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Sample records for relap5-3d-based engineering simulator

  1. Development and application of a dual RELAP5-3D-based engineering simulator for ABWR

    International Nuclear Information System (INIS)

    Yang, C.-Y.; Liang, Thomas K.S.; Pei, B.S.; Shih, C.K.; Chiang, S.C.; Wang, L.C.

    2009-01-01

    For any innovated plant design, the designed paper plant can be converted into a computer as a digital plant with advanced simulation techniques before being constructed into a real plant. A digital plant, namely engineering simulator, can be applied for: (1) verification of system design and system integration, (2) power test simulation, (3) plant transient and accident analyses, (4) plant abnormal and emergency procedure development and verification, (5) design change verification and analysis, etc. An advanced engineering simulator was successfully developed for the LungMen advanced boiling water reactor (ABWR) plant to support various applications before and after commercial operation. This plant specific engineering simulator was developed based on two separate RELAP5-3D modules synchronized on a commercial simulation platform, namely 3-Key Master. On this advanced LungMen plant simulation (ALPS) platform, major plant dynamics were simulated by two separate RELAP5-3D modules, one for reactor system modeling and the other for balance of plant (BOP) system modeling. Moreover, major control systems as well as emergency core cooling system (ECCS) were all simulated in great detail with built-in tasks of this commercial simulation platform. Different from real time calculation on training simulator, precision of engineering calculation is intentionally kept by synchronizing modules based on the most time-consuming one. During synchronization, each module will check its' own converge criteria in each small time advancement. This plant specific advanced ABWR engineering simulator has been successfully applied on: (1) licensing blowdown analysis of feed water line break (FWLB) for containment design; (2) phenomena investigation of low-pressure ECC injection bypass during FWLB; (3) analysis of FW pump performance during power ascending; (4) verification of plant vendor's pre-test calculations of each start-up test.

  2. Nuclear ship engineering simulator

    International Nuclear Information System (INIS)

    Itoh, Yasuyoshi; Kusunoki, Tsuyoshi; Hashidate, Koji

    1991-01-01

    The nuclear ship engineering simulator, which analyzes overall system response of nuclear ship numerically, is now being developed by JAERI as an advanced design tool with the latest computer technology in software and hardware. The development of the nuclear ship engineering simulator aims at grasping characteristics of a reactor plant under the situation generated by the combination of ocean, a ship hull and a reactor. The data from various tests with the nuclear ship 'MUTSU' will be used for this simulator to modulate and verify its functions of reproducing realistic response of nuclear ship, and then the simulator will be utilized for the research and development of advanced marine reactors. (author)

  3. LOFT Engineering Simulator

    International Nuclear Information System (INIS)

    Venhuizen, J.R.

    1982-02-01

    The LOFT Engineering Simulator was developed to supply plant equivalent data for evaluating graphic aids and advanced control concepts for nuclear plant operators. The Simulator, a combination of hardware and software, combines some of the features of best estimate (safety analysis) computer codes with reactor operator training simulators. The LOFT Engineering Simulator represents an attempt to develop a simulation with sufficient physical detail (solution of the conservation equations) for moderate accident simulation, but which will still run in real time and provide an interface for the operator to interact with the model. As a result of this combination, a real time simulation of the LOFT plant has been developed which yields realistic transient results. These data can be used for evaluating reactor control room aids such as Safety Parameter Displays and Janus Predictive Displays

  4. Enhanced productivity of simulation engineers

    International Nuclear Information System (INIS)

    Rohrmann, C.

    1999-01-01

    Simulation has always required a hybrid collection of individuals for software development and maintenance, half engineers and half computer scientists. This paper presents a chronology and an indication of some of the technology currently available to simplify simulation software development and maintenance so that engineers can truly be engineers and not computer scientists. (author)

  5. RELAP5 based engineering simulator

    International Nuclear Information System (INIS)

    Charlton, T.R.; Laats, E.T.; Burtt, J.D.

    1990-01-01

    The INEL Engineering Simulation Center was established in 1988 to provide a modern, flexible, state-of-the-art simulation facility. This facility and two of the major projects which are part of the simulation center, the Advance Test Reactor (ATR) engineering simulator project and the Experimental Breeder Reactor II (EBR-II) advanced reactor control system, have been the subject of several papers in the past few years. Two components of the ATR engineering simulator project, RELAP5 and the Nuclear Plant Analyzer (NPA), have recently been improved significantly. This paper will present an overview of the INEL Engineering Simulation Center, and discuss the RELAP5/MOD3 and NPA/MOD1 codes, specifically how they are being used at the INEL Engineering Simulation Center. It will provide an update on the modifications to these two codes and their application to the ATR engineering simulator project, as well as, a discussion on the reactor system representation, control system modeling, two phase flow and heat transfer modeling. It will also discuss how these two codes are providing desktop, stand-alone reactor simulation. 12 refs., 2 figs

  6. RELAP5 based engineering simulator

    International Nuclear Information System (INIS)

    Charlton, T.R.; Laats, E.T.; Burtt, J.D.

    1990-01-01

    The INEL Engineering Simulation Center was established in 1988 to provide a modern, flexible, state-of-the-art simulation facility. This facility and two of the major projects which are part of the simulation center, the Advance Test Reactor (ATR) engineering simulator project and the Experimental Breeder Reactor (EBR-II) advanced reactor control system, have been the subject of several papers in the past few years. Two components of the ATR engineering simulator project, RELAP5 and the Nuclear Plant Analyzer (NPA), have recently been improved significantly. This paper presents an overview of the INEL Engineering Simulation Center, and discusses the RELAP5/MOD3 and NPA/MOD1 codes, specifically how they are being used at the INEL Engineering Simulation Center. It provides an update on the modifications to these two codes and their application to the ATR engineering simulator project, as well as, a discussion on the reactor system representation, control system modeling, two phase flow and heat transfer modeling. It will also discuss how these two codes are providing desktop, stand-alone reactor simulation

  7. Simulation of a combined-cycle engine

    Science.gov (United States)

    Vangerpen, Jon

    1991-01-01

    A FORTRAN computer program was developed to simulate the performance of combined-cycle engines. These engines combine features of both gas turbines and reciprocating engines. The computer program can simulate both design point and off-design operation. Widely varying engine configurations can be evaluated for their power, performance, and efficiency as well as the influence of altitude and air speed. Although the program was developed to simulate aircraft engines, it can be used with equal success for stationary and automative applications.

  8. Simulation and material testing of jet engines

    International Nuclear Information System (INIS)

    Tariq, M.M.

    2006-01-01

    The NASA software engine simulator version U 1.7a beta has been used for simulation and material testing of jet engines. Specifications of Modem Jet Engines are stated, and then engine simulator is applied on these specifications. This simulator can simulate turbojet, afterburner, turbofan and ram jet. The material of many components of engine may be varied. Conventional and advanced materials for jet engines can be simulated and tested. These materials can be actively cooled to increase the operating temperature limit. As soon as temperature of any engine component exceeds the temperature limit of material, a warning message flashes across screen. Temperature Limits Exceeded. This flashing message remainst here until necessaryc hangesa re carried out in engine operationp rocedure. Selection Criteria of Engines is stated for piston prop, turboprop, turbofan, turbojet, and turbojet with afterburner and Ramjet. Several standard engines are modeled in Engine Simulator. These engines can. be compared by several engineering specifications. The design, modeling, simulation and testing of engines helps to better understand different types of materials used in jet engines. (author)

  9. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent

    2016-01-01

    Backed by substantive case studies, the novel approach to software engineering for distributed simulation outlined in this text demonstrates the potent synergies between model-driven techniques, simulation, intelligent agents, and computer systems development.

  10. Microcomputer Simulated CAD for Engineering Graphics.

    Science.gov (United States)

    Huggins, David L.; Myers, Roy E.

    1983-01-01

    Describes a simulated computer-aided-graphics (CAD) program at The Pennsylvania State University. Rationale for the program, facilities, microcomputer equipment (Apple) used, and development of a software package for simulating applied engineering graphics are considered. (JN)

  11. Engineering dynamics from the Lagrangian to simulation

    CERN Document Server

    Gans, Roger F

    2013-01-01

    This engineering dynamics textbook is aimed at beginning graduate students in mechanical engineering and other related engineering disciplines who need training in dynamics as applied to engineering mechanisms. It introduces the formal mathematical development of Lagrangian mechanics (and its corollaries), while solving numerous engineering applications. The author’s goal is to instill an understanding of the basic physics required for engineering dynamics, while providing a recipe (algorithm) for the simulation of engineering mechanisms such as robots. The book is reasonably self-contained so that the practicing engineer interested in this area can also make use of it. This book is made accessible to the widest possible audience by numerous, solved examples and diagrams that apply the principles to real engineering applications. • Provides an applied textbook for intermediate/advanced engineering dynamics courses; • Discusses Lagrangian mechanics in the context of numerous engineering applications...

  12. Virtual engine management simulator for educational purposes

    Science.gov (United States)

    Drosescu, R.

    2017-10-01

    This simulator was conceived as a software program capable of generating complex control signals, identical to those in the electronic management systems of modern spark ignition or diesel engines. Speed in rpm and engine load percentage defined by throttle opening angle represent the input variables in the simulation program and are graphically entered by two-meter instruments from the simulator central block diagram. The output signals are divided into four categories: synchronization and position of each cylinder, spark pulses for spark ignition engines, injection pulses and, signals for generating the knock window for each cylinder in the case of a spark ignition engine. The simulation program runs in real-time so each signal evolution reflects the real behavior on a physically thermal engine. In this way, the generated signals (ignition or injection pulses) can be used with additionally drivers to control an engine on the test bench.

  13. Simulation and Spacecraft Design: Engineering Mars Landings.

    Science.gov (United States)

    Conway, Erik M

    2015-10-01

    A key issue in history of technology that has received little attention is the use of simulation in engineering design. This article explores the use of both mechanical and numerical simulation in the design of the Mars atmospheric entry phases of the Viking and Mars Pathfinder missions to argue that engineers used both kinds of simulation to develop knowledge of their designs' likely behavior in the poorly known environment of Mars. Each kind of simulation could be used as a warrant of the other's fidelity, in an iterative process of knowledge construction.

  14. Computer Simulation in Information and Communication Engineering

    CERN Multimedia

    Anton Topurov

    2005-01-01

    CSICE'05 Sofia, Bulgaria 20th - 22nd October, 2005 On behalf of the International Scientific Committee, we would like to invite you all to Sofia, the capital city of Bulgaria, to the International Conference in Computer Simulation in Information and Communication Engineering CSICE'05. The Conference is aimed at facilitating the exchange of experience in the field of computer simulation gained not only in traditional fields (Communications, Electronics, Physics...) but also in the areas of biomedical engineering, environment, industrial design, etc. The objective of the Conference is to bring together lectures, researchers and practitioners from different countries, working in the fields of computer simulation in information engineering, in order to exchange information and bring new contribution to this important field of engineering design and education. The Conference will bring you the latest ideas and development of the tools for computer simulation directly from their inventors. Contribution describ...

  15. Analysis and simulation of Wiseman hypocycloid engine

    OpenAIRE

    Priyesh Ray; Sangram Redkar

    2014-01-01

    This research studies an alternative to the slider-crank mechanism for internal combustion engines, which was proposed by the Wiseman Technologies Inc. Their design involved replacing the crankshaft with a hypocycloid gear assembly. The unique hypocycloid gear arrangement allowed the piston and connecting rod to move in a straight line creating a perfect sinusoidal motion, without any side loads. In this work, the Wiseman hypocycloid engine was modeled in a commercial engine simulation softwa...

  16. 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.

  17. Analysis and simulation of Wiseman hypocycloid engine

    Directory of Open Access Journals (Sweden)

    Priyesh Ray

    2014-12-01

    Full Text Available This research studies an alternative to the slider-crank mechanism for internal combustion engines, which was proposed by the Wiseman Technologies Inc. Their design involved replacing the crankshaft with a hypocycloid gear assembly. The unique hypocycloid gear arrangement allowed the piston and connecting rod to move in a straight line creating a perfect sinusoidal motion, without any side loads. In this work, the Wiseman hypocycloid engine was modeled in a commercial engine simulation software and compared to slider-crank engine of the same size. The engine’s performance was studied, while operating on diesel, ethanol, and gasoline fuel. Furthermore, a scaling analysis on the Wiseman engine prototypes was carried out to understand how the performance of the engine is affected by increasing the output power and cylinder displacement. It was found that the existing 30cc Wiseman engine produced about 7% less power at peak speeds than the slider-crank engine of the same size. These results were concurrent with the dynamometer tests performed in the past. It also produced lower torque and was about 6% less fuel efficient than the slider-crank engine. The four-stroke diesel variant of the same Wiseman engine performed better than the two-stroke gasoline version. The Wiseman engine with a contra piston (that allowed to vary the compression ratio showed poor fuel efficiency but produced higher torque when operating on E85 fuel. It also produced about 1.4% more power than while running on gasoline. While analyzing effects of the engine size on the Wiseman hypocycloid engine prototypes, it was found that the engines performed better in terms of power, torque, fuel efficiency, and cylinder brake mean effective pressure as the displacement increased. The 30 horsepower (HP conceptual Wiseman prototype, while operating on E85, produced the most optimum results in all aspects, and the diesel test for the same engine proved to be the most fuel efficient.

  18. Simulation of diesel engine energy conversion processes

    Directory of Open Access Journals (Sweden)

    А. С. Афанасьев

    2016-12-01

    Full Text Available In order to keep diesel engines in good working order the troubleshooting methods shall be improved. For their further improvement by parameters of associated processes a need has arisen to develop a diesel engine troubleshooting method based on time parameters of operating cycle. For such method to be developed a computational experiment involving simulation of diesel engine energy conversion processes has been carried out. The simulation was based on the basic mathematical model of reciprocating internal combustion engines, representing a closed system of equations and relationships. The said model has been supplemented with the engine torque dynamics taking into account the current values of in-cylinder processes with different amounts of fuel injected, including zero feed.The torque values obtained by the in-cylinder pressure conversion does not account for mechanical losses, which is why the base simulation program has been supplemented with calculations for the friction and pumping forces. In order to determine the indicator diagram of idle cylinder a transition to zero fuel feed mode and exclusion of the combustion process from calculation have been provisioned.

  19. Interactive Mathematica Simulations in Chemical Engineering Courses

    Science.gov (United States)

    Falconer, John L.; Nicodemus, Garret D.

    2014-01-01

    Interactive Mathematica simulations with graphical displays of system behavior are an excellent addition to chemical engineering courses. The Manipulate command in Mathematica creates on-screen controls that allow users to change system variables and see the graphical output almost instantaneously. They can be used both in and outside class. More…

  20. Software-Engineering Process Simulation (SEPS) model

    Science.gov (United States)

    Lin, C. Y.; Abdel-Hamid, T.; Sherif, J. S.

    1992-01-01

    The Software Engineering Process Simulation (SEPS) model is described which was developed at JPL. SEPS is a dynamic simulation model of the software project development process. It uses the feedback principles of system dynamics to simulate the dynamic interactions among various software life cycle development activities and management decision making processes. The model is designed to be a planning tool to examine tradeoffs of cost, schedule, and functionality, and to test the implications of different managerial policies on a project's outcome. Furthermore, SEPS will enable software managers to gain a better understanding of the dynamics of software project development and perform postmodern assessments.

  1. Simulation software: engineer processes before reengineering.

    Science.gov (United States)

    Lepley, C J

    2001-01-01

    People make decisions all the time using intuition. But what happens when you are asked: "Are you sure your predictions are accurate? How much will a mistake cost? What are the risks associated with this change?" Once a new process is engineered, it is difficult to analyze what would have been different if other options had been chosen. Simulating a process can help senior clinical officers solve complex patient flow problems and avoid wasted efforts. Simulation software can give you the data you need to make decisions. The author introduces concepts, methodologies, and applications of computer aided simulation to illustrate their use in making decisions to improve workflow design.

  2. Nuclear engine system simulation (NESS) program update

    International Nuclear Information System (INIS)

    Scheil, C.M.; Pelaccio, D.G.; Petrosky, L.J.

    1993-01-01

    The second phase of development of a Nuclear Thermal Propulsion (NTP) engine system design analysis code has been completed. The standalone, versatile Nuclear Engine System Simulation (NESS) code provides an accurate, detailed assessment of engine system operating performance, weight, and sizes. The critical information is required to support ongoing and future engine system and stage design study efforts. This recent development effort included incorporation of an updated solid-core nuclear thermal reactor model that yields a reduced core weight and higher fuel power density when compared to a NERVA type reactor. NESS can now analyze expander, gas generator, and bleed cycles, along with multi-redundant propellant pump feed systems. Performance and weight of efficient multi-stage axial turbopump can now be determined, in addition to the traditional centrifugal pump

  3. Software for Engineering Simulations of a Spacecraft

    Science.gov (United States)

    Shireman, Kirk; McSwain, Gene; McCormick, Bernell; Fardelos, Panayiotis

    2005-01-01

    Spacecraft Engineering Simulation II (SES II) is a C-language computer program for simulating diverse aspects of operation of a spacecraft characterized by either three or six degrees of freedom. A functional model in SES can include a trajectory flight plan; a submodel of a flight computer running navigational and flight-control software; and submodels of the environment, the dynamics of the spacecraft, and sensor inputs and outputs. SES II features a modular, object-oriented programming style. SES II supports event-based simulations, which, in turn, create an easily adaptable simulation environment in which many different types of trajectories can be simulated by use of the same software. The simulation output consists largely of flight data. SES II can be used to perform optimization and Monte Carlo dispersion simulations. It can also be used to perform simulations for multiple spacecraft. In addition to its generic simulation capabilities, SES offers special capabilities for space-shuttle simulations: for this purpose, it incorporates submodels of the space-shuttle dynamics and a C-language version of the guidance, navigation, and control components of the space-shuttle flight software.

  4. Dynamics simulations for engineering macromolecular interactions

    Science.gov (United States)

    Robinson-Mosher, Avi; Shinar, Tamar; Silver, Pamela A.; Way, Jeffrey

    2013-01-01

    The predictable engineering of well-behaved transcriptional circuits is a central goal of synthetic biology. The artificial attachment of promoters to transcription factor genes usually results in noisy or chaotic behaviors, and such systems are unlikely to be useful in practical applications. Natural transcriptional regulation relies extensively on protein-protein interactions to insure tightly controlled behavior, but such tight control has been elusive in engineered systems. To help engineer protein-protein interactions, we have developed a molecular dynamics simulation framework that simplifies features of proteins moving by constrained Brownian motion, with the goal of performing long simulations. The behavior of a simulated protein system is determined by summation of forces that include a Brownian force, a drag force, excluded volume constraints, relative position constraints, and binding constraints that relate to experimentally determined on-rates and off-rates for chosen protein elements in a system. Proteins are abstracted as spheres. Binding surfaces are defined radially within a protein. Peptide linkers are abstracted as small protein-like spheres with rigid connections. To address whether our framework could generate useful predictions, we simulated the behavior of an engineered fusion protein consisting of two 20 000 Da proteins attached by flexible glycine/serine-type linkers. The two protein elements remained closely associated, as if constrained by a random walk in three dimensions of the peptide linker, as opposed to showing a distribution of distances expected if movement were dominated by Brownian motion of the protein domains only. We also simulated the behavior of fluorescent proteins tethered by a linker of varying length, compared the predicted Förster resonance energy transfer with previous experimental observations, and obtained a good correspondence. Finally, we simulated the binding behavior of a fusion of two ligands that could

  5. An Emotional Engine for Behavior Simulators

    Directory of Open Access Journals (Sweden)

    Santiago García Carbajal

    2015-06-01

    Full Text Available Interpreting, modeling and representing emotions is a key feature of new generation games. This paper describes the first version of the Emotional Engine we have developed as a component of more complex behavior simulators. The purpose of this module is to manage the state and behavior of the characters present in a scene while they interact with a human user. We use preexistent language recognition libraries like Windows™ Speech API, and Kinect™ devices to communicate real humans with artificial characters participating in a virtual scene. The Emotional Engine works upon numeric variables extracted from such devices and calculated after some natural language interpretation process. It then produces numerical results that lead the behavior, modify both the verbal and body language of the characters, and influence the general evolution of the scene that takes place inside the simulator. This paper presents the system architecture and discusses some key components, such as the Language Interpretation and the Body Language Interpreter modules.

  6. Simulation teaching method in Engineering Optics

    Science.gov (United States)

    Lu, Qieni; Wang, Yi; Li, Hongbin

    2017-08-01

    We here introduce a pedagogical method of theoretical simulation as one major means of the teaching process of "Engineering Optics" in course quality improvement action plan (Qc) in our school. Students, in groups of three to five, complete simulations of interference, diffraction, electromagnetism and polarization of light; each student is evaluated and scored in light of his performance in the interviews between the teacher and the student, and each student can opt to be interviewed many times until he is satisfied with his score and learning. After three years of Qc practice, the remarkable teaching and learning effect is obatined. Such theoretical simulation experiment is a very valuable teaching method worthwhile for physical optics which is highly theoretical and abstruse. This teaching methodology works well in training students as to how to ask questions and how to solve problems, which can also stimulate their interest in research learning and their initiative to develop their self-confidence and sense of innovation.

  7. Cardiovascular system simulation in biomedical engineering education.

    Science.gov (United States)

    Rideout, V. C.

    1972-01-01

    Use of complex cardiovascular system models, in conjunction with a large hybrid computer, in biomedical engineering courses. A cardiovascular blood pressure-flow model, driving a compartment model for the study of dye transport, was set up on the computer for use as a laboratory exercise by students who did not have the computer experience or skill to be able to easily set up such a simulation involving some 27 differential equations running at 'real time' rate. The students were given detailed instructions regarding the model, and were then able to study effects such as those due to septal and valve defects upon the pressure, flow, and dye dilution curves. The success of this experiment in the use of involved models in engineering courses was such that it seems that this type of laboratory exercise might be considered for use in physiology courses as an adjunct to animal experiments.

  8. Simulation based engineering in solid mechanics

    CERN Document Server

    Rao, J S

    2017-01-01

    This book begins with a brief historical perspective of the advent of rotating machinery in 20th century Solid Mechanics and the development of the discipline of the Strength of Materials. High Performance Computing (HPC) and Simulation Based Engineering Science (SBES) have gradually replaced the conventional approach in Design bringing science directly into engineering without approximations. A recap of the required mathematical principles is given. The science of deformation, strain and stress at a point under the application of external traction loads is next presented. Only one-dimensional structures classified as Bars (axial loads), Rods (twisting loads) and Beams (bending loads) are considered in this book. The principal stresses and strains and von Mises stress and strain that used in design of structures are next presented. Lagrangian solution was used to derive the governing differential equations consistent with assumed deformation field and solution for deformations, strains and stresses were obtai...

  9. Computational simulation of concurrent engineering for aerospace propulsion systems

    Science.gov (United States)

    Chamis, C. C.; Singhal, S. N.

    1992-01-01

    Results are summarized of an investigation to assess the infrastructure available and the technology readiness in order to develop computational simulation methods/software for concurrent engineering. These results demonstrate that development of computational simulations methods for concurrent engineering is timely. Extensive infrastructure, in terms of multi-discipline simulation, component-specific simulation, system simulators, fabrication process simulation, and simulation of uncertainties - fundamental in developing such methods, is available. An approach is recommended which can be used to develop computational simulation methods for concurrent engineering for propulsion systems and systems in general. Benefits and facets needing early attention in the development are outlined.

  10. Computational simulation for concurrent engineering of aerospace propulsion systems

    Science.gov (United States)

    Chamis, C. C.; Singhal, S. N.

    1993-01-01

    Results are summarized for an investigation to assess the infrastructure available and the technology readiness in order to develop computational simulation methods/software for concurrent engineering. These results demonstrate that development of computational simulation methods for concurrent engineering is timely. Extensive infrastructure, in terms of multi-discipline simulation, component-specific simulation, system simulators, fabrication process simulation, and simulation of uncertainties--fundamental to develop such methods, is available. An approach is recommended which can be used to develop computational simulation methods for concurrent engineering of propulsion systems and systems in general. Benefits and issues needing early attention in the development are outlined.

  11. Software Engineering for Scientific Computer Simulations

    Science.gov (United States)

    Post, Douglass E.; Henderson, Dale B.; Kendall, Richard P.; Whitney, Earl M.

    2004-11-01

    Computer simulation is becoming a very powerful tool for analyzing and predicting the performance of fusion experiments. Simulation efforts are evolving from including only a few effects to many effects, from small teams with a few people to large teams, and from workstations and small processor count parallel computers to massively parallel platforms. Successfully making this transition requires attention to software engineering issues. We report on the conclusions drawn from a number of case studies of large scale scientific computing projects within DOE, academia and the DoD. The major lessons learned include attention to sound project management including setting reasonable and achievable requirements, building a good code team, enforcing customer focus, carrying out verification and validation and selecting the optimum computational mathematics approaches.

  12. Benchmarking of SIMULATE-3 on engineering workstations

    International Nuclear Information System (INIS)

    Karlson, C.F.; Reed, M.L.; Webb, J.R.; Elzea, J.D.

    1990-01-01

    The nuclear fuel management department of Arizona Public Service Company (APS) has evaluated various computer platforms for a departmental engineering and business work-station local area network (LAN). Historically, centralized mainframe computer systems have been utilized for engineering calculations. Increasing usage and the resulting longer response times on the company mainframe system and the relative cost differential between a mainframe upgrade and workstation technology justified the examination of current workstations. A primary concern was the time necessary to turn around routine reactor physics reload and analysis calculations. Computers ranging from a Definicon 68020 processing board in an AT compatible personal computer up to an IBM 3090 mainframe were benchmarked. The SIMULATE-3 advanced nodal code was selected for benchmarking based on its extensive use in nuclear fuel management. SIMULATE-3 is used at APS for reload scoping, design verification, core follow, and providing predictions of reactor behavior under nominal conditions and planned reactor maneuvering, such as axial shape control during start-up and shutdown

  13. Engineering Fracking Fluids with Computer Simulation

    Science.gov (United States)

    Shaqfeh, Eric

    2015-11-01

    There are no comprehensive simulation-based tools for engineering the flows of viscoelastic fluid-particle suspensions in fully three-dimensional geometries. On the other hand, the need for such a tool in engineering applications is immense. Suspensions of rigid particles in viscoelastic fluids play key roles in many energy applications. For example, in oil drilling the ``drilling mud'' is a very viscous, viscoelastic fluid designed to shear-thin during drilling, but thicken at stoppage so that the ``cuttings'' can remain suspended. In a related application known as hydraulic fracturing suspensions of solids called ``proppant'' are used to prop open the fracture by pumping them into the well. It is well-known that particle flow and settling in a viscoelastic fluid can be quite different from that which is observed in Newtonian fluids. First, it is now well known that the ``fluid particle split'' at bifurcation cracks is controlled by fluid rheology in a manner that is not understood. Second, in Newtonian fluids, the presence of an imposed shear flow in the direction perpendicular to gravity (which we term a cross or orthogonal shear flow) has no effect on the settling of a spherical particle in Stokes flow (i.e. at vanishingly small Reynolds number). By contrast, in a non-Newtonian liquid, the complex rheological properties induce a nonlinear coupling between the sedimentation and shear flow. Recent experimental data have shown both the shear thinning and the elasticity of the suspending polymeric solutions significantly affects the fluid-particle split at bifurcations, as well as the settling rate of the solids. In the present work, we use the Immersed Boundary Method to develop computer simulations of viscoelastic flow in suspensions of spheres to study these problems. These simulations allow us to understand the detailed physical mechanisms for the remarkable physical behavior seen in practice, and actually suggest design rules for creating new fluid recipes.

  14. Development of a full scope reactor engineering simulator

    International Nuclear Information System (INIS)

    Venhuizen, J.R.; Laats, E.T.

    1988-01-01

    An engineering laboratory is pursuing the development of an engineering simulator for use by several agencies of the U.S. Government. According to the authors, this simulator will provide the highest fidelity simulation with initial objectives for studying augmented nuclear reactor operator training, and later for advanced concepts testing as applicable to control room accident diagnosis and management

  15. Numerical simulations of coupled problems in engineering

    CERN Document Server

    2014-01-01

    This book presents and discusses mathematical models, numerical methods and computational techniques used for solving coupled problems in science and engineering. It takes a step forward in the formulation and solution of real-life problems with a multidisciplinary vision, accounting for all of the complex couplings involved in the physical description. Simulation of multifaceted physics problems is a common task in applied research and industry. Often a suitable solver is built by connecting together several single-aspect solvers into a network. In this book, research in various fields was selected for consideration: adaptive methodology for multi-physics solvers, multi-physics phenomena and coupled-field solutions, leading to computationally intensive structural analysis. The strategies which are used to keep these problems computationally affordable are of special interest, and make this an essential book.

  16. Front panel engineering with CAD simulation tool

    Science.gov (United States)

    Delacour, Jacques; Ungar, Serge; Mathieu, Gilles; Hasna, Guenther; Martinez, Pascal; Roche, Jean-Christophe

    1999-04-01

    THe progress made recently in display technology covers many fields of application. The specification of radiance, colorimetry and lighting efficiency creates some new challenges for designers. Photometric design is limited by the capability of correctly predicting the result of a lighting system, to save on the costs and time taken to build multiple prototypes or bread board benches. The second step of the research carried out by company OPTIS is to propose an optimization method to be applied to the lighting system, developed in the software SPEOS. The main features of the tool requires include the CAD interface, to enable fast and efficient transfer between mechanical and light design software, the source modeling, the light transfer model and an optimization tool. The CAD interface is mainly a prototype of transfer, which is not the subjects here. Photometric simulation is efficiently achieved by using the measured source encoding and a simulation by the Monte Carlo method. Today, the advantages and the limitations of the Monte Carlo method are well known. The noise reduction requires a long calculation time, which increases with the complexity of the display panel. A successful optimization is difficult to achieve, due to the long calculation time required for each optimization pass including a Monte Carlo simulation. The problem was initially defined as an engineering method of study. The experience shows that good understanding and mastering of the phenomenon of light transfer is limited by the complexity of non sequential propagation. The engineer must call for the help of a simulation and optimization tool. The main point needed to be able to perform an efficient optimization is a quick method for simulating light transfer. Much work has been done in this area and some interesting results can be observed. It must be said that the Monte Carlo method wastes time calculating some results and information which are not required for the needs of the simulation

  17. Experiences on dynamic simulation software in chemical engineering education

    DEFF Research Database (Denmark)

    Komulainen, Tiina M.; Enemark-rasmussen, Rasmus; Sin, Gürkan

    2012-01-01

    Commercial process simulators are increasing interest in the chemical engineer education. In this paper, the use of commercial dynamic simulation software, D-SPICE® and K-Spice®, for three different chemical engineering courses is described and discussed. The courses cover the following topics...

  18. Simulation of Temperature Fluctuations in Stirling Engine Regenerator Matrices

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegaard; Carlsen, Henrik; Thomsen, Per Grove

    2003-01-01

    The objective of this study has been to create a model for studying the effects of fluctuations in regenerator matrix temperatures on Stirling engine performance. A one-dimensional model with axial discretisation of engine components has been formulated using the balance equations for mass, energy...... and accurately calculated. Simulation results have been compared to experimental data for a 9 kW Stirling engine and reasonable agreement has been found over a wide range of operating conditions using Helium or Nitrogen as working gas. Simulation results indicate that fluctuations in the regenerator matrix...... temperatures have significant impact on the regenerator loss, the engine power output, and the cycle efficiency....

  19. Simulation Of The Internal-Combustion Engine

    Science.gov (United States)

    Zeleznik, Frank J.; Mcbride, Bonnie J.

    1987-01-01

    Program adapts to available information about particular engine. Mathematical model of internal-combustion engine constructed and implemented as computer program suitable for use on large digital computer systems. ZMOTTO program calculates Otto-cycle performance parameters as well as working-fluid compositions and properties throughout cycle for number of consecutive cycles and for variety of input parameters. Written in standard FORTRAN IV.

  20. Discrete-Event Simulation in Chemical Engineering.

    Science.gov (United States)

    Schultheisz, Daniel; Sommerfeld, Jude T.

    1988-01-01

    Gives examples, descriptions, and uses for various types of simulation systems, including the Flowtran, Process, Aspen Plus, Design II, GPSS, Simula, and Simscript. Explains similarities in simulators, terminology, and a batch chemical process. Tables and diagrams are included. (RT)

  1. Simulation of compression engine powered by Biofuels

    International Nuclear Information System (INIS)

    Hamdan, M.A.; Khalil, Runa Haj

    2010-01-01

    The present work describes a theoretical investigation concerning the performance of a four strokes compression engine, which is powered by alternative fuels in the form of diesel-ethanol and diesel-ether mixtures, the properties of which were sited from literature. The amount of each alcohol added was 5%, 10% and 15% by volume. The engine speed during the experimental work was within the range from 1000 to 4000 rpm, with engine was set at full throttle opening and hence the engine was operating under full load conditions. Several parameters were calculated namely: engine torque, brake mean effective pressure, brake power, specific fuel consumption and the thermal efficiency, this was carried out using DIESEL-RK software. It was found that the engine is of highest thermal efficiency when it is powered by a 15% ethanol-diesel blend, wile it is of minimum thermal efficiency when it is powered by pure diesel fuel. Further, it was found that both the thermal efficiency of the engine and the specific fuel consumption increases with the percentage of either ethanol or ether in the fuel blend. However, the power was found to decrease with the amount of either ethanol or ether in the fuel blends.

  2. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

    Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

  3. Comparison of Engine Simulation Software for Development of Control System

    Directory of Open Access Journals (Sweden)

    KinYip Chan

    2013-01-01

    Full Text Available Most commonly used commercial engine simulation packages generate detailed estimation of the combustion and gas flow parameters. These parameters are required for advanced research on fluid flow and heat transfer and development of geometries of engine components. However, engine control involves different operating parameters. Various sensors are installed into the engine, the combustion performance is recorded, and data is sent to engine control unit (ECU. ECU computes the new set of parameters to make fine adjustments to actuators providing better engine performance. Such techniques include variable valve timing, variable ignition timing, variable air to fuel ratio, and variable compression ratio. In the present study, two of the commercial packages, Ricardo Wave and Lotus Engine Simulation, have been tested on the capabilities for engine control purposes. These packages are compared with an in-house developed package and with reference results available from the literature. Different numerical experiments have been carried out from which it can be concluded that all packages predict similar profiles of pressure and temperature in the engine cylinder. Moreover, those are in reasonable agreement with the reference results while in-house developed package is possible to run simulations with changing speed for engine control purpose.

  4. WDM Systems and Networks Modeling, Simulation, Design and Engineering

    CERN Document Server

    Ellinas, Georgios; Roudas, Ioannis

    2012-01-01

    WDM Systems and Networks: Modeling, Simulation, Design and Engineering provides readers with the basic skills, concepts, and design techniques used to begin design and engineering of optical communication systems and networks at various layers. The latest semi-analytical system simulation techniques are applied to optical WDM systems and networks, and a review of the various current areas of optical communications is presented. Simulation is mixed with experimental verification and engineering to present the industry as well as state-of-the-art research. This contributed volume is divided into three parts, accommodating different readers interested in various types of networks and applications. The first part of the book presents modeling approaches and simulation tools mainly for the physical layer including transmission effects, devices, subsystems, and systems), whereas the second part features more engineering/design issues for various types of optical systems including ULH, access, and in-building system...

  5. Engineering uses of physics-based ground motion simulations

    Science.gov (United States)

    Baker, Jack W.; Luco, Nicolas; Abrahamson, Norman A.; Graves, Robert W.; Maechling, Phillip J.; Olsen, Kim B.

    2014-01-01

    This paper summarizes validation methodologies focused on enabling ground motion simulations to be used with confidence in engineering applications such as seismic hazard analysis and dynmaic analysis of structural and geotechnical systems. Numberical simullation of ground motion from large erthquakes, utilizing physics-based models of earthquake rupture and wave propagation, is an area of active research in the earth science community. Refinement and validatoin of these models require collaboration between earthquake scientists and engineering users, and testing/rating methodolgies for simulated ground motions to be used with confidence in engineering applications. This paper provides an introduction to this field and an overview of current research activities being coordinated by the Souther California Earthquake Center (SCEC). These activities are related both to advancing the science and computational infrastructure needed to produce ground motion simulations, as well as to engineering validation procedures. Current research areas and anticipated future achievements are also discussed.

  6. Design of compact nuclear power marine engineering simulator

    International Nuclear Information System (INIS)

    Gao Jinghui; Xing Hongchuan; Zhang Ronghua; Yang Yanhua; Xu Jijun

    2004-01-01

    The essentiality of compact nuclear power marine engineering simulator (NPMES) is discussed. The technology of nuclear power plant engineering simulator (NPPES) for NPMES development is introduced, and the function design, general design and model design are given in details. A compact NPMES based on the nuclear power marine of 'Mutsu' is developed. The design can help the development of NPMES, which will improve operation safety and management efficiency of marine. (authors)

  7. Development of HANARO engineering simulator (I)

    International Nuclear Information System (INIS)

    Jung, Hoan Sung; Han, G. Y.; Kim, M. J.; Kim, Y. K.; Lee, K. H.; Park, S. J.; Kim, H. K.; Park, J. H.

    2001-01-01

    The simulation models for HANARO have been developed. Core dynamics is modeled by two-point kinetics. Thermal-hydraulic characteristics are also modeled for the primary, secondary, and reflector cooling systems. Control algorithms used in the digital controller are modeled to control the reactor in same manner with the real system. Prototype simulator was implemented to test developed models. The computer system for distributed simulation was prepared

  8. Engine process simulation and supercharging. Proceedings; Motorprozesssimulation und Aufladung. Tagungsbeitraege

    Energy Technology Data Exchange (ETDEWEB)

    Pucher, H.; Kahrstedt, J. (eds.)

    2005-07-01

    Engine process simulation has become an integral part of research and development for all types of internal combustion engines. It allows developers to obtain information on the steady-state and dynamic operating behavior of any type of internal combustion engine at early development stages without costly and laborious testing. Moreover, the entire powertrain can be included in the system under investigation. Engine process simulation is particularly important when it comes to assessing potentials and studying parameters for the development of supercharging concepts. For the investigation of existing combustion systems, however, thermodynamic analysis must be used. Furthermore, simulation nowadays is an important tool for the design and development of controllers. This documentation summarizes an exchange of knowledge and experience on the above-mentioned issues that took place during the first 'Engine Process Simulation and Supercharging' symposium held in Berlin on 30 June and 1 July 2005, i.e. the year marking 100 years of supercharging. The paper in this book report on the following subjects: (a) Use of engine process simulation in the development process. (b) Requirements placed on supercharging in conjunction with conventional and alternative combustion processes. (c) Modeling of supercharging units. (d) Combustion curve analysis as a tool to optimize combustion processes. (e) Engine control: algorithm development up to model-based approaches, sensors/actuators, hardware-in-the-loop. (orig.)

  9. Simulating the Use of Alternative Fuels in a Turbofan Engine

    Science.gov (United States)

    Litt, Jonathan S.; Chin, Jeffrey Chevoor; Liu, Yuan

    2013-01-01

    The interest in alternative fuels for aviation has created a need to evaluate their effect on engine performance. The use of dynamic turbofan engine simulations enables the comparative modeling of the performance of these fuels on a realistic test bed in terms of dynamic response and control compared to traditional fuels. The analysis of overall engine performance and response characteristics can lead to a determination of the practicality of using specific alternative fuels in commercial aircraft. This paper describes a procedure to model the use of alternative fuels in a large commercial turbofan engine, and quantifies their effects on engine and vehicle performance. In addition, the modeling effort notionally demonstrates that engine performance may be maintained by modifying engine control system software parameters to account for the alternative fuel.

  10. Application of Modern Simulation Technology in Mechanical Outstanding Engineer Training

    Directory of Open Access Journals (Sweden)

    Gongfa Li

    2014-03-01

    Full Text Available This text has described the relationship between outstanding engineer training and modern simulation technology, have recommended the characteristics of mechanical outstanding engineer in detail. Aiming at the importance of the teaching practice link to course of theory of mechanics, mechanical design and mechanical signal analysis, have expounded the function of modern simulation technology in the mechanical outstanding engineer training, especially on teaching practice in the theory of mechanics, mechanical design and mechanical signal analysis. It has the advantages of economizing the teaching cost, overcoming the hardware constrains, model prediction, promoting student's innovation and manipulative ability, so can popularize and develop in a more cost-effective manner in the university.

  11. Expert System Architecture for Rocket Engine Numerical Simulators: A Vision

    Science.gov (United States)

    Mitra, D.; Babu, U.; Earla, A. K.; Hemminger, Joseph A.

    1998-01-01

    Simulation of any complex physical system like rocket engines involves modeling the behavior of their different components using mostly numerical equations. Typically a simulation package would contain a set of subroutines for these modeling purposes and some other ones for supporting jobs. A user would create an input file configuring a system (part or whole of a rocket engine to be simulated) in appropriate format understandable by the package and run it to create an executable module corresponding to the simulated system. This module would then be run on a given set of input parameters in another file. Simulation jobs are mostly done for performance measurements of a designed system, but could be utilized for failure analysis or a design job such as inverse problems. In order to use any such package the user needs to understand and learn a lot about the software architecture of the package, apart from being knowledgeable in the target domain. We are currently involved in a project in designing an intelligent executive module for the rocket engine simulation packages, which would free any user from this burden of acquiring knowledge on a particular software system. The extended abstract presented here will describe the vision, methodology and the problems encountered in the project. We are employing object-oriented technology in designing the executive module. The problem is connected to the areas like the reverse engineering of any simulation software, and the intelligent systems for simulation.

  12. Comparison of Engineering Wake Models with CFD Simulations

    DEFF Research Database (Denmark)

    Andersen, Søren Juhl; Sørensen, Jens Nørkær; Ivanell, S.

    2014-01-01

    The engineering wake models by Jensen [1] and Frandsen et al. [2] are assessed for different scenarios simulated using Large Eddy Simulation and the Actuator Line method implemented in the Navier-Stokes equations. The scenarios include the far wake behind a single wind turbine, a long row of turb...

  13. Numerical Simulation of Methane Slip in Dual Fuel Marine Engines

    OpenAIRE

    Han, Jaehyun; Jensen, Michael Vincent; Pang, Kar Mun; Walther, Jens Honore; Schramm, Jesper; Bae, Choongsik

    2017-01-01

    The methane slip is the problematic issue for the engines using natural gas(NG). Because methane is more powerful greenhouse gas (GHG) than CO2, understanding of the methane slip during gas exchange process of the engines is essential. In this study, the influence of the gas pipe geometry and the valve timings on the methane slip was investigated. MAN L28/32DF engine was modeled to simulate the gas exchange process of the four stroke NG-diesel dual fuel engines. The mesh size of the model was...

  14. Apollo experience report: Guidance and control systems. Engineering simulation program

    Science.gov (United States)

    Gilbert, D. W.

    1973-01-01

    The Apollo Program experience from early 1962 to July 1969 with respect to the engineering-simulation support and the problems encountered is summarized in this report. Engineering simulation in support of the Apollo guidance and control system is discussed in terms of design analysis and verification, certification of hardware in closed-loop operation, verification of hardware/software compatibility, and verification of both software and procedures for each mission. The magnitude, time, and cost of the engineering simulations are described with respect to hardware availability, NASA and contractor facilities (for verification of the command module, the lunar module, and the primary guidance, navigation, and control system), and scheduling and planning considerations. Recommendations are made regarding implementation of similar, large-scale simulations for future programs.

  15. Simulation based engineering in fluid flow design

    CERN Document Server

    Rao, J S

    2017-01-01

    This volume offers a tool for High Performance Computing (HPC). A brief historical background on the subject is first given. Fluid Statics dealing with Pressure in fluids at rest, Buoyancy and Basics of Thermodynamics are next presented. The Finite Volume Method, the most convenient process for HPC, is explained in one-dimensional approach to diffusion with convection and pressure velocity coupling. Adiabatic, isentropic and supersonic flows in quasi-one dimensional flows in axisymmetric nozzles is considered before applying CFD solutions. Though the theory is restricted to one-dimensional cases, three-dimensional CFD examples are also given. Lastly, nozzle flows with normal shocks are presented using turbulence models. Worked examples and exercises are given in each chapter. Fluids transport thermal energy for its conversion to kinetic energy, thus playing a major role that is central to all heat engines. With the advent of rotating machinery in the 20th century, Fluid Engineering was developed in the form o...

  16. Development of an engine system simulation software package - ESIM

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, Olof

    2000-10-01

    A software package, ESIM is developed for simulating internal combustion engine systems, including models for engine, manifolds, turbocharger, charge-air cooler (inter cooler) and inlet air heater. This study focus on the thermodynamic treatment and methods used in the models. It also includes some examples of system simulations made with these models for validation purposes. The engine model can be classified as a zero-dimensional, single zone model. It includes calculation of the valve flow process, models for heat release and models for in-cylinder, exhaust port and manifold heat transfer. Models are developed for handling turbocharger performance and charge air cooler characteristics. The main purpose of the project related to this work is to use the ESIM software to study heat balance and performance of homogeneous charge compression ignition (HCCI) engine systems. A short description of the HCCI engine is therefore included, pointing out the difficulties, or challenges regarding the HCCI engine, from a system perspective. However, the relations given here, and the code itself, is quite general, making it possible to use these models to simulate spark ignited, as well as direct injected engines.

  17. Multidimensional computer simulation of Stirling cycle engines

    Science.gov (United States)

    Hall, Charles A.; Porsching, Thomas A.

    1992-01-01

    This report summarizes the activities performed under NASA-Grant NAG3-1097 during 1991. During that period, work centered on the following tasks: (1) to investigate more effective solvers for ALGAE; (2) to modify the plotting package for ALGAE; and (3) to validate ALGAE by simulating oscillating flow problems similar to those studied by Kurzweg and Ibrahim.

  18. Computer simulation in nuclear science and engineering

    International Nuclear Information System (INIS)

    Akiyama, Mamoru; Miya, Kenzo; Iwata, Shuichi; Yagawa, Genki; Kondo, Shusuke; Hoshino, Tsutomu; Shimizu, Akinao; Takahashi, Hiroshi; Nakagawa, Masatoshi.

    1992-01-01

    The numerical simulation technology used for the design of nuclear reactors includes the scientific fields of wide range, and is the cultivated technology which grew in the steady efforts to high calculation accuracy through safety examination, reliability verification test, the assessment of operation results and so on. Taking the opportunity of putting numerical simulation to practical use in wide fields, the numerical simulation of five basic equations which describe the natural world and the progress of its related technologies are reviewed. It is expected that numerical simulation technology contributes to not only the means of design study but also the progress of science and technology such as the construction of new innovative concept, the exploration of new mechanisms and substances, of which the models do not exist in the natural world. The development of atomic energy and the progress of computers, Boltzmann's transport equation and its periphery, Navier-Stokes' equation and its periphery, Maxwell's electromagnetic field equation and its periphery, Schroedinger wave equation and its periphery, computational solid mechanics and its periphery, and probabilistic risk assessment and its periphery are described. (K.I.)

  19. Framatome's ''SAF'' engineering simulator: a first step toward defining the engineer's simulation tool of the year 2000

    International Nuclear Information System (INIS)

    Constantieux, T.

    1986-01-01

    Among the techniques available to engineers today, computerized simulation is taking on an ever-growing importance. The ''SAF'' simulator, designed by Framatome for the use of its own engineers, has been in service since 1985. The SAF simulator provides continuous assistance to the engineer, from the preliminary design stage to the precise definition of operating procedures, including safety analysis and sizing computations. For the engineer of the year 2000, who will be used to dialoguing with the computer from a very young age, the SAF represents a first step toward a comprehensive simulation tool. Interactive and thus ''alive'', the SAF combines both extensive programming and data processing capabilities. Its simulation domain can still be considerably extended. Highly modular and equipped with easy-to-use compilers, the SAF can be readily modified and reconfigured by the user, to enable testing new models or new systems, in the complex and detailed environment of the nuclear unit being analysed. Employing the advanced computer programs used in project design, the SAF simulator is a particularly high-performance tool for simulating and analysing complex accident scenarios, including multiple equipment failures and possible operator errors, which may extend to complete draining of the reactor vessel and the release of radioactive fission products within the containment structure

  20. Review of research on simulation engineering in FY2009

    International Nuclear Information System (INIS)

    2011-03-01

    Research on simulation engineering for nuclear applications, based on 'the plan for meeting the mid-term goal of the Japan Atomic Energy Agency', has been performed at Center for Computational Science and e-Systems, Japan Atomic Energy Agency (CCSE/JAEA). CCSE established the committee consisting outside experts and authorities which does research evaluation and advices for the assistance of the research and development. This report summarizes results of the evaluation by the committee on the followings. (1) Research and development on simulation engineering performed at CCSE/JAEA in FY2009. (2) Research and development on simulation engineering performed at CCSE/JAEA in the period of the midterm plan (October 1st, 2005 - March 31st, 2010). (author)

  1. Design of 3D simulation engine for oilfield safety training

    Science.gov (United States)

    Li, Hua-Ming; Kang, Bao-Sheng

    2015-03-01

    Aiming at the demand for rapid custom development of 3D simulation system for oilfield safety training, this paper designs and implements a 3D simulation engine based on script-driven method, multi-layer structure, pre-defined entity objects and high-level tools such as scene editor, script editor, program loader. A scripting language been defined to control the system's progress, events and operating results. Training teacher can use this engine to edit 3D virtual scenes, set the properties of entity objects, define the logic script of task, and produce a 3D simulation training system without any skills of programming. Through expanding entity class, this engine can be quickly applied to other virtual training areas.

  2. Computer simulation of a turbocharged direct injection diesel engine

    International Nuclear Information System (INIS)

    Bannikiv, M.G.; Saeed, M.

    2005-01-01

    Engine model described in this paper was developed to investigate the working process and overall performance of a heavy-duty turbocharged direct injection diesel engine. The primary focus was made on exploring the methods of engine power boosting, study of engine behaviour after their implementation and optimization of all engine parameters. Engine model is classified as on zone, zero dimensional and phenomenological and includes submodels for in cylinder heat transfer, heat release and valve flow processes. Turbocharger model is developed using the available maps of turbine and compressor. The whole engine system is zero dimensional and the different system components are liked by means of mean values for mass flow, temperatures, pressures and gas composition. NASA polynomials are used for computing thermal properties of mixture of gasses. Model is flexible and easy to accommodate additional submodels of various physical phenomena such as emission formation, fuel injection, ignition delay period calculation etc. The software is developed in MATLAB. Software was used to analyse an evaporative cooling of boost air as a method of an increase of engine power. Results of simulation are provided in the paper. For the augmented engine, mechanical and thermal loads required for the strength analyses were obtained. (author)

  3. Development of Simulator Maintenance Engineer Qualification Program Draft

    International Nuclear Information System (INIS)

    Chung, Kyung Hun

    2010-01-01

    As of 2009, KHNP has currently seven full scope simulators that are used for training of Nuclear Power Plant (NPP) Operators. Well-trained Simulator Maintenance Engineers (SME) are required to support these simulators. These SMEs will maintain and address any issues identified or any changes required for keep up the simulator with their respective plant sites. These issues will be identified as Simulator Discrepancy Reports (DR) or Work Order (WO) by the simulator operation personnel in KHNP. The simulator maintenance is a very complex. The simulator consists of many areas of process and requires experts in software modeling for different processes such as Neutronics, thermohydraulics, Logics, control, Electrical systems and computer systems as well as hardware subjects such as I and C, I/O, computers, etc. All these areas need experts the subject expertise need to be divided among SME's. In other word the SME's need to be trained for different expertise as well as having different level of SME's. KHNP has seen the need to outsource the maintenance work for these complex simulators. To have one company concentrating on this work will have many benefits such as: · Provides proper and well trained experts · Maintains consistent support personnel · Maintains the maintenance history for the simulator · Coordinates and Maintains the knowledge in house · The simulator maintenance will be consistent In order to accomplish the goals, KEPCO RI has recognized that there is a need for a program to adequately train and qualify the SME's. KEPCO RI and GSE, which has provided 6 simulators among 7 NPP simulators in Korea, have jointly developed this Simulator Maintenance Engineer Qualification Program (SMEQP). After issue of this plan, KEPCO RI will maintain and modify as needed periodically to meet the goals and purpose of the plan

  4. Review of research on simulation engineering in FY2007

    International Nuclear Information System (INIS)

    2009-02-01

    Research on simulation engineering for nuclear applications, based on the plan for meeting the mid-term goal of the Japan Atomic Energy Agency', has been performed at Center for Computational Science and e-Systems, Japan Atomic Energy Agency (CCSE/JAEA). CCSE established the committee consisting outside experts and authorities which does research evaluation and advices for the assistance of the research and development. This report summarizes the result of the evaluation by the committee on the research on simulation engineering performed at CCSE/JAEA in FY2007. (author)

  5. Review of research on simulation engineering in FY2008

    International Nuclear Information System (INIS)

    2010-02-01

    Research on simulation engineering for nuclear applications, based on 'the plan for meeting the mid-term goal of the Japan Atomic Energy Agency', has been performed at Center for Computational Science and e-Systems, Japan Atomic Energy Agency (CCSE/JAEA). CCSE established the committee consisting outside experts and authorities which does research evaluation and advices for the assistance of the research and development. This report summarizes the result of the evaluation by the committee on the research on simulation engineering performed at CCSE/JAEA in FY2008. (author)

  6. A gene network simulator to assess reverse engineering algorithms.

    Science.gov (United States)

    Di Camillo, Barbara; Toffolo, Gianna; Cobelli, Claudio

    2009-03-01

    In the context of reverse engineering of biological networks, simulators are helpful to test and compare the accuracy of different reverse-engineering approaches in a variety of experimental conditions. A novel gene-network simulator is presented that resembles some of the main features of transcriptional regulatory networks related to topology, interaction among regulators of transcription, and expression dynamics. The simulator generates network topology according to the current knowledge of biological network organization, including scale-free distribution of the connectivity and clustering coefficient independent of the number of nodes in the network. It uses fuzzy logic to represent interactions among the regulators of each gene, integrated with differential equations to generate continuous data, comparable to real data for variety and dynamic complexity. Finally, the simulator accounts for saturation in the response to regulation and transcription activation thresholds and shows robustness to perturbations. It therefore provides a reliable and versatile test bed for reverse engineering algorithms applied to microarray data. Since the simulator describes regulatory interactions and expression dynamics as two distinct, although interconnected aspects of regulation, it can also be used to test reverse engineering approaches that use both microarray and protein-protein interaction data in the process of learning. A first software release is available at http://www.dei.unipd.it/~dicamill/software/netsim as an R programming language package.

