (United States)

    Vranos, A.; Marteney, P. J.

    1980-01-01

    The thermal stability of aircraft gas turbines fuels was investigated. The objectives were: (1) to design and build an aircraft fuel system simulator; (2) to establish criteria for quantitative assessment of fuel thermal degradation; and (3) to measure the thermal degradation of Jet A and an alternative fuel. Accordingly, an aircraft fuel system simulator was built and the coking tendencies of Jet A and a model alternative fuel (No. 2 heating oil) were measured over a range of temperatures, pressures, flows, and fuel inlet conditions.

  12. Multi-pass TIG welding process: simulating thermal SS304

    International Nuclear Information System (INIS)

    Harinadh, Vemanaboina; Akella, S.; Buddu, Ramesh Kumar; Edision, G.

    2015-01-01

    Welding is basic requirement in the construction of nuclear reactors, power plants and structural components development. A basic studies on various aspects of the welding is essential to ensure the stability and structural requirement conditions. The present study explored the thermo-mechanical analysis of the multipass welds of austenitic stainless steels which are widely used in fusion and fission reactor components development. A three-dimensional (3D) finite element model is developed to investigate thermally induced stress field during TIG welding process for SS304 material. The transient thermal analysis is performed to obtain the temperature history, which then is applied to the mechanical (stress) analysis. The present thermal analysis is conducted using element type DC3D8. This element type has a three dimensional thermal conduction capability and eight nodes. The 6 mm thick plated is welded with six numbers of passes. The geometry and meshed model with tetrahedral shape with volume sweep. The analysis is on TIG welding process using 3D-weld interface plug-in on ABAQUS-6.14. The results are reported in the present paper

  13. Simulation of global warming effect on outdoor thermal comfort conditions

    Energy Technology Data Exchange (ETDEWEB)

    Roshan, G.R.; Ranjbar, F. [Univ. of Tehran (IR). Dept. of Physical Geography; Orosa, J.A. [Univ. of A Coruna (Spain). Dept. of Energy

    2010-07-01

    In the coming decades, global warming and increase in temperature, in different regions of the world, may change indoor and outdoor thermal comfort conditions and human health. The aim of this research was to study the effects of global warming on thermal comfort conditions in indoor ambiences in Iran. To study the increase in temperature, model for assessment of greenhouse-gas induced climate change scenario generator compound model has been used together with four scenarios and to estimate thermal comfort conditions, adaptive model of the American Society of Heating, Refrigerating and Air-Conditioning Engineers has been used. In this study, Iran was divided into 30 zones, outdoor conditions were obtained using meteorological data of 80 climatological stations and changes in neutral comfort conditions in 2025, 2050, 2075 and 2100 were predicted. In accordance with each scenario, findings from this study showed that temperature in the 30 zones will increase by 2100 to between 3.4 C and 5.6 C. In the coming decades and in the 30 studied zones, neutral comfort temperature will increase and be higher and more intense in the central and desert zones of Iran. The low increase in this temperature will be connected to the coastal areas of the Caspian and Oman Sea in southeast Iran. This increase in temperature will be followed by a change in thermal comfort and indoor energy consumption from 8.6 % to 13.1 % in air conditioning systems. As a result, passive methods as thermal inertia are proposed as a possible solution.

  14. Thermal plume above a simulated sitting person with different complexity of body geometry

    DEFF Research Database (Denmark)

    Zukowska, Daria; Melikov, Arsen Krikor; Popiolek, Zbigniew J.

    2007-01-01

    Occupants are one of the main heat sources in rooms. They generate thermal plumes with characteristics, which depend on geometry, surface temperature and area of the human body in contact with the surrounding air as well as temperature, velocity and turbulence intensity distribution in the room....... The characteristics of the thermal plume generated by a sitting person were studied using four human body simulators with different complexity of geometry but equal surface area: a vertical cylinder, a rectangular box, a dummy, and a thermal manikin. The results show that the dummy and the thermal manikin generate...

  15. Numerical simulation of thermal behaviors of a clothed human body with evaluation of indoor solar radiation

    International Nuclear Information System (INIS)

    Mao, Aihua; Luo, Jie; Li, Yi

    2017-01-01

    Highlights: • Solar radiation evaluation is integrated with the thermal transfer in clothed humans. • Thermal models are developed for clothed humans exposed in indoor solar radiation. • The effect of indoor solar radiation on humans can be predicted in different situations in living. • The green solar energy can be efficiently utilized in the building development. - Abstract: Solar radiation is a valuable green energy, which is important in achieving a successful building design for thermal comfort in indoor environment. This paper considers solar radiation indoors into the transient thermal transfer models of a clothed human body and offers a new numerical method to analyze the dynamic thermal status of a clothed human body under different solar radiation incidences. The evaluation model of solar radiation indoors and a group of coupled thermal models of the clothed human body are developed and integrated. The simulation capacities of these integrated models are validated through a comparison between the predicted results and the experimental data in reference. After that, simulation cases are also conducted to show the influence of solar radiation on the thermal status of individual clothed body segments when the human body is staying indoors in different seasons. This numerical simulation method provides a useful tool to analyze the thermal status of clothed human body under different solar radiation incidences indoors and thus enables the architect to efficiently utilize the green solar energy in building development.

  16. Thermal Expansion of Ni3Al Intermetallic Compound: Experiment and Simulation

    International Nuclear Information System (INIS)

    Wang Hai-Peng; Lü Peng; Zhou Kai; Wei Bing-Bo

    2016-01-01

    The thermal expansion of Ni 3 Al intermetallic compound is determined by a thermal dilatometer and simulated by the molecular dynamics method. The results of the linear thermal expansion coefficients are presented from 200 K up to the maximum temperature of 1600 K. The single phase of Ni 3 Al intermetallic compound is confirmed by x-ray diffraction together with DSC melting and solidification peaks, from which the solidus and the liquidus temperatures are obtained to be 1660 and 1695 K, respectively. The measured linear thermal expansion coefficient increases from 1.5 × 10 −5 to 2.7 × 10 −5 K −1 in the experimental temperature range, in good agreement with the data obtained by the molecular dynamics simulation, just a slight difference from the temperature dependence coefficient. Furthermore, the atomic structure and position are presented to reveal the atom distribution change during thermal expansion of Ni 3 Al compound. (paper)

  17. Finite-difference time-domain simulation of thermal noise in open cavities

    International Nuclear Information System (INIS)

    Andreasen, Jonathan; Cao Hui; Taflove, Allen; Kumar, Prem; Cao Changqi

    2008-01-01

    A numerical model based on the finite-difference time-domain (FDTD) method is developed to simulate thermal noise in open cavities owing to output coupling. The absorbing boundary of the FDTD grid is treated as a blackbody, whose thermal radiation penetrates the cavity in the grid. The calculated amount of thermal noise in a one-dimensional dielectric cavity recovers the standard result of the quantum Langevin equation in the Markovian regime. Our FDTD simulation also demonstrates that in the non-Markovian regime the buildup of the intracavity noise field depends on the ratio of the cavity photon lifetime to the coherence time of thermal radiation. The advantage of our numerical method is that the thermal noise is introduced in the time domain without prior knowledge of cavity modes

  18. Solar panel thermal cycling testing by solar simulation and infrared radiation methods

    Science.gov (United States)

    Nuss, H. E.

    1980-01-01

    For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

  19. Energy improvement of a conventional dwelling in Argentina through thermal simulation

    Energy Technology Data Exchange (ETDEWEB)

    Filippin, C. [CONICET-CC302, Santa Rosa 6300, La Pampa (Argentina); Flores Larsen, S. [INENCO-Instituto de Investigaciones en Energias No Convencionales, Universidad Nacional de Salta, CONICET, Avda. Bolivia 5150, CP 4400 Salta Capital (Argentina); Lopez Gay, E.

    2008-10-15

    This paper analyses the design, technology, thermal behaviour, and energy consumption of both a conventional and a refurbished dwelling located in a region with a temperate-cold climate in central Argentina. The thermal behaviour and the energy consumption of the conventional building were monitored during winter. The experimental data were analysed and included in a simulation of the transient thermal behaviour of the house. Measurements and simulation were in agreement, showing a mean deviation below 0.5{sup o}C. To reduce the heating and cooling loads, the dwelling was refurbished and its thermal behaviour was studied through a computer simulation, for the critical seasons (winter and summer) and for two occupancy schedules (with and without inhabitants). The refurbishment included passive solar heating, shading, and an insulated envelope. These successful changes allowed energy savings of 66% and 52% for winter and summer, respectively. (author)

  20. Simulation of adiabatic thermal beams in a periodic solenoidal magnetic focusing field

    Directory of Open Access Journals (Sweden)

    T. J. Barton

    2012-12-01

    Full Text Available Self-consistent particle-in-cell simulations are performed to verify earlier theoretical predictions of adiabatic thermal beams in a periodic solenoidal magnetic focusing field [K. R. Samokhvalova, J. Zhou, and C. Chen, Phys. Plasmas 14, 103102 (2007PHPAEN1070-664X10.1063/1.2779281; J. Zhou, K. R. Samokhvalova, and C. Chen, Phys. Plasmas 15, 023102 (2008PHPAEN1070-664X10.1063/1.2837891]. In particular, results are obtained for adiabatic thermal beams that do not rotate in the Larmor frame. For such beams, the theoretical predictions of the rms beam envelope, the conservations of the rms thermal emittances, the adiabatic equation of state, and the Debye length are verified in the simulations. Furthermore, the adiabatic thermal beam is found be stable in the parameter regime where the simulations are performed.

  1. Monte Carlo simulations to advance characterisation of landmines by pulsed fast/thermal neutron analysis

    NARCIS (Netherlands)

    Maucec, M.; Rigollet, C.

    The performance of a detection system based on the pulsed fast/thermal neutron analysis technique was assessed using Monte Carlo simulations. The aim was to develop and implement simulation methods, to support and advance the data analysis techniques of the characteristic gamma-ray spectra,

  2. Simulation of thermal effectiveness under coal dust burning

    International Nuclear Information System (INIS)

    Korabejnikova, V.K.

    2001-01-01

    The simulation equation of polydisperse fuel (coal dust) torch combustion in the definite zones of burning cameras of stream generator and taking into account reactions in kinetic and diffusion areas at distinguishing temperatures of particles and gas are considered. (author)

  3. Measuring third year undergraduate nursing students' reflective thinking skills and critical reflection self-efficacy following high fidelity simulation: A pilot study.

    Science.gov (United States)

    Tutticci, Naomi; Lewis, Peter A; Coyer, Fiona

    2016-05-01

    Critical reflection underpins critical thinking, a highly desirable generic nursing graduate capability. To improve the likelihood of critical thinking transferring to clinical practice, reflective thinking needs to be measured within the learning space of simulation. This study was divided into two phases to address the reliability and validity measures of previously untested surveys. Phase One data was collected from individuals (n = 6) using a 'think aloud' approach and an expert panel to review content validity, and verbatim comment analysis was undertaken. The Reflective Thinking Instrument and Critical Reflection Self-Efficacy Visual Analogue Scale items were contextualised to simulation. The expert review confirmed these instruments exhibited content validity. Phase Two data was collected through an online survey (n = 58). Cronbach's alpha measured internal consistency and was demonstrated by all subscales and the Instrument as a whole (.849). There was a small to medium positive correlation between critical reflection self-efficacy and general self-efficacy (r = .324, n = 56, p = .048). Participant responses were positive regarding the simulation experience. The research findings demonstrated that the Reflective Thinking and Simulation Satisfaction survey is reliable. Further development of this survey to establish validity is recommended to make it viable. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Fidelity for kicked atoms with gravity near a quantum resonance.

    Science.gov (United States)

    Dubertrand, Rémy; Guarneri, Italo; Wimberger, Sandro

    2012-03-01

    Kicked atoms under a constant Stark or gravity field are investigated for experimental setups with cold and ultracold atoms. The parametric stability of the quantum dynamics is studied using the fidelity. In the case of a quantum resonance, it is shown that the behavior of the fidelity depends on arithmetic properties of the gravity parameter. Close to a quantum resonance, the long-time asymptotics of the fidelity is studied by means of a pseudoclassical approximation introduced by Fishman et al. [J. Stat. Phys. 110, 911 (2003)]. The long-time decay of fidelity arises from the tunneling out of pseudoclassical stable islands, and a simple ansatz is proposed which satisfactorily reproduces the main features observed in numerical simulations.

  5. Thermal hydraulic simulation of the CANDU nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Athos M.S.S. de; Ramos, Mario C.; Costa, Antonella L.; Fernandes, Gustavo H.N., E-mail: athos1495@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Instituto Nacional de Ciência e Tecnologia de Reatores Nucleares Inovadores (INCT/CNPq), Rio de janeiro, RJ (Brazil)

    2017-07-01

    The CANDU (Canada Deuterium Uranium) is a Canadian-designed power reactor of PHWR type (Pressurized Heavy Water Reactor) that uses heavy water (deuterium oxide) for moderator and coolant, and natural uranium for fuel. There are about 47 reactors of this type in operation around the world generating more than 23 GWe, highlighting the importance of this kind of device. In this way, the main purpose of this study is to develop a thermal hydraulic model for a CANDU reactor to aggregate knowledge in this line of research. In this way, a core modeling was performed using RELAP5-3D code. Results were compared with reference data to verify the model behavior in steady state operation. Thermal hydraulic parameters as temperature, pressure and mass flow rate were verified and the results are in good agreement with reference data, as it is being presented in this work. (author)

  6. Simulation of Thermal-hydraulic Process in Reactor of HTR-PM

    International Nuclear Information System (INIS)

    Zhou Kefeng; Zhou Yangping; Sui Zhe; Ma Yuanle

    2014-01-01

    This paper provides the physical process in the reactor of High Temperature Gas-cooled Reactor Pebble-bed Module (HTR-PM) and introduces the standard operation conditions. The FORTRAN code developed for the thermal hydraulic module of Full-Scale Simulator (FSS) of HTR-PM is used to simulate two typical operation transients including cold startup process and cold shutdown process. And the results were compared to the safety analysis code, namely TINTE. The good agreement indicates that the code is applicable for simulating the thermal-hydraulic process in reactor of HTR-PM. And for long time transient process, the code shows good stability and convergence. (author)

  7. Cellular and Porous Materials Thermal Properties Simulation and Prediction

    CERN Document Server

    Öchsner, Andreas; de Lemos, Marcelo J S

    2008-01-01

    Providing the reader with a solid understanding of the fundamentals as well as an awareness of recent advances in properties and applications of cellular and porous materials, this handbook and ready reference covers all important analytical and numerical methods for characterizing and predicting thermal properties. In so doing it directly addresses the special characteristics of foam-like and hole-riddled materials, combining theoretical and experimental aspects for characterization purposes.

  8. Simulation of Thermal Signature of Tires and Tracks

    Science.gov (United States)

    2012-08-01

    the body-ply is a linear elastic material. To facilitate the analysis, the tire was divided into Tread and Sidewall by the dash line as shown in...only one element is assigned through the thickness of the tire . Therefore, the thickness of the element is the same as the thickness of the tire ...to the whole part of the 3D full tire in the thermal analysis. The average strain energy density for each part ( tread or sidewall) in the cross

  9. Test results of the new NSSS thermal-hydraulics program of the KNPEC-2 simulator

    International Nuclear Information System (INIS)

    Jeong, J. Z.; Kim, K. D.; Lee, M. S.; Hong, J. H.; Lee, Y. K.; Seo, J. S.; Kweon, K. J.; Lee, S. W.

    2001-01-01

    As a part of the KNPEC-2 Simulator Upgrade Project, KEPRI and KAERI have developed a new NSSS thermal-hydraulics program, which is based on the best-estimate system code, RETRAN. The RETRAN code was originally developed for realistic simulation of thermal-hydraulic transient in power plant systems. The capability of 'real-time simulation' and robustness' should be first developed before being implemented in full-scope simulators. For this purpose, we have modified the RETRAN code by (i) eliminating the correlations' discontinuities between flow regime maps, (ii) simplifying physical correlations, (iii) correcting errors in the original program, and (iv) others. This paper briefly presents the test results fo the new NSSS thermal-hydraulics program

  10. The Development of Dispatcher Training Simulator in a Thermal Energy Generation System

    Science.gov (United States)

    Hakim, D. L.; Abdullah, A. G.; Mulyadi, Y.; Hasan, B.

    2018-01-01

    A dispatcher training simulator (DTS) is a real-time Human Machine Interface (HMI)-based control tool that is able to visualize industrial control system processes. The present study was aimed at developing a simulator tool for boilers in a thermal power station. The DTS prototype was designed using technical data of thermal power station boilers in Indonesia. It was then designed and implemented in Wonderware Intouch 10. The resulting simulator came with component drawing, animation, control display, alarm system, real-time trend, historical trend. This application used 26 tagnames and was equipped with a security system. The test showed that the principles of real-time control worked well. It is expected that this research could significantly contribute to the development of thermal power station, particularly in terms of its application as a training simulator for beginning dispatchers.

  11. A Fast Electro-Thermal Co-Simulation Modeling Approach for SiC Power MOSFETs

    DEFF Research Database (Denmark)

    Ceccarelli, Lorenzo; Bahman, Amir Sajjad; Iannuzzo, Francesco

    2017-01-01

    The purpose of this work is to propose a novel electro-thermal co-simulation approach for the new generation of SiC MOSFETs, by development of a PSpice-based compact and physical SiC MOSFET model including temperature dependency of several parameters and a Simulink-based thermal network. The PSpice...... the FEM simulation of the DUT’s structure, performed in ANSYS Icepack. A MATLAB script is used to process the simulation data and feed the needed settings and parameters back into the simulation. The parameters for a CREE 1.2 kV/30 A SiC MOSFET have been identified and the electro-thermal model has been...

  12. High-Fidelity RF Gun Simulations with the Parallel 3D Finite Element Particle-In-Cell Code Pic3P

    Energy Technology Data Exchange (ETDEWEB)

    Candel, A; Kabel, A.; Lee, L.; Li, Z.; Limborg, C.; Ng, C.; Schussman, G.; Ko, K.; /SLAC

    2009-06-19

    SLAC's Advanced Computations Department (ACD) has developed the first parallel Finite Element 3D Particle-In-Cell (PIC) code, Pic3P, for simulations of RF guns and other space-charge dominated beam-cavity interactions. Pic3P solves the complete set of Maxwell-Lorentz equations and thus includes space charge, retardation and wakefield effects from first principles. Pic3P uses higher-order Finite Elementmethods on unstructured conformal meshes. A novel scheme for causal adaptive refinement and dynamic load balancing enable unprecedented simulation accuracy, aiding the design and operation of the next generation of accelerator facilities. Application to the Linac Coherent Light Source (LCLS) RF gun is presented.

  13. OB/GYN boot cAMP using high-fidelity human simulators: enhancing residents' perceived competency, confidence in taking a leadership role, and stress hardiness.

    Science.gov (United States)

    Pliego, Jose F; Wehbe-Janek, Hania; Rajab, M Hasan; Browning, Jeff L; Fothergill, Russell E

    2008-01-01

    To evaluate the effectiveness of an obstetrical and gynecologic (Ob/Gyn) Boot Camp simulation training on perceived technical competency, confidence in a leadership role, and stress hardiness of resident training. We conducted a prospective pilot study on the effectiveness of an Ob/Gyn Boot Camp on resident training. Residents participated in an intensive immersion in clinical simulation of common obstetrical emergencies including shoulder dystocia, neonatal resuscitation, postpartum hemorrhage, and ruptured ectopic pregnancy. After the training, residents completed a Web-based survey on their perceptions of how the Ob/Gyn Boot Camp affected their 1) technical competency in the assessment and management of their patients, 2) confidence in taking a leadership role, and 3) stress hardiness. Residents rated their perceptions on a Likert scale of 1 to 5, 1 = poor to 5 = excellent. Twenty-three (14 Ob/Gyn and 9 family medicine) residents participated in this pilot study. Eighteen (78%) residents completed the online survey; 4 Ob/Gyn and 1 family medicine resident did not complete the survey. The residents reported that the simulation training stimulated an interest in learning key skills for obstetrical and gynecologic emergencies. Ob/Gyn residents reported significant improvement in their perceived technical competence and stress hardiness after the Boot Camp. However both Ob/Gyn and family medicine residents reported no significant improvement of confidence in their leadership abilities during obstetrical emergencies after the Boot Camp. Boot Camp simulation training early in the curriculum has the potential for enhancing residents' self-assessments of confidence, competency, and stress hardiness in managing obstetrical emergencies.

  14. Review of simulation techniques for Aquifer Thermal Energy Storage (ATES)

    Science.gov (United States)

    Mercer, J. W.; Faust, C. R.; Miller, W. J.; Pearson, F. J., Jr.

    1981-03-01

    The analysis of aquifer thermal energy storage (ATES) systems rely on the results from mathematical and geochemical models. Therefore, the state-of-the-art models relevant to ATES were reviewed and evaluated. These models describe important processes active in ATES including ground-water flow, heat transport (heat flow), solute transport (movement of contaminants), and geochemical reactions. In general, available models of the saturated ground-water environment are adequate to address most concerns associated with ATES; that is, design, operation, and environmental assessment. In those cases where models are not adequate, development should be preceded by efforts to identify significant physical phenomena and relate model parameters to measurable quantities.