  7. Object-oriented approach for gas turbine engine simulation

    Science.gov (United States)

    Curlett, Brian P.; Felder, James L.

    1995-01-01

    An object-oriented gas turbine engine simulation program was developed. This program is a prototype for a more complete, commercial grade engine performance program now being proposed as part of the Numerical Propulsion System Simulator (NPSS). This report discusses architectural issues of this complex software system and the lessons learned from developing the prototype code. The prototype code is a fully functional, general purpose engine simulation program, however, only the component models necessary to model a transient compressor test rig have been written. The production system will be capable of steady state and transient modeling of almost any turbine engine configuration. Chief among the architectural considerations for this code was the framework in which the various software modules will interact. These modules include the equation solver, simulation code, data model, event handler, and user interface. Also documented in this report is the component based design of the simulation module and the inter-component communication paradigm. Object class hierarchies for some of the code modules are given.

  8. Development of a mechanical maintenance training simulator in OpenSimulator for F-16 aircraft engines

    OpenAIRE

    Pinheiro, André; Fernandes, Paulo; Maia, Ana; Cruz, Gonçalo; Pedrosa, Daniela; Fonseca, Benjamim; Paredes, Hugo; Martins, Paulo; Morgado, Leonel; Rafael, Jorge

    2014-01-01

    Mechanical maintenance of F-16 engines is carried out as a team effort involving 3–4 skilled engine technicians, but the details of its procedures and requisites change constantly, to improve safety, optimize resources, and respond to knowledge learned from field outcomes. This provides a challenge for development of training simulators, since simulated actions risk becoming obsolete rapidly and require costly reimplementation. This paper presents the development of a 3D mechanical maintenanc...

  9. CFD simulations for engine intake manifolds

    International Nuclear Information System (INIS)

    Witry, A.; Zhao, A.

    2002-01-01

    This paper attempts to explain a procedure for using Computational Fluid Dynamics (CFD) for product development of engine intake manifolds. The paper uses the development of an intake manifold as an example of such a process. Using the commercial FLUENT solver, its standard wall functions and k-ε model, a four runner intake manifold with an average mesh size of 300, 000 hexa elements created in ICEM-CFD with a maximum skewness of 0.85 produces rapid results for quick product turn-around times. The setup used allows for compressibility and viscous heating effects to be modeled whilst ignoring wall heat transfer due to the high speeds of the air/foil mixture and low residence times. Eight consecutive models were modeled here whilst carrying out continuous enhancements. For every iteration, four different so called 'static' runs with only one runner open at any one time using a steady state assumption were calculated further assuming that only one intake valve is open at any one time. Even flow distributions between the runner are deemed to be 'dynamically' obtained once the pressure drops between the manifold's inlet and runner outlets are equalized. Furthermore, different modifications were attempted to ensure that the fluid's particle tracks show very little particle return tendencies along with excellent nonuniformity indexes at the runners outlets. Confirmation of these results were obtained from test data showing CFD pressure drop predictions to be within 4% error with 67% of any runner's pressure losses being caused in the runner itself due to the small cross sectional area(s). (author)

  10. Transonic aeroelastic numerical simulation in aeronautical engineering

    International Nuclear Information System (INIS)

    Yang, G.

    2005-01-01

    An LU-SGS (lower-upper symmetric Gauss-Seidel) subiteration scheme is constructed for time-marching of the fluid equations. The HLLEW (Harten-Lax-van Leer-Einfeldt-Wada) scheme is used for the spatial discretization. The same subiteration formulation is applied directly to the structural equations of motion in generalized coordinates. Through subiteration between the fluid and structural equations, a fully implicit aeroelastic solver is obtained for the numerical simulation of fluid/structure interaction. To improve the ability for application to complex configurations, a multiblock grid is used for the flow field calculation and Transfinite Interpolation (TFI) is employed for the adaptive moving grid deformation. The infinite plate spline (IPS) and the principal of virtual work are utilized for the data transformation between the fluid and structure. The developed code was first validated through the comparison of experimental and computational results for the AGARD 445.6 standard aeroelastic wing. Then the flutter character of a tail wing with control surface was analyzed. Finally, flutter boundaries of a complex aircraft configuration were predicted. (author)

  11. Numerical simulation for the design analysis of kinematic Stirling engines

    International Nuclear Information System (INIS)

    Araoz, Joseph A.; Salomon, Marianne; Alejo, Lucio; Fransson, Torsten H.

    2015-01-01

    simulation allowed to evaluate the effect that different design and operational parameters have on the engine performance, and consequently different performance curves were obtained. These curves allowed to identify ranges for the charged pressure, temperature ratio, heat exchangers dimensions, crank phase angle and crank mechanical effectiveness, where the engine performance was improved. In addition, the curves also permitted to recognise ranges were the design parameters could drastically reduce the brake power and efficiency. The results also showed that the design of the engine is affected by the conditions imposed by the CHP interactions, and that the engine could reach a brake power closer to 832 W with a corresponding brake efficiency of 26% when the adequate design parameters were considered. On the other hand, the performance could also be very low; as the reported in experimental tests, with brake power measurements ranging 52–120 W.

  12. Improving a Computer Networks Course Using the Partov Simulation Engine

    Science.gov (United States)

    Momeni, B.; Kharrazi, M.

    2012-01-01

    Computer networks courses are hard to teach as there are many details in the protocols and techniques involved that are difficult to grasp. Employing programming assignments as part of the course helps students to obtain a better understanding and gain further insight into the theoretical lectures. In this paper, the Partov simulation engine and…

  13. Visualization and simulation of complex flows in biomedical engineering

    CERN Document Server

    Imai, Yohsuke; Ishikawa, Takuji; Oliveira, Mónica

    2014-01-01

    This book focuses on the most recent advances in the application of visualization and simulation methods to understand the flow behavior of complex fluids used in biomedical engineering and other related fields. It shows the physiological flow behavior in large arteries, microcirculation, respiratory systems and in biomedical microdevices.

  14. Comparison of cross culture engineering ethics training using the simulator for engineering ethics education.

    Science.gov (United States)

    Chung, Christopher

    2015-04-01

    This paper describes the use and analysis of the Simulator for Engineering Ethics Education (SEEE) to perform cross culture engineering ethics training and analysis. Details describing the first generation and second generation development of the SEEE are published in Chung and Alfred, Science and Engineering Ethics, vol. 15, 2009 and Alfred and Chung, Science and Engineering Ethics, vol. 18, 2012. In this effort, a group of far eastern educated students operated the simulator in the instructional, training, scenario, and evaluation modes. The pre and post treatment performance of these students were compared to U.S. Educated students. Analysis of the performance indicated that the far eastern educated student increased their level of knowledge 23.7 percent while U.S. educated students increased their level of knowledge by 39.3 percent.

  15. Building of Nuclear Ship Engineering Simulation System development of the simulator for the integral type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Teruo; Shimazaki, Junya; Yabuuchi, Noriaki; Fukuhara, Yosifumi; Kusunoki, Takeshi; Ochiai, Masaaki [Department of Nuclear Energy Systems, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Nakazawa, Toshio [Department of HTTR Project, Oarai Research Establishment, Japan Atomic Energy Research Institute, Oarai, Ibaraki (Japan)

    2000-03-01

    JAERI had carried out the design study of a light-weight and compact integral type reactor of power 100 MW{sub th} with passive safety as a power source for the future nuclear ships, and completed an engineering design. To confirm the design and operation performance and to utilize the study of automation of the operations of reactor, we developed a real-time simulator for the integral type reactor. This simulator is a part of Nuclear Ship Engineering Simulation System (NESSY) and on the same hardware as 'Mutsu' simulator which was developed to simulate the first Japanese nuclear ship Mutsu'. Simulation accuracy of 'Mutsu' simulator was verified by comparing the simulation results With data got in the experimental voyage of 'Mutsu'. The simulator for the integral type reactor uses the same programs which were used in 'Mutsu' simulator for the separate type PWR, and the simulated results are approximately consistent with the calculated values using RELAP5/MOD2 (The later points are reported separately). Therefore simulation accuracy of the simulator for the integral type reactor is also expected to be reasonable, though it is necessary to verify by comparing with the real plant data or experimental data in future. We can get the perspectives to use as a real-time engineering simulator and to achieve the above-mentioned aims. This is a report on development of the simulator for the integral type reactor mainly focused on the contents of the analytical programs expressed the structural features of reactor. (author)

  16. Design and use of an engineering simulator for power plant and training simulator updates

    International Nuclear Information System (INIS)

    Sharawy, P.S.; Kennard, J.R.; Chou, Q.B.

    1990-01-01

    The advancement in real-time simulators has been facilitated by the availability of increasingly powerful computing devices at reduced costs for use in conjunction with high-fidelity simulation software. Ontario Hydro's commitment to the safe and reliable operation of its nuclear power plants was one of the factors which influenced its decision to build a plant-replica operator training simulator for each of its nuclear generating stations. This investment soon proved to have advantages beyond those originally envisaged. It become apparent that because the software developed for these simulators met rigorous acceptance criteria, it could be used on an engineering simulator to effectively investigate problems occurring at the stations. It could also serve as a design aid for station modifications. Encouraged by the success of early experimentation in the use of its training simulators for concept validation and verification, Ontario Hydro is developing a low-cost central facility - the Instrumentation and Control Engineering Simulator (ICES) - for use in its design work. This facility incorporates the software of its training simulators and includes a user-friendly generic interface which enables designers to configure and operate it. Inclusion of the engineering simulator in all phases of the design process, from the original concept to implementation and verification, will make it possible to shorten the design period significantly while achieving a high level of quality. It will also facilitate the rapid retrofit of simulators to reflect station modifications. This paper will recount Ontario Hydro's experience in the use of simulators for design work and will specifically discuss the design features and system performance of its engineering simulator

  17. Development of Nuclear ship Engineering Simulation SYstem (NESSY)

    International Nuclear Information System (INIS)

    Kusunoki, Tsuyoshi; Kyouya, Masahiko; Takahashi, Teruo; Kobayashi, Hideo; Ochiai, Masa-aki; Hashidate, Kouji.

    1993-11-01

    NESSY has been developed for design studies of advanced marine reactors as a part of nuclear ship research and development since 1987. Engineering simulation model of the Mutsu, which is the first nuclear ship in Japan, was completed in March of 1993. In this report we concentration on detail description of softwares for Mutsu modeling. The aims of development of NESSY are as follows; (1) Assessment and confirmation on plant performance of an advanced marine reactor in each step of nuclear ship design (2) Development of abnormality diagnosis system and operator support system as a part of enhanced automization study, and study of human interface with hardware The characteristics of NESSY are the followings. (1) Total engineering simulation system simulate simultaneously ship motions, propulsion system behavior, and nuclear plant behavior under given weather and sea conditions. (2) Models based on physical theory as far as possible. (3) The simulator has high extensibility and flexibility. It is able to apply to other reactors, as the simulation model consists of the part of basic model and the part of plant data which are easy to change. After completion of Mutsu modeling, we are planning to utilize this system as one of design tools for an advanced marine reactor. (author)

  18. Large Eddy Simulation (LES for IC Engine Flows

    Directory of Open Access Journals (Sweden)

    Kuo Tang-Wei

    2013-10-01

    Full Text Available Numerical computations are carried out using an engineering-level Large Eddy Simulation (LES model that is provided by a commercial CFD code CONVERGE. The analytical framework and experimental setup consist of a single cylinder engine with Transparent Combustion Chamber (TCC under motored conditions. A rigorous working procedure for comparing and analyzing the results from simulation and high speed Particle Image Velocimetry (PIV experiments is documented in this work. The following aspects of LES are analyzed using this procedure: number of cycles required for convergence with adequate accuracy; effect of mesh size, time step, sub-grid-scale (SGS turbulence models and boundary condition treatments; application of the proper orthogonal decomposition (POD technique.

  19. Numerical Simulation of Methane Slip in Dual Fuel Marine Engines

    DEFF Research Database (Denmark)

    Han, Jaehyun; Jensen, Michael Vincent; Pang, Kar Mun

    2017-01-01

    estimations. The simulations with various gas pipe geometries were conducted. It seemed that the effect of the change in injection direction is more dominant than the change in the gas hole configuration. The favorable injection direction for minimum amount of methane slip was discovered as the direction...... which helps developing the flow of methane far from the exhaust ports. The effects of various valve timing settings were also simulated. The advancement of the exhaust valve closing was more efficient than the retardation of the intake valve opening. A little retardation of the intake valve opening even......The methane slip is the problematic issue for the engines using natural gas(NG). Because methane is more powerful greenhouse gas (GHG) than CO2, understanding of the methane slip during gas exchange process of the engines is essential. In this study, the influence of the gas pipe geometry...

  20. Prediction of DI diesel engine emissions by multidimensional simulation; Tajigen simulation ni yoru DI diesel engine no seino yosoku

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Y; Zhang, L; Hamaguchi, K; Minami, T; Yokota, K [Isuzu Advanced Engineering Center, Tokyo (Japan)

    1997-10-01

    To achieve the goal of using multidimensional simulation as a useful tool for predicting engine emissions in the stage of design or choice chamber shape and nozzle specifications, much work is needed to improve and modify calculation models. In this study , the spray model of KIVA-II have been modified using experimentally measured penetration of spray liquid phase. The modified KIVA-II was applied to a HSDI engine with different chambers and injectors. As a result of comparing with experiments, it was found that the KIVA-II using the modified spray model could relatively predict the change of emissions. 6 refs., 12 figs., 2 tabs.

  1. Simulational nanoengineering: Molecular dynamics implementation of an atomistic Stirling engine.

    Science.gov (United States)

    Rapaport, D C

    2009-04-01

    A nanoscale-sized Stirling engine with an atomistic working fluid has been modeled using molecular dynamics simulation. The design includes heat exchangers based on thermostats, pistons attached to a flywheel under load, and a regenerator. Key aspects of the behavior, including the time-dependent flows, are described. The model is shown to be capable of stable operation while producing net work at a moderate level of efficiency.

  2. Enhancing food engineering education with interactive web-based simulations

    OpenAIRE

    Alexandros Koulouris; Georgios Aroutidis; Dimitrios Vardalis; Petros Giannoulis; Paraskevi Karakosta

    2015-01-01

    In the traditional deductive approach in teaching any engineering topic, teachers would first expose students to the derivation of the equations that govern the behavior of a physical system and then demonstrate the use of equations through a limited number of textbook examples. This methodology, however, is rarely adequate to unmask the cause-effect and quantitative relationships between the system variables that the equations embody. Web-based simulation, which is the integration of simulat...

  3. A Virtual Engineering Framework for Simulating Advanced Power System

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Dave Swensen; Martin Denison; Stanislav Borodai

    2008-06-18

    In this report is described the work effort performed to provide NETL with VE-Suite based Virtual Engineering software and enhanced equipment models to support NETL's Advanced Process Engineering Co-simulation (APECS) framework for advanced power generation systems. Enhancements to the software framework facilitated an important link between APECS and the virtual engineering capabilities provided by VE-Suite (e.g., equipment and process visualization, information assimilation). Model enhancements focused on improving predictions for the performance of entrained flow coal gasifiers and important auxiliary equipment (e.g., Air Separation Units) used in coal gasification systems. In addition, a Reduced Order Model generation tool and software to provide a coupling between APECS/AspenPlus and the GE GateCycle simulation system were developed. CAPE-Open model interfaces were employed where needed. The improved simulation capability is demonstrated on selected test problems. As part of the project an Advisory Panel was formed to provide guidance on the issues on which to focus the work effort. The Advisory Panel included experts from industry and academics in gasification, CO2 capture issues, process simulation and representatives from technology developers and the electric utility industry. To optimize the benefit to NETL, REI coordinated its efforts with NETL and NETL funded projects at Iowa State University, Carnegie Mellon University and ANSYS/Fluent, Inc. The improved simulation capabilities incorporated into APECS will enable researchers and engineers to better understand the interactions of different equipment components, identify weaknesses and processes needing improvement and thereby allow more efficient, less expensive plants to be developed and brought on-line faster and in a more cost-effective manner. These enhancements to APECS represent an important step toward having a fully integrated environment for performing plant simulation and engineering

  4. ESSE: Engineering Super Simulation Emulation for Virtual Reality Systems Environment

    International Nuclear Information System (INIS)

    Suh, Kune Y.; Yeon, Choul W.

    2008-01-01

    The trademark 4 + D Technology TM based Engineering Super Simulation Emulation (ESSE) is introduced. ESSE resorting to three-dimensional (3D) Virtual Reality (VR) technology pledges to provide with an interactive real-time motion, sound and tactile and other forms of feedback in the man machine systems environment. In particular, the 3D Virtual Engineering Neo cybernetic Unit Soft Power (VENUS) adds a physics engine to the VR platform so as to materialize a physical atmosphere. A close cooperation system and prompt information share are crucial, thereby increasing the necessity of centralized information system and electronic cooperation system. VENUS is further deemed to contribute towards public acceptance of nuclear power in general, and safety in particular. For instance, visualization of nuclear systems can familiarize the public in answering their questions and alleviating misunderstandings on nuclear power plants answering their questions and alleviating misunderstandings on nuclear power plants (NPPs) in general, and performance, security and safety in particular. An in-house flagship project Systemic Three-dimensional Engine Platform Prototype Engineering (STEPPE) endeavors to develop the Systemic Three-dimensional Engine Platform (STEP) for a variety of VR applications. STEP is home to a level system providing the whole visible scene of virtual engineering of man machine system environment. The system is linked with video monitoring that provides a 3D Computer Graphics (CG) visualization of major events. The database linked system provides easy access to relevant blueprints. The character system enables the operators easy access to visualization of major events. The database linked system provides easy access to relevant blueprints. The character system enables the operators to access the virtual systems by using their virtual characters. Virtually Engineered NPP Informative systems by using their virtual characters. Virtually Engineered NPP Informative

  5. Loading Deformation Characteristic Simulation Study of Engineering Vehicle Refurbished Tire

    Science.gov (United States)

    Qiang, Wang; Xiaojie, Qi; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

    2018-05-01

    The paper constructed engineering vehicle refurbished tire computer geometry model, mechanics model, contact model, finite element analysis model, did simulation study on load-deformation property of engineering vehicle refurbished tire by comparing with that of the new and the same type tire, got load-deformation of engineering vehicle refurbished tire under the working condition of static state and ground contact. The analysis result shows that change rules of radial-direction deformation and side-direction deformation of engineering vehicle refurbished tire are close to that of the new tire, radial-direction and side-direction deformation value is a little less than that of the new tire. When air inflation pressure was certain, radial-direction deformation linear rule of engineer vehicle refurbished tire would increase with load adding, however, side-direction deformation showed linear change rule, when air inflation pressure was low; and it would show increase of non-linear change rule, when air inflation pressure was very high.

  6. Symbolic simulation of engineering systems on a supercomputer

    International Nuclear Information System (INIS)

    Ragheb, M.; Gvillo, D.; Makowitz, H.

    1986-01-01

    Model-Based Production-Rule systems for analysis are developed for the symbolic simulation of Complex Engineering systems on a CRAY X-MP Supercomputer. The Fault-Tree and Event-Tree Analysis methodologies from Systems-Analysis are used for problem representation and are coupled to the Rule-Based System Paradigm from Knowledge Engineering to provide modelling of engineering devices. Modelling is based on knowledge of the structure and function of the device rather than on human expertise alone. To implement the methodology, we developed a production-Rule Analysis System that uses both backward-chaining and forward-chaining: HAL-1986. The inference engine uses an Induction-Deduction-Oriented antecedent-consequent logic and is programmed in Portable Standard Lisp (PSL). The inference engine is general and can accommodate general modifications and additions to the knowledge base. The methodologies used will be demonstrated using a model for the identification of faults, and subsequent recovery from abnormal situations in Nuclear Reactor Safety Analysis. The use of the exposed methodologies for the prognostication of future device responses under operational and accident conditions using coupled symbolic and procedural programming is discussed

  7. Research of Simulation in Character Animation Based on Physics Engine

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2017-01-01

    Full Text Available Computer 3D character animation essentially is a product, which is combined with computer graphics and robotics, physics, mathematics, and the arts. It is based on computer hardware and graphics algorithms and related sciences rapidly developed new technologies. At present, the mainstream character animation technology is based on the artificial production of key technologies and capture frames based on the motion capture device technology. 3D character animation is widely used not only in the production of film, animation, and other commercial areas but also in virtual reality, computer-aided education, flight simulation, engineering simulation, military simulation, and other fields. In this paper, we try to study physics based character animation to solve these problems such as poor real-time interaction that appears in the character, low utilization rate, and complex production. The paper deeply studied the kinematics, dynamics technology, and production technology based on the motion data. At the same time, it analyzed ODE, PhysX, Bullet, and other variety of mainstream physics engines and studied OBB hierarchy bounding box tree, AABB hierarchical tree, and other collision detection algorithms. Finally, character animation based on ODE is implemented, which is simulation of the motion and collision process of a tricycle.

  8. Effect of different heat transfer models on HCCI engine simulation

    International Nuclear Information System (INIS)

    Neshat, Elaheh; Saray, Rahim Khoshbakhti

    2014-01-01

    Highlights: • A new multi zone model is developed for HCCI combustion modeling. • New heat transfer model is used for prediction of heat transfer in HCCI engines. • Model can predict engine combustion, performance and emission characteristics well. • Appropriate mass and heat transfer models cause to accurate prediction of CO, UHC and NOx. - Abstract: Heat transfer from engine walls has an important role on engine combustion, performance and emission characteristics. The main focus of this study is offering a new relation for calculation of convective heat transfer from in-cylinder charge to combustion chamber walls of HCCI engines and providing the ability of new model in comparison with the previous models. Therefore, a multi zone model is developed for homogeneous charge compression ignition engine simulation. Model consists of four different types of zones including core zone, boundary layer zone, outer zones, which are between core and boundary layer, and crevice zone. Conductive heat transfer and mass transfer are considered between neighboring zones. For accurate calculation of initial conditions at inlet valve closing, multi zone model is coupled with a single zone model, which simulates gas exchange process. Various correlations are used as convective heat transfer correlations. Woschni, modified Woschni, Hohenberg and Annand correlations are used as convective heat transfer models. The new convection model, developed by authors, is used, too. Comparative analyses are done to recognize the accurate correlation for prediction of engine combustion, performance and emission characteristics in a wide range of operating conditions. The results indicate that utilization of various heat transfer models, except for new convective heat transfer model, leads to significant differences in prediction of in-cylinder pressure and exhaust emissions. Using Woschni, Chang and new model, convective heat transfer coefficient increases near top dead center, sharply

  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. Interactive simulations as teaching tools for engineering mechanics courses

    Science.gov (United States)

    Carbonell, Victoria; Romero, Carlos; Martínez, Elvira; Flórez, Mercedes

    2013-07-01

    This study aimed to gauge the effect of interactive simulations in class as an active teaching strategy for a mechanics course. Engineering analysis and design often use the properties of planar sections in calculations. In the stress analysis of a beam under bending and torsional loads, cross-sectional properties are used to determine stress and displacement distributions in the beam cross section. The centroid, moments and products of inertia of an area made up of several common shapes (rectangles usually) may thus be obtained by adding the moments of inertia of the component areas (U-shape, L-shape, C-shape, etc). This procedure is used to calculate the second moments of structural shapes in engineering practice because the determination of their moments of inertia is necessary for the design of structural components. This paper presents examples of interactive simulations developed for teaching the ‘Mechanics and mechanisms’ course at the Universidad Politecnica de Madrid, Spain. The simulations focus on fundamental topics such as centroids, the properties of the moment of inertia, second moments of inertia with respect to two axes, principal moments of inertia and Mohr's Circle for plane stress, and were composed using Geogebra software. These learning tools feature animations, graphics and interactivity and were designed to encourage student participation and engagement in active learning activities, to effectively explain and illustrate course topics, and to build student problem-solving skills.

  11. Interactive simulations as teaching tools for engineering mechanics courses

    International Nuclear Information System (INIS)

    Carbonell, Victoria; Martínez, Elvira; Flórez, Mercedes; Romero, Carlos

    2013-01-01

    This study aimed to gauge the effect of interactive simulations in class as an active teaching strategy for a mechanics course. Engineering analysis and design often use the properties of planar sections in calculations. In the stress analysis of a beam under bending and torsional loads, cross-sectional properties are used to determine stress and displacement distributions in the beam cross section. The centroid, moments and products of inertia of an area made up of several common shapes (rectangles usually) may thus be obtained by adding the moments of inertia of the component areas (U-shape, L-shape, C-shape, etc). This procedure is used to calculate the second moments of structural shapes in engineering practice because the determination of their moments of inertia is necessary for the design of structural components. This paper presents examples of interactive simulations developed for teaching the ‘Mechanics and mechanisms’ course at the Universidad Politecnica de Madrid, Spain. The simulations focus on fundamental topics such as centroids, the properties of the moment of inertia, second moments of inertia with respect to two axes, principal moments of inertia and Mohr's Circle for plane stress, and were composed using Geogebra software. These learning tools feature animations, graphics and interactivity and were designed to encourage student participation and engagement in active learning activities, to effectively explain and illustrate course topics, and to build student problem-solving skills. (paper)

  12. Engineering simulator applications to emergency preparedness at DOE reactor sites

    International Nuclear Information System (INIS)

    Beelman, R.J.

    1990-01-01

    This paper reports that since 1984 the Idaho National Engineering Laboratory (INEL) has conducted twenty-seven comprehensive emergency preparedness exercises at the U.S. Nuclear Regulatory Commission's (NRC) Headquarters Operations Center and Regional Incident Response Centers using the NRC's Nuclear Plant Analyzer (NPA), developed at the INEL, as an engineering simulator. The objective of these exercises has been to assist the NRC in upgrading its preparedness to provide technical support backup and oversight to U.S. commercial nuclear plant licensees during emergencies. With the current focus on Department of Energy (DOE) reactor operational safety and emergency preparedness, this capability is envisioned as a means of upgrading emergency preparedness at DOE production and test reactor sites such as the K-Reactor at Savannah River Laboratory (SRL) and the Advanced Test Reactor (ATR) at INEL

  13. Simulation of air pollution due to marine engines

    Science.gov (United States)

    Stan, L. C.

    2017-08-01

    This paperwork tried to simulate the combustion inside the marine engines using the newest computer methods and technologies with the result of a diverse and rich palette of solutions, extremely useful for the study and prediction of complex phenomena of the fuel combustion. The paperwork is contributing to the theoretical systematization of the area of interest bringing into attention a thoroughly inventory of the thermodynamic description of the phenomena which take place in the combustion process into the marine diesel engines; to the in depth multidimensional combustion models description along with the interdisciplinary phenomenology taking place in the combustion models; to the FEA (Finite Elements Method) modelling for the combustion chemistry in the nonpremixed mixtures approach considered too; the CFD (Computational Fluid Dynamics) model was issued for the combustion area and a rich palette of results interesting for any researcher of the process.

  14. System Engineering Strategy for Distributed Multi-Purpose Simulation Architectures

    Science.gov (United States)

    Bhula, Dlilpkumar; Kurt, Cindy Marie; Luty, Roger

    2007-01-01

    This paper describes the system engineering approach used to develop distributed multi-purpose simulations. The multi-purpose simulation architecture focuses on user needs, operations, flexibility, cost and maintenance. This approach was used to develop an International Space Station (ISS) simulator, which is called the International Space Station Integrated Simulation (ISIS)1. The ISIS runs unmodified ISS flight software, system models, and the astronaut command and control interface in an open system design that allows for rapid integration of multiple ISS models. The initial intent of ISIS was to provide a distributed system that allows access to ISS flight software and models for the creation, test, and validation of crew and ground controller procedures. This capability reduces the cost and scheduling issues associated with utilizing standalone simulators in fixed locations, and facilitates discovering unknowns and errors earlier in the development lifecycle. Since its inception, the flexible architecture of the ISIS has allowed its purpose to evolve to include ground operator system and display training, flight software modification testing, and as a realistic test bed for Exploration automation technology research and development.

  15. Determination of representative CANDU feeder dimensions for engineering simulator

    International Nuclear Information System (INIS)

    Cho, S.; Muzumdar, A.

    1996-01-01

    This paper describes a logic for selection of representative channel groups and a methodology for determination of representative CANDU feeder dimensions and the pressure drops between inlet/outlet header and fuel channel in the primary loop. A code, MEDOC, was developed based on this logic and methodology and helps perform a calculation of representative feeder dimensions for a selected channel group on the basis of feeder geometry data (fluid volume, mass flow rate, loss factor) and given property data (pressure, quality, density) at inlet/outlet header. The representative feeder dimensions calculated based on this methodology will be useful for the engineering simulator for the CANDU type reactor. (author)

  16. 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.

  17. Parametric Optimization Through Numerical Simulation of VCR Diesel Engine

    Science.gov (United States)

    Ganji, Prabhakara Rao; Mahmood, Al-Qarttani Abdulrahman Shakir; Kandula, Aasrith; Raju, Vysyaraju Rajesh Khana; Rao, Surapaneni Srinivasa

    2017-08-01

    In the present study, the Variable Compression Ratio (VCR) engine was analyzed numerically using CONVERGE™ Computational Fluid Dynamics code in order to optimize the design/operating parameters such as Compression Ratio (CR), Start of Injection (SOI) and Exhaust Gas Recirculation (EGR). VCR engine was run for 100 % load to test its performance and it was validated for standard configuration. Simulations were performed by varying the design/operating parameters such as CR (18-14), SOI (17°-26° bTDC) and EGR (0-15 %) at constant fuel injection pressure of 230 bar and speed of 1500 rpm. The effect of each of these parameters on pressure, oxides of nitrogen (NOx) and soot are presented. Finally, regression equations were developed for pressure, NOx and soot by using the simulation results. The regression equations were solved for multi objective criteria in order to reduce the NOx and soot while maintaining the baseline performance. The optimized configuration was tested for validation and found satisfactory.

  18. Enhancing food engineering education with interactive web-based simulations

    Directory of Open Access Journals (Sweden)

    Alexandros Koulouris

    2015-04-01

    Full Text Available In the traditional deductive approach in teaching any engineering topic, teachers would first expose students to the derivation of the equations that govern the behavior of a physical system and then demonstrate the use of equations through a limited number of textbook examples. This methodology, however, is rarely adequate to unmask the cause-effect and quantitative relationships between the system variables that the equations embody. Web-based simulation, which is the integration of simulation and internet technologies, has the potential to enhance the learning experience by offering an interactive and easily accessible platform for quick and effortless experimentation with physical phenomena.This paper presents the design and development of a web-based platform for teaching basic food engineering phenomena to food technology students. The platform contains a variety of modules (“virtual experiments” covering the topics of mass and energy balances, fluid mechanics and heat transfer. In this paper, the design and development of three modules for mass balances and heat transfer is presented. Each webpage representing an educational module has the following features: visualization of the studied phenomenon through graphs, charts or videos, computation through a mathematical model and experimentation.  The student is allowed to edit key parameters of the phenomenon and observe the effect of these changes on the outputs. Experimentation can be done in a free or guided fashion with a set of prefabricated examples that students can run and self-test their knowledge by answering multiple-choice questions.

  19. The study, design and simulation of a free piston Stirling engine linear alternatorThe study, design and simulation of a free piston Stirling engine linear alternator

    Directory of Open Access Journals (Sweden)

    Teodora Susana Oros

    2014-12-01

    Full Text Available This paper presents a study, design and simulation of a Free Piston Stirling Engine Linear Alternator. There are presented the main steps of the magnetic and electric calculations for a permanent magnet linear alternator of fixed coil and moving magnets type. Finally, a detailed thermal, mechanical and electrical model for a Stirling engine linear alternator have been made in SIMULINK simulation program. The linear alternator simulation model uses a controllable DC voltage which simulates the linear alternator combined with a rectifier, a variable load and a DC-DC converter, which compensates for the variable nature of Stirling engine operation, and ensures a constant voltage output regardless of the load.

  20. Chemical interaction of tetravalent actinides simulators and the engineering barrier

    International Nuclear Information System (INIS)

    Chain, Pablo; Alba, Maria D.; Castro, Miguel A.; Pavon, Esperanza; Mar Orta, M.

    2010-01-01

    Document available in extended abstract form only. The Deep Geological Repository (DGR) is the most internationally accepted option for the storage of high radioactive wastes. This confinement is based on the Multi-barrier Concept where the engineered barrier is a crucial safety wise. Nowadays, bentonite is accepted as the best argillaceous material in the engineered barrier of DGR. Additionally to its well-known physical role, a chemical interaction between lutetium, as actinide simulator, and the smectite has been demonstrated. The existence of a reaction mechanism, which was not previously described, based on the chemical interaction between the lanthanide cations and the orthosilicate anions of the lamellar structure has been identified. This finding has aroused the interest of the scientific community because lanthanides are used as simulators of high activity radionuclide (HAR) in agreement with the guidelines established in the bibliography. It has been observed that in conditions of moderate temperature and pressure a chemical interaction exists between smectites and rare earth elements (RE) and phases of insoluble di-silicate, RE 2 Si 2 O 7 , which would immobilize RE, are generated. It is remarkable that the reaction extends to all the set of the smectites, although they do not display the same reactivity, the saponite being the most reactive. The main isotopes present in the HLW belong to the actinide elements Np, Pu, Am and Cm, in addition to uranium generated by neutron capture during the fuel combustion process. The study of the mobilization of actinide (IV) thorough the bentonite barrier is limited because of their radioactivity. However, U(IV), Np(IV), Pu(IV) and Th(IV) can be simulated by the stable isotopes of the Zr(IV) and Hf(IV), because they exhibit ionic radius and physicochemical properties very similar to those of the actinide elements. It is the main objective of this research to investigate the chemical interaction of Zr(IV) as actinide

  1. Simulation of Road Traffic Applying Model-Driven Engineering

    Directory of Open Access Journals (Sweden)

    Alberto FERNÁNDEZ-ISABEL

    2016-05-01

    Full Text Available Road traffic is an important phenomenon in modern societies. The study of its different aspects in the multiple scenarios where it happens is relevant for a huge number of problems. At the same time, its scale and complexity make it hard to study. Traffic simulations can alleviate these difficulties, simplifying the scenarios to consider and controlling their variables. However, their development also presents difficulties. The main ones come from the need to integrate the way of working of researchers and developers from multiple fields. Model-Driven Engineering (MDE addresses these problems using Modelling Languages (MLs and semi-automatic transformations to organise and describe the development, from requirements to code. This paper presents a domain-specific MDE framework for simulations of road traffic. It comprises an extensible ML, support tools, and development guidelines. The ML adopts an agent-based approach, which is focused on the roles of individuals in road traffic and their decision-making. A case study shows the process to model a traffic theory with the ML, and how to specialise that specification for an existing target platform and its simulations. The results are the basis for comparison with related work.

  2. Development of teaching material to integrate GT-POWER into combustion courses for IC engine simulations.

    Science.gov (United States)

    2009-02-01

    The main objective of this project was to develop instructional engineering projects that utilize the newly-offered PACE software GT-POWER for engine simulations in combustion-related courses at the Missouri University of Science and Technology. Stud...

  3. An introduction to network modeling and simulation for the practicing engineer

    CERN Document Server

    Burbank, Jack; Ward, Jon

    2011-01-01

    This book provides the practicing engineer with a concise listing of commercial and open-source modeling and simulation tools currently available including examples of implementing those tools for solving specific Modeling and Simulation examples. Instead of focusing on the underlying theory of Modeling and Simulation and fundamental building blocks for custom simulations, this book compares platforms used in practice, and gives rules enabling the practicing engineer to utilize available Modeling and Simulation tools. This book will contain insights regarding common pitfalls in network Modeling and Simulation and practical methods for working engineers.

  4. Autonomous Cryogenics Loading Operations Simulation Software: Knowledgebase Autonomous Test Engineer

    Science.gov (United States)

    Wehner, Walter S., Jr.

    2013-01-01

    Working on the ACLO (Autonomous Cryogenics Loading Operations) project I have had the opportunity to add functionality to the physics simulation software known as KATE (Knowledgebase Autonomous Test Engineer), create a new application allowing WYSIWYG (what-you-see-is-what-you-get) creation of KATE schematic files and begin a preliminary design and implementation of a new subsystem that will provide vision services on the IHM (Integrated Health Management) bus. The functionality I added to KATE over the past few months includes a dynamic visual representation of the fluid height in a pipe based on number of gallons of fluid in the pipe and implementing the IHM bus connection within KATE. I also fixed a broken feature in the system called the Browser Display, implemented many bug fixes and made changes to the GUI (Graphical User Interface).

  5. Simulation Based Studies in Software Engineering: A Matter of Validity

    Directory of Open Access Journals (Sweden)

    Breno Bernard Nicolau de França

    2015-04-01

    Full Text Available Despite the possible lack of validity when compared with other science areas, Simulation-Based Studies (SBS in Software Engineering (SE have supported the achievement of some results in the field. However, as it happens with any other sort of experimental study, it is important to identify and deal with threats to validity aiming at increasing their strength and reinforcing results confidence. OBJECTIVE: To identify potential threats to SBS validity in SE and suggest ways to mitigate them. METHOD: To apply qualitative analysis in a dataset resulted from the aggregation of data from a quasi-systematic literature review combined with ad-hoc surveyed information regarding other science areas. RESULTS: The analysis of data extracted from 15 technical papers allowed the identification and classification of 28 different threats to validity concerned with SBS in SE according Cook and Campbell’s categories. Besides, 12 verification and validation procedures applicable to SBS were also analyzed and organized due to their ability to detect these threats to validity. These results were used to make available an improved set of guidelines regarding the planning and reporting of SBS in SE. CONCLUSIONS: Simulation based studies add different threats to validity when compared with traditional studies. They are not well observed and therefore, it is not easy to identify and mitigate all of them without explicit guidance, as the one depicted in this paper.

  6. Development of NSSS Simulation Engine for SMART Simulator Using the Best Estimate Code, MARS3.1

    International Nuclear Information System (INIS)

    Kim, K. D.; Lee, S. W.; Lee, Sung Chul; Suh, Yong Suk; Suh, Jae Seung

    2011-01-01

    Limited computational capability and crude thermalhydraulic modeling in early 1980s forced the use of overly simplified physical models and assumptions for a real-time calculation at the cost of fidelity. Rapid advances in computer technology make it possible to improve the fidelity of the simulator models. These efforts have been made based on RELAP5 in the US, and CATHARE2 in France. The NSSS thermalhydraulic engines adopted in the most domestic fullscope power plant simulators have been replaced with RELAP5 based engines which were provided by US vendors. Since the technology dependency of the NSSS T/H engine by foreign vendors, it may cause difficulties in maintenance and model improvement. KAERI has started to develop a realistic NSSS calculation engine based on the best-estimate code MARS 3.1 for the SMART full-scope simulator. Even though we are developing the NSSS calculation engine for SMART simulator, it can be easily extended to light water reactors and GEN-IV reactors, etc. The verification of the NSSS calculation engine for SMART simulator has been conducted by an integrated test in the simulator environment, Jade 4.0, developed by GSE of Windows 2003. This paper briefly presents our efforts for the NSSS calculation engine for SMART simulator and verification test results of SAT (Site Acceptance Test)

  7. Electro-Quasistatic Simulations in Bio-Systems Engineering and Medical Engineering

    Directory of Open Access Journals (Sweden)

    U. van Rienen

    2005-01-01

    Full Text Available Slowly varying electromagnetic fields play a key role in various applications in bio-systems and medical engineering. Examples are the electric activity of neurons on neurochips used as biosensors, the stimulating electric fields of implanted electrodes used for deep brain stimulation in patients with Morbus Parkinson and the stimulation of the auditory nerves in deaf patients, respectively. In order to simulate the neuronal activity on a chip it is necessary to couple Maxwell's and Hodgkin-Huxley's equations. First numerical results for a neuron coupling to a single electrode are presented. They show a promising qualitative agreement with the experimentally recorded signals. Further, simulations are presented on electrodes for deep brain stimulation in animal experiments where the question of electrode ageing and energy deposition in the surrounding tissue are of major interest. As a last example, electric simulations for a simple cochlea model are presented comparing the field in the skull bones for different electrode types and stimulations in different positions.

  8. Stimulation of a turbofan engine for evaluation of multivariable optimal control concepts. [(computerized simulation)

    Science.gov (United States)

    Seldner, K.

    1976-01-01

    The development of control systems for jet engines requires a real-time computer simulation. The simulation provides an effective tool for evaluating control concepts and problem areas prior to actual engine testing. The development and use of a real-time simulation of the Pratt and Whitney F100-PW100 turbofan engine is described. The simulation was used in a multi-variable optimal controls research program using linear quadratic regulator theory. The simulation is used to generate linear engine models at selected operating points and evaluate the control algorithm. To reduce the complexity of the design, it is desirable to reduce the order of the linear model. A technique to reduce the order of the model; is discussed. Selected results between high and low order models are compared. The LQR control algorithms can be programmed on digital computer. This computer will control the engine simulation over the desired flight envelope.

  9. Modeling and simulation of different and representative engineering problems using Network Simulation Method.

    Science.gov (United States)

    Sánchez-Pérez, J F; Marín, F; Morales, J L; Cánovas, M; Alhama, F

    2018-01-01

    Mathematical models simulating different and representative engineering problem, atomic dry friction, the moving front problems and elastic and solid mechanics are presented in the form of a set of non-linear, coupled or not coupled differential equations. For different parameters values that influence the solution, the problem is numerically solved by the network method, which provides all the variables of the problems. Although the model is extremely sensitive to the above parameters, no assumptions are considered as regards the linearization of the variables. The design of the models, which are run on standard electrical circuit simulation software, is explained in detail. The network model results are compared with common numerical methods or experimental data, published in the scientific literature, to show the reliability of the model.

  10. Modeling and simulation of different and representative engineering problems using Network Simulation Method

    Science.gov (United States)

    2018-01-01

    Mathematical models simulating different and representative engineering problem, atomic dry friction, the moving front problems and elastic and solid mechanics are presented in the form of a set of non-linear, coupled or not coupled differential equations. For different parameters values that influence the solution, the problem is numerically solved by the network method, which provides all the variables of the problems. Although the model is extremely sensitive to the above parameters, no assumptions are considered as regards the linearization of the variables. The design of the models, which are run on standard electrical circuit simulation software, is explained in detail. The network model results are compared with common numerical methods or experimental data, published in the scientific literature, to show the reliability of the model. PMID:29518121

  11. Transient performance simulation of aircraft engine integrated with fuel and control systems

    International Nuclear Information System (INIS)

    Wang, C.; Li, Y.G.; Yang, B.Y.

    2017-01-01

    Highlights: • A new performance simulation method for engine hydraulic fuel systems is introduced. • Time delay of engine performance due to fuel system model is noticeable but small. • The method provides details of fuel system behavior in engine transient processes. • The method could be used to support engine and fuel system designs. - Abstract: A new method for the simulation of gas turbine fuel systems based on an inter-component volume method has been developed. It is able to simulate the performance of each of the hydraulic components of a fuel system using physics-based models, which potentially offers more accurate results compared with those using transfer functions. A transient performance simulation system has been set up for gas turbine engines based on an inter-component volume (ICV) method. A proportional-integral (PI) control strategy is used for the simulation of engine controller. An integrated engine and its control and hydraulic fuel systems has been set up to investigate their coupling effect during engine transient processes. The developed simulation system has been applied to a model aero engine. The results show that the delay of the engine transient response due to the inclusion of the fuel system model is noticeable although relatively small. The developed method is generic and can be applied to any other gas turbines and their control and fuel systems.

  12. Manpower simulation for the power plant design engineering

    International Nuclear Information System (INIS)

    Moon, B.S.; Juhn, P.E.

    1982-01-01

    Some observation from the examination of actual manhour curves for the power design engineering obtained from Sargent and Lundy Engineers and of a few of the model curves proposed by Bechtel, are analyzed in this paper. A model curve representing typical design engineering manhour has been determined as probability density function for the Gamma Distribution. By means of this model curve, we strategically forecast the future engineering manpower requirements to meet the Covernment's long range nuclear power plan. As a sensitivity analysis, the directions for the localization of nuclear power plant design engineering, are studied in terms of the performance factor for the experienced versus inexperienced engineers. (Author)

  13. Tabulated chemical kinetics for efficient and detailed simulations of diesel engine combustion

    NARCIS (Netherlands)

    Bekdemir, C.

    2012-01-01

    Efficient and detailed computational tools to simulate engine combustion are of great importance. The internal combustion engine will remain the primary mean for transportation in the decades to come. Especially diesel engines are, and become increasingly more, popular because of their high

  14. Mathematical model of marine diesel engine simulator for a new methodology of self propulsion tests

    Energy Technology Data Exchange (ETDEWEB)

    Izzuddin, Nur; Sunarsih,; Priyanto, Agoes [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2015-05-15

    As a vessel operates in the open seas, a marine diesel engine simulator whose engine rotation is controlled to transmit through propeller shaft is a new methodology for the self propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through a computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the target vessel’s speed. The input and output are a real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion tests in calm waters were conducted using a vessel model to validate the marine diesel engine simulator. The simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbochargers for the marine diesel engine simulator. The control system developed will be beneficial for users as to analyze different condition of vessel’s speed to obtain better characteristics and hence optimize the fuel saving rate.

  15. Development of a compact nuclear power station engineering simulator

    International Nuclear Information System (INIS)

    Jian Jianfeng; Yang Yanhua; Lin Meng; Hu Rui

    2003-01-01

    The compact nuclear power plant project simulator is developed based on the Chashma nuclear power plant. This simulator consists of simulation computation code, data communication module and human-machine interface. This paper discusses the design and implementation of the simulator from such aspect as computer system, hydrothermal model, programming language, human-machine interface and data communication in details

  16. Process/Engineering Co-Simulation of Oxy-Combustion and Chemical Looping Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Sloan, David [Alstom Power Inc., Windsor, CT (United States)

    2013-03-01

    Over the past several years, the DOE has sponsored various funded programs, collectively referred to as Advanced Process Engineering Co-Simulator (APECS) programs, which have targeted the development of a steady-state simulator for advanced power plants. The simulator allows the DOE and its contractors to systematically evaluate various power plant concepts, either for preliminary conceptual design or detailed final design.

  17. Experiences with Integrating Simulation into a Software Engineering Curriculum

    Science.gov (United States)

    Bollin, Andreas; Hochmuller, Elke; Mittermeir, Roland; Samuelis, Ladislav

    2012-01-01

    Software Engineering education must account for a broad spectrum of knowledge and skills software engineers will be required to apply throughout their professional life. Covering all the topics in depth within a university setting is infeasible due to curricular constraints as well as due to the inherent differences between educational…

  18. Real-time simulation of an F110/STOVL turbofan engine

    Science.gov (United States)

    Drummond, Colin K.; Ouzts, Peter J.

    1989-01-01

    A traditional F110-type turbofan engine model was extended to include a ventral nozzle and two thrust-augmenting ejectors for Short Take-Off Vertical Landing (STOVL) aircraft applications. Development of the real-time F110/STOVL simulation required special attention to the modeling approach to component performance maps, the low pressure turbine exit mixing region, and the tailpipe dynamic approximation. Simulation validation derives by comparing output from the ADSIM simulation with the output for a validated F110/STOVL General Electric Aircraft Engines FORTRAN deck. General Electric substantiated basic engine component characteristics through factory testing and full scale ejector data.

  19. Protein engineering and the use of molecular modeling and simulation: the case of heterodimeric Fc engineering.

    Science.gov (United States)

    Spreter Von Kreudenstein, Thomas; Lario, Paula I; Dixit, Surjit B

    2014-01-01

    Computational and structure guided methods can make significant contributions to the development of solutions for difficult protein engineering problems, including the optimization of next generation of engineered antibodies. In this paper, we describe a contemporary industrial antibody engineering program, based on hypothesis-driven in silico protein optimization method. The foundational concepts and methods of computational protein engineering are discussed, and an example of a computational modeling and structure-guided protein engineering workflow is provided for the design of best-in-class heterodimeric Fc with high purity and favorable biophysical properties. We present the engineering rationale as well as structural and functional characterization data on these engineered designs. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. A Modular Aero-Propulsion System Simulation of a Large Commercial Aircraft Engine

    Science.gov (United States)

    DeCastro, Jonathan A.; Litt, Jonathan S.; Frederick, Dean K.

    2008-01-01

    A simulation of a commercial engine has been developed in a graphical environment to meet the increasing need across the controls and health management community for a common research and development platform. This paper describes the Commercial Modular Aero Propulsion System Simulation (C-MAPSS), which is representative of a 90,000-lb thrust class two spool, high bypass ratio commercial turbofan engine. A control law resembling the state-of-the-art on board modern aircraft engines is included, consisting of a fan-speed control loop supplemented by relevant engine limit protection regulator loops. The objective of this paper is to provide a top-down overview of the complete engine simulation package.

  1. Driving engineering of novel antimicrobial peptides from simulations of peptide-micelle interactions

    DEFF Research Database (Denmark)

    Khandelia, Himanshu; Langham, Allison A; Kaznessis, Yiannis N

    2006-01-01

    Simulations of antimicrobial peptides in membrane mimics can provide the high resolution, atomistic picture that is necessary to decipher which sequence and structure components are responsible for activity and toxicity. With such detailed insight, engineering new sequences that are active but non...... peptides and their interaction with membrane mimics. In this article, we discuss the promise and the challenges of widely used models and detail our recent work on peptide-micelle simulations as an attractive alternative to peptide-bilayer simulations. We detail our results with two large structural...... classes of peptides, helical and beta-sheet and demonstrate how simulations can assist in engineering of novel antimicrobials with therapeutic potential....

  2. An Open-Source Simulation Environment for Model-Based Engineering, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed work is a new spacecraft simulation environment for model-based engineering of flight algorithms and software. The goal is to provide a much faster way...

  3. Simulating Exposure Concentrations of Engineered Nanomaterials in Surface Water Systems: WASP8

    Science.gov (United States)

    The unique properties of engineered nanomaterials led to their increased production and potential release into the environment. Currently available environmental fate models developed for traditional contaminants are limited in their ability to simulate nanomaterials’ envir...

  4. To improve training methods in an engine room simulator-based training

    OpenAIRE

    Lin, Chingshin

    2016-01-01

    The simulator based training are used widely in both industry and school education to reduce the accidents nowadays. This study aims to suggest the improved training methods to increase the effectiveness of engine room simulator training. The effectiveness of training in engine room will be performance indicators and the self-evaluation by participants. In the first phase of observation, the aim is to find out the possible shortcomings of current training methods based on train...

  5. Large Eddy Simulations of Complex Flows in IC-Engine's Exhaust Manifold and Turbine

    OpenAIRE

    Fjällman, Johan

    2014-01-01

    The thesis deals with the flow in pipe bends and radial turbines geometries that are commonly found in an Internal Combustion Engine (ICE). The development phase of internal combustion engines relies more and more on simulations as an important complement to experiments. This is partly because of the reduction in development cost and the shortening of the development time. This is one of the reasons for the need of more accurate and predictive simulations. By using more complex computational ...

  6. Simulation investigation of flow field inside the rotary engine : during intake and compression stroke

    Energy Technology Data Exchange (ETDEWEB)

    Poojitganont, T.; Berg, H.P.; Izweik, H.T. [Brandenburg Univ. of Technology Cottbus, Cottbus (Germany)

    2009-07-01

    As a result of continuously increasing oil prices, automotive industries are looking for alternative power sources for their automobiles. An excellent solution is the hybrid system. However due to the additional weight of its batteries, this causes the total weight of the car to increase. This higher battery weight can be compensated by reducing the weight of the engine. A rotary engine, such as the Wankel rotary engine, has a more attractive power to weight ratio than the normal reciprocating engine. The rotary engine can be treated and evaluated with respect to performance characteristics as a displacement type, four-stroke internal combustion engine, one-cycle similar to the reciprocating engine. For any combustion engine to reach the maximum power output, the mixture formation inside the engine should be considered. The flow phenomenon inside the engine is a key parameter which involves the mixture formation mechanism. This paper investigated the spray characteristic from the injector and the flow phenomena inside the combustion chamber. Its behaviours were studied using computational fluid dynamics simulation. The simulation setup was described in detail, with reference to meshes; initial condition; and boundary condition. Verification of the calculation was also presented. A comparison of the temperature during compression stroke from the analytical calculation and the adiabetic system simulation were also illustrated. Simulation results showed that the speed of the engine provides a proportional effect on the magnitude of air velocity inside the engine, whereas the circulation region can be expanded by increasing the intake pressure during the intake stroke. 9 refs., 1 tab., 13 figs.

  7. An approach to teaching and research of simulation for environmental engineering design

    NARCIS (Netherlands)

    Bartak, M.; Drkal, F.; Hensen, J.L.M.; Schwarzer, J.; Lain, M.; Sourek, B.

    2003-01-01

    This paper starts out by elaborating why computer modeling and simulation is such an important technique/ tool for modern state-of-the-art environmental engineering. It then continues with how this is currently integrated in engineering analysis and design. The paper continues with describing what

  8. Numerical simulation of helicopter engine plume in forward flight

    Science.gov (United States)

    Dimanlig, Arsenio C. B.; Vandam, Cornelis P.; Duque, Earl P. N.

    1994-01-01

    Flowfields around helicopters contain complex flow features such as large separated flow regions, vortices, shear layers, blown and suction surfaces and an inherently unsteady flow imposed by the rotor system. Another complicated feature of helicopters is their infrared signature. Typically, the aircraft's exhaust plume interacts with the rotor downwash, the fuselage's complicated flowfield, and the fuselage itself giving each aircraft a unique IR signature at given flight conditions. The goal of this project was to compute the flow about a realistic helicopter fuselage including the interaction of the engine air intakes and exhaust plume. The computations solve the Think-Layer Navier Stokes equations using overset type grids and in particular use the OVERFLOW code by Buning of NASA Ames. During this three month effort, an existing grid system of the Comanche Helicopter was to be modified to include the engine inlet and the hot engine exhaust. The engine exhaust was to be modeled as hot air exhaust. However, considerable changes in the fuselage geometry required a complete regriding of the surface and volume grids. The engine plume computations have been delayed to future efforts. The results of the current work consists of a complete regeneration of the surface and volume grids of the most recent Comanche fuselage along with a flowfield computation.

  9. Diffusion in Liquids : Equilibrium Molecular Simulations and Predictive Engineering Models

    NARCIS (Netherlands)

    Liu, X.

    2013-01-01

    The aim of this thesis is to study multicomponent diffusion in liquids using Molecular Dynamics (MD) simulations. Diffusion plays an important role in mass transport processes. In binary systems, mass transfer processes have been studied extensively using both experiments and molecular simulations.

  10. Learning Reverse Engineering and Simulation with Design Visualization

    Science.gov (United States)

    Hemsworth, Paul J.

    2018-01-01

    The Design Visualization (DV) group supports work at the Kennedy Space Center by utilizing metrology data with Computer-Aided Design (CAD) models and simulations to provide accurate visual representations that aid in decision-making. The capability to measure and simulate objects in real time helps to predict and avoid potential problems before they become expensive in addition to facilitating the planning of operations. I had the opportunity to work on existing and new models and simulations in support of DV and NASA’s Exploration Ground Systems (EGS).

  11. Hierarchy of simulation models for a turbofan gas engine

    Science.gov (United States)

    Longenbaker, W. E.; Leake, R. J.

    1977-01-01

    Steady-state and transient performance of an F-100-like turbofan gas engine are modeled by a computer program, DYNGEN, developed by NASA. The model employs block data maps and includes about 25 states. Low-order nonlinear analytical and linear techniques are described in terms of their application to the model. Experimental comparisons illustrating the accuracy of each model are presented.

  12. Establishing a `Centre for Engineering Experimentation and Design Simulation': a step towards restructuring engineering education in India

    Science.gov (United States)

    Venkateswarlu, P.

    2017-07-01

    Reforms in undergraduate engineering curriculum to produce engineers with entrepreneurial skills should address real-world problems relevant to industry and society with active industry support. Technology-assisted, hands-on projects involving experimentation, design simulation and prototyping will transform graduates into professionals with necessary skills to create and advance knowledge that meets global standards. To achieve this goal, this paper proposes establishing a central facility, 'Centre for Engineering Experimentation and Design Simulation' (CEEDS) in autonomous engineering colleges in India. The centre will be equipped with the most recent technology resources and computational facilities where students execute novel interdisciplinary product-oriented projects benefiting both industry and society. Students undertake two projects: a short-term project aimed at an engineering solution to a problem in energy, health and environment and the other a major industry-supported project devoted to a product that enhances innovation and creativity. The paper presents the current status, the theoretical and pedagogical foundation for the centre's relevance, an activity plan and its implementation in the centre for product-based learning with illustrative examples.

  13. Development and validation of a new turbocharger simulation methodology for marine two stroke diesel engine modelling and diagnostic applications

    International Nuclear Information System (INIS)

    Sakellaridis, Nikolaos F.; Raptotasios, Spyridon I.; Antonopoulos, Antonis K.; Mavropoulos, Georgios C.; Hountalas, Dimitrios T.

    2015-01-01

    Engine cycle simulation models are increasingly used in diesel engine simulation and diagnostic applications, reducing experimental effort. Turbocharger simulation plays an important role in model's ability to accurately predict engine performance and emissions. The present work describes the development of a complete engine simulation model for marine Diesel engines based on a new methodology for turbocharger modelling utilizing physically based meanline models for compressor and turbine. Simulation accuracy is evaluated against engine bench measurements. The methodology was developed to overcome the problem of limited experimental maps availability for compressor and turbine, often encountered in large marine diesel engine simulation and diagnostic studies. Data from the engine bench are used to calibrate the models, as well as to estimate turbocharger shaft mechanical efficiency. Closed cycle and gas exchange are modelled using an existing multizone thermodynamic model. The proposed methodology is applied on a 2-stroke marine diesel engine and its evaluation is based on the comparison of predictions against measured engine data. It is demonstrated model's ability to predict engine response with load variation regarding both turbocharger performance and closed cycle parameters, as well as NOx emission trends, making it an effective tool for both engine diagnostic and optimization studies. - Highlights: • Marine two stroke diesel engine simulation model. • Turbine and compressor simulation using physical meanline models. • Methodology to derive T/C component efficiency and T/C shaft mechanical efficiency. • Extensive validation of predictions against experimental data.

  14. Web-Based Simulation Games for the Integration of Engineering and Business Fundamentals

    Science.gov (United States)

    Calfa, Bruno; Banholzer, William; Alger, Monty; Doherty, Michael

    2017-01-01

    This paper describes a web-based suite of simulation games that have the purpose to enhance the chemical engineering curriculum with business-oriented decisions. Two simulation cases are discussed whose teaching topics include closing material and energy balances, importance of recycle streams, price-volume relationship in a dynamic market, impact…

  15. Computer simulations for state-of-the-art engineering design of a commercial building in Prague

    NARCIS (Netherlands)

    Bartak, M.; Drkal, F.; Hensen, J.L.M.; Lain, M.; Schwarzer, J.

    2003-01-01

    The paper describes the computer simulation work, which was carried out to support the engineering design team of the Luxembourg Plaza building development in Prague. The simulations for this study were based on (1) energy balance models covering the whole building for heating and cooling load

  16. Analysis and simulation of mobile air conditioning system coupled with engine cooling system

    International Nuclear Information System (INIS)

    Qi, Zhao-gang; Chen, Jiang-ping; Chen, Zhi-jiu

    2007-01-01

    Many components of the mobile air conditioning system and engine cooling system are closely interrelated and make up the vehicle climate control system. In the present paper, a vehicle climate control system model including air conditioning system and engine cooling system has been proposed under different operational conditions. All the components have been modeled on the basis of experimental data. Based on the commercial software, a computer simulation procedure of the vehicle climate control system has been developed. The performance of the vehicle climate control system is simulated, and the calculational data have good agreement with experimental data. Furthermore, the vehicle climate control simulation results have been compared with an individual air conditioning system and engine cooling system. The influences between the mobile air conditioning system and the engine cooling system are discussed

  17. Simulation, design and thermal analysis of a solar Stirling engine using MATLAB

    International Nuclear Information System (INIS)

    Shazly, J.H.; Hafez, A.Z.; El Shenawy, E.T.; Eteiba, M.B.

    2014-01-01

    Highlights: • Modeling and simulation for a prototype of the solar-powered Stirling engine. • The solar-powered Stirling engine working at the low temperature range. • Estimating output power from the solar Stirling engine using Matlab program. • Solar radiation simulation program presents a solar radiation data using MATLAB. - Abstract: This paper presents the modeling and simulation for a prototype of the solar-powered Stirling engine working at the low temperature range. A mathematical model for the thermal analysis of the solar-powered low temperature Stirling engine with heat transfer is developed using Matlab program. The model takes into consideration the effect of the absorber temperature on the thermal analysis like as radiation and convection heat transfer between the absorber and the working fluid as well as radiation and convection heat transfer between the lower temperature plate and the working fluid. Hence, the present analysis provides a theoretical guidance for designing and operating of the solar-powered low temperature Stirling engine system, as well as estimating output power from the solar Stirling engine using Matlab program. This study attempts to demonstrate the potential of the low temperature Stirling engine as an option for the prime movers for Photovoltaic tracking systems. The heat source temperature is 40–60 °C as the temperature available from the sun directly

  18. 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

  19. Enhanced Discrete-Time Scheduler Engine for MBMS E-UMTS System Level Simulator

    DEFF Research Database (Denmark)

    Pratas, Nuno; Rodrigues, António

    2007-01-01

    In this paper the design of an E-UMTS system level simulator developed for the study of optimization methods for the MBMS is presented. The simulator uses a discrete event based philosophy, which captures the dynamic behavior of the Radio Network System. This dynamic behavior includes the user...... mobility, radio interfaces and the Radio Access Network. Its given emphasis on the enhancements developed for the simulator core, the Event Scheduler Engine. Two implementations for the Event Scheduler Engine are proposed, one optimized for single core processors and other for multi-core ones....

  20. A numerical simulation method and analysis of a complete thermoacoustic-Stirling engine.

    Science.gov (United States)

    Ling, Hong; Luo, Ercang; Dai, Wei

    2006-12-22

    Thermoacoustic prime movers can generate pressure oscillation without any moving parts on self-excited thermoacoustic effect. The details of the numerical simulation methodology for thermoacoustic engines are presented in the paper. First, a four-port network method is used to build the transcendental equation of complex frequency as a criterion to judge if temperature distribution of the whole thermoacoustic system is correct for the case with given heating power. Then, the numerical simulation of a thermoacoustic-Stirling heat engine is carried out. It is proved that the numerical simulation code can run robustly and output what one is interested in. Finally, the calculated results are compared with the experiments of the thermoacoustic-Stirling heat engine (TASHE). It shows that the numerical simulation can agrees with the experimental results with acceptable accuracy.

  1. XVI 'Jacques-Louis Lions' Spanish-French School on Numerical Simulation in Physics and Engineering

    CERN Document Server

    Roldán, Teo; Torrens, Juan

    2016-01-01

    This book presents lecture notes from the XVI ‘Jacques-Louis Lions’ Spanish-French School on Numerical Simulation in Physics and Engineering, held in Pamplona (Navarra, Spain) in September 2014. The subjects covered include: numerical analysis of isogeometric methods, convolution quadrature for wave simulations, mathematical methods in image processing and computer vision, modeling and optimization techniques in food processes, bio-processes and bio-systems, and GPU computing for numerical simulation. The book is highly recommended to graduate students in Engineering or Science who want to focus on numerical simulation, either as a research topic or in the field of industrial applications. It can also benefit senior researchers and technicians working in industry who are interested in the use of state-of-the-art numerical techniques in the fields addressed here. Moreover, the book can be used as a textbook for master courses in Mathematics, Physics, or Engineering.

  2. Simulating the effects of turbocharging on the emission levels of a gasoline engine

    Directory of Open Access Journals (Sweden)

    Amir Reza Mahmoudi

    2017-12-01

    Full Text Available The main objective of this work was to respond to the global concern for the rise of the emissions and the necessity of preventing them to form rather than dealing with their after-effects. Therefore, the production levels of four main emissions, namely NOx, CO2, CO and UHC in gasoline engine of Nissan Maxima 1994 is assessed via 1-D simulation with the GT-Power code. Then, a proper matching of turbine-compressor is carried out to propose a turbocharger for the engine, and the resultant emissions are compared to the naturally aspirated engine. It is found that the emission levels of NOx, CO, and CO2 are higher in terms of their concentration in the exhaust fume of the turbocharged engine, in comparison with the naturally aspirated engine. However, at the same time, the brake power and the brake specific emissions produced by the turbocharged engine are respectively higher and lower than those of the naturally aspirated engine. Therefore, it is concluded that, for a specific application, turbocharging provides the chance to achieve the performance of a potential naturally aspirated engine while producing lower emissions. Keywords: Emission, Gasoline SI engine, Turbocharging, GT-Power, 1-D simulation, Brake specific

  3. Computational modeling, optimization and manufacturing simulation of advanced engineering materials

    CERN Document Server

    2016-01-01

    This volume presents recent research work focused in the development of adequate theoretical and numerical formulations to describe the behavior of advanced engineering materials.  Particular emphasis is devoted to applications in the fields of biological tissues, phase changing and porous materials, polymers and to micro/nano scale modeling. Sensitivity analysis, gradient and non-gradient based optimization procedures are involved in many of the chapters, aiming at the solution of constitutive inverse problems and parameter identification. All these relevant topics are exposed by experienced international and inter institutional research teams resulting in a high level compilation. The book is a valuable research reference for scientists, senior undergraduate and graduate students, as well as for engineers acting in the area of computational material modeling.

  4. Using Simulation to Increase Yields in Chemical Engineering

    Directory of Open Access Journals (Sweden)

    William C. Conley

    2003-06-01

    Full Text Available Trying to increase the yields or profit or efficiency (less pollution of chemical processes is a central goal of the chemical engineer in theory and practice. Certainly sound training in chemistry, business and pollution control help the engineer to set up optimal chemical processes. However, the ever changing demands of customers and business conditions, plus the multivariate complexity of the chemical business can make optimization challenging. Mathematical tools such as statistics and linear programming have certainly been useful to chemical engineers in their pursuit of optimal efficiency. However, some processes can be modeled linearly and some can not. Therefore, presented here will be an industrial chemical process with potentially five variables affecting the yield. Data from over one hundred runs of the process has been collected, but it is not known initially whether the yield relationship is linear or nonlinear. Therefore, the CTSP multivariate correlation coefficient will be calculated for the data to see if a relationship exists among the variables. Then once it is proven that there is a statistically significant relationship, an appropriate linear or nonlinear equation can be fitted to the data, and it can be optimized for use in the chemical plant.

  5. Exergetic analysis of cogeneration plants through integration of internal combustion engine and process simulators

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Leonardo de Oliveira [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)], E-mail: leonardo.carvalho@petrobras.com.br; Leiroz, Albino Kalab; Cruz, Manuel Ernani [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Mecanica], Emails: leiroz@mecanica.ufrj.br, manuel@mecanica.ufrj.br

    2010-07-01

    Internal combustion engines (ICEs) have been used in industry and power generation much before they were massively employed for transportation. Their high reliability, excellent power-to-weight ratio, and thermal efficiency have made them a competitive choice as main energy converters in small to medium sized power plants. Process simulators can model ICE powered energy plants with limited depth, due to the highly simplified ICE models used. Usually a better understanding of the global effects of different engine parameters is desirable, since the combustion process within the ICE is typically the main cause of exergy destruction in systems which utilize them. Dedicated commercial ICE simulators have reached such a degree of maturity, that they can adequately model a wide spectrum of phenomena that occur in ICEs. However, ICE simulators are unable to incorporate the remaining of power plant equipment and processes in their models. This paper presents and exploits the integration of an internal combustion engine simulator with a process simulator, so as to evaluate the construction of a fully coupled simulation platform to analyze the performance of ICE-based power plants. A simulation model of an actual cogeneration plant is used as a vehicle for application of the proposed computational methodology. The results show that by manipulating the engine mapping parameters, the overall efficiency of the plant can be improved. (author)

  6. Performance simulation of a spark ignited free-piston engine generator

    Energy Technology Data Exchange (ETDEWEB)

    Mikalsen, R.; Roskilly, A.P. [Sir Joseph Swan Institute for Energy Research, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU (United Kingdom)

    2008-10-15

    Free-piston engines are under investigation by a number of research groups worldwide due to potential fuel efficiency and engine emissions advantages. The free-piston engine generator, in which a linear electric generator is fixed to the mover to produce electric power, has been proposed as an alternative prime mover for hybrid-electric vehicles. This paper investigates the performance of a spark ignited free-piston engine generator and compares it to a conventional engine using a computational fluid dynamics simulation model. The particular operating characteristics of the free-piston engine were not found to give noticeable performance advantages, and it is concluded that the main potential of this technology lies in the simplicity and flexibility of the concept. (author)

  7. Numerical Simulation of Cast Distortion in Gas Turbine Engine Components

    International Nuclear Information System (INIS)

    Inozemtsev, A A; Dubrovskaya, A S; Dongauser, K A; Trufanov, N A

    2015-01-01

    In this paper the process of multiple airfoilvanes manufacturing through investment casting is considered. The mathematical model of the full contact problem is built to determine stress strain state in a cast during the process of solidification. Studies are carried out in viscoelastoplastic statement. Numerical simulation of the explored process is implemented with ProCASTsoftware package. The results of simulation are compared with the real production process. By means of computer analysis the optimization of technical process parameters is done in order to eliminate the defect of cast walls thickness variation. (paper)

  8. Education and training of future nuclear engineers through the use of an interactive plant simulator

    International Nuclear Information System (INIS)

    Ahnert, C.; Cuervo, D.; Garcia-Herranz, N.; Aragones, J.M.; Cabellos, O.; Gallego, E.; Minguez, E.; Lorente, A.; Piedra, D.; Rebollo, L.; Blanco, J.

    2010-01-01

    The International Atomic Energy Agency (IAEA) sponsors the development of nuclear reactor simulators for education, or arranges the supply of such simulation programs. Aware of this, the Department of Nuclear Engineering of the Universidad Politecnica de Madrid was provided in 2008 with the Interactive Graphical Simulator of the Spanish nuclear power plant Jose Cabrera, whose operation ceased definitively in 2006. According with the IAEA-TECDOC- 1411, the simulator is a Graphical Simulator, used for training of main control room personnel, technical support engineers, and operations management. This paper presents all the work performed at the Department to turn the simulator into a teaching/learning tool, to be use in the nuclear engineering studies following guidance found in: Shtub, A. Parush, T.T. Hewett 'The use of simulation in learning and teaching' (Int. J. Eng. Educ., 25(2), 2009, pp. 206-208). The experience obtained so far with the use of the simulator has been very successful. The graduate students involved in the development of the projects, practices and documents related with the simulator show a great interest for the work that they are doing making that the laboratory where the simulator is installed to be busy place. Regarding the undergraduate students, the practices in the simulator encourage them to follow the Nuclear Energy studies in the Engineering Schools, what is very rewarding for the Department professors. The simulator has proved to be an optimal tool to transfer the knowledge of the physical phenomena that are involved in the nuclear power plants, from the nuclear reactor to the whole set of systems and equipments on a nuclear power plant. It is also a relevant tool for motivation of the students, and to complete the theoretical lessons. This use of the simulator in the learning-teaching process meats also the criteria recommended for the Bologna adapted studies, as it helps to increase the private hands-on work of the student, and

  9. Modelling and Simulation for Requirements Engineering and Options Analysis

    Science.gov (United States)

    2010-05-01

    should be performed to work successfully in the domain; and process-based techniques model the processes that occur in the work domain. There is a crisp ...acad/sed/sedres/ dm /erg/cwa. DRDC Toronto CR 2010-049 39 23. Can the current technique for developing simulation models for assessments

  10. A simulation based engineering method to support HAZOP studies

    DEFF Research Database (Denmark)

    Enemark-Rasmussen, Rasmus; Cameron, David; Angelo, Per Bagge

    2012-01-01

    the conventional HAZOP procedure. The method systematically generates failure scenarios by considering process equipment deviations with pre-defined failure modes. The effect of failure scenarios is then evaluated using dynamic simulations -in this study the K-Spice® software used. The consequences of each failure...

  11. Virtual reality simulators for rock engineering related training.

    CSIR Research Space (South Africa)

    Squelch, A

    1997-12-01

    Full Text Available Virtual reality (VR) has been investigated by SIMRAC and CSIR Miningtek as a means of providing an enhancement to current training methods that will lead to more effective hazard awareness training programmes. A VR training simulator developed under...

  12. Thermodynamic simulation model for predicting the performance of spark ignition engines using biogas as fuel

    International Nuclear Information System (INIS)

    Nunes de Faria, Mário M.; Vargas Machuca Bueno, Juan P.; Ayad, Sami M.M. Elmassalami; Belchior, Carlos R. Pereira

    2017-01-01

    Highlights: • A 0-D model for performance prediction of SI ICE fueled with biogas is proposed. • Relative difference between simulated and experimental values was under 5%. • Can be adapted for different biogas compositions and operating ranges. • Could be a valuable tool for predicting trends and guiding experimentation. • Is suitable for use with biogas supplies in developing regions. - Abstract: Biogas found its way from developing countries and is now an alternative to fossil fuels in internal combustion engines and with the advantage of lower greenhouse gas emissions. However, its use in gas engines requires engine modifications or adaptations that may be costly. This paper reports the results of experimental performance and emissions tests of an engine-generator unit fueled with biogas produced in a sewage plant in Brazil, operating under different loads, and with suitable engine modifications. These emissions and performance results were in agreement with the literature and it was confirmed that the penalties to engine performance were more significant than emission reduction in the operating range tested. Furthermore, a zero dimensional simulation model was employed to predict performance characteristics. Moreover, a differential thermodynamic equation system was solved, obtaining the pressure inside the cylinder as a function of the crank angle for different engine conditions. Mean effective pressure and indicated power were also obtained. The results of simulation and experimental tests of the engine in similar conditions were compared and the model validated. Although several simplifying assumptions were adopted and empirical correlations were used for Wiebe function, the model was adequate in predicting engine performance as the relative difference between simulated and experimental values was lower than 5%. The model can be adapted for use with different raw or enriched biogas compositions and could prove to be a valuable tool to guide

  13. NeuroManager: A workflow analysis based simulation management engine for computational neuroscience

    Directory of Open Access Journals (Sweden)

    David Bruce Stockton

    2015-10-01

    Full Text Available We developed NeuroManager, an object-oriented simulation management software engine for computational neuroscience. NeuroManager automates the workflow of simulation job submissions when using heterogeneous computational resources, simulators, and simulation tasks. The object-oriented approach 1 provides flexibility to adapt to a variety of neuroscience simulators, 2 simplifies the use of heterogeneous computational resources, from desktops to super computer clusters, and 3 improves tracking of simulator/simulation evolution. We implemented NeuroManager in Matlab, a widely used engineering and scientific language, for its signal and image processing tools, prevalence in electrophysiology analysis, and increasing use in college Biology education. To design and develop NeuroManager we analyzed the workflow of simulation submission for a variety of simulators, operating systems, and computational resources, including the handling of input parameters, data, models, results, and analyses. This resulted in twenty-two stages of simulation submission workflow. The software incorporates progress notification, automatic organization, labeling, and time-stamping of data and results, and integrated access to Matlab's analysis and visualization tools. NeuroManager provides users with the tools to automate daily tasks, and assists principal investigators in tracking and recreating the evolution of research projects performed by multiple people. Overall, NeuroManager provides the infrastructure needed to improve workflow, manage multiple simultaneous simulations, and maintain provenance of the potentially large amounts of data produced during the course of a research project.

  14. Issues in visual support to real-time space system simulation solved in the Systems Engineering Simulator

    Science.gov (United States)

    Yuen, Vincent K.

    1989-01-01

    The Systems Engineering Simulator has addressed the major issues in providing visual data to its real-time man-in-the-loop simulations. Out-the-window views and CCTV views are provided by three scene systems to give the astronauts their real-world views. To expand the window coverage for the Space Station Freedom workstation a rotating optics system is used to provide the widest field of view possible. To provide video signals to as many viewpoints as possible, windows and CCTVs, with a limited amount of hardware, a video distribution system has been developed to time-share the video channels among viewpoints at the selection of the simulation users. These solutions have provided the visual simulation facility for real-time man-in-the-loop simulations for the NASA space program.

  15. Simulation of Cycle-to-Cycle Variation in Dual-Fuel Engines

    KAUST Repository

    Jaasim, Mohammed

    2017-03-13

    Standard practices of internal combustion (IC) engine experiments are to conduct the measurements of quantities averaged over a large number of cycles. Depending on the operating conditions, the cycle-to-cycle variation (CCV) of quantities, such as the indicated mean effective pressure (IMEP) are observed at different levels. Accurate prediction of CCV in IC engines is an important but challenging task. Computational fluid dynamics (CFD) simulations using high performance computing (HPC) can be used effectively to visualize such 3D spatial distributions. In the present study, a dual fuel large engine is considered, with natural gas injected into the manifold accompanied with direct injection of diesel pilot fuel to trigger ignition. Multiple engine cycles in 3D are simulated in series as in the experiments to investigate the potential of HPC based high fidelity simulations to accurately capture the cycle to cycle variation in dual fuel engines. Open cycle simulations are conducted to predict the combined effect of the stratification of fuel-air mixture, temperature and turbulence on the CCV of pressure. The predicted coefficient of variation (COV) of pressure compared to the results from closed cycle simulations and the experiments.

  16. Mathematical Modeling and Simulation Introduction for Scientists and Engineers

    CERN Document Server

    Velten, Kai

    2008-01-01

    This concise and clear introduction to the topic requires only basic knowledge of calculus and linear algebra—all other concepts and ideas are developed in the course of the book. Lucidly written so as to appeal to undergraduates and practitioners alike, it enables readers to set up simple mathematical models on their own and to interpret their results and those of others critically. To achieve this, many examples have been chosen from various fields, such as biology, ecology, economics, medicine, agricultural, chemical, electrical, mechanical and process engineering, which are subsequently di

  17. Semi-Immersive Virtual Turbine Engine Simulation System

    Science.gov (United States)

    Abidi, Mustufa H.; Al-Ahmari, Abdulrahman M.; Ahmad, Ali; Darmoul, Saber; Ameen, Wadea

    2018-05-01

    The design and verification of assembly operations is essential for planning product production operations. Recently, virtual prototyping has witnessed tremendous progress, and has reached a stage where current environments enable rich and multi-modal interaction between designers and models through stereoscopic visuals, surround sound, and haptic feedback. The benefits of building and using Virtual Reality (VR) models in assembly process verification are discussed in this paper. In this paper, we present the virtual assembly (VA) of an aircraft turbine engine. The assembly parts and sequences are explained using a virtual reality design system. The system enables stereoscopic visuals, surround sounds, and ample and intuitive interaction with developed models. A special software architecture is suggested to describe the assembly parts and assembly sequence in VR. A collision detection mechanism is employed that provides visual feedback to check the interference between components. The system is tested for virtual prototype and assembly sequencing of a turbine engine. We show that the developed system is comprehensive in terms of VR feedback mechanisms, which include visual, auditory, tactile, as well as force feedback. The system is shown to be effective and efficient for validating the design of assembly, part design, and operations planning.

  18. Molecular Cloning Designer Simulator (MCDS: All-in-one molecular cloning and genetic engineering design, simulation and management software for complex synthetic biology and metabolic engineering projects

    Directory of Open Access Journals (Sweden)

    Zhenyu Shi

    2016-12-01

    Full Text Available Molecular Cloning Designer Simulator (MCDS is a powerful new all-in-one cloning and genetic engineering design, simulation and management software platform developed for complex synthetic biology and metabolic engineering projects. In addition to standard functions, it has a number of features that are either unique, or are not found in combination in any one software package: (1 it has a novel interactive flow-chart user interface for complex multi-step processes, allowing an integrated overview of the whole project; (2 it can perform a user-defined workflow of cloning steps in a single execution of the software; (3 it can handle multiple types of genetic recombineering, a technique that is rapidly replacing classical cloning for many applications; (4 it includes experimental information to conveniently guide wet lab work; and (5 it can store results and comments to allow the tracking and management of the whole project in one platform. MCDS is freely available from https://mcds.codeplex.com. Keywords: BioCAD, Genetic engineering software, Molecular cloning software, Synthetic biology, Workflow simulation and management

  19. Transient simulation of a catalytic converter for a dual fuel engine

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B.; Checkel, D. [Alberta Univ., Dept. of Mechanical Enginering, Edmonton, AB (Canada); Hayes, R. E. [Alberta Univ., Department of Chemical and Material Engineering, Edmonton, AB (Canada); Zheng, M.; Mirosh, E. [Alternative Fuel Systems Inc., Calgary, AB (Canada)

    2000-06-01

    A catalytic converter of a ceramic monolith honeycomb substrate, coated with a washcoat of catalyst and attached to a natural gas/diesel dual fuel engine was simulated and studied experimentally. The paper describes the application of one-dimensional finite element model for the transient and steady state operation. Laminar flow was approximated using a dispersed plug flow model, and chemical kinetics were simulated using LHHW (Langmuir/ Hinshelwood/ Hougan/ Watson) type expressions. Simulation results were compared with experimental results for heating and cooling cycles which resulted from speed and load changes on the engine. The comparison showed a maximum difference between the two sets of emission levels of about 10 per cent, showing that the one-dimensional model is acceptable model for this dual fuel engine converter combination. 50 refs., 3 tabs., 13 figs.

  20. Use of computer simulations for the early introduction of nuclear engineering concepts

    International Nuclear Information System (INIS)

    Ougouag, A.M.; Zerguini, T.H.

    1985-01-01

    A sophomore level nuclear engineering (NE) course is being introduced at the University of Illinois. Via computer simulations, this course presents materials covering the most important aspects of the field. It is noted that computer simulations in nuclear engineering are cheaper and safer than experiments yet they provide an effective teaching tool for the early introduction of advanced concepts. The new course material can be used as a tutorial and for remedial learning. The use of computer simulation motivates learning since students associate computer activities with games. Such a course can help in the dissemination of the proper information to students from different fields, including liberal arts, and eventually increase undergraduate student enrollment in nuclear engineering

  1. Transport simulation of ITER [International Thermonuclear Engineering Reactor] startup

    International Nuclear Information System (INIS)

    Attenberger, S.E.; Houlberg, W.A.

    1989-01-01

    The present International Thermonuclear Engineering Reactor (ITER) reference configurations are the ''Technology Phase,'' in which the plasma current is maintained noninductively at a subignition density, and the ''Physics Phase,'' which is ignited but requires inductive maintenance of the current. The WHIST 1.5-D transport code is used to evaluate the volt-second requirements of both configurations. A slow current ramp (60-80's) is required for fixed-radius startup in ITER to avoid hollow current density profiles. To reach the operating point requires about 203 V·s for the Technology Phase (18 MA) and about 270 V·s for the Physics Phase (22 MA). The resistive losses can be reduced with expanding-radius startup. 5 refs., 4 figs

  2. Survey on Projects at DLR Simulation and Software Technology with Focus on Software Engineering and HPC

    OpenAIRE

    Schreiber, Andreas; Basermann, Achim

    2013-01-01

    We introduce the DLR institute “Simulation and Software Technology” (SC) and present current activities regarding software engineering and high performance computing (HPC) in German or international projects. Software engineering at SC focusses on data and knowledge management as well as tools for studies and experiments. We discuss how we apply software configuration management, validation and verification in our projects. Concrete research topics are traceability of (software devel...

  3. Simulators and their use in the training of CEGB reactor operations engineers

    International Nuclear Information System (INIS)

    Madden, V.J.; Tompsett, P.A.

    1988-01-01

    The development of simulators in the Central Electricity Generating Board's nuclear power training are traced, and, in describing the overall training programme of an advanced gas-cooled reactor operations engineer, the contribution made by a range of simulation devices from concept through to full-scope replica simulators is indicated. The capabilities of today's simulators are such that they are also making other contributions to the commissioning and safe operation of nuclear power plants. They are being successfully used for ergonomic and procedure validation work and the testing and commissioning of software for automatic control systems, and data and alarm processing systems. (author)

  4. Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE)

    Energy Technology Data Exchange (ETDEWEB)

    Eckerle, Wayne [Cummins, Inc., Columbus, IN (United States); Rutland, Chris [Univ. of Wisconsin, Madison, WI (United States); Rohlfing, Eric [Dept. of Energy (DOE), Washington DC (United States). Office of Science; Singh, Gurpreet [Dept. of Energy (DOE), Washington DC (United States). Office of Energy Efficiency and Renewable Energy; McIlroy, Andrew [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2011-03-03

    This report is based on a SC/EERE Workshop to Identify Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE), held March 3, 2011, to determine strategic focus areas that will accelerate innovation in engine design to meet national goals in transportation efficiency. The U.S. has reached a pivotal moment when pressures of energy security, climate change, and economic competitiveness converge. Oil prices remain volatile and have exceeded $100 per barrel twice in five years. At these prices, the U.S. spends $1 billion per day on imported oil to meet our energy demands. Because the transportation sector accounts for two-thirds of our petroleum use, energy security is deeply entangled with our transportation needs. At the same time, transportation produces one-quarter of the nation’s carbon dioxide output. Increasing the efficiency of internal combustion engines is a technologically proven and cost-effective approach to dramatically improving the fuel economy of the nation’s fleet of vehicles in the near- to mid-term, with the corresponding benefits of reducing our dependence on foreign oil and reducing carbon emissions. Because of their relatively low cost, high performance, and ability to utilize renewable fuels, internal combustion engines—including those in hybrid vehicles—will continue to be critical to our transportation infrastructure for decades. Achievable advances in engine technology can improve the fuel economy of automobiles by over 50% and trucks by over 30%. Achieving these goals will require the transportation sector to compress its product development cycle for cleaner, more efficient engine technologies by 50% while simultaneously exploring innovative design space. Concurrently, fuels will also be evolving, adding another layer of complexity and further highlighting the need for efficient product development cycles. Current design processes, using “build and test” prototype engineering, will not

  5. Design, development, and evaluation of an interactive simulator for engineering ethics education (SEEE).

    Science.gov (United States)

    Chung, Christopher A; Alfred, Michael

    2009-06-01

    Societal pressures, accreditation organizations, and licensing agencies are emphasizing the importance of ethics in the engineering curriculum. Traditionally, this subject has been taught using dogma, heuristics, and case study approaches. Most recently a number of organizations have sought to increase the utility of these approaches by utilizing the Internet. Resources from these organizations include on-line courses and tests, videos, and DVDs. While these individual approaches provide a foundation on which to base engineering ethics, they may be limited in developing a student's ability to identify, analyze, and respond to engineering ethics situations outside of the classroom environment. More effective approaches utilize a combination of these types of approaches. This paper describes the design and development of an internet based interactive Simulator for Engineering Ethics Education. The simulator places students in first person perspective scenarios involving different types of ethical situations. Students must gather data, assess the situation, and make decisions. This requires students to develop their own ability to identify and respond to ethical engineering situations. A limited comparison between the internet based interactive simulator and conventional internet web based instruction indicates a statistically significant improvement of 32% in instructional effectiveness. The simulator is currently being used at the University of Houston to help fulfill ABET requirements.

  6. Modeling and simulation in the systems engineering life cycle core concepts and accompanying lectures

    CERN Document Server

    Loper, Margaret L

    2015-01-01

    This easy to read text/reference provides a broad introduction to the fundamental concepts of modeling and simulation (M&S) and systems engineering, highlighting how M&S is used across the entire systems engineering lifecycle. Each chapter corresponds to a short lecture covering a core topic in M&S or systems engineering.  Topics and features: reviews the full breadth of technologies, methodologies and uses of M&S, rather than just focusing on a specific aspect of the field; presents contributions from renowned specialists in each topic covered; introduces the foundational elements and proce

  7. Calibration and Forward Uncertainty Propagation for Large-eddy Simulations of Engineering Flows

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, Jeremy Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Blaylock, Myra L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Domino, Stefan P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hewson, John C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kumar, Pritvi Raj [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ling, Julia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Najm, Habib N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ruiz, Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Safta, Cosmin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sargsyan, Khachik [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stewart, Alessia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wagner, Gregory [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    The objective of this work is to investigate the efficacy of using calibration strategies from Uncertainty Quantification (UQ) to determine model coefficients for LES. As the target methods are for engineering LES, uncertainty from numerical aspects of the model must also be quantified. 15 The ultimate goal of this research thread is to generate a cost versus accuracy curve for LES such that the cost could be minimized given an accuracy prescribed by an engineering need. Realization of this goal would enable LES to serve as a predictive simulation tool within the engineering design process.

  8. Virtual Environment Computer Simulations to Support Human Factors Engineering and Operations Analysis for the RLV Program

    Science.gov (United States)

    Lunsford, Myrtis Leigh

    1998-01-01

    The Army-NASA Virtual Innovations Laboratory (ANVIL) was recently created to provide virtual reality tools for performing Human Engineering and operations analysis for both NASA and the Army. The author's summer research project consisted of developing and refining these tools for NASA's Reusable Launch Vehicle (RLV) program. Several general simulations were developed for use by the ANVIL for the evaluation of the X34 Engine Changeout procedure. These simulations were developed with the software tool dVISE 4.0.0 produced by Division Inc. All software was run on an SGI Indigo2 High Impact. This paper describes the simulations, various problems encountered with the simulations, other summer activities, and possible work for the future. We first begin with a brief description of virtual reality systems.

  9. Research on engineering simulator for function validating of DCS in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Liu Pengfei; Lin Meng; Hou Dong; Yang Yanhua; Chen Zhi

    2009-01-01

    An engineering simulator for the function validating of Distributed Control System in Nuclear Power Plant (NPP) was developed in this paper.In the engineering simulator, the thermal-hydraulics was modeled by Relap5, the main control system of the NPP was modeled by Matlab/Simulink, the database was built by MySQL, and the control panel was developed by the Visual Studio. NET.Data acquisition system was used to realize the real-time communication between the simulator and the real Distributed Control System in the NPP. The validating results show that the simulator can meet the requirements of validating the hardware and logic control system of DCS in NPP. (authors)

  10. Epistemic Opacity, Confirmation Holism and Technical Debt: Computer Simulation in the Light of Empirical Software Engineering

    OpenAIRE

    Newman , Julian

    2015-01-01

    Epistemic opacity vis a vis human agents has been presented as an essential, ineliminable characteristic of computer simulation models resulting from the characteristics of the human cognitive agent. This paper argues, on the contrary, that such epistemic opacity as does occur in computer simulations is not a consequence of human limitations but of a failure on the part of model developers to adopt good software engineering practice for managing human error and ensuring the software artefact ...

  11. Minimizing the Discrepancy between Simulated and Historical Failures in Turbine Engines: A Simulation-Based Optimization Method

    Directory of Open Access Journals (Sweden)

    Ahmed Kibria

    2015-01-01

    Full Text Available The reliability modeling of a module in a turbine engine requires knowledge of its failure rate, which can be estimated by identifying statistical distributions describing the percentage of failure per component within the turbine module. The correct definition of the failure statistical behavior per component is highly dependent on the engineer skills and may present significant discrepancies with respect to the historical data. There is no formal methodology to approach this problem and a large number of labor hours are spent trying to reduce the discrepancy by manually adjusting the distribution’s parameters. This paper addresses this problem and provides a simulation-based optimization method for the minimization of the discrepancy between the simulated and the historical percentage of failures for turbine engine components. The proposed methodology optimizes the parameter values of the component’s failure statistical distributions within the component’s likelihood confidence bounds. A complete testing of the proposed method is performed on a turbine engine case study. The method can be considered as a decision-making tool for maintenance, repair, and overhaul companies and will potentially reduce the cost of labor associated to finding the appropriate value of the distribution parameters for each component/failure mode in the model and increase the accuracy in the prediction of the mean time to failures (MTTF.

  12. Securing Sensitive Flight and Engine Simulation Data Using Smart Card Technology

    Science.gov (United States)

    Blaser, Tammy M.

    2003-01-01

    NASA Glenn Research Center has developed a smart card prototype capable of encrypting and decrypting disk files required to run a distributed aerospace propulsion simulation. Triple Data Encryption Standard (3DES) encryption is used to secure the sensitive intellectual property on disk pre, during, and post simulation execution. The prototype operates as a secure system and maintains its authorized state by safely storing and permanently retaining the encryption keys only on the smart card. The prototype is capable of authenticating a single smart card user and includes pre simulation and post simulation tools for analysis and training purposes. The prototype's design is highly generic and can be used to protect any sensitive disk files with growth capability to urn multiple simulations. The NASA computer engineer developed the prototype on an interoperable programming environment to enable porting to other Numerical Propulsion System Simulation (NPSS) capable operating system environments.

  13. Simulation of Production Lines in the Education of Engineers: How to Choose the Right Software?

    Directory of Open Access Journals (Sweden)

    Rostkowska Marta

    2014-12-01

    Full Text Available The article discusses the problems of modeling and simulation in the design of production lines, mainly from an educator's perspective. Nowadays, there is a wide range of computer programs that can be used to design production lines and to simulate various aspects of their operation. However, the programs being available vary considerably as to their functionality, the approach to production system design, and the visualization tools. Therefore we demonstrate and evaluate in this paper four simulation programs, focusing on the easiness of system design, area of the possible applications in education of engineers, and the limitations imposed by versions dedicated for students. We evaluate three of programs for digital factory simulation on a common, simple assembly task, then demonstrate that these programs may be also used for more specialized simulations in various areas of production, and compare with a specialized program for simulation of robotised production lines and work cells.

  14. New Tools Being Developed for Engine- Airframe Blade-Out Structural Simulations

    Science.gov (United States)

    Lawrence, Charles

    2003-01-01

    One of the primary concerns of aircraft structure designers is the accurate simulation of the blade-out event. This is required for the aircraft to pass Federal Aviation Administration (FAA) certification and to ensure that the aircraft is safe for operation. Typically, the most severe blade-out occurs when a first-stage fan blade in a high-bypass gas turbine engine is released. Structural loading results from both the impact of the blade onto the containment ring and the subsequent instantaneous unbalance of the rotating components. Reliable simulations of blade-out are required to ensure structural integrity during flight as well as to guarantee successful blade-out certification testing. The loads generated by these analyses are critical to the design teams for several components of the airplane structures including the engine, nacelle, strut, and wing, as well as the aircraft fuselage. Currently, a collection of simulation tools is used for aircraft structural design. Detailed high-fidelity simulation tools are used to capture the structural loads resulting from blade loss, and then these loads are used as input into an overall system model that includes complete structural models of both the engines and the airframe. The detailed simulation (shown in the figure) includes the time-dependent trajectory of the lost blade and its interactions with the containment structure, and the system simulation includes the lost blade loadings and the interactions between the rotating turbomachinery and the remaining aircraft structural components. General-purpose finite element structural analysis codes are typically used, and special provisions are made to include transient effects from the blade loss and rotational effects resulting from the engine s turbomachinery. To develop and validate these new tools with test data, the NASA Glenn Research Center has teamed with GE Aircraft Engines, Pratt & Whitney, Boeing Commercial Aircraft, Rolls-Royce, and MSC.Software.

  15. Nuclear Engine System Simulation (NESS). Volume 1: Program user's guide. Final Report

    International Nuclear Information System (INIS)

    Pelaccio, D.G.; Scheil, C.M.; Petrosky, L.J.

    1993-03-01

    A Nuclear Thermal Propulsion (NTP) engine system design analysis tool is required to support current and future Space Exploration Initiative (SEI) propulsion and vehicle design studies. Currently available NTP engine design models are those developed during the NERVA program in the 1960's and early 1970's and are highly unique to that design or are modifications of current liquid propulsion system design models. To date, NTP engine-based liquid design models lack integrated design of key NTP engine design features in the areas of reactor, shielding, multi-propellant capability, and multi-redundant pump feed fuel systems. Additionally, since the SEI effort is in the initial development stage, a robust, verified NTP analysis design tool could be of great use to the community. This effort developed an NTP engine system design analysis program (tool), known as the Nuclear Engine System Simulation (NESS) program, to support ongoing and future engine system and stage design study efforts. In this effort, Science Applications International Corporation's (SAIC) NTP version of the Expanded Liquid Engine Simulation (ELES) program was modified extensively to include Westinghouse Electric Corporation's near-term solid-core reactor design model. The ELES program has extensive capability to conduct preliminary system design analysis of liquid rocket systems and vehicles. The program is modular in nature and is versatile in terms of modeling state-of-the-art component and system options as discussed. The Westinghouse reactor design model, which was integrated in the NESS program, is based on the near-term solid-core ENABLER NTP reactor design concept. This program is now capable of accurately modeling (characterizing) a complete near-term solid-core NTP engine system in great detail, for a number of design options, in an efficient manner

  16. Extending the Capabilities of Closed-loop Distributed Engine Control Simulations Using LAN Communication

    Science.gov (United States)

    Aretskin-Hariton, Eliot D.; Zinnecker, Alicia Mae; Culley, Dennis E.

    2014-01-01

    Distributed Engine Control (DEC) is an enabling technology that has the potential to advance the state-of-the-art in gas turbine engine control. To analyze the capabilities that DEC offers, a Hardware-In-the-Loop (HIL) test bed is being developed at NASA Glenn Research Center. This test bed will support a systems-level analysis of control capabilities in closed-loop engine simulations. The structure of the HIL emulates a virtual test cell by implementing the operator functions, control system, and engine on three separate computers. This implementation increases the flexibility and extensibility of the HIL. Here, a method is discussed for implementing these interfaces by connecting the three platforms over a dedicated Local Area Network (LAN). This approach is verified using the Commercial Modular Aero-Propulsion System Simulation 40k (C-MAPSS40k), which is typically implemented on one computer. There are marginal differences between the results from simulation of the typical and the three-computer implementation. Additional analysis of the LAN network, including characterization of network load, packet drop, and latency, is presented. The three-computer setup supports the incorporation of complex control models and proprietary engine models into the HIL framework.

  17. Design, development, and evaluation of a second generation interactive Simulator for Engineering Ethics Education (SEEE2).

    Science.gov (United States)

    Alfred, Michael; Chung, Christopher A

    2012-12-01

    This paper describes a second generation Simulator for Engineering Ethics Education. Details describing the first generation activities of this overall effort are published in Chung and Alfred (Sci Eng Ethics 15:189-199, 2009). The second generation research effort represents a major development in the interactive simulator educational approach. As with the first generation effort, the simulator places students in first person perspective scenarios involving different types of ethical situations. Students must still gather data, assess the situation, and make decisions. The approach still requires students to develop their own ability to identify and respond to ethical engineering situations. However, were as, the generation one effort involved the use of a dogmatic model based on National Society of Professional Engineers' Code of Ethics, the new generation two model is based on a mathematical model of the actual experiences of engineers involved in ethical situations. This approach also allows the use of feedback in the form of decision effectiveness and professional career impact. Statistical comparisons indicate a 59 percent increase in overall knowledge and a 19 percent improvement in teaching effectiveness over an Internet Engineering Ethics resource based approach.

  18. Parallel shooting methods for finding steady state solutions to engine simulation models

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2007-01-01

    Parallel single- and multiple shooting methods were tested for finding periodic steady state solutions to a Stirling engine model. The model was used to illustrate features of the methods and possibilities for optimisations. Performance was measured using simulation of an experimental data set...

  19. Simulation of diesel engine emissions on the example of Fiat Panda in the NEDC test

    Science.gov (United States)

    Botwinska, Katarzyna; Mruk, Remigiusz; Słoma, Jacek; Tucki, Karol; Zaleski, Mateusz

    2017-10-01

    Road transport may be deemed a strategic branch of modern economy. Unfortunately, a rapid increase in the number of on-road motor vehicles entails some negative consequences as well, for instance, excessive concentration of exhausts produced by engines which results in deterioration of air quality. EURO emission standards which define acceptable limits for exhaust emissions of power units is an example of an activity performed in attempt to improve air quality. The EURO standard defines permissible amount of exhausts produced by a vehicle. Presently new units are examined through NEDC test. For the purpose of this thesis, a virtual test stand in a form of a computer simulation of a chassis dynamometer was used to simulate emission of a diesel engine (compression-ignition engine) in the NEDC test. Actual parameters of the 1.3 MultiJet engine of the Fiat Panda passenger car of 2014 were applied in the model. The simulation was carried out in the Matlab Simulink environment. The simulation model of the Fiat Panda passenger car enables the designation of the emission waveform for all test stages which corresponds to the values received during an approval test in real-life conditions.

  20. Teaching Complicated Conceptual Knowledge with Simulation Videos in Foundational Electrical Engineering Courses

    Science.gov (United States)

    Chen, Baiyun; Wei, Lei; Li, Huihui

    2016-01-01

    Building a solid foundation of conceptual knowledge is critical for students in electrical engineering. This mixed-method case study explores the use of simulation videos to illustrate complicated conceptual knowledge in foundational communications and signal processing courses. Students found these videos to be very useful for establishing…

  1. Preliminary analysis of start up characteristics on SPWR with NESSY (Nuclear ship Engineering Simulation SYstem)

    International Nuclear Information System (INIS)

    Kusunoki, Tsuyoshi; Kyouya, Masahiko; Sako, Kiyoshi

    1993-09-01

    NESSY (Nuclear ship Engineering Simulation SYstem) has been developed to design advanced marine reactors. SPWR (System integrated PWR) has been designed by JAERI. It doesn't have control rod, and starts up by dilution of boron. we analyzed start up behavior of SPWR by NESSY, and evaluated the safety characteristics on start up and appropriate range of start up rate. (author)

  2. Simulation of diesel engine emissions on the example of Fiat Panda in the NEDC test

    Directory of Open Access Journals (Sweden)

    Botwinska Katarzyna

    2017-01-01

    Full Text Available Road transport may be deemed a strategic branch of modern economy. Unfortunately, a rapid increase in the number of on-road motor vehicles entails some negative consequences as well, for instance, excessive concentration of exhausts produced by engines which results in deterioration of air quality. EURO emission standards which define acceptable limits for exhaust emissions of power units is an example of an activity performed in attempt to improve air quality. The EURO standard defines permissible amount of exhausts produced by a vehicle. Presently new units are examined through NEDC test. For the purpose of this thesis, a virtual test stand in a form of a computer simulation of a chassis dynamometer was used to simulate emission of a diesel engine (compression-ignition engine in the NEDC test. Actual parameters of the 1.3 MultiJet engine of the Fiat Panda passenger car of 2014 were applied in the model. The simulation was carried out in the Matlab Simulink environment. The simulation model of the Fiat Panda passenger car enables the designation of the emission waveform for all test stages which corresponds to the values received during an approval test in real-life conditions.

  3. 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.

  4. Smoke simulation for fire engineering using a multigrid method on graphics hardware

    DEFF Research Database (Denmark)

    Glimberg, Stefan; Erleben, Kenny; Bennetsen, Jens

    2009-01-01

    interactive physical simulation for engineering purposes, has the benefit of reducing production turn-around time. We have measured speed-up improvements by a factor of up to 350, compared to existing CPU-based solvers. The present CUDA-based solver promises huge potential in economical benefits, as well...

  5. Hydraulic cylinder simulates parameters of a free piston engine; Hydraulikzylinder simuliert Groessen fuer einen Freikolbenmotor

    Energy Technology Data Exchange (ETDEWEB)

    Rinderknecht, Frank [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany). Inst. fuer Fahrzeugkonzepte

    2011-01-10

    Important data are obtained in the development of a free piston engine by a test stand with a hydraulic cylinder which first simulates the power curves and motion of the individual components, then induces the motion of the system piston, and finally ensures safety against undesired forces. (orig.)

  6. Computational fluid dynamics simulation of a single cylinder research engine working with biodiesel

    Directory of Open Access Journals (Sweden)

    Moldovanu Dan

    2013-01-01

    Full Text Available The main objective of the paper is to present the results of the CFD simulation of a DI single cylinder engine using diesel, biodiesel, or different mixture proportions of diesel and biodiesel and compare the results to a test bed measurement in the same functioning point. The engine used for verifying the results of the simulation is a single cylinder research engine from AVL with an open ECU, so that the injection timings and quantities can be controlled and analyzed. In Romania, until the year 2020 all the fuel stations are obliged to have mixtures of at least 10% biodiesel in diesel [14]. The main advantages using mixtures of biofuels in diesel are: the fact that biodiesel is not harmful to the environment; in order to use biodiesel in your engine no modifications are required; the price of biodiesel is smaller than diesel and also if we compare biodiesel production to the classic petroleum based diesel production, it is more energy efficient; biodiesel assures more lubrication to the engine so the life of the engine is increased; biodiesel is a sustainable fuel; using biodiesel helps maintain the environment and it keeps the people more healthy [1-3].

  7. Three-dimensional simulation of a novel rotary-piston engine in the motoring mode

    Directory of Open Access Journals (Sweden)

    Mohammadreza Khani

    2017-09-01

    Full Text Available In this simulation study, the flow and thermal characteristics of a novel rotary-piston engine, which is a kind of internal combustion engines, were investigated by computational fluid dynamics and the finite volume method. The structure of this engine is different to others, mainly for having 24 cylinders during the motoring mode. As a novel engine, creation of numerical models based on Reynolds average Navier Stokes (RANS simulation and analysis of various speed engines on the flow and thermal fields during intake and compression strokes are the focus of this work. The results were illustrated in term of the streamline patterns, in-cylinder temperature and pressure profile, swirl ratio (SR, wall heat flux, and turbulent velocity fluctuation. The present study indicates that, the mean pressure, temperature trace, and heat loss from the wall increase when switching to a higher engine speed. The temperature distribution reveals that the maximum temperature is restricted in the center of the combustion chamber near top dead center (TDC. Also, the maximum amount of turbulent velocity and swirl ratio are achieved at the beginning of the intake stroke and near TDC. It is observed that the obtained numerical results are in general agreement with the available experimental data.

  8. Simulation and optimization of logistics distribution for an engine production line

    Energy Technology Data Exchange (ETDEWEB)

    Song, L.; Jin, S.; Tang, P.