  15. Effects of simulated nuclear thermal pulses on fiber optic cables

    International Nuclear Information System (INIS)

    Baba, A.J.; Share, S.; Wasilik, J.H.

    1979-01-01

    The effects of pulsed thermal radiation on fiber optic cables with a variety of jackets (polyurethane, PVC, fluorocarbon) are presented. Exposure between 27 and 85 cal/cm 2 did not sever the optical fibers, but the radiation did cause disintegration of the jackets and the Kevlar strength members, which resulted in a significant reduction of the cable's ability to survive mechanical stress. Hardening techniques are discussed. The addition of low absorptance materials (white Teflon tape and aluminum foil) under clear or white Teflon jackets prevented some types of cables from being affected at fluences up to 110 cal/cm 2

  16. TRISO fuel thermal simulations in the LS-VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Mario C.; Scari, Maria E.; Costa, Antonella L.; Pereira, Claubia; Veloso, Maria A.F., E-mail: marc5663@gmail.com, E-mail: melizabethscari@yahoo.com, E-mail: antonella@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Instituto Nacional de Ciência e Tecnologia de Reatores Nucleares Inovadores/CNPq (Brazil)

    2017-07-01

    The liquid-salt-cooled very high-temperature reactor (LS-VHTR) is a reactor that presents very good characteristics in terms of energy production and safety aspects. It uses as fuel the TRISO particles immersed in a graphite matrix with a cylindrical shape called fuel compact, as moderator graphite and as coolant liquid salt Li{sub 2}BeF{sub 4} called Flibe. This work evaluates the thermal hydraulic performance of the heat removal system and the reactor core by performing different simplifications to represent the reactor core and the fuel compact under steady-state conditions, starting the modeling from a single fuel element, until complete the studies with the entire core model developed in the RELAP5-3D code. Two models were considered for representation of the fuel compact, homogeneous and non-homogeneous models, as well as different geometries of the heat structures was considered. The aim to develop several models was to compare the thermal hydraulic characteristics resulting from the construction of a more economical and less discretized model with much more refined models that can lead to more complexes analyzes to representing TRISO effect particles in the fuel compact. The different results found, mainly, for the core temperature distributions are presented and discussed. (author)

  17. Nursing students' evaluation of a new feedback and reflection tool for use in high-fidelity simulation - Formative assessment of clinical skills. A descriptive quantitative research design.

    Science.gov (United States)

    Solheim, Elisabeth; Plathe, Hilde Syvertsen; Eide, Hilde

    2017-11-01

    Clinical skills training is an important part of nurses' education programmes. Clinical skills are complex. A common understanding of what characterizes clinical skills and learning outcomes needs to be established. The aim of the study was to develop and evaluate a new reflection and feedback tool for formative assessment. The study has a descriptive quantitative design. 129 students participated who were at the end of the first year of a Bachelor degree in nursing. After highfidelity simulation, data were collected using a questionnaire with 19 closed-ended and 2 open-ended questions. The tool stimulated peer assessment, and enabled students to be more thorough in what to assess as an observer in clinical skills. The tool provided a structure for selfassessment and made visible items that are important to be aware of in clinical skills. This article adds to simulation literature and provides a tool that is useful in enhancing peer learning, which is essential for nurses in practice. The tool has potential for enabling students to learn about reflection and developing skills for guiding others in practice after they have graduated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Thermal conductivity predictions of herringbone graphite nanofibers using molecular dynamics simulations.

    Science.gov (United States)

    Khadem, Masoud H; Wemhoff, Aaron P

    2013-02-28

    Non-equilibrium molecular dynamics (NEMD) simulations are used to investigate the thermal conductivity of herringbone graphite nanofibers (GNFs) at room temperature by breaking down the axial and transverse conductivity values into intralayer and interlayer components. The optimized Tersoff potential is used to account for intralayer carbon-carbon interactions while the Lennard-Jones potential is used to model the interlayer carbon-carbon interactions. The intralayer thermal conductivity of the graphene layers near room temperature is calculated for different crease angles and number of layers using NEMD with a constant applied heat flux. The edge effect on a layer's thermal conductivity is investigated by computing the thermal conductivity values in both zigzag and armchair directions of the heat flow. The interlayer thermal conductivity is also predicted by imposing hot and cold Nosé-Hoover thermostats on two layers. The limiting case of a 90° crease angle is used to compare the results with those of single-layer graphene and few-layer graphene. The axial and transverse thermal conductivities are then calculated using standard trigonometric conversions of the calculated intralayer and interlayer thermal conductivities, along with calculations of few-layer graphene without a crease. The results show a large influence of the crease angle on the intralayer thermal conductivity, and the saturation of thermal conductivity occurs when number of layers is more than three. The axial thermal conductivity, transverse thermal conductivity in the crease direction, and transverse thermal conductivity normal to the crease for the case of a five-layer herringbone GNF with a 45° crease angle are calculated to be 27 W∕m K, 263 W∕m K, and 1500 W∕m K, respectively, where the axial thermal conductivity is in good agreement with experimental measurements.

  19. Effects of Anisotropic Thermal Conductivity in Magnetohydrodynamics Simulations of a Reversed-Field Pinch

    International Nuclear Information System (INIS)

    Onofri, M.; Malara, F.; Veltri, P.

    2010-01-01

    A compressible magnetohydrodynamics simulation of the reversed-field pinch is performed including anisotropic thermal conductivity. When the thermal conductivity is much larger in the direction parallel to the magnetic field than in the perpendicular direction, magnetic field lines become isothermal. As a consequence, as long as magnetic surfaces exist, a temperature distribution is observed displaying a hotter confined region, while an almost uniform temperature is produced when the magnetic field lines become chaotic. To include this effect in the numerical simulation, we use a multiple-time-scale analysis, which allows us to reproduce the effect of a large parallel thermal conductivity. The resulting temperature distribution is related to the existence of closed magnetic surfaces, as observed in experiments. The magnetic field is also affected by the presence of an anisotropic thermal conductivity.

  20. Computational Simulation of Thermal and Spattering Phenomena and Microstructure in Selective Laser Melting of Inconel 625

    Science.gov (United States)

    Özel, Tuğrul; Arısoy, Yiğit M.; Criales, Luis E.

    Computational modelling of Laser Powder Bed Fusion (L-PBF) processes such as Selective laser Melting (SLM) can reveal information that is hard to obtain or unobtainable by in-situ experimental measurements. A 3D thermal field that is not visible by the thermal camera can be obtained by solving the 3D heat transfer problem. Furthermore, microstructural modelling can be used to predict the quality and mechanical properties of the product. In this paper, a nonlinear 3D Finite Element Method based computational code is developed to simulate the SLM process with different process parameters such as laser power and scan velocity. The code is further improved by utilizing an in-situ thermal camera recording to predict spattering which is in turn included as a stochastic heat loss. Then, thermal gradients extracted from the simulations applied to predict growth directions in the resulting microstructure.

  1. Simulation of Temperature Field in HDPE Pipe Thermal Welding

    Directory of Open Access Journals (Sweden)

    LIU Li-jun

    2017-04-01

    Full Text Available For high density polyethylene pipe connection,welding technology is the key of the high density engineering plastic pressure pipe safety. And the temperature distribution in the welding process has a very important influence on the welding quality. Polyethylene pipe weld joints of one dimensional unsteady overall heat transfer model is established by MARC software and simulates temperature field and stress field distribution of the welding process,and the thermocouple temperature automatic acquisition system of welding temperature field changes were detected,and compared by simulation and experiment .The results show that,at the end of the heating,the temperature of the pipe does not reach the maximum,but reached the maximum at 300 s,which indicates that the latent heat of phase change in the process of pressure welding. In the process of pressure welding, the axial stress of the pipe is gradually changed from tensile stress to compressive stress.

  2. The SCAR project - accidental thermal-hydraulics: from the simulation to the simulators

    International Nuclear Information System (INIS)

    Farvacque, M.; Faydide, B.; Parent, M.; Iffenecker, F.; Pentori, B.; Dumas, J.M.

    2000-01-01

    The integration of the CATHARE code in the reactor simulators was completed in the beginning of the years 1990 with the design of the simulators SIPA1 and SIPA2. The SCAR project (Simulator CAthare Release), presented in this paper, is the following of this application. The objective is the adaptation of a reference CATHARE code version to the simulators environment, in order to realize the convergence between the safety analysis tool and the simulator. (A.L.B.)

  3. Minimizing cell size dependence in micromagnetics simulations with thermal noise

    Energy Technology Data Exchange (ETDEWEB)

    MartInez, E [Departamento de Ingenieria Electromecanica, Universidad de Burgos, Plaza Misael Banuelos, s/n, E-09001, Burgos (Spain); Lopez-DIaz, L [Departamento de Fisica Aplicada. Universidad Salamanca. Plaza de la Merced s/n. Salamanca E-37008 (Spain); Torres, L [Departamento de Fisica Aplicada. Universidad Salamanca. Plaza de la Merced s/n. Salamanca E-37008 (Spain); GarcIa-Cervera, C J [Department of Mathematics. University of California, Santa Barbara, CA 93106 (United States)

    2007-02-21

    Langevin dynamics treats finite temperature effects in a micromagnetics framework by adding a thermal fluctuation field to the effective field. Several works have addressed the dependence of numerical results on the cell size used to split the ferromagnetic samples on the nanoscale regime. In this paper, some former problems dealing with the dependence on the spatial discretization at finite temperature have been revised. We have focused our attention on the stability of the numerical schemes used to integrate the Langevin equation. In particular, a detailed analysis of results was carried out as a function of the time step. It was confirmed that the mentioned dependence can be minimized if an unconditional stable integration method is used to numerically solve the Langevin equation.

  4. Minimizing cell size dependence in micromagnetics simulations with thermal noise

    International Nuclear Information System (INIS)

    MartInez, E; Lopez-DIaz, L; Torres, L; GarcIa-Cervera, C J

    2007-01-01

    Langevin dynamics treats finite temperature effects in a micromagnetics framework by adding a thermal fluctuation field to the effective field. Several works have addressed the dependence of numerical results on the cell size used to split the ferromagnetic samples on the nanoscale regime. In this paper, some former problems dealing with the dependence on the spatial discretization at finite temperature have been revised. We have focused our attention on the stability of the numerical schemes used to integrate the Langevin equation. In particular, a detailed analysis of results was carried out as a function of the time step. It was confirmed that the mentioned dependence can be minimized if an unconditional stable integration method is used to numerically solve the Langevin equation

  5. A Multi-Wavelength Thermal Infrared and Reflectance Scene Simulation Model

    Science.gov (United States)

    Ballard, J. R., Jr.; Smith, J. A.; Smith, David E. (Technical Monitor)

    2002-01-01

    Several theoretical calculations are presented and our approach discussed for simulating overall composite scene thermal infrared exitance and canopy bidirectional reflectance of a forest canopy. Calculations are performed for selected wavelength bands of the DOE Multispectral Thermal Imagery and comparisons with atmospherically corrected MTI imagery are underway. NASA EO-1 Hyperion observations also are available and the favorable comparison of our reflective model results with these data are reported elsewhere.

  6. The gyro-radius scaling of ion thermal transport from global numerical simulations of ITG turbulence

    International Nuclear Information System (INIS)

    Ottaviani, M.; Manfredi, G.

    1998-12-01

    A three-dimensional, fluid code is used to study the scaling of ion thermal transport caused by Ion-Temperature-Gradient-Driven (ITG) turbulence. The code includes toroidal effects and is capable of simulating the whole torus. It is found that both close to the ITG threshold and well above threshold, the thermal transport and the turbulence structures exhibit a gyro-Bohm scaling, at least for plasmas with moderate poloidal flow. (author)

  7. Review of simulation techniques for aquifer thermal energy storage (ATES)

    Energy Technology Data Exchange (ETDEWEB)

    Mercer, J.W.; Faust, C.R.; Miller, W.J.; Pearson, F.J. Jr.

    1981-03-01

    The storage of thermal energy in aquifers has recently received considerable attention as a means to conserve and more efficiently use energy supplies. The analysis of aquifer thermal energy storage (ATES) systems will rely on the results from mathematical and geochemical models. Therefore, the state-of-the-art models relevant to ATES was reviewed and evaluated. These models describe important processes active in ATES including ground-water flow, heat transport (heat flow), solute transport (movement of contaminants), and geochemical reactions. In general, available models of the saturated ground-water environment are adequate to address most concerns associated with ATES; that is, design, operation, and environmental assessment. In those cases where models are not adequate, development should be preceded by efforts to identify significant physical phenomena and relate model parameters to measurable quantities. Model development can then proceed with the expectation of an adequate data base existing for the model's eventual use. Review of model applications to ATES shows that the major emphasis has been on generic sensitivity analysis and site characterization. Assuming that models are applied appropriately, the primary limitation on model calculations is the data base used to construct the model. Numerical transport models are limited by the uncertainty of subsurface data and the lack of long-term historical data for calibration. Geochemical models are limited by the lack of thermodynamic data for the temperature ranges applicable to ATES. Model applications undertaken with data collection activities on ATES sites should provide the most important contributions to the understanding and utilization of ATES. Therefore, the primary conclusion of this review is that model application to field sites in conjunction with data collection activities is essential to the development of this technology.

  8. Coupled large-eddy simulation of thermal mixing in a T-junction

    International Nuclear Information System (INIS)

    Kloeren, D.; Laurien, E.

    2011-01-01

    Analyzing thermal fatigue due to thermal mixing in T-junctions is part of the safety assessment of nuclear power plants. Results of two large-eddy simulations of mixing flow in a T-junction with coupled and adiabatic boundary condition are presented and compared. The temperature difference is set to 100 K, which leads to strong stratification of the flow. The main and the branch pipe intersect horizontally in this simulation. The flow is characterized by steady wavy pattern of stratification and temperature distribution. The coupled solution approach shows highly reduced temperature fluctuations in the near wall region due to thermal inertia of the wall. A conjugate heat transfer approach is necessary in order to simulate unsteady heat transfer accurately for large inlet temperature differences. (author)

  9. Thermal simulation of quenching uranium-0.75% titanium alloy in water

    International Nuclear Information System (INIS)

    Siman-Tov, M.; Llewellyn, G.H.; Childs, K.W.; Ludtka, G.M.; Aramayo, G.A.

    1985-01-01

    A computer model, The Quench Simulator, has been developed to simulate and predict in detail the behavior of U-0.75 Ti alloy when quenched at high temperature (about 850 0 C) in cold water. The code allows one to determine the time- and space-dependent distributions of temperature, residual stress, distortion, and microstructure that evolve during the quenching process. The nonlinear temperature- and microstructure-dependent properties, as well as the cooling rate-dependent heats of transformation, are incorporated into the model. The complex boiling heat transfer with its various regimes and other thermal boundary conditions are simulated. Experiments have been performed and incorporated into the model. Both sudden submersion and gradual controlled immersion can be applied. A parametric and sensitivity study has been performed demonstrating the importance of the thermal boundary conditions applied for achieving certain product characteristics. The thermal aspects of the model and its applications are discussed and demonstrated

  10. Experimental Preparation and Numerical Simulation of High Thermal Conductive Cu/CNTs Nanocomposites

    Directory of Open Access Journals (Sweden)

    Muhsan Ali Samer

    2014-07-01

    Full Text Available Due to the rapid growth of high performance electronics devices accompanied by overheating problem, heat dissipater nanocomposites material having ultra-high thermal conductivity and low coefficient of thermal expansion was proposed. In this work, a nanocomposite material made of copper (Cu reinforced by multi-walled carbon nanotubes (CNTs up to 10 vol. % was prepared and their thermal behaviour was measured experimentally and evaluated using numerical simulation. In order to numerically predict the thermal behaviour of Cu/CNTs composites, three different prediction methods were performed. The results showed that rules of mixture method records the highest thermal conductivity for all predicted composites. In contrast, the prediction model which takes into account the influence of the interface thermal resistance between CNTs and copper particles, has shown the lowest thermal conductivity which considered as the closest results to the experimental measurement. The experimentally measured thermal conductivities showed remarkable increase after adding 5 vol.% CNTs and higher than the thermal conductivities predicted via Nan models, indicating that the improved fabrication technique of powder injection molding that has been used to produced Cu/CNTs nanocomposites has overcome the challenges assumed in the mathematical models.

  11. Thermal transport characterization of hexagonal boron nitride nanoribbons using molecular dynamics simulation

    Directory of Open Access Journals (Sweden)

    Asir Intisar Khan

    2017-10-01

    Full Text Available Due to similar atomic bonding and electronic structure to graphene, hexagonal boron nitride (h-BN has broad application prospects such as the design of next generation energy efficient nano-electronic devices. Practical design and efficient performance of these devices based on h-BN nanostructures would require proper thermal characterization of h-BN nanostructures. Hence, in this study we have performed equilibrium molecular dynamics (EMD simulation using an optimized Tersoff-type interatomic potential to model the thermal transport of nanometer sized zigzag hexagonal boron nitride nanoribbons (h-BNNRs. We have investigated the thermal conductivity of h-BNNRs as a function of temperature, length and width. Thermal conductivity of h-BNNRs shows strong temperature dependence. With increasing width, thermal conductivity increases while an opposite pattern is observed with the increase in length. Our study on h-BNNRs shows considerably lower thermal conductivity compared to GNRs. To elucidate these aspects, we have calculated phonon density of states for both h-BNNRs and GNRs. Moreover, using EMD we have explored the impact of different vacancies, namely, point vacancy, edge vacancy and bi-vacancy on the thermal conductivity of h-BNNRs. With varying percentages of vacancies, significant reduction in thermal conductivity is observed and it is found that, edge and point vacancies are comparatively more destructive than bi-vacancies. Such study would contribute further into the growing interest for accurate thermal transport characterization of low dimensional nanostructures.

  12. Numerical simulation of thermal loading produced by shaped high power laser onto engine parts

    International Nuclear Information System (INIS)

    Song Hongwei; Li Shaoxia; Zhang Ling; Yu Gang; Zhou Liang; Tan Jiansong

    2010-01-01

    Recently a new method for simulating the thermal loading on pistons of diesel engines was reported. The spatially shaped high power laser is employed as the heat source, and some preliminary experimental and numerical work was carried out. In this paper, a further effort was made to extend this simulation method to some other important engine parts such as cylinder heads. The incident Gaussian beam was transformed into concentric multi-circular patterns of specific intensity distributions, with the aid of diffractive optical elements (DOEs). By incorporating the appropriate repetitive laser pulses, the designed transient temperature fields and thermal loadings in the engine parts could be simulated. Thermal-structural numerical models for pistons and cylinder heads were built to predict the transient temperature and thermal stress. The models were also employed to find the optimal intensity distributions of the transformed laser beam that could produce the target transient temperature fields. Comparison of experimental and numerical results demonstrated that this systematic approach is effective in simulating the thermal loading on the engine parts.

  13. Simulation study of negative thermal expansion in yttrium tungstate Y2W3O12.

    Science.gov (United States)

    Rimmer, Leila H N; Dove, Martin T

    2015-05-13

    A simulation study of negative thermal expansion in Y2W3O12 was carried out using calculations of phonon dispersion curves through the application of density functional perturbation theory. The mode eigenvectors were mapped onto flexibility models and results compared with calculations of the mode Grüneisen parameters. It was found that many lower-frequency phonons contribute to negative thermal expansion in Y2W3O12, all of which can be described in terms of rotations of effectively rigid WO4 tetrahedra and Y-O rods. The results are strikingly different from previous phonon studies of higher-symmetry materials that show negative thermal expansion.

  14. Particle-in-cell simulations on spontaneous thermal magnetic field fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Simões, F. J. R. Jr.; Pavan, J. [Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil); Gaelzer, R.; Ziebell, L. F. [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States)

    2013-10-15

    In this paper an electromagnetic particle code is used to investigate the spontaneous thermal emission. Specifically we perform particle-in-cell simulations employing a non-relativistic isotropic Maxwellian particle distribution to show that thermal fluctuations are related to the origin of spontaneous magnetic field fluctuation. These thermal fluctuations can become seed for further amplification mechanisms and thus be considered at the origin of the cosmological magnetic field, at microgauss levels. Our numerical results are in accordance with theoretical results presented in the literature.

  15. Driving Simulator Development and Performance Study

    OpenAIRE

    Juto, Erik

    2010-01-01

    The driving simulator is a vital tool for much of the research performed at theSwedish National Road and Transport Institute (VTI). Currently VTI posses three driving simulators, two high fidelity simulators developed and constructed by VTI, and a medium fidelity simulator from the German company Dr.-Ing. Reiner Foerst GmbH. The two high fidelity simulators run the same simulation software, developed at VTI. The medium fidelity simulator runs a proprietary simulation software. At VTI there is...