    2016-07-01

    In order to analyze and study the factors about Logistics distribution system, solve the problems of out of stock on the production line and improve the efficiency of the assembly line. Using the method of industrial engineering, put forward the optimization scheme of distribution system. The simulation model of logistics distribution system for engine assembly line was build based on Witness software. The optimization plan is efficient to improve Logistics distribution efficiency, production of assembly line efficiency and reduce the storage of production line. Based on the study of the modeling and simulation of engine production logistics distribution system, the result reflects some influence factors about production logistics system, which has reference value to improving the efficiency of the production line. (Author)

  9. Simulation and optimization of logistics distribution for an engine production line

    Directory of Open Access Journals (Sweden)

    Lijun Song

    2016-02-01

    Full Text Available Purpose: In order to analyze and study the factors about Logistics distribution system, solve the problems of out of stock on the production line and improve the efficiency of the assembly line. Design/methodology/approach: Using the method of industrial engineering, put forward the optimization scheme of distribution system. The simulation model of logistics distribution system for engine assembly line was build based on Witness software. Findings: The optimization plan is efficient to improve Logistics distribution efficiency, production of assembly line efficiency and reduce the storage of production line Originality/value: Based on the study of the modeling and simulation of engine production logistics distribution system, the result reflects some influence factors about production logistics system, which has reference value to improving the efficiency of the production line.

  10. Engineering and training simulators: A combined approach for nuclear plant construction projects

    International Nuclear Information System (INIS)

    Harnois, Olivier; Gain, Pascal; Bartak, Jan; Gathmann, Ralf

    2007-01-01

    Full text: Simulation technologies have always been widely used on nuclear applications, but with a clear division between engineering application, using highly validated code run in batch mode, and training purpose where real time computation is a mandatory requirement. Thanks to the flexibility of modern simulation technology and the increased performance of computers, it becomes now possible to develop Nuclear Power plant simulators that can be used both for engineering and training purposes. In the last years, the revival of nuclear industry raised a number of new construction or plant finishing projects in which the application of this combined approach would result in decisive improvement on plant construction lead times, better project control and cost optimizations. The simulator development is to be executed in a step-wise approach, scheduled in parallel with the plant design and construction phases. During a first step, the simulator will model the plant nuclear island systems plus the corresponding instrumentation and control, specific malfunctions and local commands. It can then be used for engineering activities defining and validating the plant operating strategies in case of incidents or accidents. The Simulator executive Station and Operator Station will be in prototype version with an interface imagery enabling monitoring and control of the simulator. Availability of such simulation platform leads to a significant increase in efficiency of the engineering works, the possibility to validate basic design hypotheses and detect defects and conflicts early. The second phase will consist in the fully detailed simulation of Main Control Room plant supervision and control MMI, taking into account I and C control loops detailed design improvement, while having sufficient fidelity in order to be suitable for the future operator training. Its use will enable the engineering units not only to specify and validate normal, incident and accident detailed plant

  11. SAFSIM: A computer program for engineering simulations of space reactor system performance

    International Nuclear Information System (INIS)

    Dobranich, D.

    1992-01-01

    SAFSIM (System Analysis Flow SIMulator) is a FORTRAN computer program that provides engineering simulations of user-specified flow networks at the system level. It includes fluid mechanics, heat transfer, and reactor dynamics capabilities. SAFSIM provides sufficient versatility to allow the simulation of almost any flow system, from a backyard sprinkler system to a clustered nuclear reactor propulsion system. In addition to versatility, speed and robustness are primary goals of SAFSIM. The current capabilities of SAFSIM are summarized, and some illustrative example results are presented

  12. Validation of an Integrated Airframe and Turbofan Engine Simulation for Evaluation of Propulsion Control Modes

    Science.gov (United States)

    Litt, Jonathan S.; Sowers, T Shane; Liu, Yuan; Owen, A. Karl; Guo, Ten-Huei

    2015-01-01

    The National Aeronautics and Space Administration (NASA) has developed independent airframe and engine models that have been integrated into a single real-time aircraft simulation for piloted evaluation of propulsion control algorithms. In order to have confidence in the results of these evaluations, the integrated simulation must be validated to demonstrate that its behavior is realistic and that it meets the appropriate Federal Aviation Administration (FAA) certification requirements for aircraft. The paper describes the test procedures and results, demonstrating that the integrated simulation generally meets the FAA requirements and is thus a valid testbed for evaluation of propulsion control modes.

  13. Simulating Effects of High Angle of Attack on Turbofan Engine Performance

    Science.gov (United States)

    Liu, Yuan; Claus, Russell W.; Litt, Jonathan S.; Guo, Ten-Huei

    2013-01-01

    A method of investigating the effects of high angle of attack (AOA) flight on turbofan engine performance is presented. The methodology involves combining a suite of diverse simulation tools. Three-dimensional, steady-state computational fluid dynamics (CFD) software is used to model the change in performance of a commercial aircraft-type inlet and fan geometry due to various levels of AOA. Parallel compressor theory is then applied to assimilate the CFD data with a zero-dimensional, nonlinear, dynamic turbofan engine model. The combined model shows that high AOA operation degrades fan performance and, thus, negatively impacts compressor stability margins and engine thrust. In addition, the engine response to high AOA conditions is shown to be highly dependent upon the type of control system employed.

  14. The performance simulation of single cylinder electric power confined piston engine

    Science.gov (United States)

    Gou, Yanan

    2017-04-01

    A new type of power plant. i.e, Electric Power Confined Piston Engine, is invented by combining the free piston engine and the crank connecting rod mechanism of the traditional internal combustion engine. Directly using the reciprocating movement of the piston, this new engine converts the heat energy produced by fuel to electrical energy and output it. The paper expounds the working mechanism of ECPE and establishes the kinematics and dynamics equations. Furthermore, by using the analytic method, the ECPE electromagnetic force is solved at load cases. Finally, in the simulation environment of MARLAB, the universal characteristic curve is obtained in the condition of rotational speed n between 1000 r/min and 2400 r/min, throttle opening α between 30% and 100%.

  15. SAPHIR, a simulator for engineering and training on N4-type nuclear power plants

    International Nuclear Information System (INIS)

    Vovan, C.

    1999-01-01

    SAPHIR, the new simulator developed by FRAMATOME, has been designed to be a convenient tool for engineering and training for different types of nuclear power plants. Its first application is for the French 'N4' four-loop 1500MWe PWR. The basic features of SAPHIR are: (1) Use of advanced codes for modelling He primary and secondary systems' including an axial steam generator model, (2) Use of a simulation workshop containing different tools for modelling fluid, electrical, instrument and control networks, (3) A Man-Machine Interface designed for an easy and convivial use which can simulate the different computerized control consoles of the 'N4' control room. This paper outlines features and capabilities of this tool, both for engineering and training purposes. (author)

  16. Multimode marine engine room simulation system based on field bus technology

    Science.gov (United States)

    Zheng, Huayao; Deng, Linlin; Guo, Yi

    2003-09-01

    Developing multi mode MER (Marine Engine Room) Labs is the main work in Marine Simulation Center, which is the key lab of Communication Ministry of China. It includes FPP (Fixed Pitch Propeller) and CPP (Controllable Pitch Propeller) mode MER simulation systems, integrated electrical propulsion mode MER simulation system, physical mode MER lab, etc. FPP mode simulation system, which was oriented to large container ship, had been completed since 1999, and got second level of Shanghai Municipal Science and Technical Progress award. This paper mainly introduces the recent development and achievements of Marine Simulation Center. Based on the Lon Works field bus, the structure characteristics and control strategies of completely distributed intelligent control network are discussed. The experiment mode of multi-nodes field bus detection and control system is described. Besides, intelligent fault diagnosis technology about some mechatronics integration control systems explored is also involved.

  17. Performance analyses of naval ships based on engineering level of simulation at the initial design stage

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Jeong

    2017-07-01

    Full Text Available Naval ships are assigned many and varied missions. Their performance is critical for mission success, and depends on the specifications of the components. This is why performance analyses of naval ships are required at the initial design stage. Since the design and construction of naval ships take a very long time and incurs a huge cost, Modeling and Simulation (M & S is an effective method for performance analyses. Thus in this study, a simulation core is proposed to analyze the performance of naval ships considering their specifications. This simulation core can perform the engineering level of simulations, considering the mathematical models for naval ships, such as maneuvering equations and passive sonar equations. Also, the simulation models of the simulation core follow Discrete EVent system Specification (DEVS and Discrete Time System Specification (DTSS formalisms, so that simulations can progress over discrete events and discrete times. In addition, applying DEVS and DTSS formalisms makes the structure of simulation models flexible and reusable. To verify the applicability of this simulation core, such a simulation core was applied to simulations for the performance analyses of a submarine in an Anti-SUrface Warfare (ASUW mission. These simulations were composed of two scenarios. The first scenario of submarine diving carried out maneuvering performance analysis by analyzing the pitch angle variation and depth variation of the submarine over time. The second scenario of submarine detection carried out detection performance analysis by analyzing how well the sonar of the submarine resolves adjacent targets. The results of these simulations ensure that the simulation core of this study could be applied to the performance analyses of naval ships considering their specifications.

  18. Computer simulation of the heavy-duty turbo-compounded diesel cycle for studies of engine efficiency and performance

    Science.gov (United States)

    Assanis, D. N.; Ekchian, J. A.; Heywood, J. B.; Replogle, K. K.

    1984-01-01

    Reductions in heat loss at appropriate points in the diesel engine which result in substantially increased exhaust enthalpy were shown. The concepts for this increased enthalpy are the turbocharged, turbocompounded diesel engine cycle. A computer simulation of the heavy duty turbocharged turbo-compounded diesel engine system was undertaken. This allows the definition of the tradeoffs which are associated with the introduction of ceramic materials in various parts of the total engine system, and the study of system optimization. The basic assumptions and the mathematical relationships used in the simulation of the model engine are described.

  19. Cost effective simulation-based multiobjective optimization in the performance of an internal combustion engine

    Science.gov (United States)

    Aittokoski, Timo; Miettinen, Kaisa

    2008-07-01

    Solving real-life engineering problems can be difficult because they often have multiple conflicting objectives, the objective functions involved are highly nonlinear and they contain multiple local minima. Furthermore, function values are often produced via a time-consuming simulation process. These facts suggest the need for an automated optimization tool that is efficient (in terms of number of objective function evaluations) and capable of solving global and multiobjective optimization problems. In this article, the requirements on a general simulation-based optimization system are discussed and such a system is applied to optimize the performance of a two-stroke combustion engine. In the example of a simulation-based optimization problem, the dimensions and shape of the exhaust pipe of a two-stroke engine are altered, and values of three conflicting objective functions are optimized. These values are derived from power output characteristics of the engine. The optimization approach involves interactive multiobjective optimization and provides a convenient tool to balance between conflicting objectives and to find good solutions.

  20. Potentials of NO{sub X} emission reduction methods in SI hydrogen engines: Simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Safari, H.; Jazayeri, S.A. [Department of Mechanical Engineering, K.N. Toosi University of Technology, No.15, Pardis Street, Vanak Square, Tehran (Iran); Ebrahimi, R. [Department of Aerospace Engineering, K.N. Toosi University of Technology, 4th Tehranpars Square, East Vafadar Street, Tehran (Iran)

    2009-01-15

    The ever increasing cost of hydrocarbon fuels and more stringent emission standards may resolve challenges in producing hydrogen and using it as an alternative fuel in industries. Internal combustion engines are well-established technology and hydrogen fuel in such engines is considered as an attractive choice in exploiting clean, efficient and renewable hydrogen energy. This work presents an improved thermo-kinetics model for simulation of hydrogen combustion in SI engines. The turbulent propagating flame is modeled using turbulent burning velocity model. During combustion the charge is divided into three zones containing unburned charge, flame and burned gas. The adiabatic flame is assumed to be in thermodynamic equilibrium while the detailed chemical kinetics scheme is considered for burned and unburned zones. The results were first validated against published experiments. Good agreements were obtained between simulation and experiment for varying equivalence ratio, ignition timing and compression ratio. Detailed analysis of engine NO{sub X} emission was performed afterward. The lean-burn and EGR strategies' potentials were examined by the current model. The effects of different amounts of cooled dry EGR and hot wet EGR on the NO{sub X} emission, engine power output and indicated thermal efficiency were investigated and compared theoretically. (author)

  1. The Advanced Modeling, Simulation and Analysis Capability Roadmap Vision for Engineering

    Science.gov (United States)

    Zang, Thomas; Lieber, Mike; Norton, Charles; Fucik, Karen

    2006-01-01

    This paper summarizes a subset of the Advanced Modeling Simulation and Analysis (AMSA) Capability Roadmap that was developed for NASA in 2005. The AMSA Capability Roadmap Team was chartered to "To identify what is needed to enhance NASA's capabilities to produce leading-edge exploration and science missions by improving engineering system development, operations, and science understanding through broad application of advanced modeling, simulation and analysis techniques." The AMSA roadmap stressed the need for integration, not just within the science, engineering and operations domains themselves, but also across these domains. Here we discuss the roadmap element pertaining to integration within the engineering domain, with a particular focus on implications for future observatory missions. The AMSA products supporting the system engineering function are mission information, bounds on information quality, and system validation guidance. The Engineering roadmap element contains 5 sub-elements: (1) Large-Scale Systems Models, (2) Anomalous Behavior Models, (3) advanced Uncertainty Models, (4) Virtual Testing Models, and (5) space-based Robotics Manufacture and Servicing Models.

  2. The Design and Semi-Physical Simulation Test of Fault-Tolerant Controller for Aero Engine

    Science.gov (United States)

    Liu, Yuan; Zhang, Xin; Zhang, Tianhong

    2017-11-01

    A new fault-tolerant control method for aero engine is proposed, which can accurately diagnose the sensor fault by Kalman filter banks and reconstruct the signal by real-time on-board adaptive model combing with a simplified real-time model and an improved Kalman filter. In order to verify the feasibility of the method proposed, a semi-physical simulation experiment has been carried out. Besides the real I/O interfaces, controller hardware and the virtual plant model, semi-physical simulation system also contains real fuel system. Compared with the hardware-in-the-loop (HIL) simulation, semi-physical simulation system has a higher degree of confidence. In order to meet the needs of semi-physical simulation, a rapid prototyping controller with fault-tolerant control ability based on NI CompactRIO platform is designed and verified on the semi-physical simulation test platform. The result shows that the controller can realize the aero engine control safely and reliably with little influence on controller performance in the event of fault on sensor.

  3. Molecular Cloning Designer Simulator (MCDS): All-in-one molecular cloning and genetic engineering design, simulation and management software for complex synthetic biology and metabolic engineering projects.

    Science.gov (United States)

    Shi, Zhenyu; Vickers, Claudia E

    2016-12-01

    Molecular Cloning Designer Simulator (MCDS) is a powerful new all-in-one cloning and genetic engineering design, simulation and management software platform developed for complex synthetic biology and metabolic engineering projects. In addition to standard functions, it has a number of features that are either unique, or are not found in combination in any one software package: (1) it has a novel interactive flow-chart user interface for complex multi-step processes, allowing an integrated overview of the whole project; (2) it can perform a user-defined workflow of cloning steps in a single execution of the software; (3) it can handle multiple types of genetic recombineering, a technique that is rapidly replacing classical cloning for many applications; (4) it includes experimental information to conveniently guide wet lab work; and (5) it can store results and comments to allow the tracking and management of the whole project in one platform. MCDS is freely available from https://mcds.codeplex.com.

  4. Modelling and Fixed Step Simulation of a Turbo Charged Diesel Engine

    OpenAIRE

    Ritzén, Jesper

    2003-01-01

    Having an engine model that is accurate but not too complicated is desirable when working with on-board diagnosis or engine control. In this thesis a four state mean value model is introduced. To make the model usable in an on-line automotive application it is discrete and simulated with a fixed step size solver. Modelling is done with simplicity as main object. Some simple static models are also presented. To validate the model measuring is carried out in a Scania R124LB truck with a 12 lit...

  5. Use of neural networks in process engineering. Thermodynamics, diffusion, and process control and simulation applications

    International Nuclear Information System (INIS)

    Otero, F

    1998-01-01

    This article presents the current status of the use of Artificial Neural Networks (ANNs) in process engineering applications where common mathematical methods do not completely represent the behavior shown by experimental observations, results, and plant operating data. Three examples of the use of ANNs in typical process engineering applications such as prediction of activity in solvent-polymer binary systems, prediction of a surfactant self-diffusion coefficient of micellar systems, and process control and simulation are shown. These examples are important for polymerization applications, enhanced-oil recovery, and automatic process control

  6. Engineering and erection of a 300kW high-flux solar simulator

    Science.gov (United States)

    Wieghardt, Kai; Laaber, Dmitrij; Hilger, Patrick; Dohmen, Volkmar; Funken, Karl-Heinz; Hoffschmidt, Bernhard

    2017-06-01

    German Aerospace Center (DLR) is currently constructing a new high-flux solar simulator synlight which shall be commissioned in late 2016. The new facility will provide three separately operated experimental spaces with expected radiant powers of about 300kW / 240kW / 240kW respectively. synlight was presented to the public for the first time at SolarPACES 2015 [1]. Its engineering and erection is running according to plan. The current presentation reports about the engineering and the ongoing erection of the novel facility, and gives an outlook on its new level of possibilities for solar testing and qualification.

  7. Modeling and dynamic control simulation of unitary gas engine heat pump

    International Nuclear Information System (INIS)

    Zhao Yang; Haibo Zhao; Zheng Fang

    2007-01-01

    Based on the dynamic model of the gas engine heat pump (GEHP) system, an intelligent control simulation is presented to research the dynamic characteristics of the system in the heating operation. The GEHP system simulation model consists of eight models for its components including a natural gas engine, a compressor, a condenser, an expansion valve, an evaporator, a cylinder jacket heat exchanger, an exhaust gas heat exchanger and an auxiliary heater. The intelligent control model is composed of the prediction controller model and the combined controller model. The Runge-Kutta Fehlberg fourth-fifth order algorithms are used to solve the differential equations. The results show that the model is very effective in analyzing the effects of the control system, and the steady state accuracy of the intelligent control scheme is higher than that of the fuzzy controller

  8. Discrete Event Modeling and Simulation-Driven Engineering for the ATLAS Data Acquisition Network

    CERN Document Server

    Bonaventura, Matias Alejandro; The ATLAS collaboration; Castro, Rodrigo Daniel

    2016-01-01

    We present an iterative and incremental development methodology for simulation models in network engineering projects. Driven by the DEVS (Discrete Event Systems Specification) formal framework for modeling and simulation we assist network design, test, analysis and optimization processes. A practical application of the methodology is presented for a case study in the ATLAS particle physics detector, the largest scientific experiment built by man where scientists around the globe search for answers about the origins of the universe. The ATLAS data network convey real-time information produced by physics detectors as beams of particles collide. The produced sub-atomic evidences must be filtered and recorded for further offline scrutiny. Due to the criticality of the transported data, networks and applications undergo careful engineering processes with stringent quality of service requirements. A tight project schedule imposes time pressure on design decisions, while rapid technology evolution widens the palett...

  9. Radiation dose assessment in nuclear plants through virtual simulations using a game engine

    International Nuclear Information System (INIS)

    Jorge, Carlos A.F.; Mol, Antonio C. A.; Aghina, Mauricio Alves C.

    2008-01-01

    Full text: This paper reports an R and D which has the purpose of performing dose assessment of workers in nuclear plants, through virtual simulations using a game engine. The main objective of this R and D is to support the planning of operational and maintenance routines in nuclear plants, aiming to reduce the dose received by workers. Game engine is the core of a computer game, that is usually made independent of both the scenarios and the original applications, and thus can be adapted for any other purposes, including scientific or technological ones. Computer games have experienced a great development in the last years, regarding computer graphics, 3D image rendering and the representation of the physics needed for the virtual simulations, such as gravity effect and collision among virtual components within the games. Thus, researchers do not need to develop an entire platform for virtual simulations, what would be a hard work itself, but they can rather take advantage of such well developed platforms, adapting them for their own applications. The game engine used in this R and D is part of a computer game widely used, Unreal, that has its source code partially open, and can be pursued for low cost. A nuclear plant in our Institution, Argonauta research reactor, has been virtually modeled in 3D, and trainees can navigate virtually through it, with realistic walking velocity, and experiencing collision. The modified game engine computes and displays in real-time the dose received by a virtual person, the avatar, as it walks through the plant, from the radiation dose rate distribution assigned to the virtual environment. In the beginning of this R and D, radiation dose rate measurements were previously collected by the radiological protection service, and input off-line to the game engine. Currently, on-line measurements can be also input to it, by taking advantage of the game's networking capabilities. A real radiation monitor has been used to collect real

  10. Numerical simulation of the flow field and fuel sprays in an IC engine

    Science.gov (United States)

    Nguyen, H. L.; Schock, H. J.; Ramos, J. I.; Carpenter, M. H.; Stegeman, J. D.

    1987-01-01

    A two-dimensional model for axisymmetric piston-cylinder configurations is developed to study the flow field in two-stroke direct-injection Diesel engines under motored conditions. The model accounts for turbulence by a two-equation model for the turbulence kinetic energy and its rate of dissipation. A discrete droplet model is used to simulate the fuel spray, and the effects of the gas phase turbulence on the droplets is considered. It is shown that a fluctuating velocity can be added to the mean droplet velocity every time step if the step is small enough. Good agreement with experimental data is found for a range of ambient pressures in Diesel engine-type microenvironments. The effects of the intake swirl angle in the spray penetration, vaporization, and mixing in a uniflow-scavenged two-stroke Diesel engine are analyzed. It is found that the swirl increases the gas phase turbulence levels and the rates of vaporization.

  11. Modeling and Simulation of Truck Engine Cooling System for Onboard Diagnosis

    Institute of Scientific and Technical Information of China (English)

    朱正礼; 张建武; 包继华

    2004-01-01

    A cooling system model of a selected internal combustion engine has been built for onboard diagnosis. The model uses driving cycle data available within the production Engine Control Module (ECM): vehicle speed, engine speed, and fuel flow rate for the given ambient temperature and pressure, etc. Based on the conservation laws for heat transfer and mass flow process, the mathematical descriptions for the components involved in the cooling circuit are obtained and all the components are integrated into a model on Matlab/Simulink platform. The model can simulate the characteristics of thermostat (e.g. time-lag, hysteresis effect).The changes of coolant temperature, heat transfer flow rate, and pressure at individual component site are also shown.

  12. Engineering design of plasma generation devices using Elmer finite element simulation methods

    Directory of Open Access Journals (Sweden)

    Daniel Bondarenko

    2017-02-01

    Full Text Available Plasma generation devices are important technology for many engineering disciplines. The process for acquiring experience for designing plasma devices requires practice, time, and the right tools. The practice and time depend on the individual and the access to the right tools can be a limiting factor to achieve experience and to get an idea on the possible risks. The use of Elmer finite element method (FEM software for verifying plasma engineering design is presented as an accessible tool that can help modeling multi-physics and verifying plasma generation devices. Furthermore, Elmer FEM will be suitable for experienced engineer and can be used for determining the risks in a design or a process that use plasma. A physical experiment was conducted to demonstrate new features of plasma generation technology where results are compared with plasma simulation using Elmer FEM.

  13. Engineering the future of military tactical vehicles and systems with modeling and simulation

    Science.gov (United States)

    Loew, Matthew; Watters, Brock

    2005-05-01

    Stewart & Stevenson has developed a Modeling and Simulation approach based on Systems Engineering principles for the development of future military vehicles and systems. This approach starts with a requirements analysis phase that captures and distills the design requirements into a list of parameterized values. A series of executable engineering models are constructed to allow the requirements to be transformed into systems with definable architectures with increasing levels of fidelity. Required performance parameters are available for importation into a variety of modeling and simulation tools including PTC Pro/ENGINEER (for initial engineering models, mechanisms, packaging, and detailed 3-Dimensional solid models), LMS International Virtual.Lab Motion (for vehicle dynamics and ride analysis) and AVL Cruise (Powertrain simulations). Structural analysis and optimization (performed in ANSYS, Pro/MECHANICA, and Altair OptiStruct) is based on the initial geometry from Pro/ENGINEER. Spreadsheets are used for requirements analysis, design documentation and first-order studies. Collectively, these models serve as templates for all design activities. Design variables initially studied within a simplified system model can be cascaded down as the new requirements for a sub-system model. By utilizing this approach premature decisions on systems architectures can be avoided. Ultimately, the systems that are developed are optimally able to meet the requirements by utilizing this top-down approach. Additionally, this M&S approach is seen as a life-cycle tool useful in initially assisting with project management activities through the initial and detail design phases and serves as a template for testing and validation/verification activities. Furthermore, because of the multi-tiered approach, there is natural re-use possible with the models as well.

  14. Simulation research on operation scheme of dissymmetrical main engine of CODOG propulsion system

    Directory of Open Access Journals (Sweden)

    HUANG Bin

    2018-02-01

    Full Text Available [Objectives] How to maintain propulsion capability in a CODOG propulsion system damage situation has important significance. [Methods] A ‘Hull-Engine-CPP-Rudder’ simulation model of a CODOG marine power plant is established on Simulink using the modularized method, and a dissymmetrical main engine urgent working mode is proposed and simulated. [Results] The results show that in the dissymmetrical working mode, two different engines cannot work simultaneously at designed capacity. However, by adjusting the pitch of the CPP, one engine can work at designed capacity and the other can work at partial load capacity; under this working mode, if high speed is demanded, the gas turbine should work at designed capacity. The CPP pitch driven by diesel should be maintained at a high value near the maximum. The maximum speed of this working mode is 84.4% of the designed speed, which is higher than the speed of the single shaft working mode driven by a gas turbine. [Conclusions] The research results of this paper can provide useful references for the design of ship propulsion systems.

  15. Numerical simulations on increasing turbojet engines exhaust mixture ratio using fluidic chevrons

    Directory of Open Access Journals (Sweden)

    Adrian GRUZEA

    2017-06-01

    Full Text Available This paper refers to some aspects regarding the terms “chevron” and “fluidic chevron” and to the process of increasing the jet engines exhaust mixing rate towards achieving noise reduction. One of the noise reduction methods consists in covering the high velocity main flow with a secondary one, having a much lower velocity, similar to the turbofan engines. The fluidic chevrons try to accomplish these requirements, being used just in particular moments of the flight. This study will be based on numerical simulations carried using the commercial software ANSYS. The geometry used will the based on the micro jet engine JetCat P80, equipping the turbines laboratory from the Faculty of Aerospace Engineering. A research based on the measured geometric, gasodynamic and cinematic parameters will be carried varying the mass flow and keeping the immersion angle constant. As a result of these simulations we’ll observe the influence of the mentioned parameters on the jet’s flow field.

  16. CFD transient simulation of an isolator shock train in a scramjet engine

    Science.gov (United States)

    Hoeger, Troy Christopher

    For hypersonic flight, the scramjet engine uses an isolator to contain the pre-combustion shock train formed by the pressure difference between the inlet and the combustion chamber. If this shock train were to reach the inlet, it would cause an engine unstart, disrupting the flow through the engine and leading to a loss of thrust and potential loss of the vehicle. Prior to this work, a Computational Fluid Dynamics (CFD) simulation of the isolator was needed for simulating and characterizing the isolator flow and for finding the relationship between back pressure and changes in the location of the leading edge of the shock train. In this work, the VULCAN code was employed with back pressure as an input to obtain the time history of the shock train leading location. Results were obtained for both transient and steady-state conditions. The simulation showed a relationship between back-to-inlet pressure ratios and final locations of the shock train. For the 2-D runs, locations were within one isolator duct height of experimental results while for 3-D runs, the results were within two isolator duct heights.

  17. Large Eddy Simulations of Two-phase Turbulent Reactive Flows in IC Engines

    Science.gov (United States)

    Banaeizadeh, Araz; Schock, Harold; Jaberi, Farhad

    2008-11-01

    The two-phase filtered mass density function (FMDF) subgrid-scale (SGS) model is used for large-eddy simulation (LES) of turbulent spray combustion in internal combustion (IC) engines. The LES/FMDF is implemented via an efficient, hybrid numerical method. In this method, the filtered compressible Navier-Stokes equations in curvilinear coordinate systems are solved with a generalized, high-order, multi-block, compact differencing scheme. The spray and the FMDF are implemented with Lagrangian methods. The reliability and the consistency of the numerical methods are established for different IC engines and the complex interactions among mean and turbulent velocity fields, fuel droplets and combustion are shown to be well captured with the LES/FMDF. In both spark-ignition/direct-injection and diesel engines, the droplet size and velocity distributions are found to be modified by the unsteady, vortical motions generated by the incoming air during the intake stroke. In turn, the droplets are found to change the in-cylinder flow structure. In the spark-ignition engine, flame propagation is similar to the experiment. In the diesel engine, the maximum evaporated fuel concentration is near the cylinder wall where the flame starts, which is again consistent with the experiment.

  18. Solar parabolic dish Stirling engine system design, simulation, and thermal analysis

    International Nuclear Information System (INIS)

    Hafez, A.Z.; Soliman, Ahmed; El-Metwally, K.A.; Ismail, I.M.

    2016-01-01

    Highlights: • Modeling and simulation for different parabolic dish Stirling engine designs using Matlab®. • The effect of solar dish design features and factors had been taken. • Estimation of output power from the solar dish using Matlab®. • The present analysis provides a theoretical guidance for designing and operating solar parabolic dish system. - Abstract: Modeling and simulation for different parabolic dish Stirling engine designs have been carried out using Matlab®. The effect of solar dish design features and factors such as material of the reflector concentrators, the shape of the reflector concentrators and the receiver, solar radiation at the concentrator, diameter of the parabolic dish concentrator, sizing the aperture area of concentrator, focal Length of the parabolic dish, the focal point diameter, sizing the aperture area of receiver, geometric concentration ratio, and rim angle have been studied. The study provides a theoretical guidance for designing and operating solar parabolic dish Stirling engines system. At Zewail city of Science and Technology, Egypt, for a 10 kW Stirling engine; The maximum solar dish Stirling engine output power estimation is 9707 W at 12:00 PM where the maximum beam solar radiation applied in solar dish concentrator is 990 W/m"2 at 12:00 PM. The performance of engine can be improved by increasing the precision of the engine parts and the heat source efficiency. The engine performance could be further increased if a better receiver working fluid is used. We can conclude that where the best time for heating the fluid and fasting the processing, the time required to heat the receiver to reach the minimum temperature for operating the Solar-powered Stirling engine for different heat transfer fluids; this will lead to more economic solar dish systems. Power output of the solar dish system is one of the most important targets in the design that show effectiveness of the system, and this has achieved when we take

  19. Thermal performance of a Stirling engine powered by a solar simulator

    International Nuclear Information System (INIS)

    Aksoy, Fatih; Karabulut, Halit; Çınar, Can; Solmaz, Hamit; Özgören, Yasar Önder; Uyumaz, Ahmet

    2015-01-01

    In this study, the performance of a beta type Stirling engine which works at relatively lower temperatures was investigated using 400 W and 1000 W halogen lamps as a heat source and helium as the working fluid. The working fluid was charged into the engine block and the pressure of the working fluid was ranged from 1 to 5 bars with 1 bar increments. The halogen lamps were placed into a cavity adjacent to the hot end of the displacer cylinder, which is made of aluminum alloy. In the experiments conducted with 400 W halogen lamp, the temperature of the cavity was 623 ± 10 K. The power, torque and thermal efficiency of the engine were determined to be 37.08 W, 1.68 Nm and 9.27%, at 5 bar charge pressure. For the 1000 W halogen lamp, the temperature of the cavity was determined to be 873 ± 10 K. The power, torque and thermal efficiency of the engine were determined to be 127.17 W, 3.4 Nm and 12.85%, at the same charge pressure. The experimental thermal efficiencies of the engine were also compared with thermodynamic nodal analysis. - Highlights: • The performance of a beta type Stirling engine was investigated. • 400 and 1000 W halogen lamps were used as a solar simulator in the experiments. • Cavity temperature was measured 623 and 873 K for 400 and 1000 W lamps. • 1000 W halogen lamp provided better engine performance and thermal efficiency. • Experimental results of efficiency were compared with nodal analysis results

  20. Combustion of simulated biogas in a dual-fuel diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Henham, A.; Makkar, M.K. [University of Surrey, Guildford (United Kingdom). School of Mechanical and Materials Engineering

    1998-12-31

    Technology related to biogas has been steadily developed over the last 50 years from small individually designed units to larger production plants. The development, however, has largely taken place on the side of biogas production and anaerobic waste treatment. Utilization of the gas produced by these methods has only recently been the subject of more scientific evaluation. The transformation of energy through biogas into the thermodynamically higher valued mechanical energy successfully and economically is now the most important research area in this field. Of the engine work already published, most concerns spark-ignited engines. The authors` research work concerns the use of biogas in dual-fuel diesel engines. It examines engine performance using simulated biogas of varying quality representing the range of methane:carbon dioxide composition which may be encountered in gas from different sources. The total programme includes the effects of biogas quality and of the proportion of energy from pilot fuel injection over a range of speeds and loads, investigations into the performance parameters over a range of compositions of gaseous mixture. A two-cylinder, indirect-injection diesel engine of stationary type is being used as the first experimental test bed in this work and the variation of quality is provided by mixing natural gas and carbon dioxide. A data acquisition system for an in-cylinder pressure and crank angle is being used successfully and some emissions measurements are also available, particularly for CO and O{sub 2}. The nature of combustion process in the dual-fuel engine is examined through pressure-crank angle data and studies of characteristics affecting engine efficiency. (author)

  1. Non-infectious plasmid engineered to simulate multiple viral threat agents.

    Science.gov (United States)

    Carrera, Monica; Sagripanti, Jose-Luis

    2009-07-01

    The aim of this study was to design and construct a non-virulent simulant to replace several pathogenic viruses in the development of detection and identification methods in biodefense. A non-infectious simulant was designed and engineered to include the nucleic acid signature of VEEV (Venezuelan Equine Encephalitis virus), Influenza virus, Rift Valley Fever virus, Machupo virus, Lassa virus, Yellow Fever virus, Ebola virus, Eastern Equine Encephalitis virus, Junin virus, Marburg virus, Dengue virus, and Crimean-Congo virus, all in a single construct. The nucleic acid sequences of all isolates available for each virus species were aligned using ClustalW software in order to obtain conserved regions of the viral genomes. Specific primers were designed to permit the identification and differentiation between viral threat agents. A chimera of 3143 base pairs was engineered to produce 13 PCR amplicons of different sizes. PCR amplification of the simulant with virus-specific primers revealed products of the predicted length, in bands of similar intensity, and without detectable unspecific products by electrophoresis analysis. The simulant described could reduce the need to use infectious viruses in the development of detection and diagnostic methods, and could also be useful as a non-virulent positive control in nucleic acid-based tests against biological threat agents.

  2. Extending the Operational Envelope of a Turbofan Engine Simulation into the Sub-Idle Region

    Science.gov (United States)

    Chapman, Jeffryes Walter; Hamley, Andrew J.; Guo, Ten-Huei; Litt, Jonathan S.

    2016-01-01

    In many non-linear gas turbine simulations, operation in the sub-idle region can lead to model instability. This paper lays out a method for extending the operational envelope of a map based gas turbine simulation to include the sub-idle region. This method develops a multi-simulation solution where the baseline component maps are extrapolated below the idle level and an alternate model is developed to serve as a safety net when the baseline model becomes unstable or unreliable. Sub-idle model development takes place in two distinct operational areas, windmilling/shutdown and purge/cranking/startup. These models are based on derived steady state operating points with transient values extrapolated between initial (known) and final (assumed) states. Model transitioning logic is developed to predict baseline model sub-idle instability, and transition smoothly and stably to the backup sub-idle model. Results from the simulation show a realistic approximation of sub-idle behavior as compared to generic sub-idle engine performance that allows the engine to operate continuously and stably from shutdown to full power.

  3. Implementation of Simulation Based-Concept Attainment Method to Increase Interest Learning of Engineering Mechanics Topic

    Science.gov (United States)

    Sultan, A. Z.; Hamzah, N.; Rusdi, M.

    2018-01-01

    The implementation of concept attainment method based on simulation was used to increase student’s interest in the subjects Engineering of Mechanics in second semester of academic year 2016/2017 in Manufacturing Engineering Program, Department of Mechanical PNUP. The result of the implementation of this learning method shows that there is an increase in the students’ learning interest towards the lecture material which is summarized in the form of interactive simulation CDs and teaching materials in the form of printed books and electronic books. From the implementation of achievement method of this simulation based concept, it is noted that the increase of student participation in the presentation and discussion as well as the deposit of individual assignment of significant student. With the implementation of this method of learning the average student participation reached 89%, which before the application of this learning method only reaches an average of 76%. And also with previous learning method, for exam achievement of A-grade under 5% and D-grade above 8%. After the implementation of the new learning method (simulation based-concept attainment method) the achievement of Agrade has reached more than 30% and D-grade below 1%.

  4. A comparative study on real lab and simulation lab in communication engineering from students' perspectives

    Science.gov (United States)

    Balakrishnan, B.; Woods, P. C.

    2013-05-01

    Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised concerns among educators on the merits and shortcomings of both physical and simulation labs; at the same time, many arguments have been raised on the differences of both labs. Investigating the effectiveness of both labs is complicated, as there are multiple factors that should be considered. In view of this challenge, a study on students' perspectives on their experience related to key aspects on engineering laboratory exercise was conducted. In this study, the Visual Auditory Read and Kinetic model was utilised to measure the students' cognitive styles. The investigation was done through a survey among participants from Multimedia University, Malaysia. The findings revealed that there are significant differences for most of the aspects in physical and simulation labs.

  5. Large eddy simulation of air pollution produced by aircraft engine emissions inside the airport

    Energy Technology Data Exchange (ETDEWEB)

    Synylo, Kateryna [National Aviation University (Ukraine)], email: synylo@nau.edu.ua

    2011-07-01

    With the increase of air traffic movement, air pollution from airport emissions has become an important concern. In the past, various research has been undertaken on the impact of aircraft engines on the upper troposphere and lower stratosphere, however the impact that emissions have on airports themselves is not taken into account by the most frequently used monitoring software programs. The aim of this paper is to present the use of a CFD simulation to determine the dynamic and fluid mechanics characteristics of aircraft emissions near the ground. The CFD simulation was carried out using Fluent 6.3 software and the effects of counter-rotating vortices and wind conditions on fulfilled gases jet. It was found that numerical simulation is able to resolve difficult equations and provide realistic results. This study demonstrated that the use of CFD computation could be used to improve local air quality modeling and assessment of the impact of aircraft emissions at airports.

  6. Comparison of Numerically Simulated and Experimentally Measured Performance of a Rotating Detonation Engine

    Science.gov (United States)

    Paxson, Daniel E.; Fotia, Matthew L.; Hoke, John; Schauer, Fred

    2015-01-01

    A quasi-two-dimensional, computational fluid dynamic (CFD) simulation of a rotating detonation engine (RDE) is described. The simulation operates in the detonation frame of reference and utilizes a relatively coarse grid such that only the essential primary flow field structure is captured. This construction and other simplifications yield rapidly converging, steady solutions. Viscous effects, and heat transfer effects are modeled using source terms. The effects of potential inlet flow reversals are modeled using boundary conditions. Results from the simulation are compared to measured data from an experimental RDE rig with a converging-diverging nozzle added. The comparison is favorable for the two operating points examined. The utility of the code as a performance optimization tool and a diagnostic tool are discussed.

  7. Applying Open Source Game Engine for Building Visual Simulation Training System of Fire Fighting

    Science.gov (United States)

    Yuan, Diping; Jin, Xuesheng; Zhang, Jin; Han, Dong

    There's a growing need for fire departments to adopt a safe and fair method of training to ensure that the firefighting commander is in a position to manage a fire incident. Visual simulation training systems, with their ability to replicate and interact with virtual fire scenarios through the use of computer graphics or VR, become an effective and efficient method for fire ground education. This paper describes the system architecture and functions of a visual simulated training system of fire fighting on oil storage, which adopting Delat3D, a open source game and simulation engine, to provide realistic 3D views. It presents that using open source technology provides not only the commercial-level 3D effects but also a great reduction of cost.

  8. Development of an engineering simulator for integral type PWR for nuclear ship

    International Nuclear Information System (INIS)

    Takahashi, Teruo; Shimazaki, Junya; Nakazawa, Toshio

    2000-01-01

    JAERI has developed a real-time engineering simulator for the integral type reactor MRX (Marine Reactor X) of power 100 MWt to evaluate the design and operational performance and to study highly automatic operations of a reactor plant. Marine reactor is operated under the conditions of pitching and rolling and load change, in comparison with a reactor for a land-based generating plant. And the MRX has systems with structural features, such as water-filled containment vessel, once-through type steam generator and emergency decay heat removal system. Considerations are paid to take these operational conditions and structural features into the simulation model. It is shown that the simulated results are consistent with the planned design and operational performance, and on the other hand present us some technical issues to be investigated in the design specifications. (author)

  9. Growing tissues in real and simulated microgravity: new methods for tissue engineering.

    Science.gov (United States)

    Grimm, Daniela; Wehland, Markus; Pietsch, Jessica; Aleshcheva, Ganna; Wise, Petra; van Loon, Jack; Ulbrich, Claudia; Magnusson, Nils E; Infanger, Manfred; Bauer, Johann

    2014-12-01

    Tissue engineering in simulated (s-) and real microgravity (r-μg) is currently a topic in Space medicine contributing to biomedical sciences and their applications on Earth. The principal aim of this review is to highlight the advances and accomplishments in the field of tissue engineering that could be achieved by culturing cells in Space or by devices created to simulate microgravity on Earth. Understanding the biology of three-dimensional (3D) multicellular structures is very important for a more complete appreciation of in vivo tissue function and advancing in vitro tissue engineering efforts. Various cells exposed to r-μg in Space or to s-μg created by a random positioning machine, a 2D-clinostat, or a rotating wall vessel bioreactor grew in the form of 3D tissues. Hence, these methods represent a new strategy for tissue engineering of a variety of tissues, such as regenerated cartilage, artificial vessel constructs, and other organ tissues as well as multicellular cancer spheroids. These aggregates are used to study molecular mechanisms involved in angiogenesis, cancer development, and biology and for pharmacological testing of, for example, chemotherapeutic drugs or inhibitors of neoangiogenesis. Moreover, they are useful for studying multicellular responses in toxicology and radiation biology, or for performing coculture experiments. The future will show whether these tissue-engineered constructs can be used for medical transplantations. Unveiling the mechanisms of microgravity-dependent molecular and cellular changes is an up-to-date requirement for improving Space medicine and developing new treatment strategies that can be translated to in vivo models while reducing the use of laboratory animals.

  10. Analysis of DOE s Roof Savings Calculator with Comparison to other Simulation Engines

    Energy Technology Data Exchange (ETDEWEB)

    New, Joshua Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huang, Yu [White Box Technologies, Salt Lake City, UT (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mellot, Joe [The Garland Company, Cleveland, OH (United States); Sanyal, Jibonananda [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Kenneth W [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    A web-based Roof Savings Calculator (RSC) has been deployed for the Department of Energy as an industry-consensus tool to help building owners, manufacturers, distributors, contractors and researchers easily run complex roof and attic simulations. This tool employs the latest web technologies and usability design to provide an easy input interface to an annual simulation of hour-by-hour, whole-building performance using the world-class simulation tools DOE-2.1E and AtticSim. Building defaults were assigned based on national averages and can provide estimated annual energy and cost savings after the user selects nothing more than building location. In addition to cool reflective roofs, the RSC tool can simulate multiple roof and attic configurations including different roof slopes, above sheathing ventilation, radiant barriers, low-emittance surfaces, HVAC duct location, duct leakage rates, multiple layers of building materials, ceiling and deck insulation levels, and other parameters. A base case and energy-efficient alternative can be compared side-by-side to generate an energy/cost savings estimate between two buildings. The RSC tool was benchmarked against field data for demonstration homes in Ft. Irwin, CA. However, RSC gives different energy savings estimates than previous cool roof simulation tools so more thorough software and empirical validation proved necessary. This report consolidates much of the preliminary analysis for comparison of RSC s projected energy savings to that from other simulation engines.

  11. Virtual suturing simulation based on commodity physics engine for medical learning.

    Science.gov (United States)

    Choi, Kup-Sze; Chan, Sze-Ho; Pang, Wai-Man

    2012-06-01

    Development of virtual-reality medical applications is usually a complicated and labour intensive task. This paper explores the feasibility of using commodity physics engine to develop a suturing simulator prototype for manual skills training in the fields of nursing and medicine, so as to enjoy the benefits of rapid development and hardware-accelerated computation. In the prototype, spring-connected boxes of finite dimension are used to simulate soft tissues, whereas needle and thread are modelled with chained segments. Spherical joints are used to simulate suture's flexibility and to facilitate thread cutting. An algorithm is developed to simulate needle insertion and thread advancement through the tissue. Two-handed manipulations and force feedback are enabled with two haptic devices. Experiments on the closure of a wound show that the prototype is able to simulate suturing procedures at interactive rates. The simulator is also used to study a curvature-adaptive suture modelling technique. Issues and limitations of the proposed approach and future development are discussed.

  12. Modeling and Simulation of a Free-Piston Engine with Electrical Generator Using HCCI Combustion

    Science.gov (United States)

    Alrbai, Mohammad

    Free-piston engines have the potential to challenge the conventional crankshaft engines by their design simplicity and higher operational efficiency. Many studies have been performed to overcome the limitations of the free-piston devices especially the stability and control issues. The investigations within the presented dissertation aim to satisfy many objectives by employing the approach of chemical kinetics to present the combustion process in the free-piston engine. This approach in addition to its advanced accuracy over the empirical methods, it has many other features like the ability to analyze the engine emissions. The effect of the heat release rate (HRR) on the engine performance is considered as the main objective. Understanding the relation between the HRR and the piston dynamics helps in enhancing the system efficiency and identifying the parameters that affect the overall performance. The dissertation covers some other objectives that belongs to the combustion phasing. Exhaust gas recirculation (EGR), equivalence ratio and the intake temperature represent the main combustion parameters, which have been discussed in this dissertation. To obtain the stability in system performance, the model requires a proper controller to simulate the operation and manage the different system parameters; for this purpose, different controlling techniques have been employed. In addition, the dissertation considers some other topics like engine emissions, fuels and fuels mechanisms. The model of the study describes the processes within a single cylinder, two stroke engine, which includes springs to support higher frequencies, reduce cyclic variations and sustain the engine compression ratio. An electrical generator presents the engine load; the generator supports different load profiles and play the key role in controlling the system. The 1st law of thermodynamics and Newton's 2nd law are applied to couple the piston dynamics with the engine thermodynamics. The model

  13. THREE-DIMENSIONAL SIMULATIONS OF LONG DURATION GAMMA-RAY BURST JETS: TIMESCALES FROM VARIABLE ENGINES

    Energy Technology Data Exchange (ETDEWEB)

    López-Cámara, D. [CONACYT—Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 70-264, Cd. Universitaria, México DF 04510, México (Mexico); Lazzati, Davide [Department of Physics, Oregon State University, 301 Weniger Hall, Corvallis, OR 97331 (United States); Morsony, Brian J., E-mail: diego@astro.unam.mx [Department of Astronomy, University of Maryland, 4296 Stadium Drive, College Park, MD 20742-2421 (United States)

    2016-08-01

    Gamma-ray burst (GRB) light curves are characterized by marked variability, each showing unique properties. The origin of this variability, at least for a fraction of long GRBs, may be the result of an unsteady central engine. It is thus important to study the effects that an episodic central engine has on the jet propagation and, eventually, on the prompt emission within the collapsar scenario. Thus, in this study we follow the interaction of pulsed outflows with their progenitor stars with hydrodynamic numerical simulations in both two and three dimensions. We show that the propagation of unsteady jets is affected by the interaction with the progenitor material well after the break-out time, especially for jets with long quiescent times comparable to or larger than a second. We also show that this interaction can lead to an asymmetric behavior in which pulse durations and quiescent periods are systematically different. After the pulsed jets drill through the progenitor and the interstellar medium, we find that, on average, the quiescent epochs last longer than the pulses (even in simulations with symmetrical active and quiescent engine times). This could explain the asymmetry detected in the light curves of long quiescent time GRBs.

  14. Analysis and simulation on two types of thrust reversers in an aircraft engine

    Directory of Open Access Journals (Sweden)

    Tian Feng

    2017-01-01

    Full Text Available With rapid development of new composite material and manufacturing, innovative engineering solutions are supplied to the advanced nacelle, such as integrated propulsion system(IPS, carbon-fiber composite inner skin by single-piece molding process,which offers a reduction in fuel burn and less noise produced by engines. The advanced nacelle has an O-duct thrust reverser demonstrator whose composite structure is in the form of an “O” as opposed to the traditional “D-duct”. A comparative study is to be conducted to investigate the differences between the latest O-duct and conventional D-duct in numerical approaches. To focus on the quantitative analysis of thrust reverser’s operation, this paper mainly uses CATIA/Digital Mock Up(DMU to simulate under deployment and stowed conditions of two different thrust reverser. After comparing the structural weight, the design models of blocker door are built for kinematic analysis of relevant mechanism and simulation. The results show that simplified design and elimination of multiple interfaces generates weight saving, O-duct improves airflows within the engine, meanwhile D-duct has excellent cost effective and maintainability.

  15. Development of a simulation model for compression ignition engine running with ignition improved blend

    Directory of Open Access Journals (Sweden)

    Sudeshkumar Ponnusamy Moranahalli

    2011-01-01

    Full Text Available Department of Automobile Engineering, Anna University, Chennai, India. The present work describes the thermodynamic and heat transfer models used in a computer program which simulates the diesel fuel and ignition improver blend to predict the combustion and emission characteristics of a direct injection compression ignition engine fuelled with ignition improver blend using classical two zone approach. One zone consists of pure air called non burning zone and other zone consist of fuel and combustion products called burning zone. First law of thermodynamics and state equations are applied in each of the two zones to yield cylinder temperatures and cylinder pressure histories. Using the two zone combustion model the combustion parameters and the chemical equilibrium composition were determined. To validate the model an experimental investigation has been conducted on a single cylinder direct injection diesel engine fuelled with 12% by volume of 2- ethoxy ethanol blend with diesel fuel. Addition of ignition improver blend to diesel fuel decreases the exhaust smoke and increases the thermal efficiency for the power outputs. It was observed that there is a good agreement between simulated and experimental results and the proposed model requires low computational time for a complete run.

  16. Jet Engine Bird Ingestion Simulations: Comparison of Rotating to Non-Rotating Fan Blades

    Science.gov (United States)

    Howard, Samuel A.; Hammer, Jeremiah T.; Carney, Kelly S.; Pereira, J. Michael

    2013-01-01

    Bird strike events in commercial airliners are a fairly common occurrence. According to data collected by the US Department of Agriculture, over 80,000 bird strikes were reported in the period 1990 to 2007 in the US alone (Ref. 1). As a result, bird ingestion is an important factor in aero engine design and FAA certification. When it comes to bird impacts on engine fan blades, the FAA requires full-scale bird ingestion tests on an engine running at full speed to pass certification requirements. These rotating tests are complex and very expensive. To reduce development costs associated with new materials for fan blades, it is desirable to develop more cost effective testing procedures than full-scale rotating engine tests for material evaluation. An impact test on a nonrotating single blade that captures most of the salient physics of the rotating test would go a long way towards enabling large numbers of evaluative material screening tests. NASA Glenn Research Center has been working to identify a static blade test procedure that would be effective at reproducing similar results as seen in rotating tests. The current effort compares analytical simulations of a bird strike on various non-rotating blades to a bird strike simulation on a rotating blade as a baseline case. Several different concepts for simulating the rotating loads on a non-rotating blade were analyzed with little success in duplicating the deformation results seen in the rotating case. The rotating blade behaves as if it were stiffer than the non-rotating blade resulting in less plastic deformation from a given bird impact. The key factor limiting the success of the non-rotating blade simulations is thought to be the effect of gyroscopics. Prior to this effort, it was anticipated the difficulty would be in matching the prestress in the blade due to centrifugal forces Additional work is needed to verify this assertion, and to determine if a static test procedure can simulate the gyroscopic effects in

  17. Using Decision Trees to Detect and Isolate Simulated Leaks in the J-2X Rocket Engine

    Science.gov (United States)

    Schwabacher, Mark A.; Aguilar, Robert; Figueroa, Fernando F.

    2009-01-01

    The goal of this work was to use data-driven methods to automatically detect and isolate faults in the J-2X rocket engine. It was decided to use decision trees, since they tend to be easier to interpret than other data-driven methods. The decision tree algorithm automatically "learns" a decision tree by performing a search through the space of possible decision trees to find one that fits the training data. The particular decision tree algorithm used is known as C4.5. Simulated J-2X data from a high-fidelity simulator developed at Pratt & Whitney Rocketdyne and known as the Detailed Real-Time Model (DRTM) was used to "train" and test the decision tree. Fifty-six DRTM simulations were performed for this purpose, with different leak sizes, different leak locations, and different times of leak onset. To make the simulations as realistic as possible, they included simulated sensor noise, and included a gradual degradation in both fuel and oxidizer turbine efficiency. A decision tree was trained using 11 of these simulations, and tested using the remaining 45 simulations. In the training phase, the C4.5 algorithm was provided with labeled examples of data from nominal operation and data including leaks in each leak location. From the data, it "learned" a decision tree that can classify unseen data as having no leak or having a leak in one of the five leak locations. In the test phase, the decision tree produced very low false alarm rates and low missed detection rates on the unseen data. It had very good fault isolation rates for three of the five simulated leak locations, but it tended to confuse the remaining two locations, perhaps because a large leak at one of these two locations can look very similar to a small leak at the other location.

  18. Nuclear Engine System Simulation (NESS). Version 2.0: Program user's guide. Final Report

    International Nuclear Information System (INIS)

    Pelaccio, D.G.; Scheil, C.M.; Petrosky, L.

    1993-03-01

    This Program User's Guide discusses the Nuclear Thermal Propulsion (NTP) engine system design features and capabilities modeled in the Nuclear Engine System Simulation (NESS): Version 2.0 program (referred to as NESS throughout the remainder of this document), as well as its operation. NESS was upgraded to include many new modeling capabilities not available in the original version delivered to NASA LeRC in Dec. 1991, NESS's new features include the following: (1) an improved input format; (2) an advanced solid-core NERVA-type reactor system model (ENABLER 2); (3) a bleed-cycle engine system option; (4) an axial-turbopump design option; (5) an automated pump-out turbopump assembly sizing option; (6) an off-design gas generator engine cycle design option; (7) updated hydrogen properties; (8) an improved output formnd (9) personal computer operation capability. Sample design cases are presented in the user's guide that demonstrate many of the new features associated with this upgraded version of NESS, as well as design modeling features associated with the original version of NESS

  19. Preparation of severely curved simulated root canals using engine-driven rotary and conventional hand instruments.

    Science.gov (United States)

    Szep, S; Gerhardt, T; Leitzbach, C; Lüder, W; Heidemann, D

    2001-03-01

    This in vitro study evaluated the efficacy and safety of six different nickel-titanium engine-driven instruments used with a torque-controlled engine device and nickel-titanium hand and stainless steel hand instruments in preparation of curved canals. A total of 80 curved (36 degrees) simulated root canals were prepared. Images before and after were superimposed, and instrumentation areas were observed. Time of instrumentation, instrument failure, change in working length and weight loss were also recorded. Results show that stainless steel hand instruments cause significantly less transportation towards the inner wall of the canal than do nickel-titanium hand instruments. No instrument fracture occurred with hand instruments, but 30-60% breakage of instruments was recorded during instrumentation with the engine-driven devices. The working length was maintained by all types of instruments. Newly developed nickel-titanium rotary files were not able to prevent straightening of the severely curved canals when a torque-controlled engine-driven device was used.

  20. Real-time graphics for the Space Station Freedom cupola, developed in the Systems Engineering Simulator

    Science.gov (United States)

    Red, Michael T.; Hess, Philip W.

    1989-01-01

    Among the Lyndon B. Johnson Space Center's responsibilities for Space Station Freedom is the cupola. Attached to the resource node, the cupola is a windowed structure that will serve as the space station's secondary control center. From the cupola, operations involving the mobile service center and orbital maneuvering vehicle will be conducted. The Systems Engineering Simulator (SES), located in building 16, activated a real-time man-in-the-loop cupola simulator in November 1987. The SES cupola is an engineering tool with the flexibility to evolve in both hardware and software as the final cupola design matures. Two workstations are simulated with closed-circuit television monitors, rotational and translational hand controllers, programmable display pushbuttons, and graphics display with trackball and keyboard. The displays and controls of the SES cupola are driven by a Silicon Graphics Integrated Raster Imaging System (IRIS) 4D/70 GT computer. Through the use of an interactive display builder program, SES, cupola display pages consisting of two dimensional and three dimensional graphics are constructed. These display pages interact with the SES via the IRIS real-time graphics interface. The focus is on the real-time graphics interface applications software developed on the IRIS.

  1. Automatic differentiation tools in the dynamic simulation of chemical engineering processes

    Directory of Open Access Journals (Sweden)

    Castro M.C.

    2000-01-01

    Full Text Available Automatic Differentiation is a relatively recent technique developed for the differentiation of functions applicable directly to the source code to compute the function written in standard programming languages. That technique permits the automatization of the differentiation step, crucial for dynamic simulation and optimization of processes. The values for the derivatives obtained with AD are exact (to roundoff. The theoretical exactness of the AD comes from the fact that it uses the same rules of differentiation as in differential calculus, but these rules are applied to an algorithmic specification of the function rather than to a formula. The main purpose of this contribution is to discuss the impact of Automatic Differentiation in the field of dynamic simulation of chemical engineering processes. The influence of the differentiation technique on the behavior of the integration code, the performance of the generated code and the incorporation of AD tools in consistent initialization tools are discussed from the viewpoint of dynamic simulation of typical models in chemical engineering.

  2. SmartSIM - a virtual reality simulator for laparoscopy training using a generic physics engine.

    Science.gov (United States)

    Khan, Zohaib Amjad; Kamal, Nabeel; Hameed, Asad; Mahmood, Amama; Zainab, Rida; Sadia, Bushra; Mansoor, Shamyl Bin; Hasan, Osman

    2017-09-01

    Virtual reality (VR) training simulators have started playing a vital role in enhancing surgical skills, such as hand-eye coordination in laparoscopy, and practicing surgical scenarios that cannot be easily created using physical models. We describe a new VR simulator for basic training in laparoscopy, i.e. SmartSIM, which has been developed using a generic open-source physics engine called the simulation open framework architecture (SOFA). This paper describes the systems perspective of SmartSIM including design details of both hardware and software components, while highlighting the critical design decisions. Some of the distinguishing features of SmartSIM include: (i) an easy-to-fabricate custom-built hardware interface; (ii) use of a generic physics engine to facilitate wider accessibility of our work and flexibility in terms of using various graphical modelling algorithms and their implementations; and (iii) an intelligent and smart evaluation mechanism that facilitates unsupervised and independent learning. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Fast Bound Methods for Large Scale Simulation with Application for Engineering Optimization

    Science.gov (United States)

    Patera, Anthony T.; Peraire, Jaime; Zang, Thomas A. (Technical Monitor)

    2002-01-01

    In this work, we have focused on fast bound methods for large scale simulation with application for engineering optimization. The emphasis is on the development of techniques that provide both very fast turnaround and a certificate of Fidelity; these attributes ensure that the results are indeed relevant to - and trustworthy within - the engineering context. The bound methodology which underlies this work has many different instantiations: finite element approximation; iterative solution techniques; and reduced-basis (parameter) approximation. In this grant we have, in fact, treated all three, but most of our effort has been concentrated on the first and third. We describe these below briefly - but with a pointer to an Appendix which describes, in some detail, the current "state of the art."

  4. Verification on spray simulation of a pintle injector for liquid rocket engine

    Science.gov (United States)

    Son, Min; Yu, Kijeong; Radhakrishnan, Kanmaniraja; Shin, Bongchul; Koo, Jaye

    2016-02-01

    The pintle injector used for a liquid rocket engine is a newly re-attracted injection system famous for its wide throttle ability with high efficiency. The pintle injector has many variations with complex inner structures due to its moving parts. In order to study the rotating flow near the injector tip, which was observed from the cold flow experiment using water and air, a numerical simulation was adopted and a verification of the numerical model was later conducted. For the verification process, three types of experimental data including velocity distributions of gas flows, spray angles and liquid distribution were all compared using simulated results. The numerical simulation was performed using a commercial simulation program with the Eulerian multiphase model and axisymmetric two dimensional grids. The maximum and minimum velocities of gas were within the acceptable range of agreement, however, the spray angles experienced up to 25% error when the momentum ratios were increased. The spray density distributions were quantitatively measured and had good agreement. As a result of this study, it was concluded that the simulation method was properly constructed to study specific flow characteristics of the pintle injector despite having the limitations of two dimensional and coarse grids.

  5. Simulation Modeling to Compare High-Throughput, Low-Iteration Optimization Strategies for Metabolic Engineering.

    Science.gov (United States)

    Heinsch, Stephen C; Das, Siba R; Smanski, Michael J

    2018-01-01

    Increasing the final titer of a multi-gene metabolic pathway can be viewed as a multivariate optimization problem. While numerous multivariate optimization algorithms exist, few are specifically designed to accommodate the constraints posed by genetic engineering workflows. We present a strategy for optimizing expression levels across an arbitrary number of genes that requires few design-build-test iterations. We compare the performance of several optimization algorithms on a series of simulated expression landscapes. We show that optimal experimental design parameters depend on the degree of landscape ruggedness. This work provides a theoretical framework for designing and executing numerical optimization on multi-gene systems.

  6. Designing of Simulation for Engine Room Km. Sinabung with Control Monitoring Web Server Based by Wireless Network and Power Line Communication

    OpenAIRE

    Hadi, Eko Sasmito; Adietya, Berlian Arswendo; S.P, Firdaus

    2013-01-01

    Engine room monitoring control system is monitoring and controlling main engine and auxiliary engine from long distance by powerline communication network and wireless network to ease the operator in operating the ship and save operational cost. To prevent error in programming the main engine and auxiliary engine, a simulation using instrument software is needed to know the machine characteristic. After simulation result fulfills the requirement which is approached the value of test record, i...

  7. DESIGNING OF SIMULATION FOR ENGINE ROOM KM. SINABUNG WITH CONTROL MONITORING WEB SERVER BASED BY WIRELESS NETWORK AND POWER LINE COMMUNICATION

    OpenAIRE

    Eko Sasmito Hadi; Berlian Arswendo Adietya; Firdaus S.P

    2013-01-01

    Engine room monitoring control system is monitoring and controlling main engine and auxiliary engine from long distance by powerline communication network and wireless network to ease the operator in operating the ship and save operational cost. To prevent error in programming the main engine and auxiliary engine, a simulation using instrument software is needed to know the machine characteristic. After simulation result fulfills the requirement which is approached the value of test record, i...

  8. Simulation of ODE/PDE models with MATLAB, OCTAVE and SCILAB scientific and engineering applications

    CERN Document Server

    Vande Wouwer, Alain; Vilas, Carlos

    2014-01-01

    Simulation of ODE/PDE Models with MATLAB®, OCTAVE and SCILAB shows the reader how to exploit a fuller array of numerical methods for the analysis of complex scientific and engineering systems than is conventionally employed. The book is dedicated to numerical simulation of distributed parameter systems described by mixed systems of algebraic equations, ordinary differential equations (ODEs) and partial differential equations (PDEs). Special attention is paid to the numerical method of lines (MOL), a popular approach to the solution of time-dependent PDEs, which proceeds in two basic steps: spatial discretization and time integration. Besides conventional finite-difference and -element techniques, more advanced spatial-approximation methods are examined in some detail, including nonoscillatory schemes and adaptive-grid approaches. A MOL toolbox has been developed within MATLAB®/OCTAVE/SCILAB. In addition to a set of spatial approximations and time integrators, this toolbox includes a collection of applicatio...

  9. ATTIRE (analytical tools for thermal infrared engineering): A sensor simulation and modeling package

    Science.gov (United States)

    Jaggi, S.

    1993-01-01

    The Advanced Sensor Development Laboratory (ASDL) at the Stennis Space Center develops, maintains and calibrates remote sensing instruments for the National Aeronautics & Space Administration (NASA). 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 Signal-to-Noise Ratio (SNR), Noise Equivalent Radiance (NER), Noise Equivalent Temperature Difference (NETD) etc. This paper describes the uses of the package and the physics that were used to derive the performance parameters.

  10. Internal combustion engine exhaust pipe flow simulation. Part I: theoretical aspects

    Directory of Open Access Journals (Sweden)

    Juan Miguel Mantilla

    2009-01-01

    Full Text Available Unsteady gas flow theory can be used for simulating a spark ignition internal combustion engine’s exhaust system, using pressure waves. The method explained here is based on the discretization of interpolated spaces (called meshes which are located throughout the whole length of the exhaust pipe, irrespective of its form or size. The most important aspects of this theory are theoretically explored, such as pressure wave movement and shock and their application to cases found in real engines’ exhaust pipes. This work also considers how the simulation must be made, based on the previous exploration. The results (presented as e- quations in this first paper show the great influence exerted by pressure wave movement on flow through the engine and there- fore on its final performance.

  11. The design of a wind tunnel VSTOL fighter model incorporating turbine powered engine simulators

    Science.gov (United States)

    Bailey, R. O.; Maraz, M. R.; Hiley, P. E.

    1981-01-01

    A wind-tunnel model of a supersonic VSTOL fighter aircraft configuration has been developed for use in the evaluation of airframe-propulsion system aerodynamic interactions. The model may be employed with conventional test techniques, where configuration aerodynamics are measured in a flow-through mode and incremental nozzle-airframe interactions are measured in a jet-effects mode, and with the Compact Multimission Aircraft Propulsion Simulator which is capable of the simultaneous simulation of inlet and exhaust nozzle flow fields so as to allow the evaluation of the extent of inlet and nozzle flow field coupling. The basic configuration of the twin-engine model has a geometrically close-coupled canard and wing, and a moderately short nacelle with nonaxisymmetric vectorable exhaust nozzles near the wing trailing edge, and may be converted to a canardless configuration with an extremely short nacelle. Testing is planned to begin in the summer of 1982.

  12. Simulator Investigation of Pilot Aids for Helicopter Terminal Area Operations with One Engine Inoperative

    Science.gov (United States)

    Iseler, Laura; Chen, Robert; Dearing, Munro; Decker, William; Aiken, Edwin W. (Technical Monitor)

    1995-01-01

    Two recent piloted simulation experiments have investigated advanced display concepts applied to civil transport helicopter terminal area operations. Civil Category A helicopter operations apply to multi-engine helicopters wherein a safe recovery (land or fly out) is required in the event of a single engine failure. The investigation used the NASA Ames Research Center Vertical Motion Simulator, which has a full six degrees of freedom, to simulate the flight task as closely as possible. The goal of these experiments was to use advanced cockpit displays to improve flight safety and enhance the mission performance of Category A terminal area operations in confined areas. The first experiment investigated the use of military display formats to assist civil rotorcraft in performing a Category A takeoff in confined terminal areas. Specifically, it addressed how well a difficult hovering backup path could be followed using conventional instruments in comparison to panel mounted integrated displays. The hovering backup takeoff, which enables pilots to land back to the confined area pad in the event of an engine failure, was chosen since it is a difficult task to perform. Seven NASA and Army test pilots participated in the experiment. Evaluations, based on task performance and pilot workload, showed that an integrated display enabled the pilot to consistently achieve adequate or desired performance with reasonable pilot workload. Use of conventional instruments, however, frequently resulted in unacceptable performance (poor flight path tracking), higher pilot workload, and poor situational awareness. Although OEI landbacks were considered a visual task, the improved performance on the backup portion, in conjunction with increased situational awareness resulting from use of integrated displays, enabled the pilots to handle an engine failure and land back safely. In contrast, use of conventional instruments frequently led to excessive rates of sink at touchdown. A second

  13. Experiment and Simulation Study of Single Cylinder Diesel Engine Performance, Using Soybean Oil Biodiesel

    Directory of Open Access Journals (Sweden)

    Muhammad Rizqi Ariefianto

    2017-01-01

    Full Text Available Abstract— The most common fuel uses in the world is made from fossil. Fossil fuel is categorized as a non-renewable energy source. For that reason, there should be an alternative fuel to replace fossil fuel by using biodiesel and one of the stock comes from soybean bean. Before using the biodiesel made from soybean bean oil, there should be a research to find out the properties and the effect of biodiesel from soybean bean oil regarding the performance of the engine. The research can be conducted in experiment and simulation. The properties result of soybean oil biodiesel should be tested to confirm whether this biodiesel have meet the standard requirement of biodieselor not. This biodiesel sproperties are Flash Point value is 182 o C , Pour Point value is -7 o C, Density at 15 o C is 890 Kg/m3, Kinematic Viscosity at 40 o C is 5.58 (cSt, and Lower Heating Value is 42.27686 MJ/kg. The result from this research is the highest power from simulation is 9% higher than the experiment. The highest torque from the experiment is 37% lower than the simulation’s torque. Lowest SFOC from experiment is  28% lower than the simulation’s SFOC. Highest BMEP from simulation is 20% higher than the highest BMEP from experiment. The  highest thermal efficiency from experiment is 6% higher than the highest thermal efficiency from simulation. The engine performance result using soybean oil biodiesel is not better than the Pertamina Dex. For that reason, the use of this biodiesel is not suggested to substitute Pertamina Dex.

  14. RESEARCH INTO VALVE-ENGINE TRANSDUCERS OF BRUSHLESS SYNCHRONOUS AND ASYNCHRONIZED MACHINES IN A CIRCUIT SIMULATION SYSTEM.

    Directory of Open Access Journals (Sweden)

    A.M. Galynovskiy

    2013-10-01

    Full Text Available Designing features for valve-engine transducers of brushless synchronous and asynchronized machines are described. Global analysis of research results on the transducer models in a MicroCap circuit simulation system is made, recommendations on the simulation system application in both scientific research and educational process given.

  15. Numerical Simulation of Condensation of Sulfuric Acid and Water in a Large Two-stroke Marine Diesel Engine

    DEFF Research Database (Denmark)

    Walther, Jens Honore; Karvounis, Nikolas; Pang, Kar Mun

    2016-01-01

    We present results from computational fluid dynamics simulations of the condensation of sulfuric acid (H2SO4) and water (H2O) in a large two-stroke marine diesel engine. The model uses a reduced n-heptane skeletal chemical mechanism coupled with a sulfur subsetto simulate the combustion process...

  16. Suppression of pool fires with HRC-125 in a simulated engine nacelle.

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, David R. (INS, Inc., Lexington Park, MD); Hewson, John C.

    2007-06-01

    CFD simulations are conducted to predict the distribution of fire suppressant in an engine nacelle and to predict the suppression of pool fires by the application of this suppressant. In the baseline configuration, which is based on an installed system, suppressant is injected through four nozzles at a rate fast enough to suppress all simulated pool fires. Variations that reduce the mass of the suppression system (reducing the impact of the suppression system on meeting mission needs) are considered, including a reduction in the rate of suppressant injection, a reduction in the mass of suppressant and a reduction in the number of nozzles. In general, these variations should work to reduce the effectiveness of the suppression system, but the CFD results point out certain changes that have negligible impact, at least for the range of phenomena considered here. The results are compared with measurements where available. Comparisons with suppressant measurements are reasonable. A series of twenty-three fire suppression tests were conducted to check the predictions. The pre-test predictions were generally successful in identifying the range of successful suppression tests. In two separate cases, each where one nozzle of the suppression system was capped, the simulation results did indicate a failure to suppress for a condition where the tests indicated successful suppression. When the test-suppressant discharge rate was reduced by roughly 25%, the tests were in agreement with the predictions. That is, the simulations predict a failure to suppress slightly before observed in these cases.

  17. Innovative Calibration Method for System Level Simulation Models of Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Ivo Prah

    2016-09-01

    Full Text Available The paper outlines a procedure for the computer-controlled calibration of the combined zero-dimensional (0D and one-dimensional (1D thermodynamic simulation model of a turbocharged internal combustion engine (ICE. The main purpose of the calibration is to determine input parameters of the simulation model in such a way as to achieve the smallest difference between the results of the measurements and the results of the numerical simulations with minimum consumption of the computing time. An innovative calibration methodology is based on a novel interaction between optimization methods and physically based methods of the selected ICE sub-systems. Therein physically based methods were used for steering the division of the integral ICE to several sub-models and for determining parameters of selected components considering their governing equations. Innovative multistage interaction between optimization methods and physically based methods allows, unlike the use of well-established methods that rely only on the optimization techniques, for successful calibration of a large number of input parameters with low time consumption. Therefore, the proposed method is suitable for efficient calibration of simulation models of advanced ICEs.

  18. Development of support tools for efficient construction of dynamic simulation program for engineering systems

    International Nuclear Information System (INIS)

    Gofuku, Akio

    1993-01-01

    In this study, two support tools are developed for construction of a dynamic simulation program for engineering systems (especially nuclear systems) by combining software modules. These are (1) a sub-system to support the module selection suitable for dynamic simulation and (2) a graphical user interface to support visual construction of simulation programs. The support tools are designed to be independent on the conception of software modules (data communication methods between modules). In the module selection sub-system of item 1, a module is characterized beforehand by keywords for several criteria. The similarity between the characteristic of requested module by users and that of registered modules in the module library is estimated by a weighted average of similarity indexes for criteria. In the module selection sub-system, the weights are flexibly extracted from users by applying the analytic hierarchy process. The graphical user interface helps users to specify both calling order of modules and data transfer between two modules. The availability of the support tools is evaluated by several sample problems of module selection and dynamic simulation model construction. The support tools will be a strong tool for the efficient usage of software modules. (author)

  19. Modeling and numerical simulation of greenhouse gas emissions from a stationary Diesel engine operating with ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Bergel, Andre; Viana, Sarah de Resende; Martins, Cristiane Aparecida [Instituto Tecnologica da Aeronautica - ITA, Sao Jose dos Campos, SP (Brazil)], e-mail: cmartins@ita.br; Souza, Francisco Jose de [Universidade Federal de Uberlandia (UFU), MG (Brazil)], e-mail: fjsouza@mecanica.ufu.br

    2010-07-01

    The present work aims at modeling and simulating a stationary, compression ignition motor, operating with ethanol at different levels of EGR. The objective is to quantify the influence of these parameters in the atmospheric pollutant emissions (CO, NO{sub X} and Particulate Matter). Specifications of a diesel engine were used, with compression ratio 19:1, operating with ethanol with a percentile of EGR of 0, 10, 20 and 30%. In the simulation, the combustion model, ECFM-3Z, and the turbulence model k-{zeta}-f were used, besides conditions for the temperatures of the combustion chamber, piston, cylinder head and glow plug. The spray characterization was done through the calculation of the injected fuel mass and parameters like spray angle, droplet size, number of holes, position of the injector and others. For the reduction of the simulation time, the crank angle range of is only 130[CAD], beginning at 30 deg BTDC and concluding at 100 deg ATDC. The assessment of the influence of the different EGR concentrations felt for the analysis of pollutant contained in the end of simulation. A very small delay in the ignition of the fuel injected and the emission of a minor amount of nitrogen oxides were observed in all cases as the EGR level used was increased. (author)

  20. DEM GPU studies of industrial scale particle simulations for granular flow civil engineering applications

    Science.gov (United States)

    Pizette, Patrick; Govender, Nicolin; Wilke, Daniel N.; Abriak, Nor-Edine

    2017-06-01

    The use of the Discrete Element Method (DEM) for industrial civil engineering industrial applications is currently limited due to the computational demands when large numbers of particles are considered. The graphics processing unit (GPU) with its highly parallelized hardware architecture shows potential to enable solution of civil engineering problems using discrete granular approaches. We demonstrate in this study the pratical utility of a validated GPU-enabled DEM modeling environment to simulate industrial scale granular problems. As illustration, the flow discharge of storage silos using 8 and 17 million particles is considered. DEM simulations have been performed to investigate the influence of particle size (equivalent size for the 20/40-mesh gravel) and induced shear stress for two hopper shapes. The preliminary results indicate that the shape of the hopper significantly influences the discharge rates for the same material. Specifically, this work shows that GPU-enabled DEM modeling environments can model industrial scale problems on a single portable computer within a day for 30 seconds of process time.

  1. An Introduction to Parallel Cluster Computing Using PVM for Computer Modeling and Simulation of Engineering Problems

    International Nuclear Information System (INIS)

    Spencer, VN

    2001-01-01

    An investigation has been conducted regarding the ability of clustered personal computers to improve the performance of executing software simulations for solving engineering problems. The power and utility of personal computers continues to grow exponentially through advances in computing capabilities such as newer microprocessors, advances in microchip technologies, electronic packaging, and cost effective gigabyte-size hard drive capacity. Many engineering problems require significant computing power. Therefore, the computation has to be done by high-performance computer systems that cost millions of dollars and need gigabytes of memory to complete the task. Alternately, it is feasible to provide adequate computing in the form of clustered personal computers. This method cuts the cost and size by linking (clustering) personal computers together across a network. Clusters also have the advantage that they can be used as stand-alone computers when they are not operating as a parallel computer. Parallel computing software to exploit clusters is available for computer operating systems like Unix, Windows NT, or Linux. This project concentrates on the use of Windows NT, and the Parallel Virtual Machine (PVM) system to solve an engineering dynamics problem in Fortran

  2. Simulation of fuel demand for wood-gas in combustion engine

    Science.gov (United States)

    Botwinska, Katarzyna; Mruk, Remigiusz; Tucki, Karol; Wata, Mateusz

    2017-10-01

    In the era of the oil crisis and proceeding contamination of the natural environment, it is attempted to substitute fossil raw materials with alternative carriers. For many years, road transport has been considered as one of the main sources of the substances deteriorating air quality. Applicable European directives oblige the member states to implement biofuels and biocomponents into the general fuel market, however, such process is proceeding gradually and relatively slowly. So far, alternative fuels have been used on a large scale to substitute diesel fuel or petrol. Derivatives of vegetable raw materials, such as vegetable oils or their esters and ethanol extracted from biomass, are used to that end. It has been noticed that there is no alternative to LPG which, due to financial reasons, is more and more popular as fuel in passenger cars. In relation to solutions adopted in the past, it has been decided to analyse the option of powering a modern passenger car with wood gas - syngas. Such fuel has been practically used since the 1920's. To that end, a computer simulation created in SciLab environment was carried out. Passenger car Fiat Seicento, fitted with Fire 1.1 8V petrol engine with power of 40kW, whose parameters were used to prepare the model, was selected as the model vehicle. The simulation allows the determination of engine demand on the given fuel. Apart from the wood gas included in the title, petrol, methane and LPG were used. Additionally, the created model enables the determination of the engine power at the time of the indicated fuels supply. The results obtained in the simulation revealed considerable decrease in the engine power when the wood gas was supplied and the increased consumption of this fuel. On the basis of the analysis of the professional literature describing numerous inconveniences connected with the use of this fuel as well as the obtained results, it has been established that using the wood gas as alternative fuel is currently

  3. Simulation of fuel demand for wood-gas in combustion engine

    Directory of Open Access Journals (Sweden)

    Botwinska Katarzyna

    2017-01-01

    Full Text Available In the era of the oil crisis and proceeding contamination of the natural environment, it is attempted to substitute fossil raw materials with alternative carriers. For many years, road transport has been considered as one of the main sources of the substances deteriorating air quality. Applicable European directives oblige the member states to implement biofuels and biocomponents into the general fuel market, however, such process is proceeding gradually and relatively slowly. So far, alternative fuels have been used on a large scale to substitute diesel fuel or petrol. Derivatives of vegetable raw materials, such as vegetable oils or their esters and ethanol extracted from biomass, are used to that end. It has been noticed that there is no alternative to LPG which, due to financial reasons, is more and more popular as fuel in passenger cars. In relation to solutions adopted in the past, it has been decided to analyse the option of powering a modern passenger car with wood gas - syngas. Such fuel has been practically used since the 1920's. To that end, a computer simulation created in SciLab environment was carried out. Passenger car Fiat Seicento, fitted with Fire 1.1 8V petrol engine with power of 40kW, whose parameters were used to prepare the model, was selected as the model vehicle. The simulation allows the determination of engine demand on the given fuel. Apart from the wood gas included in the title, petrol, methane and LPG were used. Additionally, the created model enables the determination of the engine power at the time of the indicated fuels supply. The results obtained in the simulation revealed considerable decrease in the engine power when the wood gas was supplied and the increased consumption of this fuel. On the basis of the analysis of the professional literature describing numerous inconveniences connected with the use of this fuel as well as the obtained results, it has been established that using the wood gas as alternative

  4. Direct Numerical Simulation of Turbulent Multi-Stage Autoignition Relevant to Engine Conditions

    Science.gov (United States)

    Chen, Jacqueline

    2017-11-01

    Due to the unrivaled energy density of liquid hydrocarbon fuels combustion will continue to provide over 80% of the world's energy for at least the next fifty years. Hence, combustion needs to be understood and controlled to optimize combustion systems for efficiency to prevent further climate change, to reduce emissions and to ensure U.S. energy security. In this talk I will discuss recent progress in direct numerical simulations of turbulent combustion focused on providing fundamental insights into key `turbulence-chemistry' interactions that underpin the development of next generation fuel efficient, fuel flexible engines for transportation and power generation. Petascale direct numerical simulation (DNS) of multi-stage mixed-mode turbulent combustion in canonical configurations have elucidated key physics that govern autoignition and flame stabilization in engines and provide benchmark data for combustion model development under the conditions of advanced engines which operate near combustion limits to maximize efficiency and minimize emissions. Mixed-mode combustion refers to premixed or partially-premixed flames propagating into stratified autoignitive mixtures. Multi-stage ignition refers to hydrocarbon fuels with negative temperature coefficient behavior that undergo sequential low- and high-temperature autoignition. Key issues that will be discussed include: 1) the role of mixing in shear driven turbulence on the dynamics of multi-stage autoignition and cool flame propagation in diesel environments, 2) the role of thermal and composition stratification on the evolution of the balance of mixed combustion modes - flame propagation versus spontaneous ignition - which determines the overall combustion rate in autoignition processes, and 3) the role of cool flames on lifted flame stabilization. Finally prospects for DNS of turbulent combustion at the exascale will be discussed in the context of anticipated heterogeneous machine architectures. sponsored by DOE

  5. A novel bioreactor to simulate urinary bladder mechanical properties and compliance for bladder functional tissue engineering.

    Science.gov (United States)

    Wei, Xin; Li, Dao-bing; Xu, Feng; Wang, Yan; Zhu, Yu-chun; Li, Hong; Wang, Kun-jie

    2011-02-01

    Bioreactors are pivotal tools for generating mechanical stimulation in functional tissue engineering study. This study aimed to create a bioreactor that can simulate urinary bladder mechanical properties, and to investigate the effects of a mechanically stimulated culture on urothelial cells and bladder smooth muscle cells. We designed a bioreactor to simulate the mechanical properties of bladder. A pressure-record system was used to evaluate the mechanical properties of the bioreactor by measuring the pressure in culture chambers. To test the biocompatibility of the bioreactor, viabilities of urothelial cells and smooth muscle cells cultured in the bioreactor under static and mechanically changed conditions were measured after 7-day culture. To evaluate the effect of mechanical stimulations on the vital cells, urethral cells and smooth muscle cells were cultured in the simulated mechanical conditions. After that, the viability and the distribution pattern of the cells were observed and compared with cells cultured in non-mechanical stimulated condition. The bioreactor system successfully generated waveforms similar to the intended programmed model while maintaining a cell-seeded elastic membrane between the chambers. There were no differences between viabilities of urothelial cells ((91.90 ± 1.22)% vs. (93.14 ± 1.78)%, P > 0.05) and bladder smooth muscle cells ((93.41 ± 1.49)% vs. (92.61 ± 1.34)%, P > 0.05). The viability of cells and tissue structure observation after cultured in simulated condition showed that mechanical stimulation was the only factor affected cells in the bioreactor and improved the arrangement of cells on silastic membrane. This bioreactor can effectively simulate the physiological and mechanical properties of the bladder. Mechanical stimulation is the only factor that affected the viability of cells cultured in the bioreactor. The bioreactor can change the growth behavior of urothelial cells and bladder smooth muscle cells, resulting in

  6. Computational Materials Science and Chemistry: Accelerating Discovery and Innovation through Simulation-Based Engineering and Science

    Energy Technology Data Exchange (ETDEWEB)

    Crabtree, George [Argonne National Lab. (ANL), Argonne, IL (United States); Glotzer, Sharon [University of Michigan; McCurdy, Bill [University of California Davis; Roberto, Jim [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2010-07-26

    abating, has enabled the development of computer simulations and models of unprecedented fidelity. We are at the threshold of a new era where the integrated synthesis, characterization, and modeling of complex materials and chemical processes will transform our ability to understand and design new materials and chemistries with predictive power. In turn, this predictive capability will transform technological innovation by accelerating the development and deployment of new materials and processes in products and manufacturing. Harnessing the potential of computational science and engineering for the discovery and development of materials and chemical processes is essential to maintaining leadership in these foundational fields that underpin energy technologies and industrial competitiveness. Capitalizing on the opportunities presented by simulation-based engineering and science in materials and chemistry will require an integration of experimental capabilities with theoretical and computational modeling; the development of a robust and sustainable infrastructure to support the development and deployment of advanced computational models; and the assembly of a community of scientists and engineers to implement this integration and infrastructure. This community must extend to industry, where incorporating predictive materials science and chemistry into design tools can accelerate the product development cycle and drive economic competitiveness. The confluence of new theories, new materials synthesis capabilities, and new computer platforms has created an unprecedented opportunity to implement a "materials-by-design" paradigm with wide-ranging benefits in technological innovation and scientific discovery. The Workshop on Computational Materials Science and Chemistry for Innovation was convened in Bethesda, Maryland, on July 26-27, 2010. Sponsored by the Department of Energy (DOE) Offices of Advanced Scientific Computing Research and Basic Energy Sciences, the workshop

  7. Modified Backtracking Search Optimization Algorithm Inspired by Simulated Annealing for Constrained Engineering Optimization Problems

    Directory of Open Access Journals (Sweden)

    Hailong Wang

    2018-01-01

    Full Text Available The backtracking search optimization algorithm (BSA is a population-based evolutionary algorithm for numerical optimization problems. BSA has a powerful global exploration capacity while its local exploitation capability is relatively poor. This affects the convergence speed of the algorithm. In this paper, we propose a modified BSA inspired by simulated annealing (BSAISA to overcome the deficiency of BSA. In the BSAISA, the amplitude control factor (F is modified based on the Metropolis criterion in simulated annealing. The redesigned F could be adaptively decreased as the number of iterations increases and it does not introduce extra parameters. A self-adaptive ε-constrained method is used to handle the strict constraints. We compared the performance of the proposed BSAISA with BSA and other well-known algorithms when solving thirteen constrained benchmarks and five engineering design problems. The simulation results demonstrated that BSAISA is more effective than BSA and more competitive with other well-known algorithms in terms of convergence speed.

  8. Computational fluid dynamic simulations of coal-fired utility boilers: An engineering tool

    Energy Technology Data Exchange (ETDEWEB)

    Efim Korytnyi; Roman Saveliev; Miron Perelman; Boris Chudnovsky; Ezra Bar-Ziv [Ben-Gurion University of the Negev, Beer-Sheva (Israel)

    2009-01-15

    The objective of this study was to develop an engineering tool by which the combustion behavior of coals in coal-fired utility boilers can be predicted. We presented in this paper that computational fluid dynamic (CFD) codes can successfully predict performance of - and emission from - full-scale pulverized-coal utility boilers of various types, provided that the model parameters required for the simulation are properly chosen and validated. For that purpose we developed a methodology combining measurements in a 50 kW pilot-scale test facility with CFD simulations using the same CFD code configured for both test and full-scale furnaces. In this method model parameters of the coal processes are extracted and validated. This paper presents the importance of the validation of the model parameters which are used in CFD codes. Our results show very good fit of CFD simulations with various parameters measured in a test furnace and several types of utility boilers. The results of this study demonstrate the viability of the present methodology as an effective tool for optimization coal burning in full-scale utility boilers. 41 refs., 9 figs., 3 tabs.

  9. Simulating Exposure Concentrations of Engineered Nanomaterials in Surface Water Systems: Release of WASP8

    Science.gov (United States)

    Knightes, C. D.; Bouchard, D.; Zepp, R. G.; Henderson, W. M.; Han, Y.; Hsieh, H. S.; Avant, B. K.; Acrey, B.; Spear, J.

    2017-12-01

    The unique properties of engineered nanomaterials led to their increased production and potential release into the environment. Currently available environmental fate models developed for traditional contaminants are limited in their ability to simulate nanomaterials' environmental behavior. This is due to an incomplete understanding and representation of the processes governing nanomaterial distribution in the environment and by scarce empirical data quantifying the interaction of nanomaterials with environmental surfaces. The well-known Water Quality Analysis Simulation Program (WASP) was updated to incorporate nanomaterial-specific processes, specifically hetero-aggregation with particulate matter. In parallel with this effort, laboratory studies were used to quantify parameter values parameters necessary for governing processes in surface waters. This presentation will discuss the recent developments in the new architecture for WASP8 and the newly constructed Advanced Toxicant Module. The module includes advanced algorithms for increased numbers of state variables: chemicals, solids, dissolved organic matter, pathogens, temperature, and salinity. This presentation will focus specifically on the incorporation of nanomaterials, with the applications of the fate and transport of hypothetical releases of Multi-Walled Carbon Nanotubes (MWCNT) and Graphene Oxide (GO) into the headwaters of a southeastern US coastal plains river. While this presentation focuses on nanomaterials, the advanced toxicant module can also simulate metals and organic contaminants.

  10. Conversion from Engineering Units to Telemetry Counts on Dryden Flight Simulators

    Science.gov (United States)

    Fantini, Jay A.

    1998-01-01

    Dryden real-time flight simulators encompass the simulation of pulse code modulation (PCM) telemetry signals. This paper presents a new method whereby the calibration polynomial (from first to sixth order), representing the conversion from counts to engineering units (EU), is numerically inverted in real time. The result is less than one-count error for valid EU inputs. The Newton-Raphson method is used to numerically invert the polynomial. A reverse linear interpolation between the EU limits is used to obtain an initial value for the desired telemetry count. The method presented here is not new. What is new is how classical numerical techniques are optimized to take advantage of modem computer power to perform the desired calculations in real time. This technique makes the method simple to understand and implement. There are no interpolation tables to store in memory as in traditional methods. The NASA F-15 simulation converts and transmits over 1000 parameters at 80 times/sec. This paper presents algorithm development, FORTRAN code, and performance results.

  11. SAFSIM theory manual: A computer program for the engineering simulation of flow systems

    Energy Technology Data Exchange (ETDEWEB)

    Dobranich, D.

    1993-12-01

    SAFSIM (System Analysis Flow SIMulator) is a FORTRAN computer program for simulating the integrated performance of complex flow systems. SAFSIM provides sufficient versatility to allow the engineering simulation of almost any system, from a backyard sprinkler system to a clustered nuclear reactor propulsion system. In addition to versatility, speed and robustness are primary SAFSIM development goals. SAFSIM contains three basic physics modules: (1) a fluid mechanics module with flow network capability; (2) a structure heat transfer module with multiple convection and radiation exchange surface capability; and (3) a point reactor dynamics module with reactivity feedback and decay heat capability. Any or all of the physics modules can be implemented, as the problem dictates. SAFSIM can be used for compressible and incompressible, single-phase, multicomponent flow systems. Both the fluid mechanics and structure heat transfer modules employ a one-dimensional finite element modeling approach. This document contains a description of the theory incorporated in SAFSIM, including the governing equations, the numerical methods, and the overall system solution strategies.

  12. ExNum 2016 International Symposium on Experimental Methods and Numerical Simulation in Engineering Sciences

    Directory of Open Access Journals (Sweden)

    Editorial Foreword

    2016-12-01

    Full Text Available ExNum 2016International Symposium on Experimental Methods and Numerical Simulation in Engineering SciencesSeptember 18th - 21st, 2016Conference Centre Liblice, Liblice, Czech RepublicOrganized by:Institute of Theoretical and Applied Mechanics ASCR, v.v.i.Faculty of Transportation Sciences CTU in PragueBergische Universität Wuppertal, Faculty 5 - Architecture and Civil EngineeringThe International Symposium on Experimental Methods and Numerical Simulation in Engineering Sciences continues the tradition of the Czech-German bilateral symposium founded by prof. Karl-Hans Laermann and prof. Stanislav Holý in 1985. In the following years, the symposium was extensively developed by prof. Josef Jíra. The symposium shall bring together mainly young scientists who are actively involved in experimental solid mechanics, theoretically and practically, in order to exchange experience, to report on the present state-of-art as well as on running research projects, to discuss due questions and problems and to promote the co-operation between individuals as well as between institutions. Therefore in the symposium discussions will play a highly significant role.Scientific Committeeprof. Ing. Ondřej Jiroušek, Ph.D. (Institute of Theoretical and Applied Mechanics ASCR, v.v.i.Univ.-Prof. Dr.-Ing.Dr.h.c.mult. Karl-Hans Laermann (Bergische Universität WuppertalProf. Dr.- Ing. Reinhard Harte (Bergische Universität Wuppertal, Faculty 5 - Architecture and Civil EngineeringProf. Dr.-Ing. Marc Gutermann (Hochschule BremenIng. Daniel Kytýř, Ph.D. (Czech Technical University in Prague, Faculty of Transportation SciencesIng. Petr Zlámal, Ph.D. (Institute of Theoretical and Applied Mechanics ASCR, v.v.i.Local Organizing CommitteeTomáš DoktorTomáš FílaNela KrčmářováPetr KoudelkaVeronika KoudelkováDaniel KytýřJan ŠleichrtPetr ZlámalEditorsDaniel KytýřPetr ZlámalScientific GuidanceOndřej Jiroušek

  13. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  14. Current Trends in Numerical Simulation for Parallel Engineering Environments New Directions and Work-in-Progress

    International Nuclear Information System (INIS)

    Trinitis, C; Schulz, M

    2006-01-01

    In today's world, the use of parallel programming and architectures is essential for simulating practical problems in engineering and related disciplines. Remarkable progress in CPU architecture, system scalability, and interconnect technology continues to provide new opportunities, as well as new challenges for both system architects and software developers. These trends are paralleled by progress in parallel algorithms, simulation techniques, and software integration from multiple disciplines. ParSim brings together researchers from both application disciplines and computer science and aims at fostering closer cooperation between these fields. Since its successful introduction in 2002, ParSim has established itself as an integral part of the EuroPVM/MPI conference series. In contrast to traditional conferences, emphasis is put on the presentation of up-to-date results with a short turn-around time. This offers a unique opportunity to present new aspects in this dynamic field and discuss them with a wide, interdisciplinary audience. The EuroPVM/MPI conference series, as one of the prime events in parallel computation, serves as an ideal surrounding for ParSim. This combination enables the participants to present and discuss their work within the scope of both the session and the host conference. This year, eleven papers from authors in nine countries were submitted to ParSim, and we selected five of them. They cover a wide range of different application fields including gas flow simulations, thermo-mechanical processes in nuclear waste storage, and cosmological simulations. At the same time, the selected contributions also address the computer science side of their codes and discuss different parallelization strategies, programming models and languages, as well as the use nonblocking collective operations in MPI. We are confident that this provides an attractive program and that ParSim will be an informal setting for lively discussions and for fostering new

  15. Development of NESSY (Nuclear ship Engineering Simulation SYstem) and its application to dynamic analysis

    International Nuclear Information System (INIS)

    Kusunoki, T.; Uematsu, H.; Kobayashi, H.

    1992-01-01

    A marine reactor plant sustains incessant load change and the effects of vibration and ship motions due to the maneuvering and dynamic conditions in the marine environment. The change of process variables of the reactor plant is made in accordance with the load change and other effects, and also results in the propeller revolution change and subsequently affects on ship motions. In order to grasp dynamic behavior of the reactor plant in normal operation, including port entry and departure, and also in abnormal conditions such as anticipated transient and accidents, the Nuclear ship Engineering Simulation SYstem (simply ENSSY, hereinafter) carriers out combined analysis in which the behaviors of the ship propulsion, the reactor plant and the secondary systems are simultaneously calculated in each time step. (author)

  16. Laser-Doppler velocimetry measurements in a motored IC engine simulator

    Science.gov (United States)

    Gany, A.; Sirignano, W. A.; Larrea, J.-J.

    1980-01-01

    A measurement technique and experimental results are presented for mean velocity and velocity fluctuations in a motored, axisymmetric engine chamber simulation. Three valve configurations are considered: open orifice, open valve, and operating valve. Measurements of axial and tangential velocity components have been taken at various axial and radial positions for one compression ratio (7:1) and one rpm level (31). The measurements show that the intake stroke (in both two and four stroke operations) result in a recirculating flow with substantial turbulence generation even at the low rpm value. The four-stroke results in an axisymmetric design are novel and especially significant since the ability exists to make comparisons with theoretical, axisymmetric, turbulent results.

  17. Large-eddy simulations of turbulent flows in internal combustion engines

    Science.gov (United States)

    Banaeizadeh, Araz

    The two-phase compressible scalar filtered mass density function (FMDF) model is further developed and employed for large-eddy simulations (LES) of turbulent spray combustion in internal combustion (IC) engines. In this model, the filtered compressible Navier-Stokes equations are solved in a generalized curvilinear coordinate system with high-order, multi-block, compact differencing schemes for the turbulent velocity and pressure. However, turbulent mixing and combustion are computed with a new two-phase compressible scalar FMDF model. The spray and droplet dispersion/evaporation are modeled with a Lagrangian method. A new Lagrangian-Eulerian-Lagrangian computational method is employed for solving the flow, spray and scalar equation. The pressure effect in the energy equation, as needed in compressible flows, is included in the FMDF formulation. The performance of the new compressible LES/FMDF model is assessed by simulating the flow field and scalar mixing in a rapid compression machine (RCM), in a shock tube and in a supersonic co-axial jet. Consistency of temperatures predicted by the Eulerian finite-difference (FD) and Lagrangian Monte Carlo (MC) parts of the LES/FMDF model are established by including the pressure on the FMDF. It is shown that the LES/FMDF model is able to correctly capture the scalar mixing in both compressible subsonic and supersonic flows. Using the new two-phase LES/FMDF model, fluid dynamics, heat transfer, spray and combustion in the RCM with flat and crevice piston are studied. It is shown that the temperature distribution in the RCM with crevice piston is more uniform than the RCM with flat piston. The fuel spray characteristics and the spray parameters affecting the fuel mixing inside the RCM in reacting and non-reacting flows are also studied. The predicted liquid penetration and flame lift-off lengths for respectively non-reacting and reacting sprays are found to compare well with the available experimental data. Temperatures and

  18. An Introduction to Transient Engine Applications Using the Numerical Propulsion System Simulation (NPSS) and MATLAB

    Science.gov (United States)

    Chin, Jeffrey C.; Csank, Jeffrey T.; Haller, William J.; Seidel, Jonathan A.

    2016-01-01

    This document outlines methodologies designed to improve the interface between the Numerical Propulsion System Simulation framework and various control and dynamic analyses developed in the Matlab and Simulink environment. Although NPSS is most commonly used for steady-state modeling, this paper is intended to supplement the relatively sparse documentation on it's transient analysis functionality. Matlab has become an extremely popular engineering environment, and better methodologies are necessary to develop tools that leverage the benefits of these disparate frameworks. Transient analysis is not a new feature of the Numerical Propulsion System Simulation (NPSS), but transient considerations are becoming more pertinent as multidisciplinary trade-offs begin to play a larger role in advanced engine designs. This paper serves to supplement the relatively sparse documentation on transient modeling and cover the budding convergence between NPSS and Matlab based modeling toolsets. The following sections explore various design patterns to rapidly develop transient models. Each approach starts with a base model built with NPSS, and assumes the reader already has a basic understanding of how to construct a steady-state model. The second half of the paper focuses on further enhancements required to subsequently interface NPSS with Matlab codes. The first method being the simplest and most straightforward but performance constrained, and the last being the most abstract. These methods aren't mutually exclusive and the specific implementation details could vary greatly based on the designer's discretion. Basic recommendations are provided to organize model logic in a format most easily amenable to integration with existing Matlab control toolsets.

  19. Detached eddy simulation of cyclic large scale fluctuations in a simplified engine setup

    International Nuclear Information System (INIS)

    Hasse, Christian; Sohm, Volker; Durst, Bodo

    2009-01-01

    Computational Fluid Dynamics using RANS-based modelling approaches have become an important tool in the internal combustion engine development and optimization process. However, these models cannot resolve cycle to cycle variations, which are an important aspect in the design of new combustion systems. In this study the feasibility of using a Detached Eddy Simulation (DES) SST model, which is a hybrid RANS/LES model, to predict cycle to cycle variations is investigated. In the near wall region or in regions where the grid resolution is not sufficiently fine to resolve smaller structures, the two-equation RANS SST model is used. In the other regions with higher grid resolution an LES model is applied. The case considered is a geometrically simplified engine, for which detailed experimental data for the ensemble averaged and single cycle velocity field are available from Boree et al. [Boree, J., Maurel, S., Bazile, R., 2002. Disruption of a compressed vortex, Physics of Fluids 14 (7), 2543-2556]. The fluid flow shows a strong tumbling motion, which is a major characteristic for modern turbo-charged, direct-injection gasoline engines. The general flow structure is analyzed first and the extent of the LES region and the amount of resolved fluctuations are discussed. Multiple consecutive cycles are computed and turbulent statistics of DES SST, URANS and the measured velocity field are compared for different piston positions. Cycle to cycle variations of the velocity field are analyzed for both computation and experiment with a special emphasis on the useability of the DES SST model to predict cyclic variations

  20. A PC/workstation cluster computing environment for reservoir engineering simulation applications

    International Nuclear Information System (INIS)

    Hermes, C.E.; Koo, J.

    1995-01-01

    Like the rest of the petroleum industry, Texaco has been transferring its applications and databases from mainframes to PC's and workstations. This transition has been very positive because it provides an environment for integrating applications, increases end-user productivity, and in general reduces overall computing costs. On the down side, the transition typically results in a dramatic increase in workstation purchases and raises concerns regarding the cost and effective management of computing resources in this new environment. The workstation transition also places the user in a Unix computing environment which, to say the least, can be quite frustrating to learn and to use. This paper describes the approach, philosophy, architecture, and current status of the new reservoir engineering/simulation computing environment developed at Texaco's E and P Technology Dept. (EPTD) in Houston. The environment is representative of those under development at several other large oil companies and is based on a cluster of IBM and Silicon Graphics Intl. (SGI) workstations connected by a fiber-optics communications network and engineering PC's connected to local area networks, or Ethernets. Because computing resources and software licenses are shared among a group of users, the new environment enables the company to get more out of its investments in workstation hardware and software

  1. COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

    Directory of Open Access Journals (Sweden)

    Nureddin Dinler

    2010-01-01

    Full Text Available Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1 has longer combustion duration.

  2. An Experimental and Simulation Study of Early Flame Development in a Homogeneous-charge Spark-Ignition Engine

    Directory of Open Access Journals (Sweden)

    Shekhawat Y.

    2017-09-01

    Full Text Available An integrated experimental and Large-Eddy Simulation (LES study is presented for homogeneous premixed combustion in a spark-ignition engine. The engine is a single-cylinder two-valve optical research engine with transparent liner and piston: the Transparent Combustion Chamber (TCC engine. This is a relatively simple, open engine configuration that can be used for LES model development and validation by other research groups. Pressure-based combustion analysis, optical diagnostics and LES have been combined to generate new physical insight into the early stages of combustion. The emphasis has been on developing strategies for making quantitative comparisons between high-speed/high-resolution optical diagnostics and LES using common metrics for both the experiments and the simulations, and focusing on the important early flame development period. Results from two different LES turbulent combustion models are presented, using the same numerical methods and computational mesh. Both models yield Cycle-to-Cycle Variations (CCV in combustion that are higher than what is observed in the experiments. The results reveal strengths and limitations of the experimental diagnostics and the LES models, and suggest directions for future diagnostic and simulation efforts. In particular, it has been observed that flame development between the times corresponding to the laminar-to-turbulent transition and 1% mass-burned fraction are especially important in establishing the subsequent combustion event for each cycle. This suggests a range of temporal and spatial scales over which future experimental and simulation efforts should focus.

  3. Multiscale paradigms in integrated computational materials science and engineering materials theory, modeling, and simulation for predictive design

    CERN Document Server

    Runge, Keith; Muralidharan, Krishna

    2016-01-01

    This book presents cutting-edge concepts, paradigms, and research highlights in the field of computational materials science and engineering, and provides a fresh, up-to-date perspective on solving present and future materials challenges. The chapters are written by not only pioneers in the fields of computational materials chemistry and materials science, but also experts in multi-scale modeling and simulation as applied to materials engineering. Pedagogical introductions to the different topics and continuity between the chapters are provided to ensure the appeal to a broad audience and to address the applicability of integrated computational materials science and engineering for solving real-world problems.

  4. Building energy analysis of Electrical Engineering Building from DesignBuilder tool: calibration and simulations

    Science.gov (United States)

    Cárdenas, J.; Osma, G.; Caicedo, C.; Torres, A.; Sánchez, S.; Ordóñez, G.

    2016-07-01

    This research shows the energy analysis of the Electrical Engineering Building, located on campus of the Industrial University of Santander in Bucaramanga - Colombia. This building is a green pilot for analysing energy saving strategies such as solar pipes, green roof, daylighting, and automation, among others. Energy analysis was performed by means of DesignBuilder software from virtual model of the building. Several variables were analysed such as air temperature, relative humidity, air velocity, daylighting, and energy consumption. According to two criteria, thermal load and energy consumption, critical areas were defined. The calibration and validation process of the virtual model was done obtaining error below 5% in comparison with measured values. The simulations show that the average indoor temperature in the critical areas of the building was 27°C, whilst relative humidity reached values near to 70% per year. The most critical discomfort conditions were found in the area of the greatest concentration of people, which has an average annual temperature of 30°C. Solar pipes can increase 33% daylight levels into the areas located on the upper floors of the building. In the case of the green roofs, the simulated results show that these reduces of nearly 31% of the internal heat gains through the roof, as well as a decrease in energy consumption related to air conditioning of 5% for some areas on the fourth and fifth floor. The estimated energy consumption of the building was 69 283 kWh per year.

  5. Simulation of how a geo-engineering intervention to restore arctic sea ice might work in practice

    Science.gov (United States)

    Jackson, L. S.; Crook, J. A.; Forster, P.; Jarvis, A.; Leedal, D.; Ridgwell, A. J.; Vaughan, N.