  16. Optical roughness BRDF model for reverse Monte Carlo simulation of real material thermal radiation transfer.

    Science.gov (United States)

    Su, Peiran; Eri, Qitai; Wang, Qiang

    2014-04-10

    Optical roughness was introduced into the bidirectional reflectance distribution function (BRDF) model to simulate the reflectance characteristics of thermal radiation. The optical roughness BRDF model stemmed from the influence of surface roughness and wavelength on the ray reflectance calculation. This model was adopted to simulate real metal emissivity. The reverse Monte Carlo method was used to display the distribution of reflectance rays. The numerical simulations showed that the optical roughness BRDF model can calculate the wavelength effect on emissivity and simulate the real metal emissivity variance with incidence angles.

  17. Large Blast and Thermal Simulator Reflected Wave Eliminator Study

    Science.gov (United States)

    1990-03-01

    it delays the passage of this wave through the test section until after the test is complete. The required length of extra duct depends on the strength...tube axis, which acts like an additional contraction effect since Se = Sj/[Cqsin(aj)]. Tii extra area is illustrated best by plotting (Se-Ae)/Ac versus...34Simulation de Choc et de Soaffie. Comimpensateur d’Ondes de Detente de Bouche pour tube a Choc de 2400 mm de diametre de Veine. Description, Compte- Renda

  18. Testing thermal gradient driving force for grain boundary migration using molecular dynamics simulations

    International Nuclear Information System (INIS)

    Bai, Xian-Ming; Zhang, Yongfeng; Tonks, Michael R.

    2015-01-01

    Strong thermal gradients in low-thermal-conductivity ceramics may drive extended defects, such as grain boundaries and voids, to migrate in preferential directions. In this work, molecular dynamics simulations are conducted to study thermal gradient driven grain boundary migration and to verify a previously proposed thermal gradient driving force equation, using uranium dioxide as a model system. It is found that a thermal gradient drives grain boundaries to migrate up the gradient and the migration velocity increases under a constant gradient owing to the increase in mobility with temperature. Different grain boundaries migrate at very different rates due to their different intrinsic mobilities. The extracted mobilities from the thermal gradient driven simulations are compared with those calculated from two other well-established methods and good agreement between the three different methods is found, demonstrating that the theoretical equation of the thermal gradient driving force is valid, although a correction of one input parameter should be made. The discrepancy in the grain boundary mobilities between modeling and experiments is also discussed.

  19. Importance of thermal nonequilibrium considerations for the simulation of nuclear reactor LOCA transients

    International Nuclear Information System (INIS)

    Fischer, S.R.; Nelson, R.A.; Sullivan, L.H.

    1980-01-01

    The purpose of this paper is to show the importance of considering thermal nonequilibrium effects in computer simulations of the refill and reflood portions of pressurized water reactor (PWR) loss-of-coolnat accident (LOCA) transients. Although RELAP4 assumes thermodynamic equilibrium between phases, models that account for the nonequilibrium phenomena associated with the mixing of subcooled emergency cooling water with steam and the superheating of vapor in the presence of liquid droplets have recently been incorporated into the code. Code calculated results, both with and without these new models, have been compared with experimental test data to assess the importance of including thermal nonequilibrium phenomena in computer code simulations

  20. Thermal Comfort in Simulated Office Environment with Four Convective and Radiant Cooling Systems

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Mustakallio, Panu; Kolencíková, Sona

    2013-01-01

    with overhead mixing ventilation (MVRC). Whole body thermal sensation (TS) and whole body TS acceptability under the four systems in a simulated office room for one hour exposure were collected. The simulated two-man office (4.12 x 4.20 x 2.89 m, L x W x H) was kept at 26 oC room air temperature. Moderate heat...... to “neutral” compared to male, whose votes were closer to the “slightly warm” thermal sensation. The whole body TS acceptability was rated close to ''clearly acceptable'' (EN 15251-2007) and was independent of subject's gender for all tested systems....

  1. Integrated Variable-Fidelity Tool Set for Modeling and Simulation of Aeroservothermoelasticity-Propulsion (ASTE-P) Effects for Aerospace Vehicles Ranging From Subsonic to Hypersonic Flight, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research program aims at developing a variable-fidelity software tool set for aeroservothermoelastic-propulsive (ASTE-P) modeling that can be routinely...

  2. Thermal simulation of a cooling system of hybrid commercial vehicles; Thermalsimulation eine Hybrid-LKW-Kuehlsystems

    Energy Technology Data Exchange (ETDEWEB)

    Stroh, Christoph; Schnoerch, Stefan; Rathberger, Christian [Magna Powertrain Engineering Center Steyr GmbH und Co. KG, St. Valentin (Austria)

    2012-11-01

    In the past few years hybrid vehicles have been in the center of automotive engineering efforts, in particular in the field of passenger cars. But hybrid powertrains will also be important for commercial trucks. This focus on hybrid vehicles leads to high demands on thermal management since the additional components in a hybrid vehicle need appropriate cooling or even heating. In the given paper the simulation of a complete cooling system of a hybrid commercial vehicle will be explained. For this virtual examination the commercial 1D thermal management software KULI will be used, a co-simulation with several programs will not be done deliberately. Yet all aspects which are relevant for a global assessment of the thermal management are considered. The main focus is put on the investigation of appropriate concepts for the fluid circuits, including low and high temperature circuits, electric water pumps, etc. Moreover, also a refrigerant circuit with a chiller for active battery cooling will be used, the appropriate control strategy is implemented as well. For simulating transient profiles a simple driving simulation model is included, using road profile, ambient conditions, and various vehicle parameters as input. In addition an engine model is included which enables the investigation of fuel consumption potentials. This simulation model shows how the thermal management of a hybrid vehicle can be investigated with a single program and with reasonable effort. (orig.)

  3. Statistics of strain rates and surface density function in a flame-resolved high-fidelity simulation of a turbulent premixed bluff body burner

    Science.gov (United States)

    Sandeep, Anurag; Proch, Fabian; Kempf, Andreas M.; Chakraborty, Nilanjan

    2018-06-01

    The statistical behavior of the surface density function (SDF, the magnitude of the reaction progress variable gradient) and the strain rates, which govern the evolution of the SDF, have been analyzed using a three-dimensional flame-resolved simulation database of a turbulent lean premixed methane-air flame in a bluff-body configuration. It has been found that the turbulence intensity increases with the distance from the burner, changing the flame curvature distribution and increasing the probability of the negative curvature in the downstream direction. The curvature dependences of dilatation rate ∇ṡu → and displacement speed Sd give rise to variations of these quantities in the axial direction. These variations affect the nature of the alignment between the progress variable gradient and the local principal strain rates, which in turn affects the mean flame normal strain rate, which assumes positive values close to the burner but increasingly becomes negative as the effect of turbulence increases with the axial distance from the burner exit. The axial distance dependences of the curvature and displacement speed also induce a considerable variation in the mean value of the curvature stretch. The axial distance dependences of the dilatation rate and flame normal strain rate govern the behavior of the flame tangential strain rate, and its mean value increases in the downstream direction. The current analysis indicates that the statistical behaviors of different strain rates and displacement speed and their curvature dependences need to be included in the modeling of flame surface density and scalar dissipation rate in order to accurately capture their local behaviors.

  4. In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors

    International Nuclear Information System (INIS)

    Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

    2015-01-01

    Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations. (paper)

  5. ELECTROMAGNETIC AND THERMAL SIMULATIONS FOR THE SWITCH REGION OF A COMPACT PROTON ACCELERATOR

    International Nuclear Information System (INIS)

    Wang, L; Caporaso, G J; Sullivan, J S

    2007-01-01

    A compact proton accelerator for medical applications is being developed at Lawrence Livermore National Laboratory. The accelerator architecture is based on the dielectric wall accelerator (DWA) concept. One critical area to consider is the switch region. Electric field simulations and thermal calculations of the switch area were performed to help determine the operating limits of rmed SiC switches. Different geometries were considered for the field simulation including the shape of the thin Indium solder meniscus between the electrodes and SiC. Electric field simulations were also utilized to demonstrate how the field stress could be reduced. Both transient and steady steady-state thermal simulations were analyzed to find the average power capability of the switches

  6. Thermal and thermo-mechanical simulation of laser assisted machining

    International Nuclear Information System (INIS)

    Germain, G.; Dal Santo, P.; Lebrun, J. L.; Bellett, D.; Robert, P.

    2007-01-01

    Laser Assisted Machining (LAM) improves the machinability of materials by locally heating the workpiece just prior to cutting. The heat input is provided by a high power laser focused several millimeters in front of the cutting tool. Experimental investigations have confirmed that the cutting force can be decreased, by as much as 40%, for various materials (tool steel, titanium alloys and nickel alloys). The laser heat input is essentially superficial and results in non-uniform temperature profiles within the depth of the workpiece. The temperature field in the cutting zone is therefore influenced by many parameters. In order to understand the effect of the laser on chip formation and on the temperature fields in the different deformation zones, thermo-mechanical simulation were undertaken. A thermo-mechanical model for chip formation with and without the laser was also undertaken for different cutting parameters. Experimental tests for the orthogonal cutting of 42CrMo4 steel were used to validate the simulation via the prediction of the cutting force with and without the laser. The thermo-mechanical model then allowed us to highlight the differences in the temperature fields in the cutting zone with and without the laser. In particular, it was shown that for LAM the auto-heating of the material in the primary shear zone is less important and that the friction between the tool and chip also generates less heat. The temperature fields allow us to explain the reduction in the cutting force and the resulting residual stress fields in the workpiece

  7. High-fidelity quantum driving

    DEFF Research Database (Denmark)

    Bason, Mark George; Viteau, Matthieu; Malossi, Nicola

    2011-01-01

    Accurately controlling a quantum system is a fundamental requirement in quantum information processing and the coherent manipulation of molecular systems. The ultimate goal in quantum control is to prepare a desired state with the highest fidelity allowed by the available resources...... and the experimental constraints. Here we experimentally implement two optimal high-fidelity control protocols using a two-level quantum system comprising Bose–Einstein condensates in optical lattices. The first is a short-cut protocol that reaches the maximum quantum-transformation speed compatible...

  8. A simplified tool for building layout design based on thermal comfort simulations

    Directory of Open Access Journals (Sweden)

    Prashant Anand

    2017-06-01

    Full Text Available Thermal comfort aspects of indoor spaces are crucial during the design stages of building layout planning. This study presents a simplified tool based on thermal comfort using predicted mean vote (PMV index. Thermal comfort simulations were performed for 14 different possible room layouts based on window configurations. ECOTECT 12 was used to determine the PMV of these rooms for one full year, leading to 17,808 simulations. Simulations were performed for three different climatic zones in India and were validated using in-situ measurements from one of these climatic zones. For moderate climates, rooms with window openings on the south façade exhibited the best thermal comfort conditions for nights, with comfort conditions prevailing for approximately 79.25% of the time annually. For operation during the day, windows on the north façade are favored, with thermal comfort conditions prevailing for approximately 77.74% of the time annually. Similar results for day and night time operation for other two climatic zones are presented. Such an output is essential in deciding the layout of buildings on the basis of functionality of the different rooms (living room, bedroom, kitchen corresponding to different operation times of the day.

  9. Thermal Field Analysis and Simulation of an Infrared Belt Furnace Used for Solar Cells

    Directory of Open Access Journals (Sweden)

    Bai Lu

    2014-01-01

    Full Text Available During solar cell firing, volatile organic compounds (VOC and a small number of metal particles were removed using the gas flow. When the gas flow was disturbed by the thermal field of infrared belt furnace and structure, the metal particles in the discharging gas flow randomly adhered to the surface of solar cell, possibly causing contamination. Meanwhile, the gas flow also affected the thermal uniformity of the solar cell. In this paper, the heating mechanism of the solar cell caused by radiation, convection, and conduction during firing was analyzed. Afterward, four 2-dimensional (2D models of the furnace were proposed. The transient thermal fields with different gas inlets, outlets, and internal structures were simulated. The thermal fields and the temperature of the solar cell could remain stable and uniform when the gas outlets were installed at the ends and in the middle of the furnace, with the gas inlets being distributed evenly. To verify the results, we produced four types of furnaces according to the four simulated results. The experimental results indicated that the thermal distribution of the furnace and the characteristics of the solar cells were consistent with the simulation. These experiments improved the efficiency of the solar cells while optimizing the solar cell manufacturing equipment.

  10. User's manual for computer code SOLTES-1 (simulator of large thermal energy systems)

    International Nuclear Information System (INIS)

    Fewell, M.E.; Grandjean, N.R.; Dunn, J.C.; Edenburn, M.W.

    1978-09-01

    SOLTES simulates the steady-state response of thermal energy systems to time-varying data such as weather and loads. Thermal energy system models of both simple and complex systems can easily be modularly constructed from a library of routines. These routines mathematically model solar collectors, pumps, switches, thermal energy storage, thermal boilers, auxiliary boilers, heat exchangers, extraction turbines, extraction turbine/generators, condensers, regenerative heaters, air conditioners, heating and cooling of buildings, process vapor, etc.; SOLTES also allows user-supplied routines. The analyst need only specify fluid names to obtain readout of property data for heat-transfer fluids and constants that characterize power-cycle working fluids from a fluid property data bank. A load management capability allows SOLTES to simulate total energy systems that simultaneously follow heat and power loads and demands. Generalized energy accounting is available, and values for system performance parameters may be automatically determined by SOLTES. Because of its modularity and flexibility, SOLTES can be used to simulate a wide variety of thermal energy systems such as solar power/total energy, fossil fuel power plants/total energy, nuclear power plants/total energy, solar energy heating and cooling, geothermal energy, and solar hot water heaters

  11. Design of 6 Mev linear accelerator based pulsed thermal neutron source: FLUKA simulation and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Patil, B.J., E-mail: bjp@physics.unipune.ac.in [Department of Physics, University of Pune, Pune 411 007 (India); Chavan, S.T.; Pethe, S.N.; Krishnan, R. [SAMEER, IIT Powai Campus, Mumbai 400 076 (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ac.in [Department of Physics, University of Pune, Pune 411 007 (India)

    2012-01-15

    The 6 MeV LINAC based pulsed thermal neutron source has been designed for bulk materials analysis. The design was optimized by varying different parameters of the target and materials for each region using FLUKA code. The optimized design of thermal neutron source gives flux of 3 Multiplication-Sign 10{sup 6}ncm{sup -2}s{sup -1} with more than 80% of thermal neutrons and neutron to gamma ratio was 1 Multiplication-Sign 10{sup 4}ncm{sup -2}mR{sup -1}. The results of prototype experiment and simulation are found to be in good agreement with each other. - Highlights: Black-Right-Pointing-Pointer The optimized 6 eV linear accelerator based thermal neutron source using FLUKA simulation. Black-Right-Pointing-Pointer Beryllium as a photonuclear target and reflector, polyethylene as a filter and shield, graphite as a moderator. Black-Right-Pointing-Pointer Optimized pulsed thermal neutron source gives neutron flux of 3 Multiplication-Sign 10{sup 6} n cm{sup -2} s{sup -1}. Black-Right-Pointing-Pointer Results of the prototype experiment were compared with simulations and are found to be in good agreement. Black-Right-Pointing-Pointer This source can effectively be used for the study of bulk material analysis and activation products.

  12. Thermal boundary resistance at Si/Ge interfaces by molecular dynamics simulation

    Directory of Open Access Journals (Sweden)

    Tianzhuo Zhan

    2015-04-01

    Full Text Available In this study, we investigated the temperature dependence and size effect of the thermal boundary resistance at Si/Ge interfaces by non-equilibrium molecular dynamics (MD simulations using the direct method with the Stillinger-Weber potential. The simulations were performed at four temperatures for two simulation cells of different sizes. The resulting thermal boundary resistance decreased with increasing temperature. The thermal boundary resistance was smaller for the large cell than for the small cell. Furthermore, the MD-predicted values were lower than the diffusion mismatch model (DMM-predicted values. The phonon density of states (DOS was calculated for all the cases to examine the underlying nature of the temperature dependence and size effect of thermal boundary resistance. We found that the phonon DOS was modified in the interface regions. The phonon DOS better matched between Si and Ge in the interface region than in the bulk region. Furthermore, in interface Si, the population of low-frequency phonons was found to increase with increasing temperature and cell size. We suggest that the increasing population of low-frequency phonons increased the phonon transmission coefficient at the interface, leading to the temperature dependence and size effect on thermal boundary resistance.

  13. Experiments and numerical simulations of fluctuating thermal stratification in a branch pipe

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Akira; Murase, Michio; Sasaki, Toru [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan); Takenaka, Nobuyuki; Hamatani, Daisuke [Kobe Univ. (Japan)

    2002-09-01

    Many pipes branch off from the main pipe in plants. When the main flow in the main pipe is hotter than a branch pipe that branches off downward, the hot water penetrates into the branch pipe with the cavity flow that is induced by the main flow and causes thermal stratification. If the interface of the stratification fluctuates in an occluded branch pipe, thermal fatigue may occur in pipe wall. Some experiments and numerical simulations were conducted to elucidate the mechanism of this fluctuating thermal stratification. The vortex structures were observed in the experiments of straight or bent branch pipes. When the main flow was heated and the thermal stratification interface was at the elbow, a ''burst'' phenomenon occurred in the interface in connection with large heat fluctuation. The effects of pipe shape on the length of penetration were investigated in order to modify simulation conditions. The vortex structures and the fluctuating thermal stratification at elbow in the numerical simulation showed good agreement with experiments. (author)

  14. Parallel linear solvers for simulations of reactor thermal hydraulics

    International Nuclear Information System (INIS)

    Yan, Y.; Antal, S.P.; Edge, B.; Keyes, D.E.; Shaver, D.; Bolotnov, I.A.; Podowski, M.Z.

    2011-01-01

    The state-of-the-art multiphase fluid dynamics code, NPHASE-CMFD, performs multiphase flow simulations in complex domains using implicit nonlinear treatment of the governing equations and in parallel, which is a very challenging environment for the linear solver. The present work illustrates how the Portable, Extensible Toolkit for Scientific Computation (PETSc) and scalable Algebraic Multigrid (AMG) preconditioner from Hypre can be utilized to construct robust and scalable linear solvers for the Newton correction equation obtained from the discretized system of governing conservation equations in NPHASE-CMFD. The overall long-tem objective of this work is to extend the NPHASE-CMFD code into a fully-scalable solver of multiphase flow and heat transfer problems, applicable to both steady-state and stiff time-dependent phenomena in complete fuel assemblies of nuclear reactors and, eventually, the entire reactor core (such as the Virtual Reactor concept envisioned by CASL). This campaign appropriately begins with the linear algebraic equation solver, which is traditionally a bottleneck to scalability in PDE-based codes. The computational complexity of the solver is usually superlinear in problem size, whereas the rest of the code, the “physics” portion, usually has its complexity linear in the problem size. (author)

  15. Site fidelity, mate fidelity, and breeding dispersal in American kestrels

    Science.gov (United States)

    Steenhof, K.; Peterson, B.E.

    2009-01-01

    We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

  16. The effects of pen partitions and thermal pig simulators on airflow in a livestock test room

    DEFF Research Database (Denmark)

    Bjerg, B.; Svidt, Kjeld; Zhang, G.

    2000-01-01

    measurements and CFD simulations showed that the introduction of pen partitions and thermal pig simulators reduced the air velocities in the occupied zone of the test room. Detailed geometric modelling of the animals might often be unnecessary for simulation of airflow in livestock rooms. This will especially......The aim of this work was to investigate the influence of pen partitions and heated simulated pigs on airflow in a slot ventilated test room and to evaluate computer fluid dynamics (CFD) as a tool to predict airflow in livestock rooms. To obtain two-dimensional flow in the occupied zone, four...... guiding plates were mounted beneath the ceiling in the test room. Experiments were carried out in three arrangements: (a) the room with guiding plates; (b) the room with guiding plates and eight heated pig simulators; and (c) the room with guiding plates, eight heated pig simulators and 0.8 m high...

  17. Simulation of thermal environment in a three-layer vinyl greenhouse by natural ventilation control

    Science.gov (United States)

    Jin, Tea-Hwan; Shin, Ki-Yeol; Yoon, Si-Won; Im, Yong-Hoon; Chang, Ki-Chang

    2017-11-01

    A high energy, efficient, harmonious, ecological greenhouse has been highlighted by advanced future agricultural technology recently. This greenhouse is essential for expanding the production cycle toward growth conditions through combined thermal environmental control. However, it has a negative effect on farming income via huge energy supply expenses. Because not only production income, but operating costs related to thermal load for thermal environment control is important in farming income, it needs studies such as a harmonious ecological greenhouse using natural ventilation control. This study is simulated for energy consumption and thermal environmental conditions in a three-layered greenhouse by natural ventilation using window opening. A virtual 3D model of a three-layered greenhouse was designed based on the real one in the Gangneung area. This 3D model was used to calculate a thermal environment state such as indoor temperature, relative humidity, and thermal load in the case of a window opening rate from 0 to 100%. There was also a heat exchange operated for heating or cooling controlled by various setting temperatures. The results show that the cooling load can be reduced by natural ventilation control in the summer season, and the heat exchange capacity for heating can also be simulated for growth conditions in the winter season.

  18. Simulation of thermal environment in a three-layer vinyl greenhouse by natural ventilation control

    Directory of Open Access Journals (Sweden)

    Jin Tea-Hwan

    2017-01-01

    Full Text Available A high energy, efficient, harmonious, ecological greenhouse has been highlighted by advanced future agricultural technology recently. This greenhouse is essential for expanding the production cycle toward growth conditions through combined thermal environmental control. However, it has a negative effect on farming income via huge energy supply expenses. Because not only production income, but operating costs related to thermal load for thermal environment control is important in farming income, it needs studies such as a harmonious ecological greenhouse using natural ventilation control. This study is simulated for energy consumption and thermal environmental conditions in a three-layered greenhouse by natural ventilation using window opening. A virtual 3D model of a three-layered greenhouse was designed based on the real one in the Gangneung area. This 3D model was used to calculate a thermal environment state such as indoor temperature, relative humidity, and thermal load in the case of a window opening rate from 0 to 100%. There was also a heat exchange operated for heating or cooling controlled by various setting temperatures. The results show that the cooling load can be reduced by natural ventilation control in the summer season, and the heat exchange capacity for heating can also be simulated for growth conditions in the winter season.

  19. Development of the NSSS thermal-hydraulic program for YGN unit 1 simulator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Doo; Jeong, Jae Jun; Lee, Won Jae; Chung, Bub Dong; Ha, Kwi Seok; Kang, Kyung Ho

    2000-09-01

    The NSSS thermal-hydraulic programs installed in the domestic full-scope power plant simulators were provided in early 1980s by foreign vendors. Because of limited computational capability at that time, they usually adopt very simplified physical models for a real-time simulation of NSSS thermal-hydraulic phenomena, which entails inaccurate results and the possibility of so-called 'negative training', especially for complicated two-phase flows in the reactor coolant system. To resolve the problem, we developed a realistic NSSS T/H program (named 'ARTS' code) for use in YongGwang Nuclear Unit 1 full-scope simulator. The best-estimate code RETRAN03, developed by EPRI and approved by USNRC, was selected as a reference code of ARTS. For the development of ARTS, the followings have been performed: -Improvement of the robustness of RETRAN - Improvement of the real-time simulation capability of RETRAN - Optimum input data generation for the NSSS simulation - New model development that cannot be efficiently modeled by RETRAN - Assessment of the ARTS code. The systematic assessment of ARTS has been conducted in both personal computers (Windows 98, Visual fortran) and the simulator development environment (Windows NT, GSE simulator development tool). The results were resonable in terms of accuracy, real-time simulation and robustness.

  20. Development of the NSSS thermal-hydraulic program for YGN unit 1 simulator

    International Nuclear Information System (INIS)

    Kim, Kyung Doo; Jeong, Jae Jun; Lee, Won Jae; Chung, Bub Dong; Ha, Kwi Seok; Kang, Kyung Ho

    2000-09-01

    The NSSS thermal-hydraulic programs installed in the domestic full-scope power plant simulators were provided in early 1980s by foreign vendors. Because of limited computational capability at that time, they usually adopt very simplified physical models for a real-time simulation of NSSS thermal-hydraulic phenomena, which entails inaccurate results and the possibility of so-called 'negative training', especially for complicated two-phase flows in the reactor coolant system. To resolve the problem, we developed a realistic NSSS T/H program (named 'ARTS' code) for use in YongGwang Nuclear Unit 1 full-scope simulator. The best-estimate code RETRAN03, developed by EPRI and approved by USNRC, was selected as a reference code of ARTS. For the development of ARTS, the followings have been performed: -Improvement of the robustness of RETRAN - Improvement of the real-time simulation capability of RETRAN - Optimum input data generation for the NSSS simulation - New model development that cannot be efficiently modeled by RETRAN - Assessment of the ARTS code. The systematic assessment of ARTS has been conducted in both personal computers (Windows 98, Visual fortran) and the simulator development environment (Windows NT, GSE simulator development tool). The results were resonable in terms of accuracy, real-time simulation and robustness

  1. Comparison of fabric skins for the simulation of sweating on thermal manikins

    Science.gov (United States)

    Koelblen, Barbara; Psikuta, Agnes; Bogdan, Anna; Annaheim, Simon; Rossi, René M.

    2017-09-01

    Sweating is an important thermoregulatory process helping to dissipate heat and, thus, to prevent overheating of the human body. Simulations of human thermo-physiological responses in hot conditions or during exercising are helpful for assessing heat stress; however, realistic sweating simulation and evaporative cooling is needed. To this end, thermal manikins dressed with a tight fabric skin can be used, and the properties of this skin should help human-like sweat evaporation simulation. Four fabrics, i.e., cotton with elastane, polyester, polyamide with elastane, and a skin provided by a manikin manufacturer (Thermetrics) were compared in this study. The moisture management properties of the fabrics have been investigated in basic tests with regard to all phases of sweating relevant for simulating human thermo-physiological responses, namely, onset of sweating, fully developed sweating, and drying. The suitability of the fabrics for standard tests, such as clothing evaporative resistance measurements, was evaluated based on tests corresponding to the middle phase of sweating. Simulations with a head manikin coupled to a thermo-physiological model were performed to evaluate the overall performance of the skins. The results of the study showed that three out of four evaluated fabrics have adequate moisture management properties with regard to the simulation of sweating, which was confirmed in the coupled simulation with the head manikin. The presented tests are helpful for comparing the efficiency of different fabrics to simulate sweat-induced evaporative cooling on thermal manikins.

  2. Thermal inertia and energy efficiency – Parametric simulation assessment on a calibrated case study

    International Nuclear Information System (INIS)

    Aste, Niccolò; Leonforte, Fabrizio; Manfren, Massimiliano; Mazzon, Manlio

    2015-01-01

    Highlights: • We perform a parametric simulation study on a calibrated building energy model. • We introduce adaptive shadings and night free cooling in simulations. • We analyze the effect of thermal capacity on the parametric simulations results. • We recognize that cooling demand and savings scales linearly with thermal capacity. • We assess the advantage of medium-heavy over medium and light configurations. - Abstract: The reduction of energy consumption for heating and cooling services in the existing building stock is a key challenge for global sustainability today and buildings’ envelopes retrofit is one the main issues. Most of the existing buildings’ envelopes have low levels of insulation, high thermal losses due to thermal bridges and cracks, absence of appropriate solar control, etc. Further, in building refurbishment, the importance of a system level approach is often undervalued in favour of simplistic “off the shelf” efficient solutions, focused on the reduction of thermal transmittance and on the enhancement of solar control capabilities. In many cases, the importance of the dynamic thermal properties is often neglected or underestimated and the effective thermal capacity is not properly considered as one of the design parameters. The research presented aims to critically assess the influence of the dynamic thermal properties of the building fabric (roof, walls and floors) on sensible heating and cooling energy demand for a case study. The case study chosen is an existing office building which has been retrofitted in recent years and whose energy model has been calibrated according to the data collected in the monitoring process. The research illustrates the variations of the sensible thermal energy demand of the building in different retrofit scenarios, and relates them to the variations of the dynamic thermal properties of the construction components. A parametric simulation study has been performed, encompassing the use of

  3. Model of natural ventilation by using a coupled thermal-airflow simulation program

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg; Remmen, Arne

    2012-01-01

    This article presents a model of natural ventilation of buildings at the stage of design and a consequence of the behaviour of the occupants. An evaluation is made by coupling multizone air modelling and thermal building simulation using a deterministic set of input factors comprising among others...

  4. Application of thermal sterilization regimes simulation for improvement of canned foods quality factors

    Directory of Open Access Journals (Sweden)

    Stolyanov A.V.

    2015-03-01

    Full Text Available Results of comparison of optimization methods of thermal sterilization temperature-time regimes have been described. It has been shown that due to simulation the final canned foods’ quality factors are significantly improved, sterilization process time is decreased and energy consumption is reduced without sacrificing actual final lethality value

  5. Dynamic simulation of a biomass domestic boiler under thermally thick considerations

    NARCIS (Netherlands)

    Gómez, M. A.; Porteiro, J.; De la Cuesta de Cal, Daniel; Patiño, D.; Míguez, J. L.

    2017-01-01

    A biomass combustion model with a thermally thick approach is presented and applied to the simulation of a commercial biomass domestic boiler. A subgrid scale model is used to divide the particles into several grid points, each representing one of the different combustion stages. These grid points

  6. Molecular-dynamics simulation of crystalline 18-crown-6: thermal shortening of covalent bonds

    NARCIS (Netherlands)

    van Eerden, J.; Harkema, Sybolt; Feil, D.

    1990-01-01

    Molecular-dynamics simulations of crystalline 18-crown-6 have been performed in a study of the apparent thermal shortening of covalent bonds observed in crystal structures. At 100 K, a shortening of 0.006 _+ 0.001 A for C----C and C----O bonds was obtained. This result was found to be independent of

  7. Advances in thermal hydraulic and neutronic simulation for reactor analysis and safety

    International Nuclear Information System (INIS)

    Tentner, A.M.; Blomquist, R.N.; Canfield, T.R.; Ewing, T.F.; Garner, P.L.; Gelbard, E.M.; Gross, K.C.; Minkoff, M.; Valentin, R.A.

    1993-01-01

    This paper describes several large-scale computational models developed at Argonne National Laboratory for the simulation and analysis of thermal-hydraulic and neutronic events in nuclear reactors and nuclear power plants. The impact of advanced parallel computing technologies on these computational models is emphasized

  8. Numerical simulation of thermal stratification in cold legs by using OpenFOAM

    International Nuclear Information System (INIS)

    Cai, Jiejin; Watanabe, Tadashi

    2011-01-01

    During a small-break loss-of-coolant accident in pressurized water reactors (PWRs), emergency core cooling system (ECCS) is actuated and cold water is injected into cold legs. Insufficient mixing of injected cold water and hot primary coolant results in thermal stratification, which is a matter of concern for evaluation of pressurized thermal shock (PTS) in view of aging and life extension of nuclear power plants. In this study, an open source CFD software, OpenFOAM, is used to simulate mixing and thermal stratification in the cold leg of ROSA/LSTF, which is the largest thermal-hydraulic integral test facility simulating PWR. One of the cold-leg is numerically simulated from the outlet of primary coolant pump to the inlet of downcomer. ECCS water is injected from injection nozzle connected at the top of the cold leg into the steady-state natural circulation flow under high-pressure and high-temperature conditions. The temperature distribution in the cold leg is compared with experimental and FLUENT's results. Effects of turbulent flow models and secondary flow due to the elbow section of the cold leg are discussed for the case with the single-phase natural circulation. Injection into a two-phase stratified flow is also simulated and predictive and numerical capabilities of OpenFOAM are discussed. (author)

  9. Numerical simulation of thermal stratification in cold legs by using openFOAM

    International Nuclear Information System (INIS)

    Cai, Jiejin; Watanabe, Tadashi

    2010-01-01

    During a small-break loss-of-coolant accident in pressurized water reactors (PWRs), emergency core cooling system (ECCS) is actuated and cold water is injected into cold legs. Insufficient mixing of injected cold water and hot primary coolant results in thermal stratification, which is a matter of concern for evaluation of pressurized thermal shock (PTS) in view of aging and life extension of nuclear power plants. In this study, an open source CFD software, OpenFOAM, is used to simulate mixing and thermal stratification in the cold leg of ROSA/LSTF, which is the largest thermal-hydraulic integral test facility simulating PWR. One of the cold-leg is numerically simulated from the outlet of primary coolant pump to the inlet of downcomer. ECCS water is injected from injection nozzle connected at the top of the cold leg into the steady-state natural circulation flow under high-pressure and high-temperature conditions. The temperature distribution in the cold leg is compared with experimental and FLUENT's results. Effects of turbulent flow models and secondary flow due to the elbow section of the cold leg are discussed for the case with the single-phase natural circulation. Injection into a two-phase stratified flow is also simulated and predictive and numerical capabilities of OpenFOAM are discussed. (author)

  10. Thermal conductivity of nanofluids and size distribution of nanoparticles by Monte Carlo simulations

    International Nuclear Information System (INIS)

    Feng Yongjin; Yu Boming; Feng Kaiming; Xu Peng; Zou Mingqing

    2008-01-01

    Nanofluids, a class of solid-liquid suspensions, have received an increasing attention and studied intensively because of their anomalously high thermal conductivites at low nanoparticle concentration. Based on the fractal character of nanoparticles in nanofluids, the probability model for nanoparticle's sizes and the effective thermal conductivity model are derived, in which the effect of the microconvection due to the Brownian motion of nanoparticles in the fluids is taken into account. The proposed model is expressed as a function of the thermal conductivities of the base fluid and the nanoparticles, the volume fraction, fractal dimension for particles, the size of nanoparticles, and the temperature, as well as random number. This model has the characters of both analytical and numerical solutions. The Monte Carlo simulations combined with the fractal geometry theory are performed. The predictions by the present Monte Carlo simulations are shown in good accord with the existing experimental data.

  11. Comparison of the force applied on oral structures during intubation attempts by novice physicians between the Macintosh direct laryngoscope, Airway Scope and C-MAC PM: a high-fidelity simulator-based study.

    Science.gov (United States)

    Nakanishi, Taizo; Shiga, Takashi; Homma, Yosuke; Koyama, Yasuaki; Goto, Tadahiro

    2016-05-23

    We examined whether the use of Airway Scope (AWS) and C-MAC PM (C-MAC) decreased the force applied on oral structures during intubation attempts as compared with the force applied with the use of Macintosh direct laryngoscope (DL). Prospective cross-over study. A total of 35 novice physicians participated. We used 6 simulation scenarios based on the difficulty of intubation and intubation devices. Our primary outcome measures were the maximum force applied on the maxillary incisors and tongue during intubation attempts, measured by a high-fidelity simulator. The maximum force applied on maxillary incisors was higher with the use of the C-MAC than with the DL and AWS in the normal airway scenario (DL, 26 Newton (N); AWS, 18 N; C-MAC, 52 N; p<0.01) and the difficult airway scenario (DL, 42 N; AWS, 24 N; C-MAC, 68 N; p<0.01). In contrast, the maximum force applied on the tongue was higher with the use of the DL than with the AWS and C-MAC in both airway scenarios (DL, 16 N; AWS, 1 N; C-MAC, 7 N; p<0.01 in the normal airway scenario; DL, 12 N; AWS, 4 N; C-MAC, 7 N; p<0.01 in the difficult airway scenario). The use of C-MAC, compared with the DL and AWS, was associated with the higher maximum force applied on maxillary incisors during intubation attempts. In contrast, the use of video laryngoscopes was associated with the lower force applied on the tongue in both airway scenarios, compared with the DL. Our study was a simulation-based study, and further research on living patients would be warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  12. interThermalPhaseChangeFoam—A framework for two-phase flow simulations with thermally driven phase change

    Directory of Open Access Journals (Sweden)

    Mahdi Nabil

    2016-01-01

    Full Text Available The volume-of-fluid (VOF approach is a mature technique for simulating two-phase flows. However, VOF simulation of phase-change heat transfer is still in its infancy. Multiple closure formulations have been proposed in the literature, each suited to different applications. While these have enabled significant research advances, few implementations are publicly available, actively maintained, or inter-operable. Here, a VOF solver is presented (interThermalPhaseChangeFoam, which incorporates an extensible framework for phase-change heat transfer modeling, enabling simulation of diverse phenomena in a single environment. The solver employs object oriented OpenFOAM library features, including Run-Time-Type-Identification to enable rapid implementation and run-time selection of phase change and surface tension force models. The solver is packaged with multiple phase change and surface tension closure models, adapted and refined from earlier studies. This code has previously been applied to study wavy film condensation, Taylor flow evaporation, nucleate boiling, and dropwise condensation. Tutorial cases are provided for simulation of horizontal film condensation, smooth and wavy falling film condensation, nucleate boiling, and bubble condensation. Validation and grid sensitivity studies, interfacial transport models, effects of spurious currents from surface tension models, effects of artificial heat transfer due to numerical factors, and parallel scaling performance are described in detail in the Supplemental Material (see Appendix A. By incorporating the framework and demonstration cases into a single environment, users can rapidly apply the solver to study phase-change processes of interest.

  13. interThermalPhaseChangeFoam-A framework for two-phase flow simulations with thermally driven phase change

    Science.gov (United States)

    Nabil, Mahdi; Rattner, Alexander S.

    The volume-of-fluid (VOF) approach is a mature technique for simulating two-phase flows. However, VOF simulation of phase-change heat transfer is still in its infancy. Multiple closure formulations have been proposed in the literature, each suited to different applications. While these have enabled significant research advances, few implementations are publicly available, actively maintained, or inter-operable. Here, a VOF solver is presented (interThermalPhaseChangeFoam), which incorporates an extensible framework for phase-change heat transfer modeling, enabling simulation of diverse phenomena in a single environment. The solver employs object oriented OpenFOAM library features, including Run-Time-Type-Identification to enable rapid implementation and run-time selection of phase change and surface tension force models. The solver is packaged with multiple phase change and surface tension closure models, adapted and refined from earlier studies. This code has previously been applied to study wavy film condensation, Taylor flow evaporation, nucleate boiling, and dropwise condensation. Tutorial cases are provided for simulation of horizontal film condensation, smooth and wavy falling film condensation, nucleate boiling, and bubble condensation. Validation and grid sensitivity studies, interfacial transport models, effects of spurious currents from surface tension models, effects of artificial heat transfer due to numerical factors, and parallel scaling performance are described in detail in the Supplemental Material (see Appendix A). By incorporating the framework and demonstration cases into a single environment, users can rapidly apply the solver to study phase-change processes of interest.

  14. Effect of point defects on the thermal conductivity of UO2: molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiang-Yang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stanek, Christopher Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Andersson, Anders David Ragnar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-21

    The thermal conductivity of uranium dioxide (UO2) fuel is an important materials property that affects fuel performance since it is a key parameter determining the temperature distribution in the fuel, thus governing, e.g., dimensional changes due to thermal expansion, fission gas release rates, etc. [1] The thermal conductivity of UO2 nuclear fuel is also affected by fission gas, fission products, defects, and microstructural features such as grain boundaries. Here, molecular dynamics (MD) simulations are carried out to determine quantitatively, the effect of irradiation induced point defects on the thermal conductivity of UO2, as a function of defect concentrations, for a range of temperatures, 300 – 1500 K. The results will be used to develop enhanced continuum thermal conductivity models for MARMOT and BISON by INL. These models express the thermal conductivity as a function of microstructure state-variables, thus enabling thermal conductivity models with closer connection to the physical state of the fuel [2].

  15. Impact of vacancies on the thermal conductivity of graphene nanoribbons: A molecular dynamics simulation study

    Directory of Open Access Journals (Sweden)

    Maliha Noshin

    2017-01-01

    Full Text Available Equilibrium molecular dynamics simulation using 2nd generation Reactive Bond Order interatomic potential has been performed to model the thermal transport of nanometer sized zigzag defected graphene nanoribbons (GNRs containing several types of vacancies. We have investigated the thermal conductivity of defected GNRs as a function of vacancy concentration within a range of 0.5% to 5% and temperature ranging from 300K to 600K, along with a comparative analysis of those for pristine GNRs. We find that, a vacancy concentration of 0.5% leads to over 90% reduction in the thermal conductivity of GNRs. At low defect concentration, the decay rate is faster but ceases gradually at higher defect concentration. With the increasing temperature, thermal conductivity of defected GNRs decreases but shows less variation in comparison with that of pristine GNRs at higher temperatures. Such comprehensive study on several vacancy type defects in GNRs can provide further insight to tune up the thermal transport characteristics of low dimensional carbon nanostructures. This eventually would encourage the characterization of more stable thermal properties in thermal devices at an elevated temperature as well as the potential applicability of GNRs as thermoelectrics.

  16. Thermal large Eddy simulations and experiments in the framework of non-isothermal blowing

    International Nuclear Information System (INIS)

    Brillant, G.