    2013-12-01

    The declining trend in annual minimum Arctic sea ice coverage and years of more pronounced drops like 2007 and 2012 raise the prospect of an Arctic Ocean largely free of sea ice in late summer and the potential for a climate crisis or emergency. In a novel computer simulation, we treated one realisation of a climate model (HadGEM2) as the real world and tried to restore its Arctic sea ice by the rapid deployment of geo-engineering with emission of SO2 into the Arctic stratosphere. The objective was to restore the annual minimum Arctic sea ice coverage to levels seen in the late twentieth century using as little geo-engineering as possible. We took intervention decisions as one might do in the real world: by committee, using a limited set of uncertain 'observations' from our simulated world and using models and control theory to plan the best intervention strategy for the coming year - so learning as we went and being thrown off course by future volcanoes and technological breakdowns. Uncertainties in real world observations were simulated by applying noise to emerging results from the climate model. Volcanic forcing of twenty-first century climate was included with the timing and magnitude of the simulated eruptions unknown by the 'geo-engineers' until after the year of the eruption. Monitoring of Arctic sea ice with the option to intervene with SO2 emissions started from 2018 and continued to 2075. Simulated SO2 emissions were made in January-May each year at a latitude of 79o N and an altitude within the range of contemporary tanker aircraft. The magnitude of emissions was chosen annually using a model predictive control process calibrated using results from CMIP5 models (excluding HadGEM2), using the simplified climate model MAGICC and assimilation of emerging annual results from the HadGEM2 'real world'. We found that doubts in the minds of the 'geo-engineers' of the effectiveness and the side effects of their past intervention, and the veracity of the models

  6. SARIE upgrade: Nuclear reactor and water systems 'engineering and training' simulator

    International Nuclear Information System (INIS)

    Roth, P.

    2006-01-01

    Confronted as of its origins with the on-board layout constraints of the French Navy ships, TECHNICATOME integrates, as of the design, the ergonomics and the risks control related to the human factors. During more than 30 years, TECHNICATOME demonstrated a one of a kind know-how from the design to the execution of powerful, flexible and highly available nuclear compact reactors. A total control which includes up to the supervision and monitoring systems, the acoustic discreetly of the systems and its components, implemented on on-board reactors, testing reactors as well as experimental reactors. The functionalities of simulation were right from the start used by TECHNICATOME during the design phase of these installations to carry out operation engineering analyses on the thermal hydraulic and neutron aspects, to validate the principles of operation of the supervision systems like by the use of digital models in 3D CAD to validate the kinematics of operation or the interactions between systems. More recently, and starting from the end of the Nineties, a thought needs was launched to determine the interests related to the development of a training simulator associated with these installations with objectives, among others, to ensure the phase of initial training of the new operators, to widen the field of the training to the accidental situations, the management of crisis and crews behaviour supervision, the possibilities of replay which support the consolidation of the acquired knowledge(debriefing) with situation resume, and to increase the overall training capacity. An upgrade and modernisation project of these various simulation means was thus launched since 2001 with the objective to optimize the whole of the tasks supported by these means. (author)

  7. Prediction of cold start hydrocarbon emissions of air cooled two wheeler spark ignition engines by simple fuzzy logic simulation

    Directory of Open Access Journals (Sweden)

    Samuel Raja Ayyanan

    2014-01-01

    Full Text Available The cold start hydrocarbon emission from the increasing population of two wheelers in countries like India is one of the research issues to be addressed. This work describes the prediction of cold start hydrocarbon emissions from air cooled spark ignition engines through fuzzy logic technique. Hydrocarbon emissions were experimentally measured from test engines of different cubic capacity, at different lubricating oil temperature and at different idling speeds with and without secondary air supply in exhaust. The experimental data were used as input for modeling average hydrocarbon emissions for 180 seconds counted from cold start and warm start of gasoline bike engines. In fuzzy logic simulation, member functions were assigned for input variables (cubic capacity and idling rpm and output variables (average hydrocarbon emission for first 180 seconds at cold start and warm start. The knowledge based rules were adopted from the analyzed experimental data and separate simulations were carried out for predicting hydrocarbon emissions from engines equipped with and without secondary air supply. The simulation yielded the average hydrocarbon emissions of air cooled gasoline engine for a set of given input data with accuracy over 90%.

  8. Developing an edugame simulation application for engineering : It works in practice, but will it work in theory?

    NARCIS (Netherlands)

    Keenaghan, G.; Horvath, I.; Van der Vegte, W.F.

    2015-01-01

    This article describes the development of a web-based 3D simulation of an engineering workshop in refrigeration plant maintenance and the challenge of moving the application from a knowledge and skills acquisition model to a problem-solving edugame model across a range of possible scenarios within

  9. Model-Based Control of a Nonlinear Aircraft Engine Simulation using an Optimal Tuner Kalman Filter Approach

    Science.gov (United States)

    Connolly, Joseph W.; Csank, Jeffrey Thomas; Chicatelli, Amy; Kilver, Jacob

    2013-01-01

    This paper covers the development of a model-based engine control (MBEC) methodology featuring a self tuning on-board model applied to an aircraft turbofan engine simulation. Here, the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) serves as the MBEC application engine. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC over a wide range of operating points. The on-board model is a piece-wise linear model derived from CMAPSS40k and updated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. Investigations using the MBEC to provide a stall margin limit for the controller protection logic are presented that could provide benefits over a simple acceleration schedule that is currently used in traditional engine control architectures.

  10. Simulation as a tool for architectural design and evaluation. Resolved patterns from engineering

    Directory of Open Access Journals (Sweden)

    Johanna Trujillo

    2016-04-01

    Full Text Available La simulación como herramienta de diseño y evaluación arquitectónica. Pautas resueltas desde la ingenieríaResumenSe presenta un panorama sobre la importancia del proceso de diseño sostenible aplicado a las edificaciones. Teniendo en cuenta que el sector de la construcción es una de las áreas de más alto impacto ambiental, es importante analizar cuáles serían los nuevos procesos de diseño de las edificaciones en términos de sostenibilidad. Estos conceptos se aplicaron a un estudio de caso por medio de la simulación discreta, la cual permite una evaluación de la capacidad en un edificio junto con sus recursos, a fin de tomar decisiones de ampliación en el proceso de diseño arquitectónico. Los datos se analizaron en el programa estadístico SPSS y se simularon en ProModel. El modelo pedagógico propuesto puede llegar a ser de utilidad al momento de aplicarse en un contexto multidisciplinar, en donde interactúen estudiantes de ingeniería industrial y arquitectura. Este ejercicio puede aplicarse en las aulas de clase; con él se reducirían los tiempos de diseño, y la comunicación entre estudiantes mejoraría porque implica el trabajo multidisciplinar.Palabras clave: diseño arquitectónico, edificios industriales, educación arquitectónica, industria de la construcción, ingeniería industrial.Simulation as a tool for architectural design and evaluation. Resolved patterns from engineeringAbstractAn overview of the importance of sustainable design process applied to buildings is presented. Given that the field of construction is one of the areas with the highest environmental impact, it is important to analyze what would be the new design processes for buildings in terms of sustainability. These concepts were applied to a case study using discrete simulation, which allows an assessment of capacity building along with its resources, to make decisions expansion in the architectural design process. Data were analyzed in the SPSS

  11. A direct numerical simulation of cool-flame affected autoignition in diesel engine-relevant conditions

    Energy Technology Data Exchange (ETDEWEB)

    Krisman, Alexander; Hawkes, Evatt Robert.; Talei, Mohsen; Bhagatwala, Ankit; Chen, Jacqueline H.

    2016-11-11

    In diesel engines, combustion is initiated by a two-staged autoignition that includes both low- and high-temperature chemistry. The location and timing of both stages of autoignition are important parameters that influence the development and stabilisation of the flame. In this study, a two-dimensional direct numerical simulation (DNS) is conducted to provide a fully resolved description of ignition at diesel engine-relevant conditions. The DNS is performed at a pressure of 40 atmospheres and at an ambient temperature of 900 K using dimethyl ether (DME) as the fuel, with a 30 species reduced chemical mechanism. At these conditions, similar to diesel fuel, DME exhibits two-stage ignition. The focus of this study is on the behaviour of the low-temperature chemistry (LTC) and the way in which it influences the high-temperature ignition. The results show that the LTC develops as a “spotty” first-stage autoignition in lean regions which transitions to a diffusively supported cool-flame and then propagates up the local mixture fraction gradient towards richer regions. The cool-flame speed is much faster than can be attributed to spatial gradients in first-stage ignition delay time in homogeneous reactors. The cool-flame causes a shortening of the second-stage ignition delay times compared to a homogeneous reactor and the shortening becomes more pronounced at richer mixtures. Multiple high-temperature ignition kernels are observed over a range of rich mixtures that are much richer than the homogeneous most reactive mixture and most kernels form much earlier than suggested by the homogeneous ignition delay time of the corresponding local mixture. Altogether, the results suggest that LTC can strongly influence both the timing and location in composition space of the high-temperature ignition.

  12. Co-simulation of building energy simulation and computational fluid dynamics for whole-building heat, air and moisture engineering

    NARCIS (Netherlands)

    Mirsadeghi, M.

    2011-01-01

    Building performance simulation (BPS) is widely applied to analyse heat, air and moisture (HAM) related issues in the indoor environment such as energy consumption, thermal comfort, condensation and mould growth. The uncertainty associated with such simulations can be high, and incorrect simulation

  13. A cycle simulation model for predicting the performance of a diesel engine fuelled by diesel and biodiesel blends

    International Nuclear Information System (INIS)

    Gogoi, T.K.; Baruah, D.C.

    2010-01-01

    Among the alternative fuels, biodiesel and its blends are considered suitable and the most promising fuel for diesel engine. The properties of biodiesel are found similar to that of diesel. Many researchers have experimentally evaluated the performance characteristics of conventional diesel engines fuelled by biodiesel and its blends. However, experiments require enormous effort, money and time. Hence, a cycle simulation model incorporating a thermodynamic based single zone combustion model is developed to predict the performance of diesel engine. The effect of engine speed and compression ratio on brake power and brake thermal efficiency is analysed through the model. The fuel considered for the analysis are diesel, 20%, 40%, 60% blending of diesel and biodiesel derived from Karanja oil (Pongamia Glabra). The model predicts similar performance with diesel, 20% and 40% blending. However, with 60% blending, it reveals better performance in terms of brake power and brake thermal efficiency.

  14. A brief account of Kozloduy 6 full-scope replica control room simulator upgrade experience: An engineering point of view

    International Nuclear Information System (INIS)

    Dinkov, Y.D.

    2006-01-01

    A short excursion throughout Kozloduy NPP history, and Kozloduy 6 Full-Scope Replica Control Room Simulator procurement, is proposed for a reader, which is not familiar with the Kozloduy circumstances. A brief account of five year operation and upgrade experience is presented as seen by the Kozloduy simulator engineering team. During the last five years Kozloduy 6 is going through a complex and expensive modernization programme so Simulator is a subject of a series of changes twice per year. Simulator is used for training six months of the year during spring and autumn most of this time in two shifts daily. Remaining six months during winter and summer are allocated to other simulator uses including five months downtime for hardware reconstruction, software integration, troubleshooting and testing. Quantitative information concerning scope of software and hardware changes is given. Kozloduy NPP simulator engineering team approach toward various upgrade projects is given in an attempt to facilitate a discussion about how a simulator upgrade should be performed. Projects mentioned vary from small to big, in-house or contracted, already completed or planned for future realization

  15. Investigation the performance of 0-D and 3-d combustion simulation softwares for modelling HCCI engine with high air excess ratios

    Directory of Open Access Journals (Sweden)

    Gökhan Coşkun

    2017-10-01

    Full Text Available In this study, performance of zero and three dimensional simulations codes that used for simulate a homogenous charge compression ignition (HCCI engine fueled with Primary Reference Fuel PRF (85% iso-octane and 15% n-heptane were investigated. 0-D code, called as SRM Suite (Stochastic Reactor Model which can simulate engine combustion by using stochastic reactor model technique were used. Ansys-Fluent which can simulate computational fluid dynamics (CFD was used for 3-D engine combustion simulations. Simulations were evaluated for both commercial codes in terms of combustion, heat transfer and emissions in a HCCI engine. Chemical kinetic mechanisms which developed by Tsurushima including 33 species and 38 reactions for surrogate PRF fuel were used for combustion simulations. Analysis showed that both codes have advantages over each other.

  16. High-fidelity simulation of turbofan engine. ; Verification and improvement of model's dynamical characteristics in linear operating range. Turbofan engine no koseito simulation. ; Senkei sado han'i ni okeru model dotokusei no kensho to seido kojo ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, H; Kagiyama, S [Defence Agency, Tokyo (Japan)

    1993-09-25

    This paper describes providing pulse inputs to a fuel supply in trial operation of a turbofan engine, measurement of its response, and calculation of the frequency characteristics and time constants to acquire dynamic characteristics of the engine on the ground. The resultant engine characteristics were compared with the model characteristics of numerically analyzing a mathematical simulation model, and corrected to develop a high-accuracy simulation model. An element model and a dynamics model were prepared in detail on the main engine components, such as fans, a compressor, a combustor, and a turbine, along a flow diagram from the air intake opening to the exhaust nozzle. The pulses were inputted into the fuel supply by opening and closing an electromagnetic valve. Closing of the illustrated electromagnetic valve for about 0.7 second caused a difference (of phase and trend) in both characteristics of high and low frequencies as a result of pulse-like change in the flow rate. To correct the model characteristics, the combustion delay tie was set to 0.02 second upon considering the combustion delay time relative to the heat capacity of the combustor. Improvement in the model was verified as the phase characteristics was approximated to the engine characteristics. 13 refs., 17 figs., 2 tabs.

  17. Improvement of D.I. diesel engine combustion using numerical simulation; Chokufun diesel kikan no nensho kaizen shuho. Suchi kaiseki ni yoru torikumi

    Energy Technology Data Exchange (ETDEWEB)

    Minami, T.; Adachi, T.; Isyii, Y. [Isuzu Motors Ltd., Tokyo (Japan)

    1999-04-01

    For the purpose of improving DI diesel engine combustion, it is important to predict air flow of intake and exhaust manifold, intake port flow, combustion chamber swirl and fuel spray combustion. This paper describes the application of numerical simulation to the engines, the analysis of phenomena and a problem of simulation model modification. (author)

  18. Minimizing the Discrepancy between Simulated and Historical Failures in Turbine Engines: A Simulation-Based Optimization Method

    OpenAIRE

    Ahmed Kibria; Krystel K. Castillo-Villar; Harry Millwater

    2015-01-01

    The reliability modeling of a module in a turbine engine requires knowledge of its failure rate, which can be estimated by identifying statistical distributions describing the percentage of failure per component within the turbine module. The correct definition of the failure statistical behavior per component is highly dependent on the engineer skills and may present significant discrepancies with respect to the historical data. There is no formal methodology to approach this problem and a l...

  19. MATHEMATICAL SIMULATION AND AUTOMATION OF PROCESS ENGINEERING FOR WELDED STRUCTURE PRODUCTION

    Directory of Open Access Journals (Sweden)

    P. V. Zankovets

    2017-01-01

    Full Text Available Models and methods for presentation of database and knowledge base have been developed on the basis of composition and structure of data flow in technological process of welding. The information in data and knowledge base is presented in the form of multilevel hierarchical structure and it is organized according to its functionality in the form of separate files. Each file contains a great number of tables. While using mathematical simulation and information technologies an expert system has been developed with the purpose to take decisions in designing and process engineering for production of welded ructures. The system makes it possible to carry out technically substantiated selection of welded and welding materials, sttypes of welded connections, welding methods, parameters and modes of welding. The developed system allows to improve quality of the accepted design decisions due to reduction of manual labour costs for work with normative-reference documentation, analysis and evaluation of dozens of possible alternatives. The system also permits to reduce labour inputs for testing structures on technological effectiveness, to ensure reduction of materials consumption for welded structures, to guarantee faultless formation of welded connections at this stage.

  20. Effects of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated engine conditions

    KAUST Repository

    Zhang, Ji

    2013-08-01

    This study investigates the effect of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated compression-ignition engine conditions in a constant-volume chamber. The apparent heat release rate (AHRR) is calculated based on the measured pressure. High-speed imaging of OH* chemiluminescence and natural luminosity (NL) is employed to visualize the combustion process. Temporally and spatially resolved NL and OH* contour plots are obtained. The result indicates that AHRR depends monotonically on the ambient oxygen concentration for both fuels. A lower oxygen concentration yields a slower AHRR increase rate, a lower peak AHRR value, but a higher AHRR value during the burn-out stage when compared with higher ambient oxygen concentration conditions. OH* chemiluminescence and NL contours indicate that biodiesel may experience a longer premixed-combustion duration. The 18% ambient O2 condition works better for biodiesel than diesel in reducing soot luminosity. With 12% O2, diesel combustion is significantly degraded. However, both fuels experience low temperature combustion at 10% O2. These results may imply that biodiesel is able to achieve the desired lower soot production under a moderate oxygen level with higher combustion efficiency, while diesel needs to be burned under very low ambient oxygen concentration for low soot production. © 2013 Elsevier Ltd.

  1. Effects of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated engine conditions

    KAUST Repository

    Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang

    2013-01-01

    This study investigates the effect of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated compression-ignition engine conditions in a constant-volume chamber. The apparent heat release rate (AHRR) is calculated based on the measured pressure. High-speed imaging of OH* chemiluminescence and natural luminosity (NL) is employed to visualize the combustion process. Temporally and spatially resolved NL and OH* contour plots are obtained. The result indicates that AHRR depends monotonically on the ambient oxygen concentration for both fuels. A lower oxygen concentration yields a slower AHRR increase rate, a lower peak AHRR value, but a higher AHRR value during the burn-out stage when compared with higher ambient oxygen concentration conditions. OH* chemiluminescence and NL contours indicate that biodiesel may experience a longer premixed-combustion duration. The 18% ambient O2 condition works better for biodiesel than diesel in reducing soot luminosity. With 12% O2, diesel combustion is significantly degraded. However, both fuels experience low temperature combustion at 10% O2. These results may imply that biodiesel is able to achieve the desired lower soot production under a moderate oxygen level with higher combustion efficiency, while diesel needs to be burned under very low ambient oxygen concentration for low soot production. © 2013 Elsevier Ltd.

  2. Plastic forming simulation analysis of marine engine crankshaft single-throw

    Directory of Open Access Journals (Sweden)

    LIU Peipei

    2016-08-01

    Full Text Available The research object is for marine engine crankshaft single-throw.A 3D model of the crankshaft single-throw blank and die in forging process is established by SolidWorks software,then the 3D model is imported into metal plastic forming CAE software DEFROM-3D to carry on the plastic forming simulation,to verify the relationship between the internal flow stress and the external deformation conditions in the process of metal plastic deformation under different strain rate and temperature,and to carry on the scientific analysis based on the obtained data.The result shows that the preset temperature is higher,the stress-strain curve is relatively lower when the strain rate is constant.Sample internal flow stress will be greater and the resistance to fatigue strength will be poorer at a higher strain rate when the temperature of the blank is constant.The result also provides a theoretical basis for further optimization design.

  3. Engineering Task Plan for simulated riser installation by use of rotary drilling

    International Nuclear Information System (INIS)

    Barnes, G.A.

    1995-12-01

    This task is being performed to demonstrate the feasibility of the best riser installation alternative identified in the Engineering Study. This Engineering Task Plan (ETP) will be the WHC project management plan for the riser installation demonstration activities

  4. Comparison of aldehyde emissions simulation with FTIR measurements in the exhaust of a spark ignition engine fueled by ethanol

    Science.gov (United States)

    Zarante, Paola Helena Barros; Sodré, José Ricardo

    2018-02-01

    This work presents a numerical simulation model for aldehyde formation and exhaust emissions from ethanol-fueled spark ignition engines. The aldehyde simulation model was developed using FORTRAN software, with the input data obtained from the dedicated engine cycle simulation software AVL BOOST. The model calculates formaldehyde and acetaldehyde concentrations from post-flame partial oxidation of methane, ethane and unburned ethanol. The calculated values were compared with experimental data obtained from a mid-size sedan powered by a 1.4-l spark ignition engine, tested on a chassis dynamometer. Exhaust aldehyde concentrations were determined using a Fourier Transform Infrared (FTIR) Spectroscopy analyzer. In general, the results demonstrate that the concentrations of aldehydes and the source elements increased with engine speed and exhaust gas temperature. The measured acetaldehyde concentrations showed values from 3 to 6 times higher than formaldehyde in the range studied. The model could predict reasonably well the qualitative experimental trends, with the quantitative results showing a maximum discrepancy of 39% for acetaldehyde concentration and 21 ppm for exhaust formaldehyde.

  5. Analysis the ECFM-3Z Combustion Model for Simulating the Combustion Process and Emission Characteristics in a HSDI Diesel Engine

    Directory of Open Access Journals (Sweden)

    Raouf Mobasheri

    2015-12-01

    Full Text Available An advanced CFD simulation has been performed to analyze the ECFM-3Z (Extended Coherent Flame Model-3Z combustion model for simulating the combustion process and emission characteristics in a high speed direct injection (HSDI diesel engine. A four cylinders, HSDI diesel engine based on a Ford production engine with a 2nd generation Delphi common rail fuel injection system has been modeled in this research. 3D CFD simulation was carried out from intake valve closing (IVC to exhaust valve opening (EVO. A good agreement of calculated and measured in-cylinder pressure trace as well as pollutant formation trends could be observed for all investigated operating points. Based on the confidence gained from validation, the study is extended to evaluate the effect of fuel injection timing on engine performance and emissions. For this purpose, a comprehensive study of the effect of injection timing with respect to performance and emissions has been considered. Three main injection timing, (1 2.65 BTDC, (2 0.65 BTDC and (3 1.35 ATDC, all with 30 crank angle pilot separations has been used to investigate the effect of the injection timing. The results show that the current methodology can be applied as a beneficial tool for analyzing the parameters of the diesel combustion under HSDI operating condition.

  6. Preliminary Results from Simulations of Temperature Oscillations in Stirling Engine Regenerator Matrices

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Carlsen, Henrik; Thomsen, Per Grove

    2006-01-01

    The objective of this study has been to create a Stirling engine model for studying the effects of regenerator matrix temperature oscillations on Stirling engine performance. A one-dimensional model with axial discretisation of engine components has been formulated using the control volume method...

  7. Simulation and control of a HD diesel engine equipped with new EGR technology

    NARCIS (Netherlands)

    Dekker, H.J.; Sturm, W.L.

    1996-01-01

    A dynamic model of a Heavy Duty (HD) turbocharged and aftercooled diesel engine was developed. The engine was equipped with high pressure diesel injection, a Variable Geometry Turbine (VGT) and an Exhaust Gas Recirculation (EGR) system. This engine was targeted at meeting EURO4 emission

  8. Stable Operation and Electricity Generating Characteristics of a Single-Cylinder Free Piston Engine Linear Generator: Simulation and Experiments

    Directory of Open Access Journals (Sweden)

    Huihua Feng

    2015-01-01

    Full Text Available We present a novel design of a single-cylinder free piston engine linear generator (FPELG incorporating a linear motor as a rebound device. A systematic simulation model of this FPELG system was built containing a kinematic and dynamic model of the piston and mover, a magneto-electric model of the linear generator, a thermodynamic model of the single-cylinder engine, and a friction model between the piston ring and cylinder liner. Simulations were performed to understand the relationships between pre-set motor parameters and the running performance of the FPELG. From the simulation results, it was found that a motor rebound force with a parabolic profile had clear advantages over a force with a triangular profile, such as a higher running frequency and peak cylinder pressure, faster piston motion, etc. The rebound position and the amplitude of rebound force were also determined by simulations. The energy conversion characteristics of the generator were obtained from our FPELG test rig. The parameters of intake pressure, motor frequency, and load resistance were varied over certain ranges, and relationships among these three parameters were obtained. The electricity-generating characteristic parameters include output power and system efficiency, which can measure the quality of matching the controllable parameters. The output power can reach 25.9 W and the system efficiency can reach 13.7%. The results in terms of matching parameters and electricity-generating characteristics should be useful to future research in adapting these engines to various operating modes.

  9. Simulation of a hot air engine for a generation of electricity using biogas for Tanzania rural application

    International Nuclear Information System (INIS)

    Mkiramweni, L.L.N.; Msaki, P.; Mshoro, I.B.

    2007-01-01

    At the moment, about 80% of the rural population in Tanzania lacks grid electricity. As a result, up to 90% of energy requirements in rural areas are met by firewood and hence causing deforestation. In the present paper, the authors are advocating the application of biogas to generate electricity in rural areas to minimise deforestation. Preliminary study conducted has shown that the power required in rural areas is about 10kW for household and small economic activities. As such, the authors have investigated the possibility of applying a hot air engine using biogas as a source of energy to generate electricity. The study involved simulation of hot air engine using a Stirling Numerical Analysis Program (SNAP) with use modifiable code. In the exercise, the performance of the simulated engine was assessed with helium, hydrogen and air as working media. Reheat loss and pressure losses were also assessed for varies range of engine power and efficiency. It has been observed that with helium and hydrogen as working gas, the power output could easily reach 10kW, which is sufficient for rural household application. However, with air the engine could realise only 4kW under similar conditions. It has further been observed that air has bigger and more viscous molecular with lower thermal conductivity and heat capacity, which results in higher losses. This implies that a relatively bigger engine need be employed for running with air. However, high initial cost will be offset by the reduction in operating cost, since air is freely available. For proper operation of the engine heater temperature should be maintained above 630(deg)C, which is realizable with biogas having a flame temperature of about 870(deg)C. (author)

  10. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  11. WTEC Panel Report on International Assessment of Research and Development in Simulation-Based Engineering and Science

    Energy Technology Data Exchange (ETDEWEB)

    Glotzer, S. C.; Kim, S.; Cummings, P. T.; Deshmukh, A.; Head-Gordon, M.; Karniadakis, G.; Petzold, L.; Sagui, C.; Shinozuka, M.

    2013-07-30

    This WTEC panel report assesses the international research and development activities in the field of Simulation- Based Engineering and Science (SBE&S). SBE&S involves the use of computer modeling and simulation to solve mathematical formulations of physical models of engineered and natural systems. SBE&S today has reached a level of predictive capability that it now firmly complements the traditional pillars of theory and experimentation/observation. As a result, computer simulation is more pervasive today – and having more impact – than at any other time in human history. Many critical technologies, including those to develop new energy sources and to shift the cost-benefit factors in healthcare, are on the horizon that cannot be understood, developed, or utilized without simulation. A panel of experts reviewed and assessed the state of the art in SBE&S as well as levels of activity overseas in the broad thematic areas of life sciences and medicine, materials, and energy and sustainability; and in the crosscutting issues of next generation hardware and algorithms; software development; engineering simulations; validation, verification, and uncertainty quantification; multiscale modeling and simulation; and SBE&S education. The panel hosted a U.S. baseline workshop, conducted a bibliometric analysis, consulted numerous experts and reports, and visited 59 institutions and companies throughout East Asia and Western Europe to explore the active research projects in those institutions, the computational infrastructure used for the projects, the funding schemes that enable the research, the collaborative interactions among universities, national laboratories, and corporate research centers, and workforce needs and development for SBE&S.

  12. Rotary kiln incinerator engineering tests on simulated transuranic wastes from the Idaho National Engineering Laboratory. Final report

    International Nuclear Information System (INIS)

    Pattengill, M.G.; Brunner, F.A.; Fasso, J.L.; Mitchel, S.R.; Praskac, R.T.

    1982-09-01

    Nine rotary kiln incineration tests were performed at Colorado School of Mines Research Institute on simulated transuranic waste materials. The rotary kiln incinerator used as 3 ft ID and 30 ft long and was included in an incineration system that also included an afterburner and a baghouse. The purpose of the incineration test program was to determine the applicability and operating characteristics of the rotary kiln with relation to the complete incineration of the simulated waste materials. The results of the study showed that the rotary kiln did completely incinerate the waste materials. Off-gas determinations showed emission levels of SO 2 , NO/sub x/, H 2 SO 4 , HC1, particulate loading, and hydrocarbons, as well as exhaust gas volume, to be within reasonable controllable ranges in a production operation. Included in the report are the results of materials and energy balances, based upon data collected, and design recommendations based upon the data and upon observations during the incineration operation

  13. Simulation research on the effect of cooled EGR, supercharging and compression ratio on downsized SI engine knock

    Science.gov (United States)

    Shu, Gequn; Pan, Jiaying; Wei, Haiqiao; Shi, Ning

    2013-03-01

    Knock in spark-ignition(SI) engines severely limits engine performance and thermal efficiency. The researches on knock of downsized SI engine have mainly focused on structural design, performance optimization and advanced combustion modes, however there is little for simulation study on the effect of cooled exhaust gas recirculation(EGR) combined with downsizing technologies on SI engine performance. On the basis of mean pressure and oscillating pressure during combustion process, the effect of different levels of cooled EGR ratio, supercharging and compression ratio on engine dynamic and knock characteristic is researched with three-dimensional KIVA-3V program coupled with pressure wave equation. The cylinder pressure, combustion temperature, ignition delay timing, combustion duration, maximum mean pressure, and maximum oscillating pressure at different initial conditions are discussed and analyzed to investigate potential approaches to inhibiting engine knock while improving power output. The calculation results of the effect of just cooled EGR on knock characteristic show that appropriate levels of cooled EGR ratio can effectively suppress cylinder high-frequency pressure oscillations without obvious decrease in mean pressure. Analysis of the synergistic effect of cooled EGR, supercharging and compression ratio on knock characteristic indicates that under the condition of high supercharging and compression ratio, several times more cooled EGR ratio than that under the original condition is necessarily utilized to suppress knock occurrence effectively. The proposed method of synergistic effect of cooled EGR and downsizing technologies on knock characteristic, analyzed from the aspects of mean pressure and oscillating pressure, is an effective way to study downsized SI engine knock and provides knock inhibition approaches in practical engineering.

  14. A computer simulation of the turbocharged turbo compounded diesel engine system: A description of the thermodynamic and heat transfer models

    Science.gov (United States)

    Assanis, D. N.; Ekchian, J. E.; Frank, R. M.; Heywood, J. B.

    1985-01-01

    A computer simulation of the turbocharged turbocompounded direct-injection diesel engine system was developed in order to study the performance characteristics of the total system as major design parameters and materials are varied. Quasi-steady flow models of the compressor, turbines, manifolds, intercooler, and ducting are coupled with a multicylinder reciprocator diesel model, where each cylinder undergoes the same thermodynamic cycle. The master cylinder model describes the reciprocator intake, compression, combustion and exhaust processes in sufficient detail to define the mass and energy transfers in each subsystem of the total engine system. Appropriate thermal loading models relate the heat flow through critical system components to material properties and design details. From this information, the simulation predicts the performance gains, and assesses the system design trade-offs which would result from the introduction of selected heat transfer reduction materials in key system components, over a range of operating conditions.

  15. Shaping ability of NT Engine and McXim rotary nickel-titanium instruments in simulated root canals. Part 1.

    Science.gov (United States)

    Thompson, S A; Dummer, P M

    1997-07-01

    The aim of this study was to determine the shaping ability of NT Engine and McXim nickel-titanium rotary instruments in simulated root canals. In all, 40 canals consisting of four different shapes in terms of angle and position of curvature were prepared by a combination of NT Engine and McXim instruments using the technique recommended by the manufacturer. Part 1 of this two-part report describes the efficacy of the instruments in terms of preparation time, instrument failure, canal blockages, loss of canal length and three-dimensional canal form. Overall, the mean preparation time for all canals was 6.01 min, with canal shape having a significant effect (P Engine and McXim instruments prepared canals rapidly, with few deformations, no canal blockages and with minimal change in working length. The three-dimensional form of the canals demonstrated good flow and taper characteristics.

  16. A study on the 0D phenomenological model for diesel engine simulation: Application to combustion of Neem methyl esther biodiesel

    International Nuclear Information System (INIS)

    Ngayihi Abbe, Claude Valery; Nzengwa, Robert; Danwe, Raidandi; Ayissi, Zacharie Merlin; Obonou, Marcel

    2015-01-01

    Highlights: • We elaborate a 0D model for prediction of diesel engine operating parameters. • We implement the model for Neem methyl ester biodiesel combustion. • We show methyl butanoate and butyrate can be used as surrogates for biodiesel. • The model predicts fuel spray, in cylinder gaseous state and NOx emissions. • We show the model can be effective both in accuracy and computational speed. - Abstract: The design and monitoring of modern diesel engines running on alternative fuels require reliable models that can validly substitute experimental tests and predict their operating characteristics under different load conditions. Although there exists a multitude of models for diesel engines, 0D phenomenological models present the advantages of giving fast and accurate computed results. These models are useful for predicting fuel spray characteristics and instantaneous gas state. However, there are few reported studies on the application of 0D phenomenological models on biodiesel fuel combustion in diesel engines. This work reports the elaboration, validation and application on Neem methyl ester biodiesel (NMEB) combustion of a 0D phenomenological model for diesel engine simulation. The model addresses some specific aspects of diesel engine modeling found in previous studies such as the compromise between computers cost, accurateness and model simplicity, the reduction of the number of empirical fitting constant, the prediction of combustion kinetics with reduction of the need of experimental curve fitting, the ability to simultaneously predict under various loads engine thermodynamic and spray parameters as well as emission characteristics and finally the ability to simulate diesel engine parameters when fueled by alternative fuels. The proposed model predicts fuel spray behavior, in cylinder combustion and nitric oxides (NOx) emissions. The model is implemented through a Matlab code. The model is mainly based on Razlejtsev’s spray evaporation model

  17. Simulation, experimental validation and kinematic optimization of a Stirling engine using air and helium

    International Nuclear Information System (INIS)

    Bert, Juliette; Chrenko, Daniela; Sophy, Tonino; Le Moyne, Luis; Sirot, Frédéric

    2014-01-01

    A Stirling engine with nominal output power of 1 kW is tested using air and helium as working gases. The influence of working pressure, engine speed and temperature of the hot source is studied, analyzing instantaneous gas pressure as well as instantaneous and stationary temperature at different positions to derive the effective power. A zero dimensional finite-time thermodynamic, three zones model of a generic Stirling engine is developed and successfully validated against experimental gas temperature and pressure in each zone, providing the effective power. This validation underlines the interest of different working gases as well as different geometric configurations for different applications. Furthermore, the validated model allows parametric studies of the engine, with regard to geometry, working gas and engine kinematics. It is used in order to optimize the kinematic of a Stirling engine for different working points and gases. - Highlights: • A Stirling engine of 1 kW is tested using air and helium as working gas. • Effects of working pressure, speed and temperature on power are studied. • A zero dimensional finite-time thermodynamic, three zones model of it is validated. • The validated model is used for parametric studies and optimization of the engine

  18. An Interactive Simulator-Based Pedagogical (ISP) Approach for Teaching Microcontrollers in Engineering Programs

    Science.gov (United States)

    Tang, Shensheng

    2014-01-01

    Microcontrollers is a required course in most Electrical, Computer, and Mechanic Engineering (Technology) programs at U.S. universities. Most engineering courses (e.g., microcontrollers), by nature, introduce abstract concepts, definitions, and models, and use primarily lectures and readings (words, symbols) to transmit information. This…

  19. Validation of a zero-dimensional and 2-phase combustion model for dual-fuel compression ignition engine simulation

    Directory of Open Access Journals (Sweden)

    Mikulski Maciej

    2017-01-01

    Full Text Available Increasing demands for the reduction of exhaust emissions and the pursuit to re-duce the use of fossil fuels require the search for new fuelling technologies in combustion engines. One of the most promising technologies is the multi-fuel compression ignition engine concept, in which a small dose of liquid fuel injected directly into the cylinder acts as the ignition inhibitor of the gaseous fuel. Achieving the optimum combustion process in such an engine requires the application of advanced control algorithms which require mathematical modelling support. In response to the growing demand for new simulation tools, a 0-D model of a dual-fuel engine was proposed and validated. The validation was performed in a broad range of engine operating points, including various speeds and load condition, as well as different natural gas/diesel blend ratios. It was demonstrated that the average model calculation error within the entire cycle did not exceed 6.2%, and was comparable to the measurement results cycle to cycle variations. The maximum model calculation error in a single point of a cycle was 15% for one of the complex (multipoint injection cases. In other cases, it did not exceed 11%.

  20. Reconstruction of structure and function in tissue engineering of solid organs: Toward simulation of natural development based on decellularization.

    Science.gov (United States)

    Zheng, Chen-Xi; Sui, Bing-Dong; Hu, Cheng-Hu; Qiu, Xin-Yu; Zhao, Pan; Jin, Yan

    2018-04-27

    Failure of solid organs, such as the heart, liver, and kidney, remains a major cause of the world's mortality due to critical shortage of donor organs. Tissue engineering, which uses elements including cells, scaffolds, and growth factors to fabricate functional organs in vitro, is a promising strategy to mitigate the scarcity of transplantable organs. Within recent years, different construction strategies that guide the combination of tissue engineering elements have been applied in solid organ tissue engineering and have achieved much progress. Most attractively, construction strategy based on whole-organ decellularization has become a popular and promising approach, because the overall structure of extracellular matrix can be well preserved. However, despite the preservation of whole structure, the current constructs derived from decellularization-based strategy still perform partial functions of solid organs, due to several challenges, including preservation of functional extracellular matrix structure, implementation of functional recellularization, formation of functional vascular network, and realization of long-term functional integration. This review overviews the status quo of solid organ tissue engineering, including both advances and challenges. We have also put forward a few techniques with potential to solve the challenges, mainly focusing on decellularization-based construction strategy. We propose that the primary concept for constructing tissue-engineered solid organs is fabricating functional organs based on intact structure via simulating the natural development and regeneration processes. Copyright © 2018 John Wiley & Sons, Ltd.

  1. Tightly coupled transient analysis of EBR-II: An INEL [Idaho National Engineering Laboratory] Engineering Simulation Center Project

    International Nuclear Information System (INIS)

    Makowitz, H.; Barber, D.G.; Dean, E.M.

    1989-01-01

    A ''Tightly Coupled'' transient analysis system for the Experimental Breeder Reactor-II (FBR-II) is presently under development. The system consists of a faster-than-real-time high fidelity reactor simulation, advanced graphics displays, expert system coupling, and real-time data coupling via the EBR-II data acquisition system to and from the plant and the control system. The first generation software has been developed and tested. Various subsystem couplings and the total system integration have been checked out. A ''Lightly Coupled'' EBR-II reactor startup was conducted in August of 1988 as a demonstration of the system. This system should enhance the diagnostic and prognostic capability of EBR-II in the near term and provide automatic control during startup and power maneuvering in the future, as well as serve as a testbed for new control system development for advanced reactors. 8 refs., 7 figs., 1 tab

  2. Proceedings of the 2. international conference on simulation methods in nuclear engineering

    International Nuclear Information System (INIS)

    Brais, A.

    1986-10-01

    The fifty papers presented at this conference cover the field of computerized simulation and mathematical modelling of processes in PWR and CANDU type reactors. Topics include thermalhydraulics of system transients, complex geometries, multi-fluid systems, and general situations; reactor physics simulations; reactor simulators; fuel and fuel channel behaviour; and applications of supercomputers, parallel processing, and microcomputers

  3. Local Impact Simulation of SC Wall Structures using Aircraft Engine Projectile

    International Nuclear Information System (INIS)

    Chung, Chulhun; Lee, Jungwhee; Lee, Hanjoo; Jung, Raeyoung; Hyun, Changhun

    2013-01-01

    SC wall structure developed for nuclear power plant buildings consists of plain concrete and two steel plates on both surface of the concrete, while RC structure consists of re bar and concrete. SC structure has higher scabbing resistance than RC structure due to the action of steel plate on the rear side of impact. Therefore SC structure is known as more effective structure from the viewpoint of aircraft crash than RC structure. However, most of the recent researches and experiments about local impact damage deal with RC structures, and the effect of re bar and steel plate is not considered reasonably. Although Walter et al. and Make-work et al. suggested a formula for evaluating perforation depth of steel plate covered RC walls, most of the previous researches about SC structure are focused on perforation and scabbing due to the impact of hard projectile, rather than soft projectile such as an aircraft. In this research a soft projectile, i. e. aircraft engine, is utilized for impact simulation of RC and SC walls. To evaluate local damage of SC wall structures, parametric study with the variables of wall thickness and steel ratio of the cover plate is performed, and the results are compared with those of RC structures. Since scabbing was prevented by the steel plates, penetration mode of damage was observed in SC walls while scabbing damage was occurred in RC walls. It is confirmed that the rear steel plate not only contains concrete debris, but also reduces the internal damage of the concrete walls. Penetration depth of SC walls did not largely vary due to the increasing steel ratio, and similar results to RC walls were observed when the wall thickness is larger than a certain value since the impact resistance of SC wall is mainly governed by the thickness of concrete part. Therefore, it is expected that similar level of impact resistance to RC structure can be produced with the minimum thickness of steel plates of SC structure. According to these results, SC

  4. Operateurs et engins de calcul en virgule flottante et leur application a la simulation en temps reel sur FPGA

    Science.gov (United States)

    Ould Bachir, Tarek

    The real-time simulation of electrical networks gained a vivid industrial interest during recent years, motivated by the substantial development cost reduction that such a prototyping approach can offer. Real-time simulation allows the progressive inclusion of real hardware during its development, allowing its testing under realistic conditions. However, CPU-based simulations suffer from certain limitations such as the difficulty to reach time-steps of a few microsecond, an important challenge brought by modern power converters. Hence, industrial practitioners adopted the FPGA as a platform of choice for the implementation of calculation engines dedicated to the rapid real-time simulation of electrical networks. The reconfigurable technology broke the 5 kHz switching frequency barrier that is characteristic of CPU-based simulations. Moreover, FPGA-based real-time simulation offers many advantages, including the reduced latency of the simulation loop that is obtained thanks to a direct access to sensors and actuators. The fixed-point format is paradigmatic to FPGA-based digital signal processing. However, the format imposes a time penalty in the development process since the designer has to asses the required precision for all model variables. This fact brought an import research effort on the use of the floating-point format for the simulation of electrical networks. One of the main challenges in the use of the floating-point format are the long latencies required by the elementary arithmetic operators, particularly when an adder is used as an accumulator, an important building bloc for the implementation of integration rules such as the trapezoidal method. Hence, single-cycle floating-point accumulation forms the core of this research work. Our results help building such operators as accumulators, multiply-accumulators (MACs), and dot-product (DP) operators. These operators play a key role in the implementation of the proposed calculation engines. Therefore, this

  5. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming Analysis, Simulation and Engineering Applications

    CERN Document Server

    Hu, Ping; Liu, Li-zhong; Zhu, Yi-guo

    2013-01-01

    Over the last 15 years, the application of innovative steel concepts in the automotive industry has increased steadily. Numerical simulation technology of hot forming of high-strength steel allows engineers to modify the formability of hot forming steel metals and to optimize die design schemes. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming focuses on hot and cold forming theories, numerical methods, relative simulation and experiment techniques for high-strength steel forming and die design in the automobile industry. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming introduces the general theories of cold forming, then expands upon advanced hot forming theories and simulation methods, including: • the forming process, • constitutive equations, • hot boundary constraint treatment, and • hot forming equipment and experiments. Various calculation methods of cold and hot forming, based on the authors’ experience in commercial CAE software f...

  6. Artificial neural networks for dynamic monitoring of simulated-operating parameters of high temperature gas cooled engineering test reactor (HTTR)

    International Nuclear Information System (INIS)

    Seker, Serhat; Tuerkcan, Erdinc; Ayaz, Emine; Barutcu, Burak

    2003-01-01

    This paper addresses to the problem of utilisation of the artificial neural networks (ANNs) for detecting anomalies as well as physical parameters of a nuclear power plant during power operation in real time. Three different types of neural network algorithms were used namely, feed-forward neural network (back-propagation, BP) and two types of recurrent neural networks (RNN). The data used in this paper were gathered from the simulation of the power operation of the Japan's High Temperature Engineering Testing Reactor (HTTR). For the wide range of power operation, 56 signals were generated by the reactor dynamic simulation code for several hours of normal power operation at different power ramps between 30 and 100% nominal power. Paper will compare the outcomes of different neural networks and presents the neural network system and the determination of physical parameters from the simulated operating data

  7. Numerical simulation of fuel sprays and combustion in a premixed lean diesel engine; Kihaku yokongo diesel kikan ni okeru nenryo funmu to nensho no suchi simulation

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, T; Harada, A; Sasaki, S; Shimazaki, N; Hashizume, T; Akagawa, H; Tsujimura, K

    1997-10-01

    Fuel sprays and combustion in a direct injection Premixed lean Diesel Combustion (PREDIC) engine, which can make smokeless combustion with little NOx emission, is studied numerically. Numerical simulation was carried out by means of KIVA II based computer code with a combustion submodel. The combustion submodel describes the formation of combustible fuel vapor by turbulent mixing and four-step chemical reaction which includes low temperature oxidation. Comparison between computation and experiment shows qualitatively good agreement in terms of heat release rate and NO emission. Computational results indicate that the combustion is significantly influenced by fuel spray characteristics and injection timing to vary NO emission. 10 refs., 8 figs., 1 tab.

  8. Preliminary Results from Simulations of Temperature Fluctuations in Stirling Engine Regenerator Matrices

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Carlsen, Henrik; Thomsen, Per Grove

    2003-01-01

    The objective of this study has been to create a model for studying effects of temperature fluctuations in regenerator matrices on Stirling engine performance. A one-dimensional model with axial discretisation of engine components has been formulated using a fixed Eulerian grid. The model contains...... that adjusts solutions so that they satisfy the necessary cyclic boundary conditions as well as integral conditions for cyclic heat transfer for walls in the engine and for the mean cycle pressure. It has been found that it is possible to accurately solve the stiff ODE system that describes the coupled...

  9. Engineering Institute

    Science.gov (United States)

    Projects Past Projects Publications NSEC » Engineering Institute Engineering Institute Multidisciplinary engineering research that integrates advanced modeling and simulations, novel sensing systems and new home of Engineering Institute Contact Institute Director Charles Farrar (505) 665-0860 Email UCSD EI

  10. Simulation of hybrid propulsion system using LSRG and single cylinder engine

    Science.gov (United States)

    Han, C.; Ohyama, K.; Wang, W. Q.

    2017-11-01

    Nowadays, more and more people are beginning to use hybrid vehicles (HVs). The drive system of HVs needs to produce the electric energy with the electric generator and gearbox powered by an engine. Therefore, the structure becomes complex and the cost is high. To solve this issue, this research proposes a new drive system design that combines the engine and a linear switched reluctance generator (LSRG). When the engine is operating, the LSRG can simultaneously assist the engine’s mechanical output or can generate power to charge the battery. In this research, three research steps are executed. In the first step, the LSRG is designed according to the size of normal engine. Then, finite element analysis is used to get the data of flux linkage and calculate the inductance and translator force. Finally, Simulink models of control system are constructed to verify the performance of LSRG.

  11. Simulated environmental risk estimation of engineered nanomaterials: a case of cosmetics in Johannesburg City

    CSIR Research Space (South Africa)

    Musee, N

    2011-09-01

    Full Text Available This paper attempts to quantify the potential risks posed by engineered nanomaterials (ENMs) to the aquatic and terrestrial ecosystems from cosmetic-based nanoproducts. The predicted environmental concentrations (PEC) were modelled for the silver (n...

  12. Damage Propagation Modeling for Aircraft Engine Run-to-Failure Simulation

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper describes how damage propagation can be modeled within the modules of aircraft gas turbine engines. To that end, response surfaces of all sensors are...

  13. Beyond AIRSpeed: How Organizational Modeling and Simulation Further Reduced Engine Maintenance Time

    National Research Council Canada - National Science Library

    Hagan, Joel; Slack, William; Zolin, Roxanne; Dillard, John

    2007-01-01

    The Aircraft Intermediate Maintenance Division (AIMD) at Naval Air Station (NAS) Lemoore, CA, has worked aggressively to reduce engine maintenance time using the tools of the NAVAIR Enterprise AiRSpeed (AiRSpeed) program...

  14. Simulation of Cycle-to-Cycle Variation in Dual-Fuel Engines

    KAUST Repository

    Jaasim, Mohammed; Pasunurthi, Shyamsundar; Jupudi, Ravichandra S.; Gubba, Sreenivasa Rao; Primus, Roy; Klingbeil, Adam; Wijeyakulasuriya, Sameera; Im, Hong G.

    2017-01-01

    Standard practices of internal combustion (IC) engine experiments are to conduct the measurements of quantities averaged over a large number of cycles. Depending on the operating conditions, the cycle-to-cycle variation (CCV) of quantities

  15. Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

    Science.gov (United States)

    Liu, Yongfeng; Jia, Xiaoshe; Pei, Pucheng; Lu, Yong; Yi, Li; Shi, Yan

    2016-01-01

    For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

  16. Main control system verification and validation of NPP digital I and C system based on engineering simulator

    International Nuclear Information System (INIS)

    Lin Meng; Hou Dong; Liu Pengfei; Yang Zongwei; Yang Yanhua

    2010-01-01

    Full-scope digital instrumentation and controls system (I and C) technique is being introduced in Chinese new constructed Nuclear Power Plant (NPP), which mainly includes three parts: control system, reactor protection system and engineered safety feature actuation system. For example, SIEMENS TELEPERM XP and XS distributed control system (DCS) have been used in Ling Ao Phase II NPP, which is located in Guangdong province, China. This is the first NPP project in China that Chinese engineers are fully responsible for all the configuration of actual analog and logic diagram, although experience in NPP full-scope digital I and C is very limited. For the safety, it has to be made sure that configuration is right and control functions can be accomplished before the phase of real plant testing on reactor. Therefore, primary verification and validation (V and V) of I and C needs to be carried out. Except the common and basic way, i.e. checking the diagram configuration one by one according to original design, NPP engineering simulator is applied as another effective approach of V and V. For this purpose, a virtual NPP thermal-hydraulic model is established as a basis according to Ling Ao Phase II NPP design, and the NPP simulation tools can provide plant operation parameters to DCS, accept control signal from I and C and give response. During the test, one set of data acquisition equipments are used to build a connection between the engineering simulator (software) and SIEMENS DCS I/O cabinet (hardware). In this emulation, original diagram configuration in DCS and field hardware structures are kept unchanged. In this way, firstly judging whether there are some problems by observing the input and output of DCS without knowing the internal configuration. Then secondly, problems can be found and corrected by understanding and checking the exact and complex configuration in detail. At last, the correctness and functionality of the control system are verified. This method is

  17. Using the building energy simulation test (BESTEST) to evaluate CHENATH, the Nationwide House Energy Rating Scheme Simulation Engine

    Energy Technology Data Exchange (ETDEWEB)

    Delsante, A.E. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Highett, VIC (Australia). Div. of Building Construction and Engineering

    1995-12-31

    The Nationwide House Energy Rating Scheme (NatHERS) uses a simulation program as its reference tool to evaluate the energy demand of buildings. The Commonwealth Scientific Industrial Research Organisation (CSIRO) developed software called CHENATH, is a significantly enhanced version of the CHEETAH simulation program. As part of the NatHERS development process, it was considered important to subject CHENATH to further testing. Two separate evaluation projects were undertaken. This paper describes one of these projects. CHENATH was compared with a reference set of eight internationally recognized simulation programs using the BESTEST methodology. Annual heating and cooling energy requirements were compared for a specified set of variations on a simple double-glazed building. Annual incident and transmitted solar radiation was also compared, for which CHENATH agreed very well with the reference set. It also agreed well for heating energy, but tended to over-predict cooling energy. This is largely because it controls an environmental temperature rather than the required air temperature. For the same reason CHENATH over-predicted heating and cooling demands. No major discrepancies were found that would suggest bugs in the program. (author). 4 tabs., 10 figs., 4 refs.

  18. Simulations of Multi Combustion Modes Hydrogen Engines for Heavy Duty Trucks

    Directory of Open Access Journals (Sweden)

    Alberto A. Boretti

    2012-01-01

    Full Text Available The paper presents the numerical study of a diesel direct injection heavy duty truck engine converted to hydrogen. The engine has a power turbine connected through a clutch and a continuously variable transmission to the crankshaft. The power turbine may be disconnected and by-passed when it is inefficient or inconvenient to use. The conversion is obtained by replacing the Diesel injector with a hydrogen injector and the glow plug with a jet ignition device. The hydrogen engine operates different modes of combustion depending on the relative phasing of the main injection and the jet ignition. The engine generally operates mostly in Diesel-like mode, with the most part of the main injection following the suitable creation in cylinder conditions by jet ignition. For medium-low loads, better efficienciy is obtained with the gasoline-like mode jet igniting the premixed homogeneous mixture at top dead centre. It’s permitted at higher loads or at very low loads for the excessive peak pressure or the mixture too lean to burn rapidly. The hydrogen engine has better efficiency than Diesel outputs and fuel conversion. Thanks to the larger rate of heat release, it has the opportunity to run closer to stoichiometry and the multi mode capabilities. The critical area for this engine development is found in the design of a hydrogen injector delivering the amount of fuel needed to the large volume cylinder within a Diesel-like injection time.

  19. UV Absorption Measurements of Nitric Oxide Compared to Probe Sampling Data for Measurements in a Turbine Engine Exhaust at Simulated Altitude Conditions

    National Research Council Canada - National Science Library

    Howard, R

    1997-01-01

    Nitric oxide measurements were conducted in the exhaust of a turbofan engine at simulated altitude conditions in a ground-level test cell using both optical nonintrusive and conventional gas sampling techniques...

  20. Fate and behavior of ZnO- and Ag-engineered nanoparticles and a bacterial viability assessment in a simulated wastewater treatment plant

    CSIR Research Space (South Africa)

    Musee, N

    2014-01-01

    Full Text Available The fate and behaviour assessment of ZnO- and Ag-engineered nanoparticles (ENPs) and bacterial viability in a simulated wastewater treatment plant (WWTP) fed with municipal wastewater was investigated through determination of ENPs stability...

  1. Using Visual Simulation Tools And Learning Outcomes-Based Curriculum To Help Transportation Engineering Students And Practitioners To Better Understand And Design Traffic Signal Control Systems

    Science.gov (United States)

    2012-06-01

    The use of visual simulation tools to convey complex concepts has become a useful tool in education as well as in research. : This report describes a project that developed curriculum and visualization tools to train transportation engineering studen...

  2. A new closed-form thermodynamic model for thermal simulation of spark ignition internal combustion engines

    International Nuclear Information System (INIS)

    Barjaneh, Afshin; Sayyaadi, Hoseyn

    2015-01-01

    Highlights: • A new closed-form thermal model was developed for SI engines. • Various irreversibilities of real engines were integrated into the model. • The accuracy of the model was examined on two real SI engines. • The superiority of the model to previous closed-form models was shown. • Accuracy and losses were studied over the operating range of engines. - Abstract: A closed form model based on finite speed thermodynamics, FST, modified to consider various losses was developed on Otto cycle. In this regard, the governing equations of the finite speed thermodynamics were developed for expansion/compression processes while heat absorption/rejection of the Otto cycle was determined based on finite time thermodynamics, FTT. In addition, other irreversibility including power loss caused by heat transfer through the cylinder walls and irreversibility due to throttling process was integrated into the model. The developed model was verified by implementing on two different spark ignition internal combustion engines and the results of modeling were compared with experimental results as well as FTT model. It was found that the developed model was not only very simple in use like a closed form thermodynamic model, but also it models a real spark ignition engine with reasonable accuracy. The error in predicting the output power at rated operating range of the engine was 39%, while in the case of the FTT model, this figure was 167.5%. This comparison for predicting thermal efficiency was +7% error (as difference) for the developed model compared to +39.4% error of FTT model.

  3. Elucidating the electron transport in semiconductors via Monte Carlo simulations: an inquiry-driven learning path for engineering undergraduates

    International Nuclear Information System (INIS)

    Adorno, Dominique Persano; Pizzolato, Nicola; Fazio, Claudio

    2015-01-01

    Within the context of higher education for science or engineering undergraduates, we present an inquiry-driven learning path aimed at developing a more meaningful conceptual understanding of the electron dynamics in semiconductors in the presence of applied electric fields. The electron transport in a nondegenerate n-type indium phosphide bulk semiconductor is modelled using a multivalley Monte Carlo approach. The main characteristics of the electron dynamics are explored under different values of the driving electric field, lattice temperature and impurity density. Simulation results are presented by following a question-driven path of exploration, starting from the validation of the model and moving up to reasoned inquiries about the observed characteristics of electron dynamics. Our inquiry-driven learning path, based on numerical simulations, represents a viable example of how to integrate a traditional lecture-based teaching approach with effective learning strategies, providing science or engineering undergraduates with practical opportunities to enhance their comprehension of the physics governing the electron dynamics in semiconductors. Finally, we present a general discussion about the advantages and disadvantages of using an inquiry-based teaching approach within a learning environment based on semiconductor simulations. (paper)

  4. Elucidating the electron transport in semiconductors via Monte Carlo simulations: an inquiry-driven learning path for engineering undergraduates

    Science.gov (United States)

    Persano Adorno, Dominique; Pizzolato, Nicola; Fazio, Claudio

    2015-09-01

    Within the context of higher education for science or engineering undergraduates, we present an inquiry-driven learning path aimed at developing a more meaningful conceptual understanding of the electron dynamics in semiconductors in the presence of applied electric fields. The electron transport in a nondegenerate n-type indium phosphide bulk semiconductor is modelled using a multivalley Monte Carlo approach. The main characteristics of the electron dynamics are explored under different values of the driving electric field, lattice temperature and impurity density. Simulation results are presented by following a question-driven path of exploration, starting from the validation of the model and moving up to reasoned inquiries about the observed characteristics of electron dynamics. Our inquiry-driven learning path, based on numerical simulations, represents a viable example of how to integrate a traditional lecture-based teaching approach with effective learning strategies, providing science or engineering undergraduates with practical opportunities to enhance their comprehension of the physics governing the electron dynamics in semiconductors. Finally, we present a general discussion about the advantages and disadvantages of using an inquiry-based teaching approach within a learning environment based on semiconductor simulations.

  5. Integration of an acoustic drive simulator in the engine development process; Einbindung eines akustischen Fahrsimulators in den Motorenentwicklungsprozess

    Energy Technology Data Exchange (ETDEWEB)

    Nettelbeck, C.; Riemann, D.; Sellerbeck, P. [HEAD acoustics GmbH, Herzogenrath (Germany)

    2005-07-01

    Due to constantly decreasing development time the integration of tools for simulation and generation of a virtual reality is an efficient way in order to identify weak spots or possible improvements of products as early as possible. Referring to the engine development the NVH division becomes increasingly interesting and thus an important element of the demands on new products. With the help of the Binaural Transfer Path Analysis and Synthesis (BTPA/BTPS), a tool developed at HEAD acoustics, a binaural interior noise can be generated from engine test rig multi-channel measurements. The interactive acoustical driving simulator H3S provides the opportunity of a very realistic evaluation of the NVH behavior of vehicle interior noise and vibration. The combination of the BTPA/BTPS procedure and the driving simulator offers an product in a realistic surrounding and in combination with other NVH components like wind or tire noise for all operating conditions already at an early stage in the project phase.

  6. Measurement and Simulation of Pollutant Emissions from Marine Diesel Combustion Engine and Their Reduction by Ammonia Injection

    Directory of Open Access Journals (Sweden)

    Nader Larbi

    2009-01-01

    Full Text Available Taking into account the complexity and cost of a direct experimental approach, the recourse to a tool of simulation, which can also predict inaccessible information by measurement, offers an effective and fast alternative to apprehend the problem of pollutant emissions from internal combustion engines. An analytical model based on detailed chemical kinetics employed to calculate the pollutant emissions of a marine diesel engine gave satisfactory results, in general, compared to experimentally measured results. Especially the NO emission values are found to be higher than the limiting values tolerated by the International Maritime Organization (IMO. Thus, this study is undertaken in order to reduce these emissions to the maximum level. The reduction of pollutant emissions is apprehended with ammonia injection.

  7. Using interactive online role-playing simulations to develop global competency and to prepare engineering students for a globalised world

    Science.gov (United States)

    May, Dominik; Wold, Kari; Moore, Stephanie

    2015-09-01

    The world is changing significantly, and it is becoming increasingly globalised. This means that countries, businesses, and professionals must think and act globally to be successful. Many individuals, however, are not prepared with the global competency skills needed to communicate and perform effectively in a globalised system. To address this need, higher education institutions are looking for ways to instil these skills in their students. This paper explains one promising approach using current learning principles: transnational interactive online environments in engineering education. In 2011, the TU Dortmund and the University of Virginia initiated a collaboration in which engineering students from both universities took part in one online synchronous course and worked together on global topics. This paper describes how the course was designed and discusses specific research results regarding how interactive online role-playing simulations support students in gaining the global competency skills required to actively participate in today's international workforce.

  8. Improvement of nuclear ship engineering simulation system. Hardware renewal and interface improvement of the integral type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroki; Kyoya, Masahiko; Shimazaki, Junya [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kano, Tadashi [KCS, Co., Mito, Ibaraki (Japan); Takahashi, Teruo [Energis, Co., Kobe, Hyogo (Japan)

    2001-10-01

    JAERI had carried out the design study about a lightweight and compact integral type reactor (an advanced marine reactor) with passive safety equipment as a power source for the future nuclear ships, and completed an engineering design. We have developed the simulator for the integral type reactor to confirm the design and operation performance and to utilize the study of automation of the reactor operation. The simulator can be used also for future research and development of a compact reactor. However, the improvement in a performance of hardware and a human machine interface of software of the simulator were needed for future research and development. Therefore, renewal of hardware and improvement of software have been conducted. The operability of the integral-reactor simulator has been improved. Furthermore, this improvement with the hardware and software on the market brought about better versatility, maintainability, extendibility and transfer of the system. This report mainly focuses on contents of the enhancement in a human machine interface, and describes hardware renewal and the interface improvement of the integral type reactor simulator. (author)

  9. A Proposed Engineering Process and Prototype Toolset for Developing C2-to-Simulation Interoperability Solutions

    NARCIS (Netherlands)

    Gautreau, B.; Khimeche, L.; Reus, N.M. de; Heffner, K.; Mevassvik, O.M.

    2014-01-01

    The Coalition Battle Management Language (C-BML) is an open standard being developed for the exchange of digitized military information among command and control (C2), simulation and autonomous systems by the Simulation Interoperability Standards Organization (SISO). As the first phase of the C-BML

  10. 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.

  11. 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.

  12. Selection criteria for building performance simulation tools : contrasting architects' and engineers' needs

    NARCIS (Netherlands)

    Attia, S.G.; Hensen, J.L.M.; Beltran, L.; De Herde, A.

    2012-01-01

    This article summarises a study undertaken to reveal potential challenges and opportunities for using building performance simulation (BPS) tools. The article reviews current trends in building simulation and outlines major criteria for BPS tool selection and evaluation based on analysing users'

  13. Simulation of Surgical Cutting in Deformable Bodies using a Game Engine

    DEFF Research Database (Denmark)

    Jørgensen, Martin Kibsgaard; Kronborg Thomsen, Kasper; Kraus, Martin

    2014-01-01

    Simulators as a training tool for surgeons are becoming more important with the increase of minimally invasive surgery and a wish to limit training on animals, especially in the field of robotic surgery. Accessibility to surgery simulators is currently limited and the ability to cut is restricted...

  14. Development of a Computer Simulation Game Using a Reverse Engineering Approach

    Science.gov (United States)

    Ozkul, Ahmet

    2012-01-01

    Business simulation games are widely used in the classroom to provide students with experiential learning opportunities on business situations in a dynamic fashion. When properly designed and implemented, the computer simulation game can be a useful educational tool by integrating separate theoretical concepts and demonstrating the nature of…

  15. Numerical simulation and validation of SI-CAI hybrid combustion in a CAI/HCCI gasoline engine

    Science.gov (United States)

    Wang, Xinyan; Xie, Hui; Xie, Liyan; Zhang, Lianfang; Li, Le; Chen, Tao; Zhao, Hua

    2013-02-01

    SI-CAI hybrid combustion, also known as spark-assisted compression ignition (SACI), is a promising concept to extend the operating range of CAI (Controlled Auto-Ignition) and achieve the smooth transition between spark ignition (SI) and CAI in the gasoline engine. In this study, a SI-CAI hybrid combustion model (HCM) has been constructed on the basis of the 3-Zones Extended Coherent Flame Model (ECFM3Z). An ignition model is included to initiate the ECFM3Z calculation and induce the flame propagation. In order to precisely depict the subsequent auto-ignition process of the unburned fuel and air mixture independently after the initiation of flame propagation, the tabulated chemistry concept is adopted to describe the auto-ignition chemistry. The methodology for extracting tabulated parameters from the chemical kinetics calculations is developed so that both cool flame reactions and main auto-ignition combustion can be well captured under a wider range of thermodynamic conditions. The SI-CAI hybrid combustion model (HCM) is then applied in the three-dimensional computational fluid dynamics (3-D CFD) engine simulation. The simulation results are compared with the experimental data obtained from a single cylinder VVA engine. The detailed analysis of the simulations demonstrates that the SI-CAI hybrid combustion process is characterised with the early flame propagation and subsequent multi-site auto-ignition around the main flame front, which is consistent with the optical results reported by other researchers. Besides, the systematic study of the in-cylinder condition reveals the influence mechanism of the early flame propagation on the subsequent auto-ignition.

  16. Engineering Vibrationally Assisted Energy Transfer in a Trapped-Ion Quantum Simulator

    Science.gov (United States)

    Gorman, Dylan J.; Hemmerling, Boerge; Megidish, Eli; Moeller, Soenke A.; Schindler, Philipp; Sarovar, Mohan; Haeffner, Hartmut

    2018-01-01

    Many important chemical and biochemical processes in the condensed phase are notoriously difficult to simulate numerically. Often, this difficulty arises from the complexity of simulating dynamics resulting from coupling to structured, mesoscopic baths, for which no separation of time scales exists and statistical treatments fail. A prime example of such a process is vibrationally assisted charge or energy transfer. A quantum simulator, capable of implementing a realistic model of the system of interest, could provide insight into these processes in regimes where numerical treatments fail. We take a first step towards modeling such transfer processes using an ion-trap quantum simulator. By implementing a minimal model, we observe vibrationally assisted energy transport between the electronic states of a donor and an acceptor ion augmented by coupling the donor ion to its vibration. We tune our simulator into several parameter regimes and, in particular, investigate the transfer dynamics in the nonperturbative regime often found in biochemical situations.

  17. An Integrated Approach to Conversion, Verification, Validation and Integrity of AFRL Generic Engine Model and Simulation (Postprint)

    Science.gov (United States)

    2007-02-01

    and Astronautics 11 PS3C W3 P3 T3 FAR3 Ps3 W41 P41 T41 FAR41 Ps41 W4 P4 T4 FAR4 Ps4 7 NozFlow 6 Flow45 5 Flow44 4 Flow41 3 Flow4 2 Flow3 1 N2Bal... Motivation for Modeling and Simulation Work The Augmented Generic Engine Model (AGEM) Model Verification and Validation (V&V) Assessment of AGEM V&V

  18. Modeling, simulation, parametric study and economic assessment of reciprocating internal combustion engine integrated with multi-effect desalination unit

    International Nuclear Information System (INIS)

    Salimi, Mohsen; Amidpour, Majid

    2017-01-01

    Highlights: • Integration of small MED unit with gas engine power cycle is studied in this paper. • Modeling, simulation, parametric study and sensitivity analysis were performed. • A thermodynamic model for heat recovery and power generation of the gas engine has been presented. • Annualized Cost of System (ACS) has been employed for economic assessment. • Economic feasibilty dependence of integrated system on natural gas and water prices has been investigated. - Abstract: Due to thermal nature of multi-effect desalination (MED), its integration with a suitable power cycle is highly desirable for waste heat recovery. One of the proper power cycle for proposed integration is internal combustion engine (ICE). The exhaust gas heat of ICE is used to produce motive steam for the required heat for the first effect of MED system. Also, the water jacket heat is utilized in a heat exchanger to pre-heat the seawater. This paper studies a thermodynamic model for a tri-generation system composed of ICE integrated with MED. The ICE thermodynamic model has been used in place of different empirical efficiency relations to estimate performance – load curves reasonably. The entire system performance has been coded in MATLAB, and the results of proposed thermodynamic model for the engine have been verified by manufacturer catalogue. By increasing the engine load from 40% to 100%, the water production of MED unit will increase from 4.38 cubic meters per day to 26.78 cubic meters per day and the tri-generation efficiency from 31% to 56%. Economic analyses of the MED unit integrated with ICE was performed based on Annualized Cost of System method. This integration makes the system more economical. It has been determined that in higher market prices for fresh water (more than 7 US$ per cubic meter), the increase in effects number is more significant to the period of return decrement.

  19. Simulation of a photo-solar generator for an optimal output by a parabolic photovoltaic concentrator of Stirling engine type

    Science.gov (United States)

    Kaddour, A.; Benyoucef, B.

    Solar energy is the source of the most promising energy and the powerful one among renewable energies. Photovoltaic electricity (statement) is obtained by direct transformation of the sunlight into electricity, by means of cells statement. Then, we study the operation of cells statement by the digital simulation with an aim of optimizing the output of the parabolic concentrator of Stirling engine type. The Greenius software makes it possible to carry out the digital simulation in 2D and 3D and to study the influence of the various parameters on the characteristic voltage under illumination of the cell. The results obtained enabled us to determine the extrinsic factors which depend on the environment and the intrinsic factors which result from the properties of materials used.

  20. Simulating quantum state engineering in spontaneous parametric down-conversion using classical light

    CSIR Research Space (South Africa)

    Zhang, Y

    2014-07-01

    Full Text Available range of pump beams for quantum state engineering and confirm that the results are in agreement with theory. Our approach offers high photon count rates, is quick to yield results and can easily be converted back to a SPDC setup. It is likely to be a...

  1. Enhancing Student Learning in Food Engineering Using Computational Fluid Dynamics Simulations

    Science.gov (United States)

    Wong, Shin Y.; Connelly, Robin K.; Hartel, Richard W.

    2010-01-01

    The current generation of students coming into food science and engineering programs is very visually oriented from their early experiences. To increase their interest in learning, new and visually appealing teaching materials need to be developed. Two diverse groups of students may be identified based on their math skills. Food science students…

  2. Simulating awareness in global software engineering: a comparative analysis of Scrum and Agile Service Networks

    NARCIS (Netherlands)

    Tamburri, D.A.; Razo Zapata, I.S.; Fernandez, H.; Tedeschi, C.

    2012-01-01

    Abstract—Global software engineering (GSE) is a business strategy to realize a business idea (i.e. the development project) faster, through round-the-clock productivity. However, GSE creates a volatile and unstable process in which many actors interact together against unpredictable premises (e.g.

  3. Simulation-based production planning for engineer-to-order systems with random yield

    NARCIS (Netherlands)

    Akcay, Alp; Martagan, Tugce

    2018-01-01

    We consider an engineer-to-order production system with unknown yield. We model the yield as a random variable which represents the percentage output obtained from one unit of production quantity. We develop a beta-regression model in which the mean value of the yield depends on the unique

  4. Videogame Construction by Engineering Students for Understanding Modelling Processes: The Case of Simulating Water Behaviour

    Science.gov (United States)

    Pretelín-Ricárdez, Angel; Sacristán, Ana Isabel

    2015-01-01

    We present some results of an ongoing research project where university engineering students were asked to construct videogames involving the use of physical systems models. The objective is to help them identify and understand the elements and concepts involved in the modelling process. That is, we use game design as a constructionist approach…

  5. Development of free-piston Stirling engine performance and optimization codes based on Martini simulation technique

    Science.gov (United States)

    Martini, William R.

    1989-01-01

    A FORTRAN computer code is described that could be used to design and optimize a free-displacer, free-piston Stirling engine similar to the RE-1000 engine made by Sunpower. The code contains options for specifying displacer and power piston motion or for allowing these motions to be calculated by a force balance. The engine load may be a dashpot, inertial compressor, hydraulic pump or linear alternator. Cycle analysis may be done by isothermal analysis or adiabatic analysis. Adiabatic analysis may be done using the Martini moving gas node analysis or the Rios second-order Runge-Kutta analysis. Flow loss and heat loss equations are included. Graphical display of engine motions and pressures and temperatures are included. Programming for optimizing up to 15 independent dimensions is included. Sample performance results are shown for both specified and unconstrained piston motions; these results are shown as generated by each of the two Martini analyses. Two sample optimization searches are shown using specified piston motion isothermal analysis. One is for three adjustable input and one is for four. Also, two optimization searches for calculated piston motion are presented for three and for four adjustable inputs. The effect of leakage is evaluated. Suggestions for further work are given.

  6. A computer simulation of the transient response of a 4 cylinder Stirling engine with burner and air preheater in a vehicle

    Science.gov (United States)

    Martini, W. R.

    1981-01-01

    A series of computer programs are presented with full documentation which simulate the transient behavior of a modern 4 cylinder Siemens arrangement Stirling engine with burner and air preheater. Cold start, cranking, idling, acceleration through 3 gear changes and steady speed operation are simulated. Sample results and complete operating instructions are given. A full source code listing of all programs are included.

  7. A massively parallel framework for low-dissipation, multiphysics simulations of rocket engines, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, researchers from Cascade Technologies and Stanford University outline a multi-year research plan to develop large-eddy simulation (LES) tools to...

  8. Wear simulation of apex seal in rotary engine under mixed lubrication

    Science.gov (United States)

    Jiang, Hanying; Zuo, Zhengxing; Liu, Jinxiang

    2018-05-01

    In this work, the wear of apex seal's running face under mixed lubrication is studied. Numerical simulation is carried out by employing the couple model of Reynolds equation, Greenwood and Tripp model and Archard's wear law. The simulation is performed both for one circle and multi circle. In the multi circle simulation, the change of contact position due to wear is considered. A method that is able to find the new contact position based on the updated apex seal's contour profile is proposed, validated and used. The result of multi circle simulation indicates that contact position changes obviously around the maximum swing angles both on leading and trailing sides with the increase number of circles. The wear depth distribution becomes more uniform with the increase of operation circle number.

  9. Computer Simulation of Strain Engineering and Photonics Semiconducting Nanostructure on Parallel Architectures

    National Research Council Canada - National Science Library

    Nakano, Aiichiro

    2000-01-01

    ...; and dielectric properties of high permittivity TiO2 for ultrathin gate dielectric films. Scalable software infrastructure has been developed to enable multiscale simulations of nanoelectronic devices using MD and quantum mechanical...

  10. Photonic simulation of entanglement growth and engineering after a spin chain quench.

    Science.gov (United States)

    Pitsios, Ioannis; Banchi, Leonardo; Rab, Adil S; Bentivegna, Marco; Caprara, Debora; Crespi, Andrea; Spagnolo, Nicolò; Bose, Sougato; Mataloni, Paolo; Osellame, Roberto; Sciarrino, Fabio

    2017-11-17

    The time evolution of quantum many-body systems is one of the most important processes for benchmarking quantum simulators. The most curious feature of such dynamics is the growth of quantum entanglement to an amount proportional to the system size (volume law) even when interactions are local. This phenomenon has great ramifications for fundamental aspects, while its optimisation clearly has an impact on technology (e.g., for on-chip quantum networking). Here we use an integrated photonic chip with a circuit-based approach to simulate the dynamics of a spin chain and maximise the entanglement generation. The resulting entanglement is certified by constructing a second chip, which measures the entanglement between multiple distant pairs of simulated spins, as well as the block entanglement entropy. This is the first photonic simulation and optimisation of the extensive growth of entanglement in a spin chain, and opens up the use of photonic circuits for optimising quantum devices.

  11. Changes in soil hydraulic properties caused by construction of a simulated waste trench at the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Shakofsky, S.

    1995-03-01

    In order to assess the effect of filled waste disposal trenches on transport-governing soil properties, comparisons were made between profiles of undisturbed soil and disturbed soil in a simulated waste trench. The changes in soil properties induced by the construction of a simulated waste trench were measured near the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory (INEL) in the semiarid southeast region of Idaho. The soil samples were collected, using a hydraulically-driven sampler to minimize sample disruption, from both a simulated waste trench and an undisturbed area nearby. Results show that the undisturbed profile has distinct layers whose properties differ significantly, whereas the soil profile in the simulated waste trench is, by comparison, homogeneous. Porosity was increased in the disturbed cores, and, correspondingly, saturated hydraulic conductivities were on average three times higher. With higher soil-moisture contents (greater than 0.32), unsaturated hydraulic conductivities for the undisturbed cores were typically greater than those for the disturbed cores. With lower moisture contents, most of the disturbed cores had greater hydraulic conductivities. The observed differences in hydraulic conductivities are interpreted and discussed as changes in the soil pore geometry

  12. Effect of Fuel on Performance of a Single Combustor of an I-16 Turbojet Engine at Simulated Altitude Conditions

    Science.gov (United States)

    Zettle, Eugene V; Bolz, Ray E; Dittrich, R T

    1947-01-01

    As part of a study of the effects of fuel composition on the combustor performance of a turbojet engine, an investigation was made in a single I-16 combustor with the standard I-16 injection nozzle, supplied by the engine manufacturer, at simulated altitude conditions. The 10 fuels investigated included hydrocarbons of the paraffin olefin, naphthene, and aromatic classes having a boiling range from 113 degrees to 655 degrees F. They were hot-acid octane, diisobutylene, methylcyclohexane, benzene, xylene, 62-octane gasoline, kerosene, solvent 2, and Diesel fuel oil. The fuels were tested at combustor conditions simulating I-16 turbojet operation at an altitude of 45,000 feet and at a rotor speed of 12,200 rpm. At these conditions the combustor-inlet air temperature, static pressure, and velocity were 60 degrees F., 12.3 inches of mercury absolute, and 112 feet per second respectively, and were held approximately constant for the investigation. The reproducibility of the data is shown by check runs taken each day during the investigation. The combustion in the exhaust elbow was visually observed for each fuel investigated.

  13. Shaping ability of NT Engine and McXim rotary nickel-titanium instruments in simulated root canals. Part 2.

    Science.gov (United States)

    Thompson, S A; Dummer, P M

    1997-07-01

    The aim of this laboratory-based study was to determine the shaping ability of NT Engine and McXim nickel-titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with NT Engine and McXim instruments, using the technique recommended by the manufacturer. Part 2 of this report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape. Pre- and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and postoperative views were superimposed to highlight the amount and position of material removed during preparation. No zips, elbows, perforations or danger zones were created during preparation. Forty-two per cent of canals had ledges on the outer aspect of the curve, the majority of which (16 out of 17) occurred in canals with short acute curves. There were significant differences (P Engine and McXim rotary nickel-titanium instruments created no aberrations other than ledges and produced only minimal transportation. The overall shape of canals was good.

  14. A federated design for a neurobiological simulation engine: the CBI federated software architecture.

    Directory of Open Access Journals (Sweden)

    Hugo Cornelis

    Full Text Available Simulator interoperability and extensibility has become a growing requirement in computational biology. To address this, we have developed a federated software architecture. It is federated by its union of independent disparate systems under a single cohesive view, provides interoperability through its capability to communicate, execute programs, or transfer data among different independent applications, and supports extensibility by enabling simulator expansion or enhancement without the need for major changes to system infrastructure. Historically, simulator interoperability has relied on development of declarative markup languages such as the neuron modeling language NeuroML, while simulator extension typically occurred through modification of existing functionality. The software architecture we describe here allows for both these approaches. However, it is designed to support alternative paradigms of interoperability and extensibility through the provision of logical relationships and defined application programming interfaces. They allow any appropriately configured component or software application to be incorporated into a simulator. The architecture defines independent functional modules that run stand-alone. They are arranged in logical layers that naturally correspond to the occurrence of high-level data (biological concepts versus low-level data (numerical values and distinguish data from control functions. The modular nature of the architecture and its independence from a given technology facilitates communication about similar concepts and functions for both users and developers. It provides several advantages for multiple independent contributions to software development. Importantly, these include: (1 Reduction in complexity of individual simulator components when compared to the complexity of a complete simulator, (2 Documentation of individual components in terms of their inputs and outputs, (3 Easy removal or replacement of

  15. NIST ThermoData Engine: Extension to Solvent Design and Propagation of Uncertainties for Process Simulation

    DEFF Research Database (Denmark)

    Diky, Vladimir; Chirico, Robert D.; Muzny, Chris

    ThermoData Engine (TDE, NIST Standard Reference Databases 103a and 103b) is the first product that implements the concept of Dynamic Data Evaluation in the fields of thermophysics and thermochemistry, which includes maintaining the comprehensive and up-to-date database of experimentally measured ...... uncertainties, curve deviations, and inadequacies of the models. Uncertainty analysis shows relative contributions to the total uncertainty from each component and pair of components....

  16. A simple simulation software for effective four-stroke engine instruction

    African Journals Online (AJOL)

    No Abstract. Journal of Applied Science, Engineering and Technology Vol. 2(1) 2002: 19-25. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/jaset.v2i1.38260 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

  17. Simulations

    CERN Document Server

    Ngada, Narcisse

    2015-06-15

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  18. Simulation of transient hydraulic behaviour of process engineering plant with long pipes. Simulation des instationaeren hydraulischen Verhaltens verfahrenstechnischer Anlagen mit langen Rohrleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Raschke, E. (BASF AG, Ludwigshafen am Rhein (Germany)); Seelinger, P. (BASF AG, Ludwigshafen am Rhein (Germany)); Sperber, A. (BASF AG, Ludwigshafen am Rhein (Germany)); Strassburger, R. (BASF AG, Ludwigshafen am Rhein (Germany))

    1994-05-01

    A knowledge of transient flow processes is becoming increasingly important for the reliable design and control of process engineering plant. Transient flow processes occur, of example, in long liquid-carrying pipes: on start-up and shut-down of plant, in emergency shut-downs and fast closure, i.e. when liquid is rapidly decelerated or accelerated. The consequence of such an event is a hammer effect, i.e. a short, often violent change of pressure placing considerable stress on structures. Such hammer effects are readily calculated by numerical methods in single phase media. Technical devices for prevention of inadmissibly high pressure surges can also be designed by means of simulation calculations. However, hammer effects also occur by sudden condensation of vapours. A number of systems in which condensation hammer effects can occur are considered at the end of this contribution. Two special damping measures are presented. (orig.)

  19. The completion of the mathematical model by parameter identification for simulating a turbofan engine

    Directory of Open Access Journals (Sweden)

    Irina Carmen ANDREI

    2015-09-01

    Full Text Available The purpose of this paper is to set up a method to determine the missing engine design parameters (turbine inlet temperature T3T, airflow rate which significantly influence the jet engines thrust. The authors have introduced a new non-linear equation connecting the fan specific work with the temperature T3T, customized for turbofan. The method of chords, since it converges unconditionally, has been used for solving the non-linear equation of variable temperature T3T. An alternate method, based for the same relation between fan specific work and T3T, has been presented in purpose to determine airflow rate and fan pressure ratio. Two mixed flows turbofans have been considered as study cases. For case #1 it was determined a value comparable to the Turbomeca Larzac turbofan series 04-C6 and 04-C20 which power the AlphaJet machines (series A - Luftwaffe, series E - Dassault Dornier. For the F100-PW229 turbofan, as case #2, being given T3T, then have been determined the airflow rate, fan pressure ratio and fan specific work. After completing the mathematical model with the missing parameters, the performances of the engines at off-design regimes and the operational envelopes revealing i.e. the variations of thrust, specific thrust and fuel specific consumption with altitude and Mach number have been calculated.

  20. Cable Tension Preslack Method Construction Simulation and Engineering Application for a Prestressed Suspended Dome

    Directory of Open Access Journals (Sweden)

    Xuechun Liu

    2015-01-01

    Full Text Available To solve the shortage of traditional construction simulation methods for suspended dome structures, based on friction elements, node coupling technology, and local cooling, the cable tension preslack method is proposed in this paper, which is suitable for the whole process construction simulation of a suspended dome. This method was used to simulate the construction process of a large-span suspended dome case study. The effects on the simulation results of location deviation of joints, construction temperature, construction temporary supports, and friction of the cable-support joints were analyzed. The cable tension preslack method was demonstrated by comparing the data from the construction simulation with measured results, providing the control cable tension and the control standards for construction acceptance. The analysis demonstrated that the position deviation of the joint has little effect on the control value; the construction temperature and the friction of the cable-support joint significantly affect the control cable tension. The construction temperature, the temporary construction supports, and the friction of the cable-support joints all affect the internal force and deflection in the tensioned state but do not significantly affect the structural bearing characteristics at the load state. The forces should be primarily controlled in tensioned construction, while the deflections are controlled secondarily.

  1. Simulation and Optimization of SCR System for Direct-injection Diesel Engine

    Directory of Open Access Journals (Sweden)

    Guanqiang Ruan

    2014-11-01

    Full Text Available The turbo diesel SCR system has been researched and analyzed in this paper. By using software of CATIA, three-dimensional physical model of SCR system has been established, and with software of AVL-FIRE, the boundary conditions have been set, simulated and optimized. In the process of SCR system optimizing, it mainly optimized the pray angle. Compare the effects of processing NO to obtain batter optimization results. At last the optimization results are compared by bench test, and the experimental results are quite consistent with simulation.

  2. Development of a Twin-Spool Turbofan Engine Simulation Using the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS)

    Science.gov (United States)

    Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.

    2014-01-01

    The Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3% of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.

  3. Development of a Twin-spool Turbofan Engine Simulation Using the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)

    Science.gov (United States)

    Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Johathan S.

    2014-01-01

    The Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3 of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.

  4. Engineered safeguards systems and method in nuclear power plant training simulator

    International Nuclear Information System (INIS)

    Desalu, A.A.

    1977-01-01

    A method and system is disclosed for simulating the dynamic realtime operation of a nuclear power plant wherein a plurality of remote control devices provide input data to a digital computer to calculate physical values corresponding to plant operation to operate indicating devices for monitoring the physical operation of the plant. 24 claims, 29 figures

  5. Design of a distributed simulation environment for building control applications based on systems engineering methodology

    NARCIS (Netherlands)

    Yahiaoui, Azzedine

    2018-01-01

    The analysis of innovative designs that distributes control to buildings over a network is currently a challenging task as exciting building performance simulation tools do not offer sufficient capabilities and the flexibility to fully respond to the full complexity of Automated Buildings (ABs). For

  6. Cold flow simulation of an internal combustion engine with vertical valves using layering approach

    Science.gov (United States)

    Martinas, G.; Cupsa, O. S.; Stan, L. C.; Arsenie, A.

    2015-11-01

    Complying with emission requirements and fuel consumption efficiency are the points which drive any development of internal combustion engine. Refinement of the process of combustion and mixture formation, together with in-cylinder flow refinement, is a requirement, valves and piston bowl and intake exhaust port design optimization is essential. In order to reduce the time for design optimization cycle it is used Computational Fluid Dynamics (CFD). Being time consuming and highly costly caring out of experiment using flow bench testing this methods start to become less utilized. Air motion inside the intake manifold is one of the important factors, which govern the engine performance and emission of multi-cylinder diesel engines. Any cold flow study on IC is targeting the process of identifying and improving the fluid flow inside the ports and the combustion chamber. This is only the base for an optimization process targeting to increase the volume of air accessing the combustion space and to increase the turbulence of the air at the end of the compression stage. One of the first conclusions will be that the valve diameter is a fine tradeoff between the need for a bigger diameter involving a greater mass of air filling the cylinder, and the need of a smaller diameter in order to reduce the blind zone. Here there is room for optimization studies. The relative pressure indicates a suction effect coming from the moving piston. The more the shape of the inlet port is smoother and the diameter of the piston is bigger, the aerodynamic resistance of the geometry will be smaller so that the difference of inlet port pressure and the pressure near to piston face will be smaller. Here again there is enough room for more optimization studies.

  7. Comparison benchmark between tokamak simulation code and TokSys for Chinese Fusion Engineering Test Reactor vertical displacement control design

    International Nuclear Information System (INIS)

    Qiu Qing-Lai; Xiao Bing-Jia; Guo Yong; Liu Lei; Wang Yue-Hang

    2017-01-01

    Vertical displacement event (VDE) is a big challenge to the existing tokamak equipment and that being designed. As a Chinese next-step tokamak, the Chinese Fusion Engineering Test Reactor (CFETR) has to pay attention to the VDE study with full-fledged numerical codes during its conceptual design. The tokamak simulation code (TSC) is a free boundary time-dependent axisymmetric tokamak simulation code developed in PPPL, which advances the MHD equations describing the evolution of the plasma in a rectangular domain. The electromagnetic interactions between the surrounding conductor circuits and the plasma are solved self-consistently. The TokSys code is a generic modeling and simulation environment developed in GA. Its RZIP model treats the plasma as a fixed spatial distribution of currents which couple with the surrounding conductors through circuit equations. Both codes have been individually used for the VDE study on many tokamak devices, such as JT-60U, EAST, NSTX, DIII-D, and ITER. Considering the model differences, benchmark work is needed to answer whether they reproduce each other’s results correctly. In this paper, the TSC and TokSys codes are used for analyzing the CFETR vertical instability passive and active controls design simultaneously. It is shown that with the same inputs, the results from these two codes conform with each other. (paper)

  8. Towards engineered branch placement: Unreal™ match between vapour-liquid-solid glancing angle deposition nanowire growth and simulation

    International Nuclear Information System (INIS)

    Taschuk, M. T.; Tucker, R. T.; LaForge, J. M.; Beaudry, A. L.; Kupsta, M. R.; Brett, M. J.

    2013-01-01

    The vapour-liquid-solid glancing angle deposition (VLS-GLAD) process is capable of producing complex nanotree structures with control over azimuthal branch orientation and height. We have developed a thin film growth simulation including ballistic deposition, simplified surface diffusion, and droplet-mediated cubic crystal growth for the VLS-GLAD process using the Unreal TM Development Kit. The use of a commercial game engine has provided an interactive environment while allowing a custom physics implementation. Our simulation's output is verified against experimental data, including a volumetric film reconstruction produced using focused ion beam and scanning-electron microscopy (SEM), crystallographic texture, and morphological characteristics such as branch orientation. We achieve excellent morphological and texture agreement with experimental data, as well as qualitative agreement with SEM imagery. The simplified physics in our model reproduces the experimental films, indicating that the dominant role flux geometry plays in the VLS-GLAD competitive growth process responsible for azimuthally oriented branches and biaxial crystal texture evolution. The simulation's successful reproduction of experimental data indicates that it should have predictive power in designing novel VLS-GLAD structures

  9. Towards engineered branch placement: Unreal™ match between vapour-liquid-solid glancing angle deposition nanowire growth and simulation

    Science.gov (United States)

    Taschuk, M. T.; Tucker, R. T.; LaForge, J. M.; Beaudry, A. L.; Kupsta, M. R.; Brett, M. J.

    2013-12-01

    The vapour-liquid-solid glancing angle deposition (VLS-GLAD) process is capable of producing complex nanotree structures with control over azimuthal branch orientation and height. We have developed a thin film growth simulation including ballistic deposition, simplified surface diffusion, and droplet-mediated cubic crystal growth for the VLS-GLAD process using the UnrealTM Development Kit. The use of a commercial game engine has provided an interactive environment while allowing a custom physics implementation. Our simulation's output is verified against experimental data, including a volumetric film reconstruction produced using focused ion beam and scanning-electron microscopy (SEM), crystallographic texture, and morphological characteristics such as branch orientation. We achieve excellent morphological and texture agreement with experimental data, as well as qualitative agreement with SEM imagery. The simplified physics in our model reproduces the experimental films, indicating that the dominant role flux geometry plays in the VLS-GLAD competitive growth process responsible for azimuthally oriented branches and biaxial crystal texture evolution. The simulation's successful reproduction of experimental data indicates that it should have predictive power in designing novel VLS-GLAD structures.

  10. More than just a game: the role of simulation in the teaching of product design and entrepreneurship to mechanical engineering students

    Science.gov (United States)

    Costello, Gabriel J.

    2017-11-01

    The purpose of this work is to contribute to the debate on the best pedagogical approach to developing undergraduate mechanical engineering skills to meet the requirements of contemporary complex working environments. The paper provides an example of using student-entrepreneur collaboration in the teaching of modules to Mechanical Engineering final-year students. Problem-based learning (PBL) is one of the most significant recent innovations in the area of education for the professions. This work proposes to make an original contribution by simulating a real-life entrepreneur interaction for the students. The current literature largely confines simulation-based learning to computer applications such as games. However, this paper argues that role playing by students interfacing with technology start-ups can also be regarded as 'simulation' in a wider sense. Consequently, the paper proposes the concept of simulation-action learning as an enhancement of PBL and to distinguish it from computer simulation.

  11. Fifth in situ vitrification engineering-scale test of simulated INEL buried waste sites

    International Nuclear Information System (INIS)

    Bergsman, T.M.; Shade, J.W.; Farnsworth, R.K.

    1992-06-01

    In September 1990, an engineering-scale in situ vitrification (ISV) test was conducted on sealed canisters containing a combined mixture of buried waste materials expected to be present at the Idaho National Engineering Laboratory (INEL) Subsurface Disposal Area (SDA). The test was part of a Pacific Northwest Laboratory (PNL) program to assist INEL in treatability studies of the potential application of ISV to mixed transuranic wastes at the INEL SDA. The purpose of this test was to determine the effect of a close-packed layer of sealed containers on ISV processing performance. Specific objectives included determining (1) the effect of releases from sealed containers on hood plenum pressure and temperature, (2) the release pressure ad temperatures of the sealed canisters, (3) the relationships between canister depressurization and melt encapsulation, (4) the resulting glass and soil quality, (5) the potential effects of thermal transport due to a canister layer, (6) the effects on particle entrainment of differing angles of approach for the ISV melt front, and (7) the effects of these canisters on the volatilization of voltatile and semivolatile contaminants into the hood plenum

  12. Performance modeling & simulation of complex systems (A systems engineering design & analysis approach)

    Science.gov (United States)

    Hall, Laverne

    1995-01-01

    Modeling of the Multi-mission Image Processing System (MIPS) will be described as an example of the use of a modeling tool to design a distributed system that supports multiple application scenarios. This paper examines: (a) modeling tool selection, capabilities, and operation (namely NETWORK 2.5 by CACl), (b) pointers for building or constructing a model and how the MIPS model was developed, (c) the importance of benchmarking or testing the performance of equipment/subsystems being considered for incorporation the design/architecture, (d) the essential step of model validation and/or calibration using the benchmark results, (e) sample simulation results from the MIPS model, and (f) how modeling and simulation analysis affected the MIPS design process by having a supportive and informative impact.

  13. Simulation study on single event burnout in linear doping buffer layer engineered power VDMOSFET

    International Nuclear Information System (INIS)

    Jia Yunpeng; Su Hongyuan; Hu Dongqing; Wu Yu; Jin Rui

    2016-01-01

    The addition of a buffer layer can improve the device's secondary breakdown voltage, thus, improving the single event burnout (SEB) threshold voltage. In this paper, an N type linear doping buffer layer is proposed. According to quasi-stationary avalanche simulation and heavy ion beam simulation, the results show that an optimized linear doping buffer layer is critical. As SEB is induced by heavy ions impacting, the electric field of an optimized linear doping buffer device is much lower than that with an optimized constant doping buffer layer at a given buffer layer thickness and the same biasing voltages. Secondary breakdown voltage and the parasitic bipolar turn-on current are much higher than those with the optimized constant doping buffer layer. So the linear buffer layer is more advantageous to improving the device's SEB performance. (paper)

  14. Modeling and Simulation Resource Repository (MSRR)(System Engineering/Integrated M&S Management Approach

    Science.gov (United States)

    Milroy, Audrey; Hale, Joe

    2006-01-01

    NASA s Exploration Systems Mission Directorate (ESMD) is implementing a management approach for modeling and simulation (M&S) that will provide decision-makers information on the model s fidelity, credibility, and quality, including the verification, validation and accreditation information. The NASA MSRR will be implemented leveraging M&S industry best practices. This presentation will discuss the requirements that will enable NASA to capture and make available the "meta data" or "simulation biography" data associated with a model. The presentation will also describe the requirements that drive how NASA will collect and document relevant information for models or suites of models in order to facilitate use and reuse of relevant models and provide visibility across NASA organizations and the larger M&S community.

  15. Cloud Computing in Science and Engineering and the “SciShop.ru” Computer Simulation Center

    Directory of Open Access Journals (Sweden)

    E. V. Vorozhtsov

    2011-12-01

    Full Text Available Various aspects of cloud computing applications for scientific research, applied design, and remote education are described in this paper. An analysis of the different aspects is performed based on the experience from the “SciShop.ru” Computer Simulation Center. This analysis shows that cloud computing technology has wide prospects in scientific research applications, applied developments and also remote education of specialists, postgraduates, and students.

  16. Internal combustion engine exhaust pipe flow simulation. Part I: theoretical aspects

    OpenAIRE

    Juan Miguel Mantilla; Camilo Andrés Falla; Jorge Arturo Gómez

    2010-01-01

    Unsteady gas flow theory can be used for simulating a spark ignition internal combustion engine’s exhaust system, using pressure waves. The method explained here is based on the discretization of interpolated spaces (called meshes) which are located throughout the whole length of the exhaust pipe, irrespective of its form or size. The most important aspects of this theory are theoretically explored, such as pressure wave movement and shock and their application to cases found in re...

  17. Internal combustion engine exhaust pipe flow simulation. Part I: theoretical aspects

    OpenAIRE

    Juan Miguel Mantilla; Camilo Andrés Falla; Jorge Arturo Gómez

    2009-01-01

    Unsteady gas flow theory can be used for simulating a spark ignition internal combustion engine’s exhaust system, using pressure waves. The method explained here is based on the discretization of interpolated spaces (called meshes) which are located throughout the whole length of the exhaust pipe, irrespective of its form or size. The most important aspects of this theory are theoretically explored, such as pressure wave movement and shock and their application to cases found in real engines’...

  18. Pre-engineering Spaceflight Validation of Environmental Models and the 2005 HZETRN Simulation Code

    Science.gov (United States)

    Nealy, John E.; Cucinotta, Francis A.; Wilson, John W.; Badavi, Francis F.; Dachev, Ts. P.; Tomov, B. T.; Walker, Steven A.; DeAngelis, Giovanni; Blattnig, Steve R.; Atwell, William

    2006-01-01

    The HZETRN code has been identified by NASA for engineering design in the next phase of space exploration highlighting a return to the Moon in preparation for a Mars mission. In response, a new series of algorithms beginning with 2005 HZETRN, will be issued by correcting some prior limitations and improving control of propagated errors along with established code verification processes. Code validation processes will use new/improved low Earth orbit (LEO) environmental models with a recently improved International Space Station (ISS) shield model to validate computational models and procedures using measured data aboard ISS. These validated models will provide a basis for flight-testing the designs of future space vehicles and systems of the Constellation program in the LEO environment.

  19. Numerical simulation of optical and electronic properties for multilayer organic light-emitting diodes and its application in engineering education

    Science.gov (United States)

    Chang, Shu-Hsuan; Chang, Yung-Cheng; Yang, Cheng-Hong; Chen, Jun-Rong; Kuo, Yen-Kuang

    2006-02-01

    Organic light-emitting diodes (OLEDs) have been extensively developed in the past few years. The OLED displays have advantages over other displays, such as CRT, LCD, and PDP in thickness, weight, brightness, response time, viewing angle, contrast, driving power, flexibility, and capability of self-emission. In this work, the optical and electronic properties of multilayer OLED devices are numerically studied with an APSYS (Advanced Physical Model of Semiconductor Devices) simulation program. Specifically, the emission and absorption spectra of the Alq 3, DCM, PBD, and SA light-emitting layers, and energy band diagrams, electron-hole recombination rates, and current-voltage characteristics of the simulated OLED devices, typically with a multilayer structure of metal/Alq 3/EML/TPD/ITO constructed by Lim et al., are investigated and compared to the experimental results. The physical models utilized in this work are similar to those presented by Ruhstaller et al. and Hoffmann et al. The simulated results indicate that the emission spectra of the Alq 3, DCM, PBD, and SA light-emitting layers obtained in this study are in good agreement with those obtained experimentally by Zugang et al. Optimization of the optical and electronic performance of the multilayer OLED devices are attempted. In order to further promote the research results, the whole numerical simulation process for optimizing the design of OLED devices has been applied to a project-based course of OLED device design to enhance the students' skills in photonics device design at the Graduate Institute of Photonics of National Changhua University of Education in Taiwan. In the meantime, the effectiveness of the course has been proved by various assessments. The application of the results is a useful point of reference for the research on photonics device design and engineering education. Therefore, it proffers a synthetic effect between innovation and practical application.

  20. Numerical simulation of nanosecond pulsed DBD in lean methane–air mixture for typical conditions in internal engines

    International Nuclear Information System (INIS)

    Takana, Hidemasa; Nishiyama, Hideya

    2014-01-01

    Detailed two-dimensional numerical simulations of a high energy loading nanosecond dc pulse DBD in a lean methane–air mixture were conducted for plasma-assisted combustion by integrating individual models of plasma chemistry, photoionization and energy loading. The DBD streamer propagation process with radical productions was clarified at 10 atm and 600 K as under the condition of actual internal engines at ignition. Energy is loaded to the streamer first by the formation of plasma channel and then ceased due to the self-shielding effect. Because of the inversed electric field in a discharge space during decrease in applied voltage, energy is loaded to the discharge again. It was found that higher energy is loaded to the DBD streamer for larger dielectric constant even at lower applied voltage, and higher number density of oxygen radical is produced at almost the same radical production efficiency. (paper)

  1. Design study of shaft face seal with self-acting lift augmentation. 5: Performance in simulated gas turbine engine operation

    Science.gov (United States)

    Ludwig, L. P.; Johnson, R. L.

    1971-01-01

    The feasibility and the noncontact operation of the self-acting seal was demonstrated over a range of simulated gas turbine engine conditions from 200 to 500 ft/sec sliding speed. Sealed pressure differentials were 50 to 300 psi and sealed temperatures were 150 to 1200 F. Low leakage (about 1/10 that of conventional labyrinth seals) was exhibited in two endurance runs (200 and 338 hr) at 400 ft/sec, 200 psi and 1000 F (gas temperature). For these endurance runs, the self-acting pad wear was less than 3.8 micrometers (0.00015 in.); this low wear was attributed to the noncontact operation of the primary seal. Operating problems identified were fretting wear of the secondary seal and erosion of the primary seal by hard particles.

  2. Process Simulation and Characterization of Substrate Engineered Silicon Thin Film Transistor for Display Sensors and Large Area Electronics

    International Nuclear Information System (INIS)

    Hashmi, S M; Ahmed, S

    2013-01-01

    Design, simulation, fabrication and post-process qualification of substrate-engineered Thin Film Transistors (TFTs) are carried out to suggest an alternate manufacturing process step focused on display sensors and large area electronics applications. Damage created by ion implantation of Helium and Silicon ions into single-crystalline n-type silicon substrate provides an alternate route to create an amorphized region responsible for the fabrication of TFT structures with controllable and application-specific output parameters. The post-process qualification of starting material and full-cycle devices using Rutherford Backscattering Spectrometry (RBS) and Proton or Particle induced X-ray Emission (PIXE) techniques also provide an insight to optimize the process protocols as well as their applicability in the manufacturing cycle

  3. Simulation of biodiesel combustion in a light-duty diesel engine using integrated compact biodiesel–diesel reaction mechanism

    DEFF Research Database (Denmark)

    Ng, Hoon Kiat; Gan, Suyin; Ng, Jo-Han

    2013-01-01

    This computational fluid dynamics (CFD) study is performed to investigate the combustion characteristics and emissions formation processes of biodiesel fuels in a light-duty diesel engine. A compact reaction mechanism with 80 species and 303 reactions is used to account for the effects of chemical...... kinetics. Here, the mechanism is capable of emulating biodiesel–diesel mixture of different blending levels and biodiesel produced from different feedstock. The integrated CFD-kinetic model was validated against a test matrix which covers the entire saturated–unsaturated methyl ester range typical...... of biodiesel fuels, as well as the biodiesel–diesel blending levels. The simulated cases were then validated for in-cylinder pressure profiles and peak pressure values/timings. Errors in the peak pressure values did not exceed 1%, while the variations in peak pressure timings were kept within 1.5 crank angle...

  4. Large-Eddy Simulations of Motored Flow and Combustion in a Homogeneous-Charge Spark-Ignition Engine

    Science.gov (United States)

    Shekhawat, Yajuvendra Singh

    Cycle-to-cycle variations (CCV) of flow and combustion in internal combustion engines (ICE) limit their fuel efficiency and emissions potential. Large-eddy simulation (LES) is the most practical simulation tool to understand the nature of these CCV. In this research, multi-cycle LES of a two-valve, four-stroke, spark-ignition optical engine has been performed for motored and fired operations. The LES mesh quality is assessed using a length scale resolution parameter and a energy resolution parameter. For the motored operation, two 50-consecutive-cycle LES with different turbulence models (Smagorinsky model and dynamic structure model) are compared with the experiment. The pressure comparison shows that the LES is able to capture the wave-dynamics in the intake and exhaust ports. The LES velocity fields are compared with particle-image velocimetry (PIV) measurements at three cutting planes. Based on the structure and magnitude indices, the dynamic structure model is somewhat better than the Smagorinsky model as far as the ensemble-averaged velocity fields are concerned. The CCV in the velocity fields is assessed by proper-orthogonal decomposition (POD). The POD analysis shows that LES is able to capture the level of CCV seen in the experiment. For the fired operation, two 60-cycle LES with different combustion models (thickened frame model and coherent frame model) are compared with experiment. The in-cylinder pressure and the apparent heat release rate comparison shows higher CCV for LES compared to the experiment, with the thickened frame model showing higher CCV than the coherent frame model. The correlation analysis for the LES using thickened frame model shows that the CCV in combustion/pressure is correlated with: the tumble at the intake valve closing, the resolved and subfilter-scale kinetic energy just before spark time, and the second POD mode (shear flow near spark gap) of the velocity fields just before spark time.

  5. Simulation-Based e-Learning Tools for Science,Engineering, and Technology Education(SimBeLT)

    Science.gov (United States)

    Davis, Doyle V.; Cherner, Y.

    2006-12-01

    The focus of Project SimBeLT is the research, development, testing, and dissemination of a new type of simulation-based integrated e-learning set of modules for two-year college technical and engineering curricula in the areas of thermodynamics, fluid physics, and fiber optics that can also be used in secondary schools and four-year colleges. A collection of sophisticated virtual labs is the core component of the SimBeLT modules. These labs will be designed to enhance the understanding of technical concepts and underlying fundamental principles of these topics, as well as to master certain performance based skills online. SimBeLT software will help educators to meet the National Science Education Standard that "learning science and technology is something that students do, not something that is done to them". A major component of Project SimBeLT is the development of multi-layered technology-oriented virtual labs that realistically mimic workplace-like environments. Dynamic data exchange between simulations will be implemented and links with instant instructional messages and data handling tools will be realized. A second important goal of Project SimBeLT labs is to bridge technical skills and scientific knowledge by enhancing the teaching and learning of specific scientific or engineering subjects. SimBeLT builds upon research and outcomes of interactive teaching strategies and tools developed through prior NSF funding (http://webphysics.nhctc.edu/compact/index.html) (Project SimBeLT is partially supported by a grant from the National Science Foundation DUE-0603277)

  6. [Runoff and sediment yielding processes on red soil engineering accumulation containing gravels by a simulated rainfall experiment].