    2004-06-01

    The aim of this work is to study thermal large-eddy simulations and to determine the nonisothermal blowing impact on a turbulent boundary layer. An experimental study is also carried out in order to complete and validate simulation results. In a first time, we developed a turbulent inlet condition for the velocity and the temperature, which is necessary for the blowing simulations.We studied the asymptotic behavior of the velocity, the temperature and the thermal turbulent fluxes in a large-eddy simulation point of view. We then considered dynamics models for the eddy-diffusivity and we simulated a turbulent channel flow with imposed temperature, imposed flux and adiabatic walls. The numerical and experimental study of blowing permitted to obtain to the modifications of a thermal turbulent boundary layer with the blowing rate. We observed the consequences of the blowing on mean and rms profiles of velocity and temperature but also on velocity-velocity and velocity-temperature correlations. Moreover, we noticed an increase of the turbulent structures in the boundary layer with blowing. (author)

  17. TRSM-a thermal-hydraulic real-time simulation model for PWR

    International Nuclear Information System (INIS)

    Zhou Weichang

    1997-01-01

    TRSM (a Thermal-hydraulic Real-time Simulation Model) has been developed for PWR real-time simulation and best-estimate prediction of normal operating and abnormal accident conditions. It is a non-equilibrium two phase flow thermal-hydraulic model based on five basic conservation equations. A drift flux model is used to account for the unequal velocities of liquid and gaseous mixture, with or without the presence of the noncondensibles. Critical flow models are applied for break flow and valve flow calculations. A 5-regime two phase heat convection model is applied for clad-to-coolant as well as fluid-to-tubing heat transfer. A rigorous reactor coolant pump model is used to calculate the pressure drop and rise for the suction and discharge ends with complete pump characteristics curves included. The TRSM model has been adapted in the full-scale training simulator of Qinshan Nuclear Power Plant 300 MW unit to simulate the thermal-hydraulic performance of the NSSS. The simulation results of a cold leg LOCA and a steam generator tube rupture (SGTR) accident are presented

  18. Numerical Simulations of Pillar Structured Solid State Thermal Neutron Detector Efficiency and Gamma Discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Conway, A; Wang, T; Deo, N; Cheung, C; Nikolic, R

    2008-06-24

    This work reports numerical simulations of a novel three-dimensionally integrated, {sup 10}boron ({sup 10}B) and silicon p+, intrinsic, n+ (PIN) diode micropillar array for thermal neutron detection. The inter-digitated device structure has a high probability of interaction between the Si PIN pillars and the charged particles (alpha and {sup 7}Li) created from the neutron - {sup 10}B reaction. In this work, the effect of both the 3-D geometry (including pillar diameter, separation and height) and energy loss mechanisms are investigated via simulations to predict the neutron detection efficiency and gamma discrimination of this structure. The simulation results are demonstrated to compare well with the measurement results. This indicates that upon scaling the pillar height, a high efficiency thermal neutron detector is possible.

  19. Simulation of attenuation of thermal fluctuations near a plate impinged by jets

    International Nuclear Information System (INIS)

    Simoneau, J.P.

    2001-01-01

    In nuclear reactors, and especially in liquid sodium cooled ones, the combination of temperature differences inside cooling fluid, turbulent flows and high heat transfer coefficients is a potential source of the thermal striping process. Such a phenomenon has been studied for several years by using Large Eddy Simulation models. The present paper focuses on the attenuation of the thermal fluctuations in the boundary layer. The knowledge of this amplitude reduction is of prime importance for subsequent mechanical analyses. A Large Eddy Simulation model is implemented in the Star-cd code, including discretization of the viscous sublayer. The numerical simulation of two parallel jets impinging a flat plate in water is then performed and positively compared to corresponding experimental results. (author)

  20. 3D thermal simulations and modeling of multi-finger InP DHBTs for millimeter-wave power amplifiers

    DEFF Research Database (Denmark)

    Midili, Virginio; Nodjiadjim, V.; Johansen, Tom Keinicke

    2017-01-01

    This paper presents the comparison between the simulated and measured thermal resistance of InP Double Heterojunction Bipolar Transistors (DHBT). 3D thermal simulations were carried out in order to compute the temperature distribution across the full structure due to a constant power excitation...

  1. The effect of thermal velocities on structure formation in N-body simulations of warm dark matter

    Science.gov (United States)

    Leo, Matteo; Baugh, Carlton M.; Li, Baojiu; Pascoli, Silvia

    2017-11-01

    We investigate the impact of thermal velocities in N-body simulations of structure formation in warm dark matter models. Adopting the commonly used approach of adding thermal velocities, randomly selected from a Fermi-Dirac distribution, to the gravitationally-induced velocities of the simulation particles, we compare the matter and velocity power spectra measured from CDM and WDM simulations, in the latter case with and without thermal velocities. This prescription for adding thermal velocities introduces numerical noise into the initial conditions, which influences structure formation. At early times, the noise affects dramatically the power spectra measured from simulations with thermal velocities, with deviations of the order of ~ Script O(10) (in the matter power spectra) and of the order of ~ Script O(102) (in the velocity power spectra) compared to those extracted from simulations without thermal velocities. At late times, these effects are less pronounced with deviations of less than a few percent. Increasing the resolution of the N-body simulation shifts these discrepancies to higher wavenumbers. We also find that spurious haloes start to appear in simulations which include thermal velocities at a mass that is ~3 times larger than in simulations without thermal velocities.

  2. Fidelity Optimization of Microprocessor System Simulations.

    Science.gov (United States)

    1981-03-01

    effort feasible in terms of required CPU time would be to employ a separate clock with an artificially compressed time base in the serial...RETURN ILINCR -NU𔃾OPS D.% PROt.ESSING 900 IF IIERP2.NF.41 GO TO 1000 IFRCOD - L CALL VAIRCO 1A(61,NUMVALLEPCOOl IEPRZ -IEACCO IF hEARR .GT. 01 RETURN I

  3. A model selection support system for numerical simulations of nuclear thermal-hydraulics

    International Nuclear Information System (INIS)

    Gofuku, Akio; Shimizu, Kenji; Sugano, Keiji; Yoshikawa, Hidekazu; Wakabayashi, Jiro

    1990-01-01

    In order to execute efficiently a dynamic simulation of a large-scaled engineering system such as a nuclear power plant, it is necessary to develop intelligent simulation support system for all phases of the simulation. This study is concerned with the intelligent support for the program development phase and is engaged in the adequate model selection support method by applying AI (Artificial Intelligence) techniques to execute a simulation consistent with its purpose and conditions. A proto-type expert system to support the model selection for numerical simulations of nuclear thermal-hydraulics in the case of cold leg small break loss-of-coolant accident of PWR plant is now under development on a personal computer. The steps to support the selection of both fluid model and constitutive equations for the drift flux model have been developed. Several cases of model selection were carried out and reasonable model selection results were obtained. (author)

  4. A non-equilibrium simulation of thermal constriction in a cascaded arc hydrogen plasma

    International Nuclear Information System (INIS)

    Peerenboom, K S C; Goedheer, W J; Van Dijk, J; Kroesen, G M W

    2014-01-01

    The cascaded arc hydrogen plasma of Pilot-PSI is studied in a non-LTE model. We demonstrate that the effect of vibrationally excited molecules on the heavy-particle-assisted dissociation is crucial for obtaining thermal constriction. To the best of our knowledge, thermal constriction has not been obtained before in a non-LTE simulation. Probably, realistic numerical studies of this type of plasma were hindered by numerical problems, preventing the non-LTE simulations to show characteristic physical mechanisms such as thermal constriction. In this paper we show that with the help of appropriate numerical strategies thermal constriction can be obtained in a non-LTE simulation. To this end, a new source term linearization technique is developed, which ensures physical solutions even near chemical equilibrium where the composition is dominated by chemical source terms. Results of the model are compared with experiments on Pilot-PSI and show good agreement with pressure and voltage measurements in the source. (paper)

  5. Standard Practice for Solar Simulation for Thermal Balance Testing of Spacecraft

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1973-01-01

    1.1 Purpose: 1.1.1 The primary purpose of this practice is to provide guidance for making adequate thermal balance tests of spacecraft and components where solar simulation has been determined to be the applicable method. Careful adherence to this practice should ensure the adequate simulation of the radiation environment of space for thermal tests of space vehicles. 1.1.2 A corollary purpose is to provide the proper test environment for systems-integration tests of space vehicles. An accurate space-simulation test for thermal balance generally will provide a good environment for operating all electrical and mechanical systems in their various mission modes to determine interferences within the complete system. Although adherence to this practice will provide the correct thermal environment for this type of test, there is no discussion of the extensive electronic equipment and procedures required to support systems-integration testing. 1.2 Nonapplicability—This practice does not apply to or provide inco...

  6. HELIOSEISMIC HOLOGRAPHY OF SIMULATED SUNSPOTS: MAGNETIC AND THERMAL CONTRIBUTIONS TO TRAVEL TIMES

    Energy Technology Data Exchange (ETDEWEB)

    Felipe, T. [Departamento de Astrofísica, Universidad de La Laguna, E-38205 La Laguna, Tenerife (Spain); Braun, D. C.; Crouch, A. D. [NorthWest Research Associates, Colorado Research Associates, Boulder, CO 80301 (United States); Birch, A. C., E-mail: tobias@iac.es [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2016-10-01

    Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of local helioseismic measurements of sunspots has long been a challenge. With the aim of understanding these measurements, we carry out numerical simulations of wave propagation through sunspots. Helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. We use additional numerical experiments to determine, separately, the influence of the thermal structure of the sunspot and the direct effect of the sunspot magnetic field. We use the ray approximation to show that the travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level in the simulations) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it would suggest a path toward inversions for sunspot structure.

  7. HELIOSEISMIC HOLOGRAPHY OF SIMULATED SUNSPOTS: MAGNETIC AND THERMAL CONTRIBUTIONS TO TRAVEL TIMES

    International Nuclear Information System (INIS)

    Felipe, T.; Braun, D. C.; Crouch, A. D.; Birch, A. C.

    2016-01-01

    Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of local helioseismic measurements of sunspots has long been a challenge. With the aim of understanding these measurements, we carry out numerical simulations of wave propagation through sunspots. Helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. We use additional numerical experiments to determine, separately, the influence of the thermal structure of the sunspot and the direct effect of the sunspot magnetic field. We use the ray approximation to show that the travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level in the simulations) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it would suggest a path toward inversions for sunspot structure.

  8. Direct numerical simulation of thermally-stratified turbulent boundary layer subjected to adverse pressure gradient

    International Nuclear Information System (INIS)

    Hattori, Hirofumi; Kono, Amane; Houra, Tomoya

    2016-01-01

    Highlights: • We study various thermally-stratified turbulent boundary layers having adverse pressure gradient (APG) by means of DNS. • The detailed turbulent statistics and structures in various thermally-stratified turbulent boundary layers having APG are discussed. • It is found that the friction coefficient and Stanton number decrease along the streamwise direction due to the effects of stable thermal stratification and APG, but those again increase due to the APG effect in the case of weak stable thermal stratification. • In the case of strong stable stratification with or without APG, the flow separation is observed in the downstream region. - Abstract: The objective of this study is to investigate and observe turbulent heat transfer structures and statistics in thermally-stratified turbulent boundary layers subjected to a non-equilibrium adverse pressure gradient (APG) by means of direct numerical simulation (DNS). DNSs are carried out under conditions of neutral, stable and unstable thermal stratifications with a non-equilibrium APG, in which DNS results reveal heat transfer characteristics of thermally-stratified non-equilibrium APG turbulent boundary layers. In cases of thermally-stratified turbulent boundary layers affected by APG, heat transfer performances increase in comparison with a turbulent boundary layer with neutral thermal stratification and zero pressure gradient (ZPG). Especially, it is found that the friction coefficient and Stanton number decrease along the streamwise direction due to the effects of stable thermal stratification and APG, but those again increase due to the APG effect in the case of weak stable thermal stratification (WSBL). Thus, the analysis for both the friction coefficient and Stanton number in the case of WSBL with/without APG is conducted using the FIK identity in order to investigate contributions from the transport equations, in which it is found that both Reynolds-shear-stress and the mean convection terms

  9. Monte Carlo simulation of a coded-aperture thermal neutron camera

    International Nuclear Information System (INIS)

    Dioszegi, I.; Salwen, C.; Forman, L.

    2011-01-01

    We employed the MCNPX Monte Carlo code to simulate image formation in a coded-aperture thermal-neutron camera. The camera, developed at Brookhaven National Laboratory (BNL), consists of a 20 x 17 cm"2 active area "3He-filled position-sensitive wire chamber in a cadmium enclosure box. The front of the box is a coded-aperture cadmium mask (at present with three different resolutions). We tested the detector experimentally with various arrangements of moderated point-neutron sources. The purpose of using the Monte Carlo modeling was to develop an easily modifiable model of the device to predict the detector's behavior using different mask patterns, and also to generate images of extended-area sources or large numbers (up to ten) of them, that is important for nonproliferation and arms-control verification, but difficult to achieve experimentally. In the model, we utilized the advanced geometry capabilities of the MCNPX code to simulate the coded aperture mask. Furthermore, the code simulated the production of thermal neutrons from fission sources surrounded by a thermalizer. With this code we also determined the thermal-neutron shadow cast by the cadmium mask; the calculations encompassed fast- and epithermal-neutrons penetrating into the detector through the mask. Since the process of signal production in "3He-filled position-sensitive wire chambers is well known, we omitted this part from our modeling. Simplified efficiency values were used for the three (thermal, epithermal, and fast) neutron-energy regions. Electronic noise and the room's background were included as a uniform irradiation component. We processed the experimental- and simulated-images using identical LabVIEW virtual instruments. (author)

  10. Thermal-hydraulic simulation and analysis of Research Reactor Cooling Systems

    International Nuclear Information System (INIS)

    EL Khatib, H.H.A.

    2013-01-01

    The objective of the present study is to formulate a model to simulate the thermal hydraulic behavior of integrated cooling system in a typical material testing reactor (MTR) under loss of ultimate heat sink, the model involves three interactively coupled sub-models for reactor core, heat exchanger and cooling tower. The developed model predicts the temperature profiles in addition it predicts inlet and outlet temperatures of the hot and cold stream as well as the heat exchangers and cooling tower. The model is validated against PARET code for steady-state operation and also verified by the reactor operational records, and then the model is used to simulate the thermal-hydraulic behavior of the reactor under a loss of ultimate heat sink. The simulation is performed for two operational regimes named regime I of (11 MW) thermal power and three operated cooling tower cells and regime II of (22 MW) thermal power and six operated cooling tower cells. In regime I, the simulation is performed for 1, 2 and 3 cooling tower failed cells while in regime II, it is performed for 1, 2, 3, 4, 5 and 6 cooling tower failed cells. The safety action is conducted by the reactor protection system (RPS) named power reduction safety action, it is triggered to decrease the reactor power by amount of 20% of the present power when the water inlet temperature to the core reaches 43 degree C and a scram (emergency shutdown) is triggered in case of the inlet temperature reaches 44 degree C. The model results are analyzed and discussed. The temperature profiles of fuel, clad and coolant are predicted during transient where its maximum values are far from thermal hydraulic limits.

  11. Thermal hydraulic-Mechanic Integrated Simulation for Advanced Cladding Thermal Shock Fracture Analysis during Reflood Phase in LBLOCA

    Energy Technology Data Exchange (ETDEWEB)

    Son, Seong Min; Lee, You Ho; Cho, Jae Wan; Lee, Jeong Ik [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This study suggested thermal hydraulic-mechanical integrated stress based methodology for analyzing the behavior of ATF type claddings by SiC-Duplex cladding LBLOCA simulation. Also, this paper showed that this methodology could predict real experimental result well. That concept for enhanced safety of LWR called Advanced Accident-Tolerance Fuel Cladding (ATF cladding, ATF) is researched actively. However, current nuclear fuel cladding design criteria for zircaloy cannot be apply to ATF directly because those criteria are mainly based on limiting their oxidation. So, the new methodology for ATF design criteria is necessary. In this study, stress based analysis methodology for ATF cladding design criteria is suggested. By simulating LBLOCA scenario of SiC cladding which is the one of the most promising candidate of ATF. Also we'll confirm our result briefly through comparing some facts from other experiments. This result is validating now. Some of results show good performance with 1-D failure analysis code for SiC fuel cladding that already developed and validated by Lee et al,. It will present in meeting. Furthermore, this simulation presented the possibility of understanding the behavior of cladding deeper. If designer can predict the dangerous region and the time precisely, it may be helpful for designing nuclear fuel cladding geometry and set safety criteria.

  12. Power cables thermal protection by interval simulation of imprecise dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    Bontempi, G. [Universite Libre de Brussels (Belgium). Dept. d' Informatique; Vaccaro, A.; Villacci, D. [Universita del Sannio Benevento (Italy). Dept. of Engineering

    2004-11-01

    The embedding of advanced simulation techniques in power cables enables improved thermal protection because of higher accuracy, adaptiveness and. flexibility. In particular, they make possible (i) the accurate solution of differential equations describing the cables thermal dynamics and (ii) the adoption of the resulting solution in the accomplishment of dedicated protective functions. However, the use of model-based protective systems is exposed to the uncertainty affecting some model components (e.g. weather along the line route, thermophysical properties of the soil, cable parameters). When uncertainty can be described in terms of probability distribution, well-known techniques, such as Monte Carlo, are used to simulate the system behaviour. On the other hand, when the description of uncertainty in probabilistic terms is unfeasible or problematic, nonprobabilistic alternatives should be taken into consideration. This paper will discuss and compare three interval-based techniques as alternatives to probabilistic methods in the simulation of power cable dynamics. The experimental session will assess the interval-based approaches by simulating the thermal behaviour of medium voltage power cables.(author)

  13. Effects of deformability and thermal motion of lipid membrane on electroporation: By molecular dynamics simulations

    International Nuclear Information System (INIS)

    Sun, Sheng; Yin, Guangyao; Lee, Yi-Kuen; Wong, Joseph T.Y.; Zhang, Tong-Yi

    2011-01-01

    Research highlights: → MD simulations show that deformability and thermal motion of membrane affect electroporation. → Stiffer membrane inhibits electroporation and makes water penetrate from both sides. → Higher temperature accelerates electroporation. -- Abstract: Effects of mechanical properties and thermal motion of POPE lipid membrane on electroporation were studied by molecular dynamics simulations. Among simulations in which specific atoms of lipids were artificially constrained at their equilibrium positions using a spring with force constant of 2.0 kcal/(mol A 2 ) in the external electric field of 1.4 kcal/(mol A e), only constraint on lateral motions of lipid tails prohibited electroporation while non-tail parts had little effects. When force constant decreased to 0.2 kcal/(mol A 2 ) in the position constraints on lipid tails in the external electric field of 2.0 kcal/(mol A e), water molecules began to enter the membrane. Position constraints of lipid tails allow water to penetrate from both sides of membrane. Thermal motion of lipids can induce initial defects in the hydrophobic core of membrane, which are favorable nucleation sites for electroporation. Simulations at different temperatures revealed that as the temperature increases, the time taken to the initial pore formation will decrease.

  14. Peculiar features of modeling of thermal processes of the cutting area in the SOLIDWORKS SIMULATION system

    Directory of Open Access Journals (Sweden)

    Stepchin Ya.A.

    2017-04-01

    Full Text Available Management of thermo-physical process of cutting zone by changing certain parameters of the cutting regime, tool geometry or coolant using allows to achieve a higher level of handling performance. The forecasting of thermal processes during metal cutting is characterized by the multifactor of the model and the nonlinearity of the connection between the temperature field of the cutting zone and the processing parameters. Therefore realistic modeling of these processes with regard to the maximum number of influencing factors which will minimize the time and cost of experimental studies is very important. The research investigates the use of computer-aided design SolidWorks Simulation system to analyze the thermal processes occurring in the cutting zone during finishing turning of hardened circular steel cutting blade of superhard material. While modeling, the distribution of heat generated in cut (in the zone of plastic deformation of the workpiece and on the surfaces of friction of the cutting blade with chips and the treated surface is observed by four flows: to the tool, chips, workpiece and the environment. The limiting conditions for the existence of the developed model-geometric, physical and temporal limits are defined. Simulation is performed in steady and transient modes. Control of adequacy of simulation results is made. The conclusions of the analysis of opportunities of CAD SolidWorks Simulation System for research of thermal processes the cutting zone are drawn.

  15. Nuclear Thermal Rocket Element Environmental Simulator (NTREES) Phase II Upgrade Activities

    Science.gov (United States)

    Emrich, William J.; Moran, Robert P.; Pearson, J. Bose

    2013-01-01

    To support the on-going nuclear thermal propulsion effort, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The facility to perform this testing is referred to as the Nuclear Thermal Rocket Element Environment Simulator (NTREES). This device can simulate the environmental conditions (minus the radiation) to which nuclear rocket fuel components will be subjected during reactor operation. Test articles mounted in the simulator are inductively heated in such a manner so as to accurately reproduce the temperatures and heat fluxes which would normally occur as a result of nuclear fission and would be exposed to flowing hydrogen. Initial testing of a somewhat prototypical fuel element has been successfully performed in NTREES and the facility has now been shutdown to allow for an extensive reconfiguration of the facility which will result in a significant upgrade in its capabilities. Keywords: Nuclear Thermal Propulsion, Simulator

  16. Evaluation of the litcit software for thermal simulation of superficial lasers such as hair removal lasers

    Directory of Open Access Journals (Sweden)

    Shirkavand A

    2007-01-01

    Full Text Available Background and Objectives : In this study, we evaluate LITCIT software for its application as a thermal simulation software for superficial hair removal laser systems. Materials and Methods: Two articles were used as our references. Complete information regarding the tissues, such as optical/thermal properties and geometrical modeling and also the laser systems such as wavelength, spot size, pulse duration and fluence were extracted from these texts. Then, this information regarding the tissues and systems was entered into the LITCIT simulation software. Further, we ran the program and saved the results. Finally, we compared our results with the results in references and evaluated the. Results : Output results of the LITCIT show that they are consistent with the results of references that were calculated with a different thermal modeling. Such a small average error shows the accuracy of the software for simulation and calculating the temperature. Conclusions : This simulating software has a good ability to be used as a treatment planning software for superficial lasers. Thus, it can be used for the optimization of treatment parameters and protocols.

  17. Using Coupled Mesoscale Experiments and Simulations to Investigate High Burn-Up Oxide Fuel Thermal Conductivity

    Science.gov (United States)

    Teague, Melissa C.; Fromm, Bradley S.; Tonks, Michael R.; Field, David P.

    2014-12-01

    Nuclear energy is a mature technology with a small carbon footprint. However, work is needed to make current reactor technology more accident tolerant and to allow reactor fuel to be burned in a reactor for longer periods of time. Optimizing the reactor fuel performance is essentially a materials science problem. The current understanding of fuel microstructure have been limited by the difficulty in studying the structure and chemistry of irradiated fuel samples at the mesoscale. Here, we take advantage of recent advances in experimental capabilities to characterize the microstructure in 3D of irradiated mixed oxide (MOX) fuel taken from two radial positions in the fuel pellet. We also reconstruct these microstructures using Idaho National Laboratory's MARMOT code and calculate the impact of microstructure heterogeneities on the effective thermal conductivity using mesoscale heat conduction simulations. The thermal conductivities of both samples are higher than the bulk MOX thermal conductivity because of the formation of metallic precipitates and because we do not currently consider phonon scattering due to defects smaller than the experimental resolution. We also used the results to investigate the accuracy of simple thermal conductivity approximations and equations to convert 2D thermal conductivities to 3D. It was found that these approximations struggle to predict the complex thermal transport interactions between metal precipitates and voids.

  18. Simulating Physiological Response with a Passive Sensor Manikin and an Adaptive Thermal Manikin to Predict Thermal Sensation and Comfort

    Energy Technology Data Exchange (ETDEWEB)

    Rugh, John P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chaney, Larry [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hepokoski, Mark [ThermoAnalytics Inc.; Curran, Allen [ThermoAnalytics Inc.; Burke, Richard [Measurement Technology NW; Maranville, Clay [Ford Motor Company

    2015-04-14

    Reliable assessment of occupant thermal comfort can be difficult to obtain within automotive environments, especially under transient and asymmetric heating and cooling scenarios. Evaluation of HVAC system performance in terms of comfort commonly requires human subject testing, which may involve multiple repetitions, as well as multiple test subjects. Instrumentation (typically comprised of an array of temperature sensors) is usually only sparsely applied across the human body, significantly reducing the spatial resolution of available test data. Further, since comfort is highly subjective in nature, a single test protocol can yield a wide variation in results which can only be overcome by increasing the number of test replications and subjects. In light of these difficulties, various types of manikins are finding use in automotive testing scenarios. These manikins can act as human surrogates from which local skin and core temperatures can be obtained, which are necessary for accurately predicting local and whole body thermal sensation and comfort using a physiology-based comfort model (e.g., the Berkeley Comfort Model). This paper evaluates two different types of manikins, i) an adaptive sweating thermal manikin, which is coupled with a human thermoregulation model, running in real-time, to obtain realistic skin temperatures; and, ii) a passive sensor manikin, which is used to measure boundary conditions as they would act on a human, from which skin and core temperatures can be predicted using a thermophysiological model. The simulated physiological responses and comfort obtained from both of these manikin-model coupling schemes are compared to those of a human subject within a vehicle cabin compartment transient heat-up scenario.

  19. Survival of juvenile fishes receiving thermal and mechanical stresses in a simulated power plant condenser

    International Nuclear Information System (INIS)

    Kedl, R.J.; Coutant, C.C.

    Experiments were conducted in a water-recirculating loop to determine the effects of fluid-induced stresses (e.g., turbulence, pressure, and vacuum) on six species of larval fish and one species each of frog tadpoles and zooplankton. These stresses simulate the insults developed in the condenser portion, but not including the pump, of a steam power plant. Some experiments were conducted with thermal stresses superimposed on fluid-induced stresses. Fluid-induced stresses of the magnitude developed in these experiments were generally not fatal to the larval fish within the precision of the experiments, although some sublethal effects were noted. When thermal stress was superimposed on the fluid-induced stresses, the mortalities were equivalent to those resulting from thermal stress alone. Fluid-induced stresses of low magnitude were not fatal to Daphnia magna, but fluid-induced stresses of higher magnitude were responsible for significant mortalities. (U.S.)

  20. Thermal comfort in residential buildings: Comfort values and scales for building energy simulation

    Energy Technology Data Exchange (ETDEWEB)

    Peeters, Leen; D' haeseleer, William [Division of Applied Mechanics and Energy Conversion, University of Leuven (K.U.Leuven), Celestijnenlaan 300 A, B-3001 Leuven (Belgium); Dear, Richard de [Division of Environmental and Life Sciences, Macquarie University, Sydney (Australia); Hensen, Jan [Faculty of Architecture, Building and Planning, Technische Universiteit Eindhoven, Vertigo 6.18, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2009-05-15

    Building Energy Simulation (BES) programmes often use conventional thermal comfort theories to make decisions, whilst recent research in the field of thermal comfort clearly shows that important effects are not incorporated. The conventional theories of thermal comfort were set up based on steady state laboratory experiments. This, however, is not representing the real situation in buildings, especially not when focusing on residential buildings. Therefore, in present analysis, recent reviews and adaptations are considered to extract acceptable temperature ranges and comfort scales. They will be defined in an algorithm, easily implementable in any BES code. The focus is on comfortable temperature levels in the room, more than on the detailed temperature distribution within that room. (author)

  1. The CFD Simulation on Thermal Comfort in a library Building in the Tropics

    International Nuclear Information System (INIS)

    Yau, Y. H.; Ghazali, N. N. N.; Badarudin, A.; Goh, F. C.

    2010-01-01

    This paper presents a three-dimensional analysis for thermal comfort in a library. The room model includes library layout, equipment and peripheral positions as well as the positions of inlet and outlet air for IAQ controls. Cold clean air is supplied to the room through ceiling-mounted air grilles and exhausted through air grilles situated on the same ceiling. A commercial CFD package was used in this study to achieve solutions of the distribution of airflow velocity and temperature. Using high quality meshes is vital to the overall accuracy of the results. Simulation results show a good agreement with experimental data from the literature. This study has thoroughly analysed the indoor thermal conditions and airflow characteristics of the building. In addition, verification of the CFD program with experimental data showed that the program can provide reasonable and reliable predictions on thermal comfort performance with the help of precise boundary conditions.

  2. Large eddy simulation on thermal fluid mixing in a T-junction piping system

    Energy Technology Data Exchange (ETDEWEB)

    Selvam, P. Karthick; Kulenovic, R.; Laurien, E. [Stuttgart Univ. (Germany). Inst fuer Kernenergie und Energiesysteme (IKE)

    2014-11-15

    High cycle thermal fatigue damage caused in piping systems is an important problem encountered in the context of nuclear safety and lifetime management of a Nuclear Power Plant (NPP). The T-junction piping system present in the Residual Heat Removal System (RHRS) is more vulnerable to thermal fatigue cracking. In this numerical study, thermal mixing of fluids at temperature difference (?T) of 117 K between the mixing fluids is analyzed. Large Eddy Simulation (LES) is performed with conjugate heat transfer between the fluid and structure. LES is performed based on the Fluid-Structure Interaction (FSI) test facility at University of Stuttgart. The results show an intense turbulent mixing of fluids downstream of T-junction. Amplitude of temperature fluctuations near the wall region and its corresponding frequency distribution is analyzed. LES is performed using commercial CFD software ANSYS CFX 14.0.

  3. Numerical Simulation of the Thermal Performance of a Dry Storage Cask for Spent Nuclear Fuel

    Directory of Open Access Journals (Sweden)

    Heui-Yung Chang

    2018-01-01

    Full Text Available In this study, the heat flow characteristics and thermal performance of a dry storage cask were investigated via thermal flow experiments and a computational fluid dynamics (CFD simulation. The results indicate that there are many inner circulations in the flow channel of the cask (the channel width is 10 cm. These circulations affect the channel airflow efficiency, which in turn affects the heat dissipation of the dry storage cask. The daily operating temperatures at the top concrete lid and the upper locations of the concrete cask are higher than those permitted by the design specification. The installation of the salt particle collection device has a limited negative effect on the thermal dissipation performance of the dry storage cask.

  4. Detailed Balance of Thermalization Dynamics in Rydberg-Atom Quantum Simulators.

    Science.gov (United States)

    Kim, Hyosub; Park, YeJe; Kim, Kyungtae; Sim, H-S; Ahn, Jaewook

    2018-05-04

    Dynamics of large complex systems, such as relaxation towards equilibrium in classical statistical mechanics, often obeys a master equation that captures essential information from the complexities. Here, we find that thermalization of an isolated many-body quantum state can be described by a master equation. We observe sudden quench dynamics of quantum Ising-like models implemented in our quantum simulator, defect-free single-atom tweezers in conjunction with Rydberg-atom interaction. Saturation of their local observables, a thermalization signature, obeys a master equation experimentally constructed by monitoring the occupation probabilities of prequench states and imposing the principle of the detailed balance. Our experiment agrees with theories and demonstrates the detailed balance in a thermalization dynamics that does not require coupling to baths or postulated randomness.

  5. Comparative thermal cyclic test of different beryllium grades previously subjected to simulated disruption loads

    International Nuclear Information System (INIS)

    Gervash, A.; Giniyatulin, R.; Mazul, I.

    1999-01-01

    Considering beryllium as plasma facing armour this paper presents recent results obtained in Russia. A special process of joining beryllium to a Cu-alloy material structure is described and recent results of thermal cycling tests of such joints are presented. Summarizing the results, the authors show that a Cu-alloy heat sink structure armoured with beryllium can survive high heat fluxes (≥10 MW/m 2 ) during 1000 heating/cooling cycles without serious damage to the armour material and its joint. The principal feasibility of thermal cycling of beryllium grades and their joints directly in the core of a nuclear reactor is demonstrated and the main results of this test are presented. The paper also describes the thermal cycling of different beryllium grades having cracks initiated by previously applied high heat loads simulating plasma disruptions. (orig.)

  6. Detailed Balance of Thermalization Dynamics in Rydberg-Atom Quantum Simulators

    Science.gov (United States)

    Kim, Hyosub; Park, YeJe; Kim, Kyungtae; Sim, H.-S.; Ahn, Jaewook

    2018-05-01

    Dynamics of large complex systems, such as relaxation towards equilibrium in classical statistical mechanics, often obeys a master equation that captures essential information from the complexities. Here, we find that thermalization of an isolated many-body quantum state can be described by a master equation. We observe sudden quench dynamics of quantum Ising-like models implemented in our quantum simulator, defect-free single-atom tweezers in conjunction with Rydberg-atom interaction. Saturation of their local observables, a thermalization signature, obeys a master equation experimentally constructed by monitoring the occupation probabilities of prequench states and imposing the principle of the detailed balance. Our experiment agrees with theories and demonstrates the detailed balance in a thermalization dynamics that does not require coupling to baths or postulated randomness.

  7. Molecular dynamics simulations for the motion of evaporative droplets driven by thermal gradients along nanochannels

    KAUST Repository

    Wu, Congmin

    2013-04-04

    For a one-component fluid on a solid substrate, a thermal singularity may occur at the contact line where the liquid-vapor interface intersects the solid surface. Physically, the liquid-vapor interface is almost isothermal at the liquid-vapor coexistence temperature in one-component fluids while the solid surface is almost isothermal for solids of high thermal conductivity. Therefore, a temperature discontinuity is formed if the two isothermal interfaces are of different temperatures and intersect at the contact line. This leads to the so-called thermal singularity. The localized hydrodynamics involving evaporation/condensation near the contact line leads to a contact angle depending on the underlying substrate temperature. This dependence has been shown to lead to the motion of liquid droplets on solid substrates with thermal gradients (Xu and Qian 2012 Phys. Rev. E 85 061603). In the present work, we carry out molecular dynamics (MD) simulations as numerical experiments to further confirm the predictions made from our previous continuum hydrodynamic modeling and simulations, which are actually semi-quantitatively accurate down to the small length scales in the problem. Using MD simulations, we investigate the motion of evaporative droplets in one-component Lennard-Jones fluids confined in nanochannels with thermal gradients. The droplet is found to migrate in the direction of decreasing temperature of solid walls, with a migration velocity linearly proportional to the temperature gradient. This agrees with the prediction of our continuum model. We then measure the effect of droplet size on the droplet motion. It is found that the droplet mobility is inversely proportional to a dimensionless coefficient associated with the total rate of dissipation due to droplet movement. Our results show that this coefficient is of order unity and increases with the droplet size for the small droplets (∼10 nm) simulated in the present work. These findings are in semi

  8. A fully coupled finite element framework for thermal fracturing simulation in subsurface cold CO2 injection

    Directory of Open Access Journals (Sweden)

    Shunde Yin

    2018-03-01

    Simulation of thermal fracturing during cold CO2 injection involves the coupled processes of heat transfer, mass transport, rock deforming as well as fracture propagation. To model such a complex coupled system, a fully coupled finite element framework for thermal fracturing simulation is presented. This framework is based on the theory of non-isothermal multiphase flow in fracturing porous media. It takes advantage of recent advances in stabilized finite element and extended finite element methods. The stabilized finite element method overcomes the numerical instability encountered when the traditional finite element method is used to solve the convection dominated heat transfer equation, while the extended finite element method overcomes the limitation with traditional finite element method that a model has to be remeshed when a fracture is initiated or propagating and fracturing paths have to be aligned with element boundaries.

  9. Simulating the Thermal History of the Unsaturated Zone at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    B.D. Marshal; J.F. Whelan

    2001-01-01

    Heat transfer within Earth's upper crust is primarily by conduction, and conductive thermal models adequately explain the cooling history of deep, batholith-scale intrusions and surrounding wall rocks, as confirmed by numerous thermochronometric studies. However, caldera magmatic systems require consideration of the small and localized component of hydrothermal convection and numerical models to simulate additional boundary conditions, irregular magma chamber shapes, and complex intrusive histories. At Yucca Mountain, Nevada, the site of a potential high-level nuclear waste repository, simulating the detailed thermal history at any location in the unsaturated zone requires knowledge of the shape of the magma chamber and its proximity to Yucca Mountain (the southern margin of the Timber Mountain caldera complex is approximately 8 km north of the potential repository site), the temporal and spatial extent of hydrothermal convection, the erosional history of the area, and past levels of the water table

  10. Simulation studies on structural and thermal properties of alkane thiol capped gold nanoparticles.

    Science.gov (United States)

    Devi, J Meena

    2017-06-01

    The structural and thermal properties of the passivated gold nanoparticles were explored employing molecular dynamics simulation for the different surface coverage densities of the self-assembled monolayer (SAM) of alkane thiol. The structural properties of the monolayer protected gold nanoparticles such us overall shape, organization and conformation of the capping alkane thiol chains were found to be influenced by the capping density. The structural order of the thiol capped gold nanoparticles enhances with the increase in the surface coverage density. The specific heat capacity of the alkane thiol capped gold nanoparticles was found to increase linearly with the thiol coverage density. This may be attributed to the enhancement in the lattice vibrational energy. The present simulation results suggest, that the structural and thermal properties of the alkane thiol capped gold nanoparticles may be modified by the suitable selection of the SAM coverage density. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Research on simulation of supercritical steam turbine system in large thermal power station

    Science.gov (United States)

    Zhou, Qiongyang

    2018-04-01

    In order to improve the stability and safety of supercritical steam turbine system operation in large thermal power station, the body of the steam turbine is modeled in this paper. And in accordance with the hierarchical modeling idea, the steam turbine body model, condensing system model, deaeration system model and regenerative system model are combined to build a simulation model of steam turbine system according to the connection relationship of each subsystem of steam turbine. Finally, the correctness of the model is verified by design and operation data of the 600MW supercritical unit. The results show that the maximum simulation error of the model is 2.15%, which meets the requirements of the engineering. This research provides a platform for the research on the variable operating conditions of the turbine system, and lays a foundation for the construction of the whole plant model of the thermal power plant.

  12. ATWS thermal-hydraulic analysis for Krsko Full Scope Simulator validation

    International Nuclear Information System (INIS)

    Parzer, I.; Kljenak, I.

    2005-01-01

    The purpose of this analysis was to simulate Anticipated Transient without Scram transient for Krsko NPP. The results of these calculations were used for annual ANSI/ANS validation of reactor coolant system thermal-hydraulic response predicted by Krsko Full Scope Simulator. For the thermal-hydraulic analyses the RELAP5/MOD3.3 code and the input model for NPP Krsko, delivered by NPP Krsko, was used. In the presented paper the most severe ATWS scenario has been analyzed, starting with the loss of Main Feedwater at both steam generators. Thus, gradual loss of secondary heat sink occurred. On top of that, control rods were not supposed to scram, leaving the chain reaction to be controlled only by inherent physical properties of the fuel and moderator and eventual actions of the BOP system. The primary system response has been studied assuming AMSAC availability. (author)

  13. Stochastic simulation of PWR vessel integrity for pressurized thermal shock conditions

    International Nuclear Information System (INIS)

    Jackson, P.S.; Moelling, D.S.

    1984-01-01

    A stochastic simulation methodology is presented for performing probabilistic analyses of Pressurized Water Reactor vessel integrity. Application of the methodology to vessel-specific integrity analyses is described in the context of Pressurized Thermal Shock (PTS) conditions. A Bayesian method is described for developing vessel-specific models of the density of undetected volumetric flaws from ultrasonic inservice inspection results. Uncertainty limits on the probabilistic results due to sampling errors are determined from the results of the stochastic simulation. An example is provided to illustrate the methodology

  14. A mathematical model for the simulation of thermal transients in the water loop of IPEN

    International Nuclear Information System (INIS)

    Pontedeiro, A.C.

    1980-01-01

    A mathematical model for simulation of thermal transients in the water loop at the Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo, Brasil, is developed. The model is based on energy equations applied to the components of the experimental water loop. The non-linear system of first order diferencial equations and of non-linear algebraic equations obtained through the utilization of the IBM 'System/360-Continous System Modeling Program' (CSMP) is resolved. An optimization of the running time of the computer is made and a typical simulation of the water loop is executed. (Author) [pt

  15. Stress induced conditioning and thermal relaxation in the simulation of quasi-static compression experiments

    International Nuclear Information System (INIS)

    Scalerandi, M; Delsanto, P P; Johnson, P A

    2003-01-01

    Local interaction simulation approach simulations of the ultrasonic wave propagation in multi-grained materials have succeeded in reproducing most of the recently observed nonclassical nonlinear effects, such as stress-strain hysteresis and discrete memory in quasi-static experiments and a downwards shift of the resonance frequency and the generation of odd harmonics at specific amplitude rates in dynamics experiments. By including a simple mechanism of thermally activated random transitions, we can predict the occurrence of experimentally observed effects, such as the conditioning and relaxation of the specimen. Experiments are also suggested for a quantitative assessment of the validity of the model

  16. Converter-level FEM simulation for lifetime prediction of an LED driver with improved thermal modelling

    DEFF Research Database (Denmark)

    Niu, H.; Wang, H.; Ye, X.

    2017-01-01

    application. A converter-level finite element simulation (FEM) simulation is carried out to obtain the ambient temperature of electrolytic capacitors and power MOSFETs used in the LED driver, which takes into account the impact of the driver enclosure and the thermal coupling among different components....... Therefore, the proposed method bridges the link between the global ambient temperature profile outside of the enclosure and the local ambient temperature profiles of the components of interest inside the driver. A quantitative comparison of the estimated annual lifetime consumptions of MOSFETs...

  17. Simulated transient thermal infrared emissions of forest canopies during rainfall events

    Science.gov (United States)

    Ballard, Jerrell R.; Hawkins, William R.; Howington, Stacy E.; Kala, Raju V.

    2017-05-01

    We describe the development of a centimeter-scale resolution simulation framework for a theoretical tree canopy that includes rainfall deposition, evaporation, and thermal infrared emittance. Rainfall is simulated as discrete raindrops with specified rate. The individual droplets will either fall through the canopy and intersect the ground; adhere to a leaf; bounce or shatter on impact with a leaf resulting in smaller droplets that are propagated through the canopy. Surface physical temperatures are individually determined by surface water evaporation, spatially varying within canopy wind velocities, solar radiation, and water vapor pressure. Results are validated by theoretical canopy gap and gross rainfall interception models.

  18. Stress induced conditioning and thermal relaxation in the simulation of quasi-static compression experiments

    CERN Document Server

    Scalerandi, M; Johnson, P A

    2003-01-01

    Local interaction simulation approach simulations of the ultrasonic wave propagation in multi-grained materials have succeeded in reproducing most of the recently observed nonclassical nonlinear effects, such as stress-strain hysteresis and discrete memory in quasi-static experiments and a downwards shift of the resonance frequency and the generation of odd harmonics at specific amplitude rates in dynamics experiments. By including a simple mechanism of thermally activated random transitions, we can predict the occurrence of experimentally observed effects, such as the conditioning and relaxation of the specimen. Experiments are also suggested for a quantitative assessment of the validity of the model.

  19. An integrated algorithm for hypersonic fluid-thermal-structural numerical simulation

    Science.gov (United States)

    Li, Jia-Wei; Wang, Jiang-Feng

    2018-05-01

    In this paper, a fluid-structural-thermal integrated method is presented based on finite volume method. A unified integral equations system is developed as the control equations for physical process of aero-heating and structural heat transfer. The whole physical field is discretized by using an up-wind finite volume method. To demonstrate its capability, the numerical simulation of Mach 6.47 flow over stainless steel cylinder shows a good agreement with measured values, and this method dynamically simulates the objective physical processes. Thus, the integrated algorithm proves to be efficient and reliable.

  20. Thermal radiators with embedded pulsating heat pipes: Infra-red thermography and simulations

    International Nuclear Information System (INIS)

    Hemadri, Vadiraj A.; Gupta, Ashish; Khandekar, Sameer

    2011-01-01

    With the aim of exploring potential applications of Pulsating Heat Pipes (PHP), for space/terrestrial sectors, experimental study of embedded PHP thermal radiators, having two different effective Biot numbers respectively, and subjected to conjugate heat transfer conditions on their surface, i.e., natural convection and radiation, has been carried out under different thermo-mechanical boundary conditions. High resolution infrared camera is used to obtain spatial temperature profiles of the radiators. To complement the experimental study, detailed 3D computational heat transfer simulation has also been undertaken. By embedding PHP structures, it was possible to make the net thermal resistance of the mild steel radiator plate equivalent to the aluminum radiator plate, in spite of the large difference in their respective thermal conductivities (k Al ∼ 4k MS ). The study reveals that embedded PHP structures can be beneficial only under certain boundary conditions. The degree of isothermalization achieved in these structures strongly depends on its effective Biot number. The relative advantage of embedded PHP is appreciably higher if the thermal conductivity of the radiator plate material itself is low. The study indicates that the effective thermal conductivity of embedded PHP structure is of the order of 400 W/mK to 2300 W/mK, depending on the operating conditions. - Research highlights: → Study of radiator plates with embedded Pulsating Heat Pipe by infrared thermography. → Radiator is subjected to natural convection and radiation boundary conditions. → Experimental study is supported by 3D simulation. → Effective thermal conductivity of PHPs of the order of 2000 W/mK is obtained. → Efficacy of embedded PHPs depends on the effective Biot number of the system.

  1. Development of CFD software for the simulation of thermal hydraulics in advanced nuclear reactors. Final report

    International Nuclear Information System (INIS)

    Bachar, Abdelaziz; Haslinger, Wolfgang; Scheuerer, Georg; Theodoridis, Georgios

    2015-01-01

    The objectives of the project were: Improvement of the simulation accuracy for nuclear reactor thermo-hydraulics by coupling system codes with three-dimensional CFD software; Extension of CFD software to predict thermo-hydraulics in advanced reactor concepts; Validation of the CFD software by simulation different UPTF TRAM-C test cases and development of best practice guidelines. The CFD module was based on the ANSYS CFD software and the system code ATHLET of GRS. All three objectives were met: The coupled ATHLET-ANSYS CFD software is in use at GRS and TU Muenchen. Besides the test cases described in the report, it has been used for other applications, for instance the TALL-3D experiment of KTH Stockholm. The CFD software was extended with material properties for liquid metals, and validated using existing data. Several new concepts were tested when applying the CFD software to the UPTF test cases: Simulations with Conjugate Heat Transfer (CHT) were performed for the first time. This led to better agreement between predictions and data and reduced uncertainties when applying temperature boundary conditions. The meshes for the CHT simulation were also used for a coupled fluid-structure-thermal analysis which was another novelty. The results of the multi-physics analysis showed plausible results for the mechanical and thermal stresses. The workflow developed as part of the current project can be directly used for industrial nuclear reactor simulations. Finally, simulations for two-phase flows with and without interfacial mass transfer were performed. These showed good agreement with data. However, a persisting problem for the simulation of multi-phase flows are the long simulation times which make use for industrial applications difficult.

  2. Measurement and simulation of thermal neutron flux distribution in the RTP core

    Science.gov (United States)

    Rabir, Mohamad Hairie B.; Jalal Bayar, Abi Muttaqin B.; Hamzah, Na'im Syauqi B.; Mustafa, Muhammad Khairul Ariff B.; Karim, Julia Bt. Abdul; Zin, Muhammad Rawi B. Mohamed; Ismail, Yahya B.; Hussain, Mohd Huzair B.; Mat Husin, Mat Zin B.; Dan, Roslan B. Md; Ismail, Ahmad Razali B.; Husain, Nurfazila Bt.; Jalil Khan, Zareen Khan B. Abdul; Yakin, Shaiful Rizaide B. Mohd; Saad, Mohamad Fauzi B.; Masood, Zarina Bt.

    2018-01-01

    The in-core thermal neutron flux distribution was determined using measurement and simulation methods for the Malaysian’s PUSPATI TRIGA Reactor (RTP). In this work, online thermal neutron flux measurement using Self Powered Neutron Detector (SPND) has been performed to verify and validate the computational methods for neutron flux calculation in RTP calculations. The experimental results were used as a validation to the calculations performed with Monte Carlo code MCNP. The detail in-core neutron flux distributions were estimated using MCNP mesh tally method. The neutron flux mapping obtained revealed the heterogeneous configuration of the core. Based on the measurement and simulation, the thermal flux profile peaked at the centre of the core and gradually decreased towards the outer side of the core. The results show a good agreement (relatively) between calculation and measurement where both show the same radial thermal flux profile inside the core: MCNP model over estimation with maximum discrepancy around 20% higher compared to SPND measurement. As our model also predicts well the neutron flux distribution in the core it can be used for the characterization of the full core, that is neutron flux and spectra calculation, dose rate calculations, reaction rate calculations, etc.

  3. CFD simulation for thermal mixing of a SMART flow mixing header assembly

    International Nuclear Information System (INIS)

    Kim, Young In; Bae, Youngmin; Chung, Young Jong; Kim, Keung Koo

    2015-01-01

    Highlights: • Thermal mixing performance of a FMHA installed in SMART is investigated numerically. • Effects of operating condition and discharge hole configuration are examined. • FMHA performance satisfies the design requirements under various abnormal conditions. - Abstract: A flow mixing header assembly (FMHA) is installed in a system-integrated modular advanced reactor (SMART) to enhance the thermal mixing capability and create a uniform core flow distribution under both normal operation and accident conditions. In this study, the thermal mixing characteristics of the FMHA are investigated for various steam generator conditions using a commercial CFD code. Simulations include investigations for the effects of FMHA discharge flow rate differences, turbulence models, and steam generator conditions. The results of the analysis show that the FMHA works effectively for thermal mixing in various conditions and makes the temperature difference at the core inlet decrease noticeably. We verified that the mixing capability of the FMHA is excellent and satisfies the design requirement in all simulation cases tested here

  4. Occupant evaluation of 7-hour exposures in a simulated aircraft cabin - Part 2: Thermal effects

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Wyon, David Peter; Zukowska, Daria

    2005-01-01

    Experiments were carried out in a simulated section of an aircraft cabin with 21 seats installed in a climate chamber, to determine the extent to which passengers’ perception of cabin air quality is affected by air temperature. The temperature inside the cabin was set at three differ-ent levels, 20......, and thermal sensation - the lower the temperature, the higher the perceived air quality and freshness....

  5. 2-D CFD time-dependent thermal-hydraulic simulations of CANDU-6 moderator flows

    Energy Technology Data Exchange (ETDEWEB)

    Mehdi Zadeh, Foad [Department of Engineering Physics/Polytechnique Montréal, Montréal, QC (Canada); Étienne, Stéphane [Department of Mechanical Engineering/Polytechnique Montréal, Montréal, QC (Canada); Teyssedou, Alberto, E-mail: alberto.teyssedou@polymtl.ca [Department of Engineering Physics/Polytechnique Montréal, Montréal, QC (Canada)

    2016-12-01

    Highlights: • 2-D time-dependent CFD simulations of CANDU-6 moderator flows are presented. • A thermal-hydraulic code using thermal physical fluid properties is used. • The numerical approach and convergence is validated against available data. • Flow configurations are correlated using Richardson’s number. • Frequency components indicate moderator flow oscillations vs. Richardson numbers. - Abstract: The distribution of the fluid temperature and mass density of the moderator flow in CANDU-6 nuclear power reactors may affect the reactivity coefficient. For this reason, any possible moderator flow configuration and consequently the corresponding temperature distributions must be studied. In particular, the variations of the reactivity may result in major safety issues. For instance, excessive temperature excursions in the vicinity of the calandria tubes nearby local flow stagnation zones, may bring about partial boiling. Moreover, steady-state simulations have shown that for operating condition, intense buoyancy forces may be dominant, which can trigger a thermal stratification. Therefore, the numerical study of the time-dependent flow transition to such a condition, is of fundamental safety concern. Within this framework, this paper presents detailed time-dependent numerical simulations of CANDU-6 moderator flow for a wide range of flow conditions. To get a better insight of the thermal-hydraulic phenomena, the simulations were performed by covering long physical-time periods using an open-source code (Code-Saturne V3) developed by Électricité de France. The results show not only a region where the flow is characterized by coherent structures of flow fluctuations but also the existence of two limit cases where fluid oscillations disappear almost completely.

  6. Comparison of thermal behavior of different PWR fuel rod simulators for LOCA experiments

    International Nuclear Information System (INIS)

    Casal, V.; Malang, S.; Rust, K.

    1982-10-01

    For experimental investigations of a loss-of-coolant accident (LOCA) of a PWR electrical heater rods are applied as thermal fuel rod simulators. To substitute heater rods from the SEMISCALE program by INTERATOM-KfK heater rods in a current experimental program at the Instituut for Energiteknikk-(OECD-Halden), the thermodynamic behavior of different heater rods during a LOCA were compared. The results show, that SEMISCALE-heater rods can be replaced by those fabricated by INTERATOM. (orig.) [de

  7. Numerical simulation of thermal radiation from smoking flames; Numerische Simulation der Waermestrahlung von russenden Flammen

    Energy Technology Data Exchange (ETDEWEB)

    Koch, T. [Duisburg Univ. (Gesamthochschule) (Germany). Lehrstuhl fuer Technische Chemie; Staus, S. [Duisburg Univ. (Gesamthochschule) (Germany). Lehrstuhl fuer Technische Chemie; Schoenbucher, A. [Duisburg Univ. (Gesamthochschule) (Germany). Lehrstuhl fuer Technische Chemie

    1997-08-01

    After presenting the most common semi-empirical simulation model, the authors describe the newly developed field model and its modules with their mathematical and physical fundamentals. First results are presented for the calculation of a diffusion flame. (orig./GL) [Deutsch] In der vorliegenden Arbeit wird, nach einer Darstellung der gebraeuchlichen halbempirischen Simulationsmodelle, das entwickelte Feldmodell beschrieben und seine einzelnen Module mit ihren mathematischen und physikalischen Grundlagen vorgestellt. Im Anschluss werden erste Ergebnisse fuer die Berechnung einer Diffusionsflamme aufgezeigt. (orig./GL)

  8. Direct numerical simulation of stable and unstable turbulent thermal boundary layers

    International Nuclear Information System (INIS)

    Hattori, Hirofumi; Houra, Tomoya; Nagano, Yasutaka

    2007-01-01

    This paper presents direct numerical simulations (DNS) of stable and unstable turbulent thermal boundary layers. Since a buoyancy-affected boundary layer is often encountered in an urban environmental space where stable and unstable stratifications exist, exploring a buoyancy-affected boundary layer is very important to know the transport phenomena of the flow in an urban space. Although actual observation may qualitatively provide the characteristics of these flows, the relevant quantitative turbulent quantities are very difficult to measure. Thus, in order to quantitatively investigate a buoyancy-affected boundary layer in detail, we have here carried out for the first time time- and space-developing DNS of slightly stable and unstable turbulent thermal boundary layers. The DNS results show the quantitative turbulent statistics and structures of stable and unstable thermal boundary layers, in which the characteristic transport phenomena of thermally stratified boundary layers are demonstrated by indicating the budgets of turbulent shear stress and turbulent heat flux. Even though the input of buoyant force is not large, the influence of buoyancy is clearly revealed in both stable and unstable turbulent boundary layers. In particular, it is found that both stable and unstable thermal stratifications caused by the weak buoyant force remarkably alter the structure of near-wall turbulence

  9. Hydraulic performance of compacted clay liners under simulated daily thermal cycles.

    Science.gov (United States)

    Aldaeef, A A; Rayhani, M T

    2015-10-01

    Compacted clay liners (CCLs) are commonly used as hydraulic barriers in several landfill applications to isolate contaminants from the surrounding environment and minimize the escape of leachate from the landfill. Prior to waste placement in landfills, CCLs are often exposed to temperature fluctuations which can affect the hydraulic performance of the liner. Experimental research was carried out to evaluate the effects of daily thermal cycles on the hydraulic performance of CCLs under simulated landfill conditions. Hydraulic conductivity tests were conducted on different soil specimens after being exposed to various thermal and dehydration cycles. An increase in the CCL hydraulic conductivity of up to one order of magnitude was recorded after 30 thermal cycles for soils with low plasticity index (PI = 9.5%). However, medium (PI = 25%) and high (PI = 37.2%) plasticity soils did not show significant hydraulic deviation due to their self-healing potential. Overlaying the CCL with a cover layer minimized the effects of daily thermal cycles, and maintained stable hydraulic performance in the CCLs even after exposure to 60 thermal cycles. Wet-dry cycles had a significant impact on the hydraulic aspect of low plasticity CCLs. However, medium and high plasticity CCLs maintained constant hydraulic performance throughout the test intervals. The study underscores the importance of protecting the CCL from exposure to atmosphere through covering it by a layer of geomembrane or an interim soil layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Numerical Simulation Procedure for Modeling TGO Crack Propagation and TGO Growth in Thermal Barrier Coatings upon Thermal-Mechanical Cycling

    Directory of Open Access Journals (Sweden)

    Ding Jun

    2014-01-01

    Full Text Available This paper reports a numerical simulation procedure to model crack propagation in TGO layer and TGO growth near a surface groove in metal substrate upon multiple thermal-mechanical cycles. The material property change method is employed to model TGO formation cycle by cycle, and the creep properties for constituent materials are also incorporated. Two columns of repeated nodes are placed along the interface of the potential crack, and these nodes are bonded together as one node at a geometrical location. In terms of critical crack opening displacement criterion, onset of crack propagation in TGO layer has been determined by finite element analyses in comparison with that without predefined crack. Then, according to the results from the previous analyses, the input values for the critical failure parameters for the subsequent analyses can be decided. The robust capabilities of restart analysis in ABAQUS help to implement the overall simulation for TGO crack propagation. The comparison of the TGO final deformation profile between numerical and experimental observation shows a good agreement indicating the correctness and effectiveness of the present procedure, which can guide the prediction of the failure in TGO for the future design and optimization for TBC system.

  11. Thermal simulations of the new design for the BELLE silicon vertex detector

    International Nuclear Information System (INIS)

    Dragic, J.

    2000-01-01

    Full text: The experienced imperfections of the BELLE silicon vertex detector, SVD1 motioned the design of a new detector, SVD2, which targets on improving the main weaknesses encountered in the old design. In this report we focus on tile thermal aspects of the SVD2 ladder, whereby sufficient cooling of the detector is necessary in order to minimise the detector leakage currents. It is estimated that reducing the temperature of the silicon detector from 25 deg C to 15 deg C would result in a 50% reduction in leak current. Further, cooling the detector would help minimize mechanical stresses from the thermal cycling. Our task is to ensure that the heat generated by the readout chips is conducted down the SVD hybrid unit effectively, such that the chip and the hybrid temperature does not overbear the SVD silicon sensor temperature. We considered the performance of two materials to act as a heat spreading plate which is glued between the two hybrids in order to improve the heat conductivity of the hybrid unit, namely Copper and Thermal Pyrolytic Graphite (TPG). The effects of other ladder components were also considered in order to enhance the cooling of the silicon detectors. Finite element analysis with ANSYS software was used to simulate the thermal conditions of the SVD2 hybrid unit, in accordance with the baseline design for the mechanical structure of the ladder. It was found that Cu was a preferred material as it achieved equivalent silicon sensor cooling (3.6 deg C above cooling point), while its mechanical properties rendered it a lot more practical. Suppressing, the thermal path via a rib support block, by increasing its thermal resistivity, as well as increasing thermal conductivity of the ribs in the hybrid region, were deemed essential in the effective cooling of the silicon sensors

  12. IMPACT OF IRRADIATION AND THERMAL AGING ON DWPF SIMULATED SLUDGE PROPERTIES

    International Nuclear Information System (INIS)

    Eibling, R; Michael Stone, M

    2006-01-01

    The research and development programs in support of the Defense Waste Processing Facility (DWPF) and other high-level waste vitrification processes require the use of both nonradioactive waste simulants and actual waste samples. While actual waste samples are the ideal materials to study, acquiring large quantities of actual waste is difficult and expensive. Tests utilizing actual high-level waste require the use of expensive shielded cells facilities to provide sufficient shielding for the researchers. Nonradioactive waste simulants have been used for laboratory testing, pilot-scale testing and full-scale integrated facility testing. These waste simulants were designed to reproduce the chemical and, if possible, the physical properties of the actual high-level waste. This technical report documents a study on the impact of irradiating a Sludge Batch 3 (SB3) simulant and of additional tests on aging a SB3 simulant by additional thermal processing. Prior simulant development studies examined methods of producing sludge and supernate simulants and processes that could be used to alter the physical properties of the simulant to more accurately mimic the properties of actual waste. Development of a precipitated sludge simulant for the River Protection Project (RPP) demonstrated that the application of heat for a period of time could significantly alter the rheology of the sludge simulant. The RPP precipitated simulant used distillation to concentrate the sludge solids and produced a reduction in sludge yield stress of up to 80% compared to the initial sludge properties. Observations at that time suggested that a substantial fraction of the iron hydroxide had converted to the oxide during the distillation. DWPF sludge simulant studies showed a much smaller reduction in yield stress (∼10%), demonstrated the impact of shear on particle size, and showed that smaller particle sizes yielded higher yield stress products. The current study documented in this report focuses

  13. Semiquantum molecular dynamics simulation of thermal properties and heat transport in low-dimensional nanostructures

    Science.gov (United States)

    Savin, Alexander V.; Kosevich, Yuriy A.; Cantarero, Andres

    2012-08-01

    We present a detailed description of semiquantum molecular dynamics simulation of stochastic dynamics of a system of interacting particles. Within this approach, the dynamics of the system is described with the use of classical Newtonian equations of motion in which the effects of phonon quantum statistics are introduced through random Langevin-like forces with a specific power spectral density (the color noise). The color noise describes the interaction of the molecular system with the thermostat. We apply this technique to the simulation of thermal properties and heat transport in different low-dimensional nanostructures. We describe the determination of temperature in quantum lattice systems, to which the equipartition limit is not applied. We show that one can determine the temperature of such a system from the measured power spectrum and temperature- and relaxation-rate-independent density of vibrational (phonon) states. We simulate the specific heat and heat transport in carbon nanotubes, as well as the heat transport in molecular nanoribbons with perfect (atomically smooth) and rough (porous) edges, and in nanoribbons with strongly anharmonic periodic interatomic potentials. We show that the effects of quantum statistics of phonons are essential for the carbon nanotube in the whole temperature range T<500K, in which the values of the specific heat and thermal conductivity of the nanotube are considerably less than that obtained within the description based on classical statistics of phonons. This conclusion is also applicable to other carbon-based materials and systems with high Debye temperature like graphene, graphene nanoribbons, fullerene, diamond, diamond nanowires, etc. We show that the existence of rough edges and quantum statistics of phonons change drastically the low-temperature thermal conductivity of the nanoribbon in comparison with that of the nanoribbon with perfect edges and classical phonon dynamics and statistics. The semiquantum molecular

  14. Molecular dynamics simulations of thermally activated edge dislocation unpinning from voids in α -Fe

    Science.gov (United States)

    Byggmästar, J.; Granberg, F.; Nordlund, K.

    2017-10-01

    In this study, thermal unpinning of edge dislocations from voids in α -Fe is investigated by means of molecular dynamics simulations. The activation energy as a function of shear stress and temperature is systematically determined. Simulations with a constant applied stress are compared with dynamic simulations with a constant strain rate. We found that a constant applied stress results in a temperature-dependent activation energy. The temperature dependence is attributed to the elastic softening of iron. If the stress is normalized with the softening of the specific shear modulus, the activation energy is shown to be temperature-independent. From the dynamic simulations, the activation energy as a function of critical shear stress was determined using previously developed methods. The results from the dynamic simulations are in good agreement with the constant stress simulations, after the normalization. This indicates that the computationally more efficient dynamic method can be used to obtain the activation energy as a function of stress and temperature. The obtained relation between stress, temperature, and activation energy can be used to introduce a stochastic unpinning event in larger-scale simulation methods, such as discrete dislocation dynamics.

  15. Multiscale simulation of thermal disruption in resistance switching process in amorphous carbon

    International Nuclear Information System (INIS)

    Popov, A M; Nikishin, N G; Shumkin, G N

    2015-01-01

    The switching of material atomic structure and electric conductivity is used in novel technologies of making memory on the base of phase change. The possibility of making memory on the base of amorphous carbon is shown in experiment [1]. Present work is directed to simulation of experimentally observed effects. Ab initio quantum calculations were used for simulation of atomic structure changes in amorphous carbon [2]. These simulations showed that the resistance change is connected with thermally induced effects. The temperature was supposed to be the function of time. In present paper we propose a new multiscale, self-consistent model which combines three levels of simulation scales and takes into account the space and time dependencies of the temperature. On the first level of quantum molecular dynamic we provide the calculations of phase change in atomic structure with space and time dependence of the temperature. Nose-Hover thermostats are used for MD simulations to reproduce space dependency of the temperature. It is shown that atomic structure is localized near graphitic layers in conducting dot. Structure parameter is used then on the next levels of the modeling. Modified Ehrenfest Molecular Dynamics is used on the second level. Switching evolution of electronic subsystem is obtained. In macroscopic scale level the heat conductivity equation for continuous media is used for calculation space-time dependence of the temperature. Joule heat source depends on structure parameter and electric conductivity profiles obtained on previous levels of modeling. Iterative procedure is self-consistently repeated combining three levels of simulation. Space localization of Joule heat source leads to the thermal disruption. Obtained results allow us to explain S-form of the Volt-Ampere characteristic observed in experiment. Simulations were performed on IBM Blue Gene/P supercomputer at Moscow State University. (paper)

  16. Thermal Simulation of the Fresh Food Compartment in a Domestic Refrigerator

    Directory of Open Access Journals (Sweden)

    Juan M. Belman-Flores

    2017-01-01

    Full Text Available In the field of domestic refrigeration, it is important to look for methods that can be used to simulate, and, thus, improve the thermal behavior of the fresh food compartment. In this sense, this study proposes some methods to model the thermal behavior of this compartment when the shelves’ positions are changed. Temperature measurements at specific locations in this compartment were obtained. Several shelf position combinations were performed to use three 2D interpolation methods in order to simulate the temperature mean and the temperature variance. The methods used were: Lagrange’s interpolation, cubic spline interpolation and bilinear interpolation. Two validation points were chosen to verify the proposed methods. By comparing the experimental results with the computer simulations, it was possible to conclude that the method of Lagrange’s interpolation provided values that were not close to the real measured values. On the other hand, it was observed that the method of bilinear interpolation offered the best results, estimating values which were very close to the actual experimental measurements. These interpolation methods were used to build color thermal graphs that can be used to find some of the most appropriate shelf position combinations in this type of refrigerator. By inspection of these thermal graphs, it can be seen that the lowest average temperature was obtained when one shelf was located at 24.5 cm while the second shelf was located at 29.5 cm measured from the top of the compartment. In the same way, it can be seen that the minimum temperature variance was obtained when only one shelf was inside the compartment and this shelf was located at 29.5 cm.

  17. Laser treatment of female stress urinary incontinence: optical, thermal, and tissue damage simulations

    Science.gov (United States)

    Hardy, Luke A.; Chang, Chun-Hung; Myers, Erinn M.; Kennelly, Michael J.; Fried, Nathaniel M.

    2016-02-01

    Treatment of female stress urinary incontinence (SUI) by laser thermal remodeling of subsurface tissues is studied. Light transport, heat transfer, and thermal damage simulations were performed for transvaginal and transurethral methods. Monte Carlo (MC) provided absorbed photon distributions in tissue layers (vaginal wall, endopelvic fascia, urethral wall). Optical properties (n,μa,μs,g) were assigned to each tissue at λ=1064 nm. A 5-mm-diameter laser beam and power of 5 W for 15 s was used, based on previous experiments. MC output was converted into absorbed energy, serving as input for ANSYS finite element heat transfer simulations of tissue temperatures over time. Convective heat transfer was simulated with contact cooling probe set at 0 °C. Thermal properties (κ,c,ρ) were assigned to each tissue layer. MATLAB code was used for Arrhenius integral thermal damage calculations. A temperature matrix was constructed from ANSYS output, and finite sum was incorporated to approximate Arrhenius integral calculations. Tissue damage properties (Ea,A) were used to compute Arrhenius sums. For the transvaginal approach, 37% of energy was absorbed in endopelvic fascia layer with 0.8% deposited beyond it. Peak temperature was 71°C, treatment zone was 0.8-mm-diameter, and almost all of 2.7-mm-thick vaginal wall was preserved. For transurethral approach, 18% energy was absorbed in endopelvic fascia with 0.3% deposited beyond it. Peak temperature was 80°C, treatment zone was 2.0-mm-diameter, and only 0.6 mm of 2.4-mm-thick urethral wall was preserved. A transvaginal approach is more feasible than transurethral approach for laser treatment of SUI.

  18. THE CONCEPT OF FIDELITY IN COMICS TRANSLATION

    Directory of Open Access Journals (Sweden)

    Erico Assis

    2016-11-01

    Full Text Available The long-discussed – and frequently dismissed – concept of translation faithfulness or translation fidelity, though usually applied to literary texts, has its fair share of applications when considered for comics translation. In literary translation, non-linguistic portions such as illustrations are often considered addenda or “paratexts” relative to the main, linguistic text. Comics, by its turn, present a certain set of features which single them out as a form that demands a new concept of “text” and, therefore, of translation fidelity. The comic-reading process, as pertaining to cognitive apprehension, implies interpretative accords that differ from the ones in purely linguistic texts: each and every element of the comics page – non-linguistic (mainly imagetic signs, linguistic signs, panel borders, typography and such – are intertwined and should be perceived in regards to its spatial and topological relations. This approach to understanding comics is based on Groensteen (1999 and his concepts of arthrology, spatio-topia, page layout, breakdown and braiding. As for translation fidelity, we rely on authors such as Berman (1984, Guidere (2010 and Aubert (1993. On comics translation, Zanettin (2008, Rota (2008 and Yuste Frías (2010, 2011 are of particular interest. Based on various concepts of fidelity – supported by samples of translated comics with varied degrees of fidelity to the source text – we discuss the different grounds of source-text fidelity, target-reader fidelity and source-author fidelity in the following instances: linguistic sign fidelity, imagetic sign fidelity, spatio-topia fidelity, typographic fidelity and format fidelity.

  19. Phase-field simulations of pore migration and morphology change in thermal gradients

    Energy Technology Data Exchange (ETDEWEB)

    Vance, Ian W.; Millett, Paul C., E-mail: pmillett@uark.edu

    2017-07-15

    Here we present a phase-field simulation model that captures the thermal-gradient-driven migration of pores in oxide fuel associated with fuel restructuring. The model utilizes a Cahn-Hilliard equation supplemented with an advection term to describe the vapor transport of fuel material through the pore interior due to gradients in vapor pressure. Simulations demonstrate that the model not only predicts pore migration towards the centerline of the fuel, but also a concurrent change in pore shape during migration from an initially isotropic morphology to either a lenticular morphology or a prolate morphology depending on the vapor transport conditions. This model is a necessary first step to conducting accurate simulations of the microscopic changes that occur during the complicated process of oxide fuel restructuring.

  20. Thermography During Thermal Test of the Gaia Deployable Sunshield Assembly Qualification Model in the ESTEC Large Space Simulator

    Science.gov (United States)

    Simpson, R.; Broussely, M.; Edwards, G.; Robinson, D.; Cozzani, A.; Casarosa, G.

    2012-07-01

    The National Physical Laboratory (NPL) and The European Space Research and Technology Centre (ESTEC) have performed for the first time successful surface temperature measurements using infrared thermal imaging in the ESTEC Large Space Simulator (LSS) under vacuum and with the Sun Simulator (SUSI) switched on during thermal qualification tests of the GAIA Deployable Sunshield Assembly (DSA). The thermal imager temperature measurements, with radiosity model corrections, show good agreement with thermocouple readings on well characterised regions of the spacecraft. In addition, the thermal imaging measurements identified potentially misleading thermocouple temperature readings and provided qualitative real-time observations of the thermal and spatial evolution of surface structure changes and heat dissipation during hot test loadings, which may yield additional thermal and physical measurement information through further research.

  1. SENSOR++: Simulation of Remote Sensing Systems from Visible to Thermal Infrared

    Science.gov (United States)

    Paproth, C.; Schlüßler, E.; Scherbaum, P.; Börner, A.

    2012-07-01

    During the development process of a remote sensing system, the optimization and the verification of the sensor system are important tasks. To support these tasks, the simulation of the sensor and its output is valuable. This enables the developers to test algorithms, estimate errors, and evaluate the capabilities of the whole sensor system before the final remote sensing system is available and produces real data. The presented simulation concept, SENSOR++, consists of three parts. The first part is the geometric simulation which calculates where the sensor looks at by using a ray tracing algorithm. This also determines whether the observed part of the scene is shadowed or not. The second part describes the radiometry and results in the spectral at-sensor radiance from the visible spectrum to the thermal infrared according to the simulated sensor type. In the case of earth remote sensing, it also includes a model of the radiative transfer through the atmosphere. The final part uses the at-sensor radiance to generate digital images by using an optical and an electronic sensor model. Using SENSOR++ for an optimization requires the additional application of task-specific data processing algorithms. The principle of the simulation approach is explained, all relevant concepts of SENSOR++ are discussed, and first examples of its use are given, for example a camera simulation for a moon lander. Finally, the verification of SENSOR++ is demonstrated.

  2. Thermal Hydraulic Computational Fluid Dynamics Simulations and Experimental Investigation of Deformed Fuel Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Mays, Brian [AREVA Federal Services, Lynchburg, VA (United States); Jackson, R. Brian [TerraPower, Bellevue, WA (United States)

    2017-03-08

    The project, Toward a Longer Life Core: Thermal Hydraulic CFD Simulations and Experimental Investigation of Deformed Fuel Assemblies, DOE Project code DE-NE0008321, was a verification and validation project for flow and heat transfer through wire wrapped simulated liquid metal fuel assemblies that included both experiments and computational fluid dynamics simulations of those experiments. This project was a two year collaboration between AREVA, TerraPower, Argonne National Laboratory and Texas A&M University. Experiments were performed by AREVA and Texas A&M University. Numerical simulations of these experiments were performed by TerraPower and Argonne National Lab. Project management was performed by AREVA Federal Services. The first of a kind project resulted in the production of both local point temperature measurements and local flow mixing experiment data paired with numerical simulation benchmarking of the experiments. The project experiments included the largest wire-wrapped pin assembly Mass Index of Refraction (MIR) experiment in the world, the first known wire-wrapped assembly experiment with deformed duct geometries and the largest numerical simulations ever produced for wire-wrapped bundles.

  3. Measurements of Regolith Simulant Thermal Conductivity Under Asteroid and Mars Surface Conditions

    Science.gov (United States)

    Ryan, A. J.; Christensen, P. R.

    2017-12-01

    Laboratory measurements have been necessary to interpret thermal data of planetary surfaces for decades. We present a novel radiometric laboratory method to determine temperature-dependent thermal conductivity of complex regolith simulants under rough to high vacuum and across a wide range of temperatures. This method relies on radiometric temperature measurements instead of contact measurements, eliminating the need to disturb the sample with thermal probes. We intend to determine the conductivity of grains that are up to 2 cm in diameter and to parameterize the effects of angularity, sorting, layering, composition, and eventually cementation. We present the experimental data and model results for a suite of samples that were selected to isolate and address regolith physical parameters that affect bulk conductivity. Spherical glass beads of various sizes were used to measure the effect of size frequency distribution. Spherical beads of polypropylene and well-rounded quartz sand have respectively lower and higher solid phase thermal conductivities than the glass beads and thus provide the opportunity to test the sensitivity of bulk conductivity to differences in solid phase conductivity. Gas pressure in our asteroid experimental chambers is held at 10^-6 torr, which is sufficient to negate gas thermal conduction in even our coarsest of samples. On Mars, the atmospheric pressure is such that the mean free path of the gas molecules is comparable to the pore size for many regolith particulates. Thus, subtle variations in pore size and/or atmospheric pressure can produce large changes in bulk regolith conductivity. For each sample measured in our martian environmental chamber, we repeat thermal measurement runs at multiple pressures to observe this behavior. Finally, we present conductivity measurements of angular basaltic simulant that is physically analogous to sand and gravel that may be present on Bennu. This simulant was used for OSIRIS-REx TAGSAM Sample Return

  4. Numerical simulation of CTE mismatch and thermal-structural stresses in the design of interconnects

    Science.gov (United States)

    Peter, Geoffrey John M.

    With the ever-increasing chip complexity, interconnects have to be designed to meet the new challenges. Advances in optical lithography have made chip feature sizes available today at 70 nm dimensions. With advances in Extreme Ultraviolet Lithography, X-ray Lithography, and Ion Projection Lithography it is expected that the line width will further decrease to 20 nm or less. With the decrease in feature size, the number of active devices on the chip increases. With higher levels of circuit integration, the challenge is to dissipate the increased heat flux from the chip surface area. Thermal management considerations include coefficient of thermal expansion (CTE) matching to prevent failure between the chip and the board. This in turn calls for improved system performance and reliability of the electronic structural systems. Experience has shown that in most electronic systems, failures are mostly due to CTE mismatch between the chip, board, and the solder joint (solder interconnect). The resulting high thermal-structural stress and strain due to CTE mismatch produces cracks in the solder joints with eventual failure of the electronic component. In order to reduce the thermal stress between the chip, board, and the solder joint, this dissertation examines the effect of inserting wire bundle (wire interconnect) between the chip and the board. The flexibility of the wires or fibers would reduce the stress at the rigid joints. Numerical simulations of two, and three-dimensional models of the solder and wire interconnects are examined. The numerical simulation is linear in nature and is based on linear isotropic material properties. The effect of different wire material properties is examined. The effect of varying the wire diameter is studied by changing the wire diameter. A major cause of electronic equipment failure is due to fatigue failure caused by thermal cycling, and vibrations. A two-dimensional modal and harmonic analysis was simulated for the wire interconnect

  5. Simulation of Missing Pellet Surface thermal behavior with 3D dynamic gap element

    International Nuclear Information System (INIS)

    Kim, Hyo Chan; Yang, Yong Sik; Koo, Yang Hyun; Kang, Chang Hak; Lee Sung Uk; Yang, Dong Yol

    2014-01-01

    Most of the fuel performance codes that are able to simulate a multidimensional analysis are used to calculate the radial temperature distribution and perform a multidimensional mechanical analysis based on a one-dimensional (1D) temperature result. The FRAPCON-FRAPTRAN code system incorporates a 1D thermal module and two-dimensional (2D) mechanical module when FEM option is activated. In this method, the multidimensional gap conductance model is not required because one-dimensional thermal analysis is carried out. On the other hand, a gap conductance model for a multi-dimension should be developed in the code to perform a multidimensional thermal analysis. ALCYONE developed by CEA introduces an equivalent heat convection coefficient that represents the multidimensional gap conductance. However, the code does not employ dynamic gap conductance which is a function of gap thickness and gap characteristics in direct. The BISON code, which has been developed by INL (Idaho National Laboratory), employed a thermo-mechanical contact method that is specifically designed for tightly-coupled implicit solutions that employ Jacobian-free solution methods. Owing to tightly-coupled implicit solutions, the BISON code solves gap conductance and gap thickness simultaneously with given boundary conditions. In this paper, 3D dynamic gap element has been proposed to resolve convergence issue and nonlinear characteristic of multidimensional gap conductance. To evaluate 3D dynamic gap element module, 3D thermomechanical module using FORTRAN77 has been implemented incorporating 3D dynamic gap element. To demonstrate effect of 3D dynamic gap element, thermal behavior of missing pellet surface (MPS) has been simulated by the developed module. LWR fuel performance codes should incorporate thermo-mechanical loop to solve gap conductance problem, iteratively. However, gap conductance in multidimensional model is difficult issue owing to its nonlinearity and convergence characteristics. In

  6. Simulation of thermal response of the 250 MWT modular HTGR during hypothetical uncontrolled heatup accidents

    International Nuclear Information System (INIS)

    Harrington, R.M.; Ball, S.J.

    1985-01-01

    One of the central design features of the 250 MWT modular HTGR is the ability to withstand uncontrolled heatup accidents without severe consequences. This paper describes calculational studies, conducted to test this design feature. A multi-node thermal-hydraulic model of the 250 MWT modular HTGR reactor core was developed and implemented in the IBM CSMP (Continuous System Modeling Program) simulation language. Survey calculations show that the loss of forced circulation accident with loss of steam generator cooling water and with accidental depressurization is the most severe heatup accident. The peak hot-spot fuel temperature is in the neighborhood of 1600 0 C. Fuel failure and fission product releases for such accidents would be minor. Sensitivity studies show that code input assumptions for thermal properties such as the side reflector conductivity have a significant effect on the peak temperature. A computer model of the reactor vessel cavity concrete wall and its surrounding earth was developed to simulate the extremely unlikely and very slowly-developing heatup accident that would take place if the worst-case loss of forced primary coolant circulation accident were further compounded by the loss of cooling water to the reactor vessel cavity liner cooling system. Results show that the ability of the earth surrounding the cavity to act as a satisfactory long-term heat sink is very sensitive to the assumed rate of decay heat generation and on the effective thermal conductivity of the earth

  7. Two-dimensional simulation of the thermal stress effect on static and dynamic VDMOS characteristics

    International Nuclear Information System (INIS)

    Alwan, M.; Beydoun, B.; Ketata, K.; Zoaeter, M.

    2005-01-01

    Using a two-dimensional simulator, the effect of the thermal stress on static and dynamic vertical double-diffusion metal oxide semiconductor (VDMOS) characteristics have been investigated. The use of the device under certain thermal stress conditions can produce modifications of its physical and electrical properties. Based on physics and 2D simulations, this paper proposes an analysis of this stress effect observed on the electrical characteristics of the device. Parameters responsible of these modifications are determined. Approximate expressions of the ionization coefficients and breakdown voltage in terms of temperature are proposed. Non-punch-through junction theory is used to express the breakdown voltage and the space charge extension with respect to the impurity concentration and the temperature. The capacitances of the device have been also studied. The effect of the stress on C-V characteristics is observed and analyzed. We notice that the drain-gate, drain-source and gate-source capacitances are shifted due to the degradation of device physical properties versus thermal stress

  8. Design, simulation and optimization of a solar dish collector with spiral-coil thermal absorber

    Directory of Open Access Journals (Sweden)

    Pavlović Saša R.

    2016-01-01

    Full Text Available The efficient conversion of solar radiation into heat at high temperature levels requires the use of concentrating solar collectors. The goal of this paper is to present the optical and the thermal analysis of a parabolic dish concentrator with a spiral coil receiver. The parabolic dish reflector consists of 11 curvilinear trapezoidal reflective petals constructed by PMMA with silvered mirror layer and has a diameter of 3.8 m, while its focal distance is 2.26m. This collector is designed with commercial software SolidWorks and simulated, optically and thermally in its Flow Simulation Studio. The optical analysis proved that the ideal position of the absorber is at 2.1m from the reflector in order to maximize the optical efficiency and to create a relative uniform heat flux over the absorber. In thermal part of the analysis, the energetic efficiency was calculated approximately 65%, while the exergetic efficiency is varied from 4% to 15% according to the water inlet temperature. Moreover, other important parameters as the heat flux and temperature distribution over the absorber are presented. The pressure drop of the absorber coil is calculated at 0.07bar, an acceptable value.

  9. Weldability examination of ASTM A 240 S41500 martensitic stainless steel by thermal cycles simulation testings

    Directory of Open Access Journals (Sweden)

    Alberto Velázquez-del Rosario

    2015-07-01

    Full Text Available The weldability assets of ASTM A 240 S41500 (ASTM A 240/A 240M martensitic stainless steel are presented through the study of the effects of single and double thermal weld cycles on mechanical properties and microstructure of base metal (BM and the artificial heat affected zone (HAZ created by thermal weld simulations. For single cycles, separate peak temperatures of 1000 ºC/12 s and 1350 ºC/12 s (cooling times: 12 s in both cases were evaluated, whilst two combinations of peak temperatures: (1350 ºC/5 s + 1000 ºC/5 s ºC and (1350 ºC/12 s + 1000 ºC/12 s ºC (cooling times: 5 s and 12 s, were applied for double cycles. Post weld heat treatment (PWHT with short and long holding times were applied and Vickers hardness, impact toughness and metallographic examinations were used in order to assess mechanical and metallographic properties in the as-simulated (no heat treated and postweld heat treated conditions. Best properties of the welded joint for double thermal weld cycles with long holding times were reached, which reveals the good weldability and applicability of the tested material in post weld heat treated conditions.

  10. Thermal conductivity of nanocrystalline SiGe alloys using molecular dynamics simulations<