    Science.gov (United States)

    Shi, Qian-hua; Wang, Wen-long; Guo, Ming-ming; Bai, Yun; Deng, Li-qiang; Li, Jian-ming; Li, Yao-lin

    2015-09-01

    Engineering accumulation formed in production and construction projects is characterized by unique structure and complex material composition. Characteristics of soil erosion on the engineering accumulation significantly differ from those on farmland. An artificially simulated rainfall experiment was carried out to investigate the effects of rainfall intensity on the processes of runoff and sediment yielding on the engineering accumulation of different gravel contents (0%, 10%, 20% and 30%) in red soil regions. Results showed that the initial time of runoff generation decreased with increases in rainfall intensity and gravel content, the decreased amplitudes being about 48.5%-77.9% and 4.2%-34.2%, respectively. The initial time was found to be a power function of rainfall intensity. Both runoff velocity and runoff rate manifested a trend of first rising and then in a steady state with runoff duration. Rainfall intensity was found to be the main factor influencing runoff velocity and runoff rate, whereas the influence of gravel content was not significant. About 10% of gravel content was determined to be a critical value in the influence of gravel content on runoff volume. For the underlying surface of 10% gravel content, the runoff volume was least at rainfall intensity of 1.0 mm · min(-1) and maximum at rainfall intensity of greater than 1.0 mm · min(-1). The runoff volume in- creased 10%-60% with increase in rainfall intensity. Sediment concentration showed a sharp decline in first 6 min and then in a stable state in rest of time. Influence of rainfall intensity on sediment concentration decreased as gravel content increased. Gravels could reduce sediment yield significantly at rainfall intensity of greater than 1.0 mm · min(-1). Sediment yield was found to be a linear function of rainfall intensity and gravel content.

  7. A compact skeletal mechanism for n -dodecane with optimized semi-global low-temperature chemistry for diesel engine simulations

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Tong; Pei, Yuanjiang; Zhong, Bei-Jing; Som, Sibendu; Lu, Tianfeng; Luo, Kai Hong

    2017-03-01

    A skeletal mechanism with 54 species and 269 reactions was developed to predict pyrolysis and oxidation of n-dodecane as a diesel fuel surrogate involving both high-temperature (high-T) and low-temperature (low-T) conditions. The skeletal mechanism was developed from a semi-detailed mechanism developed at the University of Southern California (USC). Species and reactions for high-T pyrolysis and oxidation of C5-C12 were reduced by using reaction flow analysis (RFA), isomer lumping, and then merged into a skeletal C0-C4 core to form a high-T sub-mechanism. Species and lumped semi-global reactions for low-T chemistry were then added to the high-T sub-mechanism and a 54-species skeletal mechanism is obtained. The rate parameters of the low-T reactions were tuned against a detailed mechanism by the Lawrence Livermore National Laboratory (LLNL), as well as the Spray A flame experimental data, to improve the prediction of ignition delay at low-T conditions, while the high-T chemistry remained unchanged. The skeletal mechanism was validated for auto-ignition, perfectly stirred reactors (PSR), flow reactors and laminar premixed flames over a wide range of flame conditions. The skeletal mechanism was then employed to simulate three-dimensional turbulent spray flames at compression ignition engine conditions and validated against experimental data from the Engine Combustion Network (ECN).

  8. Sandia National Laboratories Advanced Simulation and Computing (ASC) software quality plan : ASC software quality engineering practices Version 3.0.

    Energy Technology Data Exchange (ETDEWEB)

    Turgeon, Jennifer L.; Minana, Molly A.; Hackney, Patricia; Pilch, Martin M.

    2009-01-01

    The purpose of the Sandia National Laboratories (SNL) Advanced Simulation and Computing (ASC) Software Quality Plan is to clearly identify the practices that are the basis for continually improving the quality of ASC software products. Quality is defined in the US Department of Energy/National Nuclear Security Agency (DOE/NNSA) Quality Criteria, Revision 10 (QC-1) as 'conformance to customer requirements and expectations'. This quality plan defines the SNL ASC Program software quality engineering (SQE) practices and provides a mapping of these practices to the SNL Corporate Process Requirement (CPR) 001.3.6; 'Corporate Software Engineering Excellence'. This plan also identifies ASC management's and the software project teams responsibilities in implementing the software quality practices and in assessing progress towards achieving their software quality goals. This SNL ASC Software Quality Plan establishes the signatories commitments to improving software products by applying cost-effective SQE practices. This plan enumerates the SQE practices that comprise the development of SNL ASC's software products and explains the project teams opportunities for tailoring and implementing the practices.

  9. Modeling and simulation of graphene/palladium catalyst reformer for hydrogen generation from waste of IC engine

    Science.gov (United States)

    Rahman, A.; Aung, K. M.

    2018-01-01

    A small amount of hydrogen made by on-board reformer is added to the normal intake air and gasoline mixture in the vehicle’s engine could improves overall combustion quality by allowing nearly twice as much air for a given amount of fuel introduced into the combustion chamber. This can be justified based on the calorific value of Hydrogen (H2) 141.9 MJ/kg while the gasoline (C6.4H11.8) is 47MJ/kg. Different weight % of Pd and GO uses for the reformer model and has conducted simulation by COMSOL software. The best result found for the composition of catalyst (palladium 30% and graphene 70%). The study shows that reformer yield hydrogen 23% for the exhaust temperature of 600-900°C and 20% for 80-90°C. Pumping hydrogen may boost the fuel atomization and vaporization at engine idle condition, which could enhances the fuel combustion efficiency. Thus, this innovative technology would be able to save fuel about 12% and reduce the emission about 35%.

  10. Quantitative Imaging of Turbulent Mixing Dynamics in High-Pressure Fuel Injection to Enable Predictive Simulations of Engine Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Jonathan H. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Reacting Flows Dept.; Pickett, Lyle M. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Engine Combustion Dept.; Bisson, Scott E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Remote Sensing and Energetic Materials Dept.; Patterson, Brian D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). combustion Chemistry Dept.; Ruggles, Adam J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Reacting Flows Dept.; Skeen, Scott A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Engine Combustion Dept.; Manin, Julien Luc [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Engine Combustion Dept.; Huang, Erxiong [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Reacting Flows Dept.; Cicone, Dave J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Engine Combustion Dept.; Sphicas, Panos [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Engine Combustion Dept.

    2015-09-01

    In this LDRD project, we developed a capability for quantitative high - speed imaging measurements of high - pressure fuel injection dynamics to advance understanding of turbulent mixing in transcritical flows, ignition, and flame stabilization mechanisms, and to provide e ssential validation data for developing predictive tools for engine combustion simulations. Advanced, fuel - efficient engine technologies rely on fuel injection into a high - pressure, high - temperature environment for mixture preparation and com bustion. Howe ver, the dynamics of fuel injection are not well understood and pose significant experimental and modeling challenges. To address the need for quantitative high - speed measurements, we developed a Nd:YAG laser that provides a 5ms burst of pulses at 100 kHz o n a robust mobile platform . Using this laser, we demonstrated s patially and temporally resolved Rayleigh scattering imaging and particle image velocimetry measurements of turbulent mixing in high - pressure gas - phase flows and vaporizing sprays . Quantitativ e interpretation of high - pressure measurements was advanced by reducing and correcting interferences and imaging artifacts.

  11. Innovations in systems engineering and analysis for the simulation of beyond design-base accidents

    International Nuclear Information System (INIS)

    Frisch, W.; Beraha, D.

    1990-01-01

    An important target in improving reactor safety is to have the most realistic simulation possible of beyond design-base accidents in the computer. This paper presents new developments in ATHLET and further developments (description of the thermo-fluid-dynamic conditions in the core and cooling circuits during serious incidents in the computer programme ATHLET-SA) and extensions (link-up to RALOC). RALOC is a computer programme for describing thermodynamic conditions inside the containment during design-base accidents and accidents involving core meltdown. Further research is dedicated to code acceleration. (DG) [de

  12. Control system design and validation platform development for small pressurized water reactors (SPWR) by coupling an engineering simulator and MATLAB/Simulink

    International Nuclear Information System (INIS)

    Sun, Peiwei; Zhao, Huanhuan; Liao, Longtao; Zhang, Jianmin; Su, Guanghui

    2017-01-01

    Highlights: • An SPWR control system design and validation platform is developed. • The platform is developed by coupling MATLAB/Simulink and an engineering simulator. • SPWR is modeled using Relap5 and preliminary control system is designed. • The platform is verified through numerical simulation over two typical load patterns. - Abstract: Significant progress has been made in the development of the small pressurized water reactors (SPWR). Unique characteristics of the SPWR deliver challenges to its control system design. In order to facilitate the control system design process and enhance its efficiency, it is important and necessary to establish a control system design and validation platform. Using shared memory technology, an engineering simulator coupled with MATLAB/Simulink is employed to achieve this objective. Shared memory is an efficient method to exchange data within programs. Dynamic data exchange and simulation time synchronization methods are particularly treated. To verify the platform, an SPWR with its control system is modeled using the platform and the simulator. Thermal-hydraulic modeling of the SPWR is carried out using Relap5, and its nodalization is introduced. The objectives of the control strategy are to maintain the average coolant temperature linearly varying with the reactor power and steam pressure constant. A preliminary SPWR control system is designed with proportional-integral-derivative (PID) controllers, and is implemented in MATLAB/Simulink associated with the engineering simulator. Subsequently, in order to evaluate the performance of the established simulation platform, transients of abrupt load changes and wide range load changes are simulated and simulation results are verified against those obtained from the engineering simulator alone. It is demonstrated that simulation results of both platforms are consistent with each other, which proves that the coupling of engineering simulator and MATLAB/Simulink is successful

  13. Mechanical Stimulation of Adipose-Derived Stem Cells for Functional Tissue Engineering of the Musculoskeletal System via Cyclic Hydrostatic Pressure, Simulated Microgravity, and Cyclic Tensile Strain.

    Science.gov (United States)

    Nordberg, Rachel C; Bodle, Josie C; Loboa, Elizabeth G

    2018-01-01

    It is critical that human adipose stem cell (hASC) tissue-engineering therapies possess appropriate mechanical properties in order to restore function of the load bearing tissues of the musculoskeletal system. In an effort to elucidate the hASC response to mechanical stimulation and develop mechanically robust tissue engineered constructs, recent research has utilized a variety of mechanical loading paradigms including cyclic tensile strain, cyclic hydrostatic pressure, and mechanical unloading in simulated microgravity. This chapter describes methods for applying these mechanical stimuli to hASC to direct differentiation for functional tissue engineering of the musculoskeletal system.

  14. Simulation study on single event burnout in linear doping buffer layer engineered power VDMOSFET

    Science.gov (United States)

    Yunpeng, Jia; Hongyuan, Su; Rui, Jin; Dongqing, Hu; Yu, Wu

    2016-02-01

    The addition of a buffer layer can improve the device's secondary breakdown voltage, thus, improving the single event burnout (SEB) threshold voltage. In this paper, an N type linear doping buffer layer is proposed. According to quasi-stationary avalanche simulation and heavy ion beam simulation, the results show that an optimized linear doping buffer layer is critical. As SEB is induced by heavy ions impacting, the electric field of an optimized linear doping buffer device is much lower than that with an optimized constant doping buffer layer at a given buffer layer thickness and the same biasing voltages. Secondary breakdown voltage and the parasitic bipolar turn-on current are much higher than those with the optimized constant doping buffer layer. So the linear buffer layer is more advantageous to improving the device's SEB performance. Project supported by the National Natural Science Foundation of China (No. 61176071), the Doctoral Fund of Ministry of Education of China (No. 20111103120016), and the Science and Technology Program of State Grid Corporation of China (No. SGRI-WD-71-13-006).

  15. Numerical simulation of catalysis combustion inside micro free-piston engine

    International Nuclear Information System (INIS)

    Wang, Qian; Zhang, Di; Bai, Jin; He, Zhixia

    2016-01-01

    Highlights: • A modeling study is applied on methane HCCI process of micro power device. • Mathematical formulas are established to predict the combustion characteristics. • Impacts of catalysis on the combustion characteristics are analyzed respectively. • The catalyst can improve the work steadily and reliability of micro power device. - Abstract: In order to investigate the catalytic combustion characteristics concerning homogeneous charge compression ignition (HCCI) in micro power device, numerical simulations with a 3D computation model that coupled motion of free piston and fluid dynamics of methane–air mixture flow were carried out and detailed gas-phase and surface catalytic reaction mechanisms of methane–air mixture were applied to the catalytic reactions model, a series of mathematical formula are established to predict the characteristics of compression ignition condition, impacts of catalysis on temperature, pressure, work capacity and other factors were analyzed respectively. Simulation results reveal that catalytic combustion facilitates the improvement of energy conversion efficiency and extends the ignition limit of methane–air mixture obviously, the ignition timing is brought forward as well, while compression ratio decreases and ignition delay period shrinks significantly. Numerical results demonstrate that the existence of catalytic wall helped to restrain the peak combustion pressure and maximum rate of pressure rise contributing to the steadily and reliability of operation inside micro free-piston power device.

  16. Operating cycle resolved modelling and hardware-in-the-loop-simulation of diesel engines of automobiles with turbocharging; Arbeitsspielaufgeloeste Modellbildung und Hardware-in-the-Loop-Simulation von Pkw-Dieselmotoren mit Abgasturboaufladung

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, Sebastian

    2012-11-01

    Model-based and simulation-based approaches increasingly are used in the process of software development and function development for automobile control devices in order to reduce the development time as well as to save test-stand trials. The author of the contribution under consideration reports on the design of a dynamic model of a diesel engine for the hardware-in-the-loop test environment. The development, the test and pre-application of modern engine control units of automobiles with a cylinder-based combustion control is in the focus of the model application. The developed real-time model of the engine consists of a air pathway model, an exhaust gas pathway model, a VTG turbocharger model, a model of the cylinder group as well as an emission model. The parametrization of the engine model requires a continuous setting method. The model is validated by means of stationary and dynamic measured data of the engine test stand.

  17. In-Depth Analysis of Simulation Engine Codes for Comparison with DOE s Roof Savings Calculator and Measured Data

    Energy Technology Data Exchange (ETDEWEB)

    New, Joshua Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Huang, Yu [White Box Technologies, Salt Lake City, UT (United States); Sanyal, Jibonananda [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mellot, Joe [The Garland Company, Cleveland, OH (United States); Childs, Kenneth W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kriner, Scott [Green Metal Consulting, Inc., Macungie, PA (United States)

    2014-06-01

    The Roof Savings Calculator (RSC) was developed through collaborations among Oak Ridge National Laboratory (ORNL), White Box Technologies, Lawrence Berkeley National Laboratory (LBNL), and the Environmental Protection Agency in the context of a California Energy Commission Public Interest Energy Research project to make cool-color roofing materials a market reality. The RSC website and a simulation engine validated against demonstration homes were developed to replace the liberal DOE Cool Roof Calculator and the conservative EPA Energy Star Roofing Calculator, which reported different roof savings estimates. A preliminary analysis arrived at a tentative explanation for why RSC results differed from previous LBNL studies and provided guidance for future analysis in the comparison of four simulation programs (doe2attic, DOE-2.1E, EnergyPlus, and MicroPas), including heat exchange between the attic surfaces (principally the roof and ceiling) and the resulting heat flows through the ceiling to the building below. The results were consolidated in an ORNL technical report, ORNL/TM-2013/501. This report is an in-depth inter-comparison of four programs with detailed measured data from an experimental facility operated by ORNL in South Carolina in which different segments of the attic had different roof and attic systems.

  18. Data on loss of off-site electric power simulation tests of the high temperature engineering test reactor

    International Nuclear Information System (INIS)

    Takeda, Takeshi; Nakagawa, Shigeaki; Fujimoto, Nozomu; Tachibana, Yukio; Iyoku, Tatsuo

    2002-07-01

    The high temperature engineering test reactor (HTTR), the first high temperature gas-cooled reactor (HTGR) in Japan, achieved the first full power of 30 MW on December 7 in 2001. In the rise-to-power test of the HTTR, simulation tests on loss of off-site electric power from 15 and 30 MW operations were carried out by manual shutdown of off-site electric power. Because helium circulators and water pumps coasted down immediately after the loss of off-site electric power, flow rates of helium and water decreased to the scram points. To shut down the reactor safely, the subcriticality should be kept by the insertion of control rods and the auxiliary cooling system should cool the core continuously avoiding excessive cold shock to core graphite components. About 50 s later from the loss of off-site electric power, the auxiliary cooling system started up by supplying electricity from emergency power feeders. Temperature of hot plenum block among core graphite structures decreased continuously after the startup of the auxiliary cooling system. This report describes sequences of dynamic components and transient behaviors of the reactor and its cooling system during the simulation tests from 15 and 30 MW operations. (author)

  19. Simulating Engineering Flows through Complex Porous Media via the Lattice Boltzmann Method

    Directory of Open Access Journals (Sweden)

    Vesselin Krassimirov Krastev

    2018-03-01

    Full Text Available In this paper, recent achievements in the application of the lattice Boltzmann method (LBM to complex fluid flows are reported. More specifically, we focus on flows through reactive porous media, such as the flow through the substrate of a selective catalytic reactor (SCR for the reduction of gaseous pollutants in the automotive field; pulsed-flow analysis through heterogeneous catalyst architectures; and transport and electro-chemical phenomena in microbial fuel cells (MFC for novel waste-to-energy applications. To the authors’ knowledge, this is the first known application of LBM modeling to the study of MFCs, which represents by itself a highly innovative and challenging research area. The results discussed here essentially confirm the capabilities of the LBM approach as a flexible and accurate computational tool for the simulation of complex multi-physics phenomena of scientific and technological interest, across physical scales.

  20. Tip-to-tail numerical simulation of a hypersonic air-breathing engine with ethylene fuel

    Science.gov (United States)

    Dharavath, Malsur; Manna, P.; Chakraborty, Debasis

    2016-11-01

    End to end CFD simulations of external and internal flow paths of an ethylene fueled hypersonic airbreathing vehicle with including forebody, horizontal fins, vertical fins, intake, combustor, single expansion ramp nozzle are carried out. The performance of the scramjet combustor and vehicle net thrust-drag is calculated for hypersonic cruise condition. Three-dimensional Navier-Stokes equations are solved along with SST-k-ω turbulence model using the commercial CFD software CFX-14. Single step chemical reaction based on fast chemistry assumption is used for combustion of gaseous ethylene fuel. Simulations captured complex shock structures including the shocks generated from the vehicle nose and compression ramps, impingement of cowl-shock on vehicle undersurface and its reflection in the intake and combustor etc. Various thermochemical parameters are analyzed and performance parameters are evaluated for nonreacting and reacting cases. Very good mixing ( 98%) of fuel with incoming air stream is observed. Positive thrust-drag margins are obtained for fuel equivalence ratio of 0.6 and computed combustion efficiency is observed to be 94 %. Effect of equivalence ratio on the vehicle performance is studied parametrically. Though the combustion efficiency has come down by 8% for fuel equivalence ratio of 0.8, net vehicle thrust is increased by 44%. Heat flux distribution on the various walls of the whole vehicle including combustor is estimated for the isothermal wall condition of 1000 K in reacting flow. Higher local heat flux values are observed at all the leading edges of the vehicle (i.e., nose, wing, fin and cowl leading edges) and strut regions of the combustor.

  1. Vitrification of noble metals containing NCAW simulant with an engineering scale melter (ESM): Campaign report

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, W.; Roth, G.; Tobie, W.; Weisenburger, S.; Weiss, K.; Elliott, M.; Eyler, L.L.

    1996-03-01

    ESM has been designed as a 10th-scale model of the DWPF-type melter, currently the reference melter for nitrification of Hanford double shell tankwaste. ESM and related equipment have been integrated to the existing mockup vitrification plant VA-WAK at KfK. On June 2-July 10, 1992, a shakedown test using 2.61 m{sup 3} of NCAW (neutralized current acid waste) simulant without noble metals was performed. On July 11-Aug. 30, 1992, 14.23 m{sup 3} of the same simulant with nominal concentrations of Ru, Rh, and Pd were vitrified. Objective was to investigate the behavior of such a melter with respect to discharge of noble metals with routine glass pouring via glass overflow. Results indicate an accumulation of noble metals in the bottom area of the flat-bottomed ESM. About 65 wt% of the noble metals fed to the melter could be drained out, whereas 35 wt% accumulated in the melter, based on analysis of glass samples from glass pouring stream in to the canisters. After the melter was drained at the end of the campaign through a bottom drain valve, glass samples were taken from the residual bottom layer. The samples had significantly increased noble metals content (factor of 20-45 to target loading). They showed also a significant decrease of the specific electric resistance compared to bulk glass (factor of 10). A decrease of 10- 15% of the resistance between he power electrodes could be seen at the run end, but the total amount of noble metals accumulated was not yet sufficient enough to disturb the Joule heating of the glass tank severely.

  2. Dynamic simulation of a beta-type Stirling engine with cam-drive mechanism via the combination of the thermodynamic and dynamic models

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chin-Hsiang; Yu, Ying-Ju [Department of Aeronautics and Astronautics, National Cheng Kung University, No. 1, Ta-Shieh Road, Tainan, Taiwan (China)

    2011-02-15

    Dynamic simulation of a beta-type Stirling engine with cam-drive mechanism used in concentrating solar power system has been performed. A dynamic model of the mechanism is developed and then incorporated with the thermodynamic model so as to predict the transient behavior of the engine in the hot-start period. In this study, the engine is started from an initial rotational speed. The torques exerted by the flywheel of the engine at any time instant can be calculated by the dynamic model as long as the gas pressures in the chambers, the mass inertia, the friction force, and the external load have been evaluated. The instantaneous rotation speed of the engine is then determined by integration of the equation of rotational motion with respect to time, which in return affects the instantaneous variations in pressure and other thermodynamic properties of the gas inside the chambers. Therefore, the transient variations in gas properties inside the engine chambers and the dynamic behavior of the engine mechanism should be handled simultaneously via the coupling of the thermodynamic and dynamic models. An extensive parametric study of the effects of different operating and geometrical parameters has been performed, and results regarding the effects of mass moment of inertia of the flywheel, initial rotational speed, initial charged pressure, heat source temperature, phase angle, gap size, displacer length, and piston stroke on the engine transient behavior are investigated. (author)

  3. Flow Field Simulation and Noise Control of a Twin-Screw Engine-Driven Supercharger

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2016-01-01

    Full Text Available With the advantages of good low-speed torque capability and excellent instant response performance, twin-screw superchargers have great potential in the automobile market, but the noise of these superchargers is the main factor that discourages their use. Therefore, it is important to study their noise mechanism and methods of reducing it. This study included a transient numerical simulation of a twin-screw supercharger flow field with computational fluid dynamics software and an analysis of the pressure field of the running rotor. The results showed that overcompression was significant in the compression end stage of the supercharger, resulting in a surge in airflow to a supersonic speed and the production of shock waves that resulted in loud noise. On the basis of these findings, optimization of the supercharger is proposed, including expansion of the supercharger exhaust orifice and creation of a slot along the direction of the rotor spiral normal line at the exhaust port, so as to reduce the compression end pressure, improve the exhaust flow channel, and weaken the source of the noise. Experimental results showed that the noise level value of the improved twin-screw supercharger was significantly lower at the same speed than the original model, with an average decrease of about 5 dB (A.

  4. Techno-economic simulation data based deterministic and stochastic for product engineering research and development BATAN

    International Nuclear Information System (INIS)

    Petrus Zacharias; Abdul Jami

    2010-01-01

    Researches conducted by Batan's researchers have resulted in a number competences that can be used to produce goods and services, which will be applied to industrial sector. However, there are difficulties how to convey and utilize the R and D products into industrial sector. Evaluation results show that each research result should be completed with techno-economy analysis to obtain the feasibility of a product for industry. Further analysis on multy-product concept, in which one business can produce many main products, will be done. For this purpose, a software package simulating techno-economy I economic feasibility which uses deterministic and stochastic data (Monte Carlo method) was been carried out for multi-product including side product. The programming language used in Visual Basic Studio Net 2003 and SQL as data base processing software. This software applied sensitivity test to identify which investment criteria is sensitive for the prospective businesses. Performance test (trial test) has been conducted and the results are in line with the design requirement, such as investment feasibility and sensitivity displayed deterministically and stochastically. These result can be interpreted very well to support business decision. Validation has been performed using Microsoft Excel (for single product). The result of the trial test and validation show that this package is suitable for demands and is ready for use. (author)

  5. ADVANCED COMPUTATIONALMETHODS FOR COMPLEX SIMULATION OF THERMAL PROCESSES IN POWER ENGINEERING

    Directory of Open Access Journals (Sweden)

    Risto V. Filkoski

    2007-04-01

    Full Text Available The overall frame and principal steps of complex numerical modelling of thermal processes in power boiler furnaces on pulverised coal with tangential disposition of the burners are presented in the paper. Computational fluid dynamics (CFD technique is used as a tool to perform comprehensive thermal analysis in two test cases. The methodology for creation of three-dimensional models of boiler furnaces is briefly described. Standard steady k- model is employed for description of the turbulent flow. The coupling of continuity and momentum is achieved by the SIMPLEC method. Coal combustion is modelled by the mixture fraction/probability density function approach for the reaction chemistry, with equilibrium assumption applied for description of the system chemistry. Thermal radiation is computed by means of the simplified P-N model, based on expansion of the radiation intensity into an orthogonal series of spherical harmonics.Comparison between the simulation predictions and available site measurements leads to a conclusion that the model produces realistic insight into the furnace processes. Qualitative agreement of the results indicates reasonability of the calculations and validates the employed sub-models. The described test cases and other experiences with CFD modelling stress the advantages over a purely field data study, such as the ability to quickly and cheaply analyse a variety of design options without actually modifying the object and the availability of significantly more data to interpret the results.

  6. Simulation and Empirical Studies of the Commercial SI Engine Performance and Its Emission Levels When Running on a CNG and Hydrogen Blend

    Directory of Open Access Journals (Sweden)

    Rafaa Saaidia

    2017-12-01

    Full Text Available This article is a report on a simulation based on Computational Fluid Dynamics (CFD and an empirical investigation of in-cylinder flow characteristics, In addition, it assesses the performance and emission levels of a commercial-spark ignited engine running on a CNG and Hydrogen blend in different ratios. The main objective was to determine the optimum hydrogen ratio that would yield the best brake torque and release the least polluting gases. The in-cylinder flow velocity and turbulence aspects were investigated during the intake stroke in order to analyze the intake flow behavior. To reach this goal, a 3D CFD code was adopted. For various engine speeds were investigated for gasoline, CNG and hydrogen and CNG blend (HCNG fueled engines via external mixtures. The variation of brake torque (BT, NOX and CO emissions. A series of tests were conducted on the engine within the speed range of 1000 to 5000 rpm. For this purpose, a commercial Hyundai Sonata S.I engine was modified to operate with a blend of CNG and Hydrogen in different ratios. The experiments attempted to determine the optimum allowable hydrogen ratio with CNG for normal engine operation. The engine performance and the emission levels were also analyzed. At the engine speed of 4200 rpm, the results revealed that beyond a ratio of 50% of the volume of hydrogen added to CNG a backfire phenomenon appeared. Below this ratio (0~40% of the hydrogen volume, the CNG and Hydrogen blend seemed to be beneficial for the engine performance and for curtailing the emission level. However, at low engine speeds, the NOX concentration increased simultaneously with hydrogen content. In contrast, at high engine speeds, the NOX concentration decreased to its lowest level compared to that reached with gasoline as a running fuel. The concentration levels of HC, CO2, and CO decreased with the increase of hydrogen percentage.

  7. The Effects of Computer Simulation and Animation (CSA) on Students' Cognitive Processes: A Comparative Case Study in an Undergraduate Engineering Course

    Science.gov (United States)

    Fang, N.; Tajvidi, M.

    2018-01-01

    This study focuses on the investigation of the effects of computer simulation and animation (CSA) on students' cognitive processes in an undergraduate engineering course. The revised Bloom's taxonomy, which consists of six categories in the cognitive process domain, was employed in this study. Five of the six categories were investigated,…

  8. Explicit Finite Element Modeling of Multilayer Composite Fabric for Gas Turbine Engine Containment Systems, Phase II. Part 3; Material Model Development and Simulation of Experiments

    Science.gov (United States)

    Simmons, J.; Erlich, D.; Shockey, D.

    2009-01-01

    A team consisting of Arizona State University, Honeywell Engines, Systems & Services, the National Aeronautics and Space Administration Glenn Research Center, and SRI International collaborated to develop computational models and verification testing for designing and evaluating turbine engine fan blade fabric containment structures. This research was conducted under the Federal Aviation Administration Airworthiness Assurance Center of Excellence and was sponsored by the Aircraft Catastrophic Failure Prevention Program. The research was directed toward improving the modeling of a turbine engine fabric containment structure for an engine blade-out containment demonstration test required for certification of aircraft engines. The research conducted in Phase II began a new level of capability to design and develop fan blade containment systems for turbine engines. Significant progress was made in three areas: (1) further development of the ballistic fabric model to increase confidence and robustness in the material models for the Kevlar(TradeName) and Zylon(TradeName) material models developed in Phase I, (2) the capability was improved for finite element modeling of multiple layers of fabric using multiple layers of shell elements, and (3) large-scale simulations were performed. This report concentrates on the material model development and simulations of the impact tests.

  9. 3-D simulation of soot formation in a direct-injection diesel engine based on a comprehensive chemical mechanism and method of moments

    Science.gov (United States)

    Zhong, Bei-Jing; Dang, Shuai; Song, Ya-Na; Gong, Jing-Song

    2012-02-01

    Here, we propose both a comprehensive chemical mechanism and a reduced mechanism for a three-dimensional combustion simulation, describing the formation of polycyclic aromatic hydrocarbons (PAHs), in a direct-injection diesel engine. A soot model based on the reduced mechanism and a method of moments is also presented. The turbulent diffusion flame and PAH formation in the diesel engine were modelled using the reduced mechanism based on the detailed mechanism using a fixed wall temperature as a boundary condition. The spatial distribution of PAH concentrations and the characteristic parameters for soot formation in the engine cylinder were obtained by coupling a detailed chemical kinetic model with the three-dimensional computational fluid dynamic (CFD) model. Comparison of the simulated results with limited experimental data shows that the chemical mechanisms and soot model are realistic and correctly describe the basic physics of diesel combustion but require further development to improve their accuracy.

  10. Numerical Simulation of PAHs Formation and Effect of Operating Conditions in DI-Diesel Engines Based on a Comprehensive Chemical Mechanism

    Directory of Open Access Journals (Sweden)

    Bei-Jing Zhong

    2013-01-01

    Full Text Available Three-dimensional numerical simulations of polycyclic aromatic hydrocarbon (PAH formation in a Chaochai 6102bzl direct injection diesel engine are performed. n-Heptane is chosen as the fuel. A detailed mechanism, which includes 108 species and 572 elementary reactions that describe n-heptane oxidation and PAH formation, is proposed. A reduced kinetic mechanism, with only 86 reactions and 57 species, is developed and incorporated into computational fluid dynamics (CFD software for the numerical simulations. Results show that PAHs, which were mostly deposited at the bottom of the diesel combustion chamber wall, first increased and then decreased with the increase in diesel crank angle. Furthermore, the diesel engine operating conditions (intake vortex intensity, intake air pressure, fuel injection advance angle, diesel load, and engine speed had a significant effect on PAH formation.

  11. Tool for the Integrated Dynamic Numerical Propulsion System Simulation (NPSS)/Turbine Engine Closed-Loop Transient Analysis (TTECTrA) User's Guide

    Science.gov (United States)

    Chin, Jeffrey C.; Csank, Jeffrey T.

    2016-01-01

    The Tool for Turbine Engine Closed-Loop Transient Analysis (TTECTrA ver2) is a control design tool thatenables preliminary estimation of transient performance for models without requiring a full nonlinear controller to bedesigned. The program is compatible with subsonic engine models implemented in the MATLAB/Simulink (TheMathworks, Inc.) environment and Numerical Propulsion System Simulation (NPSS) framework. At a specified flightcondition, TTECTrA will design a closed-loop controller meeting user-defined requirements in a semi or fully automatedfashion. Multiple specifications may be provided, in which case TTECTrA will design one controller for each, producing acollection of controllers in a single run. Each resulting controller contains a setpoint map, a schedule of setpointcontroller gains, and limiters; all contributing to transient characteristics. The goal of the program is to providesteady-state engine designers with more immediate feedback on the transient engine performance earlier in the design cycle.

  12. Computational engineering

    CERN Document Server

    2014-01-01

    The book presents state-of-the-art works in computational engineering. Focus is on mathematical modeling, numerical simulation, experimental validation and visualization in engineering sciences. In particular, the following topics are presented: constitutive models and their implementation into finite element codes, numerical models in nonlinear elasto-dynamics including seismic excitations, multiphase models in structural engineering and multiscale models of materials systems, sensitivity and reliability analysis of engineering structures, the application of scientific computing in urban water management and hydraulic engineering, and the application of genetic algorithms for the registration of laser scanner point clouds.

  13. Advanced 3D tools used in reverse engineering and ray tracing simulation of phased array inspection of turbine components with complex geometry

    International Nuclear Information System (INIS)

    Daks, W.; Kovacshazy, C.; Mair, D.; Ciorau, P.

    2002-01-01

    This paper outlines the practical aspects of reverse engineering and the integration of multiple pieces of software (Drafting, CNC Machining, Ray Tracing, Inspection Simulation Scenario and Phased Array UT Analysis), in order to inspect turbine components comprised of complex geometry. The CNC software, Mastercam, and design software, CADKEY/FastSURF, were used to validate the phased-array automated and manual inspection of blade root, rotor steeples and disk-blade rim attachment. The integration of a 3D part in the software engine, Imagine 3D and SimScan, as well as Tomoview analysis (specimen feature) is based on CADKEY Developer Kit - IGES/SAT file format. A generic Ray Tracing simulation for multi-probe beam was integrated into Imagine 3D. Representative examples of reference blocks and mock-ups, UT simulation and phased-array data comparison are presented. (author)

  14. Simulation of CO and NO emissions in a SI engine using a 0D coherent flame model coupled with a tabulated chemistry approach

    International Nuclear Information System (INIS)

    Bougrine, S.; Richard, S.; Michel, J.-B.; Veynante, D.

    2014-01-01

    Highlights: • A new 0D combustion model (CFM1D-TC) based on a tabulation approach is proposed. • Complex chemistry calculations are used to deduce composition and relaxation times. • NO and CO exponentially relax from a perturbed state to the equilibrium state. • The new model is implemented in an engine simulation software. • Validations are performed by comparison with a wide range of experimental data. - Abstract: Environmental issues stimulate the elaboration of new powertrain systems and fuels for transport as an essential priority to decrease air pollution and green house gases emissions. Developments ranging from architecture definition to engine control and calibration are today increasingly performed using complete vehicle simulators running close to real times. The challenge for engineers is therefore to develop models able to accurately reproduce the engine response without altering the CPU efficiency of the simulator. For this purpose, 0-dimensional models are commonly used to describe combustion processes in engine combustion chambers. This paper extends a 0-dimensional coherent flame model (CFM), called CFM1D, to incorporate chemical effects related to the fuel composition and thermodynamic conditions at low computational costs. Improvements are carried out integrating the NO relaxation approach (NORA) based on a priori homogeneous reactor computations and initially developed for 3D simulations to describe post-oxidation processes in the burnt gases. In this work, this method is extended to the modeling of CO production and oxidation leading to the CORA (CO Relaxation Approach) model. Both NO and CO reaction rates are therefore written as linear relaxations towards their equilibrium mass fraction values Y k eq (where k stands for NO or CO) within a characteristic time τ k . In this approach, Y k eq and τ k are tabulated as functions of equivalence ratio, fresh gases dilution rate by burnt gases, pressure and enthalpy. The resulting new

  15. Model-driven requirements engineering (MDRE) for real-time ultra-wide instantaneous bandwidth signal simulation

    Science.gov (United States)

    Chang, Daniel Y.; Rowe, Neil C.

    2013-05-01

    While conducting a cutting-edge research in a specific domain, we realize that (1) requirements clarity and correctness are crucial to our success [1], (2) hardware is hard to change, most work is in software requirements development, coding and testing [2], (3) requirements are constantly changing, so that configurability, reusability, scalability, adaptability, modularity and testability are important non-functional attributes [3], (4) cross-domain knowledge is necessary for complex systems [4], and (5) if our research is successful, the results could be applied to other domains with similar problems. In this paper, we propose to use model-driven requirements engineering (MDRE) to model and guide our requirements/development, since models are easy to understand, execute, and modify. The domain for our research is Electronic Warfare (EW) real-time ultra-wide instantaneous bandwidth (IBW1) signal simulation. The proposed four MDRE models are (1) Switch-and-Filter architecture, (2) multiple parallel data bit streams alignment, (3) post-ADC and pre-DAC bits re-mapping, and (4) Discrete Fourier Transform (DFT) filter bank. This research is unique since the instantaneous bandwidth we are dealing with is in gigahertz range instead of conventional megahertz.

  16. A simulator-based analysis of engineering treatments for right-hook bicycle crashes at signalized intersections.

    Science.gov (United States)

    Warner, Jennifer; Hurwitz, David S; Monsere, Christopher M; Fleskes, Kayla

    2017-07-01

    A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures - regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design - at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections with a shared right-turn and through lane. Changes in driver performance in response to treatments were measured in a high-fidelity driving simulator. Twenty-eight participants each completed 22 right-turn maneuvers. A partially counterbalanced experimental design exposed drivers to critical scenarios, which had been determined in a previous experiment. For each turn, driver performance measures, including visual attention, crash avoidance, and potential crash severity, were collected. A total of 75 incidents (47 near-collisions and 28 collisions) were observed during the 616 right turns. All treatments had some positive effect on measured driver performance with respect to the right-turn vehicle conflicts. Further work is required to map the magnitude of these changes in driver performance to crash-based outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Large eddy simulation of combustion characteristics in a kerosene fueled rocket-based combined-cycle engine combustor

    Science.gov (United States)

    Huang, Zhi-wei; He, Guo-qiang; Qin, Fei; Cao, Dong-gang; Wei, Xiang-geng; Shi, Lei

    2016-10-01

    This study reports combustion characteristics of a rocket-based combined-cycle engine combustor operating at ramjet mode numerically. Compressible large eddy simulation with liquid kerosene sprayed and vaporized is used to study the intrinsic unsteadiness of combustion in such a propulsion system. Results for the pressure oscillation amplitude and frequency in the combustor as well as the wall pressure distribution along the flow-path, are validated using experimental data, and they show acceptable agreement. Coupled with reduced chemical kinetics of kerosene, results are compared with the simultaneously obtained Reynolds-Averaged Navier-Stokes results, and show significant differences. A flow field analysis is also carried out for further study of the turbulent flame structures. Mixture fraction is used to determine the most probable flame location in the combustor at stoichiometric condition. Spatial distributions of the Takeno flame index, scalar dissipation rate, and heat release rate reveal that different combustion modes, such as premixed and non-premixed modes, coexisted at different sections of the combustor. The RBCC combustor is divided into different regions characterized by their non-uniform features. Flame stabilization mechanism, i.e., flame propagation or fuel auto-ignition, and their relative importance, is also determined at different regions in the combustor.

  18. Modeling and simulation of combustion dynamics in lean-premixed swirl-stabilized gas-turbine engines

    Science.gov (United States)

    Huang, Ying

    This research focuses on the modeling and simulation of combustion dynamics in lean-premixed gas-turbines engines. The primary objectives are: (1) to establish an efficient and accurate numerical framework for the treatment of unsteady flame dynamics; and (2) to investigate the parameters and mechanisms responsible for driving flow oscillations in a lean-premixed gas-turbine combustor. The energy transfer mechanisms among mean flow motions, periodic motions and background turbulent motions in turbulent reacting flow are first explored using a triple decomposition technique. Then a comprehensive numerical study of the combustion dynamics in a lean-premixed swirl-stabilized combustor is performed. The analysis treats the conservation equations in three dimensions and takes into account finite-rate chemical reactions and variable thermophysical properties. Turbulence closure is achieved using a large-eddy-simulation (LES) technique. The compressible-flow version of the Smagorinsky model is employed to describe subgrid-scale turbulent motions and their effect on large-scale structures. A level-set flamelet library approach is used to simulate premixed turbulent combustion. In this approach, the mean flame location is modeled using a level-set G-equation, where G is defined as a distance function. Thermophysical properties are obtained using a presumed probability density function (PDF) along with a laminar flamelet library. The governing equations and the associated boundary conditions are solved by means of a four-step Runge-Kutta scheme along with the implementation of the message passing interface (MPI) parallel computing architecture. The analysis allows for a detailed investigation into the interaction between turbulent flow motions and oscillatory combustion of a swirl-stabilized injector. Results show good agreement with an analytical solution and experimental data in terms of acoustic properties and flame evolution. A study of flame bifurcation from a stable

  19. Simulation of a heavy-duty diesel engine with electrical turbocompounding system using operating charts for turbocharger components and power turbine

    International Nuclear Information System (INIS)

    Katsanos, C.O.; Hountalas, D.T.; Zannis, T.C.

    2013-01-01

    Highlights: • A diesel model was developed using charts for turbocharger and power turbine. • The maximum value of bsfc improvement is 4.1% at 100% engine load. • The generated electric power ranges from 23 kW to 62 kW. • Turbocharger turbine efficiency decreases slightly with the power turbine speed. • Turbocompounding increases the average pressure value in the exhaust manifold. - Abstract: In diesel engines, approximately 30–40% of the energy supplied by the fuel is rejected to the ambience through exhaust gases. Therefore, there is a potentiality for further considerable increase of diesel engine efficiency with the utilization of exhaust gas heat and its conversion to mechanical or electrical energy. In the present study, the operational behavior of a heavy-duty (HD) diesel truck engine equipped with an electric turbocompounding system is examined on a theoretical basis. The electrical turbocompounding configuration comprised of a power turbine coupled to an electric generator, which is installed downstream to the turbocharger (T/C) turbine. A diesel engine simulation model has been developed using operating charts for both turbocharger and power turbine. A method for introducing the operating charts into the engine model is described thoroughly. A parametric analysis is conducted with the developed simulation tool, where the varying parameter is the rotational speed of power turbine shaft. In this study, the interaction between the power turbine and the turbocharged diesel engine is examined in detail. The effect of power turbine speed on T/C components efficiencies, power turbine efficiency, exhaust pressure and temperature, engine boost pressure and air to fuel ratio is evaluated. In addition, theoretical results for the potential impact of electrical turbocompounding on the generated electric power, net engine power and relative improvement of brake specific fuel consumption (bsfc) are provided. The critical evaluation of the theoretical

  20. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable p...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  1. Developing an Internet Oriented Platform for Earthquake Engineering Application and Web-based Virtual Reality Simulation System for Seismic hazards: Towards Disaster Mitigation in Metropolises

    Directory of Open Access Journals (Sweden)

    Ali Alaghehbandian

    2003-04-01

    Full Text Available This paper reviews the state of the art on risk communication to the public, with an emphasis on simulation of seismic hazards using VRML. Rapid growth computer technologies, especially the Internet provide human beings new measures to deal with engineering and social problems which were hard to solve in traditional ways. This paper presents a prototype of an application platform based on the Internet using VR (Virtual Reality for civil engineering considering building an information system of risk communication for seismic hazards and at the moment in the case of bridge structure.

  2. A Modified Version of the RNG k–ε Turbulence Model for the Scale-Resolving Simulation of Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Vesselin Krassimirov Krastev

    2017-12-01

    Full Text Available The unsteady and random character of turbulent flow motion is a key aspect of the multidimensional modeling of internal combustion engines (ICEs. A typical example can be found in the prediction of the cycle-to-cycle variability (CCV in modern, highly downsized gasoline direct injection (GDI engines, which strongly depends on the accurate simulation of turbulent in-cylinder flow structures. The current standard for turbulence modeling in ICEs is still represented by the unsteady form of Reynold-averaged Navier Stokes equations (URANS, which allows the simulation of full engine cycles at relatively low computational costs. URANS-based methods, however, are only able to return a statistical description of turbulence, as the effects of all scales of motion are entirely modeled. Therefore, during the last decade, scale-resolving methods such as large eddy simulation (LES or hybrid URANS/LES approaches are gaining increasing attention among the engine-modeling community. In the present paper, we propose a scale-resolving capable modification of the popular RNG k– ε URANS model. The modification is based on a detached-eddy simulation (DES framework and allows one to explicitly set the behavior (URANS, DES or LES of the model in different zones of the computational domain. The resulting zonal formulation has been tested on two reference test cases, comparing the numerical predictions with the available experimental data sets and with previous computational studies. Overall, the scale-resolved part of the computed flow has been found to be consistent with the expected flow physics, thus confirming the validity of the proposed simulation methodology.

  3. Pathways and mechanisms for product release in the engineered haloalkane dehalogenases explored using classical and random acceleration molecular dynamics simulations.

    Science.gov (United States)

    Klvana, Martin; Pavlova, Martina; Koudelakova, Tana; Chaloupkova, Radka; Dvorak, Pavel; Prokop, Zbynek; Stsiapanava, Alena; Kuty, Michal; Kuta-Smatanova, Ivana; Dohnalek, Jan; Kulhanek, Petr; Wade, Rebecca C; Damborsky, Jiri

    2009-10-09

    Eight mutants of the DhaA haloalkane dehalogenase carrying mutations at the residues lining two tunnels, previously observed by protein X-ray crystallography, were constructed and biochemically characterized. The mutants showed distinct catalytic efficiencies with the halogenated substrate 1,2,3-trichloropropane. Release pathways for the two dehalogenation products, 2,3-dichloropropane-1-ol and the chloride ion, and exchange pathways for water molecules, were studied using classical and random acceleration molecular dynamics simulations. Five different pathways, denoted p1, p2a, p2b, p2c, and p3, were identified. The individual pathways showed differing selectivity for the products: the chloride ion releases solely through p1, whereas the alcohol releases through all five pathways. Water molecules play a crucial role for release of both products by breakage of their hydrogen-bonding interactions with the active-site residues and shielding the charged chloride ion during its passage through a hydrophobic tunnel. Exchange of the chloride ions, the alcohol product, and the waters between the buried active site and the bulk solvent can be realized by three different mechanisms: (i) passage through a permanent tunnel, (ii) passage through a transient tunnel, and (iii) migration through a protein matrix. We demonstrate that the accessibility of the pathways and the mechanisms of ligand exchange were modified by mutations. Insertion of bulky aromatic residues in the tunnel corresponding to pathway p1 leads to reduced accessibility to the ligands and a change in mechanism of opening from permanent to transient. We propose that engineering the accessibility of tunnels and the mechanisms of ligand exchange is a powerful strategy for modification of the functional properties of enzymes with buried active sites.

  4. Study of ignition in a high compression ratio SI (spark ignition) methanol engine using LES (large eddy simulation) with detailed chemical kinetics

    International Nuclear Information System (INIS)

    Zhen, Xudong; Wang, Yang

    2013-01-01

    Methanol has been recently used as an alternative to conventional fuels for internal combustion engines in order to satisfy some environmental and economical concerns. In this paper, the ignition in a high compression ratio SI (spark ignition) methanol engine was studied by using LES (large eddy simulation) with detailed chemical kinetics. A 21-species, 84-reaction methanol mechanism was adopted to simulate the auto-ignition process of the methanol/air mixture. The MIT (minimum ignition temperature) and MIE (minimum ignition energy) are two important properties for designing safety standards and understanding the ignition process of combustible mixtures. The effects of the flame kernel size, flame kernel temperature and equivalence ratio were also examined on MIT, MIE and IDP (ignition delay period). The methanol mechanism was validated by experimental test. The simulated results showed that the flame kernel size, temperature and energy dramatically affected the values of the MIT, MIE and IDP for a methanol/air mixture, the value of the ignition delay period was not only related to the flame kernel energy, but also to the flame kernel temperature. - Highlights: • We used LES (large eddy simulation) coupled with detailed chemical kinetics to simulate methanol ignition. • The flame kernel size and temperature affected the minimum ignition temperature. • The flame kernel temperature and energy affected the ignition delay period. • The equivalence ratio of methanol–air mixture affected the ignition delay period

  5. Application of a hybrid breakup model for the spray simulation of a multi-hole injector used for a DISI gasoline engine

    International Nuclear Information System (INIS)

    Li, Zhi-Hua; He, Bang-Quan; Zhao, Hua

    2014-01-01

    A hybrid atomization and breakup model was developed for the simulation of the fuel injection processes of multi-hole injectors for direct injection spark ignition (DISI) gasoline engines. In modeling primary breakup, a competition between the Huh–Gosman and Kelvin–Helmholtz (KH) breakup mechanisms was adopted. In addition to the two breakup mechanisms above, the Rayleigh–Taylor (RT) model was selected as a third competing mechanism in simulating secondary breakup. The hybrid model was implemented in the Star-CD software to simulate the effect of the background and injection pressures on the breakup processes of gasoline jets in a constant volume vessel, and on the mixture stratification of a wall-guided DISI gasoline engine with a newly-designed cavity in the piston. Results indicate that a higher background pressure intensifies the aerodynamically induced breakup along the tip of spray although it tends to reduce the overall breakup of spray. The spray atomization enhanced by increasing injection pressures is more pronounced at elevated background pressures. With the retard of fuel injection timing, the inhomogeneity of mixture increases in the DISI gasoline engine. Double injection with elevated second injection pressure can reduce the overall inhomogeneity of the mixture and effectively direct the mixture towards the spark plug. - Highlights: •A hybrid breakup model was developed to simulate injection process in a DISI engine. •Higher fuel injection pressure enhances breakup and evaporation at the spray tip. •Single fuel injection leads to a narrow spark timing range. •Two-stage fuel injection improves the homogeneity of the mixture. •The second injection with higher fuel pressure decreases over-rich mixture

  6. Validation of a zero-dimensional and two-phase combustion model for dual-fuel compression ignition engine simulation

    NARCIS (Netherlands)

    Mikulski, M.; Wierzbicki, S.

    2017-01-01

    Increasing demands for the reduction of exhaust emissions and the pursuit to reduce the use of fossil fuels require the search for new fuelling technologies in combustion engines. One of the most promising technologies is the multi-fuel compression ignition engine concept, in which a small dose of

  7. Simulation of the long term alteration of clay minerals in engineered bentonite barriers: nucleation and growth of secondary clay particles

    International Nuclear Information System (INIS)

    Fritz, B.; Clement, A.; Zwingmann, H.; Noguera, C.

    2010-01-01

    Document available in extended abstract form only. The long term stability of clay rich rocks used as barriers to the migration of radionuclides in the environment of nuclear wastes has been intensively studied, looking at the geochemical interactions between clay minerals and aqueous solutions. These studies combine experimental approaches for the short term and numerical modellings for the long term extrapolations, in the frame of the research supported by ANDRA in the French design for High Level Waste (HLW) repository. The main objective of the geochemical numerical tools devoted to clay-solutions interaction processes was to predict the feed-back effects of mineralogical and chemical transformations of clay mineral, in repository conditions as defined by Andra, on their physical and transport properties (porosity, molecular diffusion, permeability). The 1D transport-reaction coupled simulation was done using the code KIRMAT, at 100 deg. C for 100000 years. The fluid considered is that of the Callovo-Oxfordian geological formation (COX) and assumed to diffuse into the clay barrier from one side. On the other side, ferrous iron, is provided by the steel overpack corrosion. Under these conditions, montmorillonite of the clay barrier is only partially transformed into illite, chlorite, and saponite. The simulation shows that only outer parts of the clay barrier is significantly modified, mainly at the interface with the geological environment. These modifications correspond to a closure of the porosity, followed by a decrease of mass transport by molecular diffusion. Near the COX, the swelling pressure of the clays from the barrier is predicted to decrease, but in its major part, the engineered barrier seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure). In this modelling approach, the very important role of secondary clay minerals has to be taken into account with relevant kinetic rate laws; particularly

  8. Simulation of water-surface elevations for a hypothetical 100-year peak flow in Birch Creek at the Idaho National Engineering and Environmental Laboratory, Idaho

    International Nuclear Information System (INIS)

    Berenbrock, C.; Kjelstrom, L.C.

    1997-01-01

    Delineation of areas at the Idaho National Engineering and Environmental Laboratory that would be inundated by a 100-year peak flow in Birch Creek is needed by the US Department of Energy to fulfill flood-plain regulatory requirements. Birch Creek flows southward about 40 miles through an alluvium-filled valley onto the northern part of the Idaho National Engineering and Environmental laboratory site on the eastern Snake River Plain. The lower 10-mile reach of Birch Creek that ends in Birch Creek Playa near several Idaho National Engineering and Environmental Laboratory facilities is of particular concern. Twenty-six channel cross sections were surveyed to develop and apply a hydraulic model to simulate water-surface elevations for a hypothetical 100-year peak flow in Birch Creek. Model simulation of the 100-year peak flow (700 cubic feet per second) in reaches upstream from State Highway 22 indicated that flow was confined within channels even when all flow was routed to one channel. Where the highway crosses Birch Creek, about 315 cubic feet per second of water was estimated to move downstream--115 cubic feet per second through a culvert and 200 cubic feet per second over the highway. Simulated water-surface elevation at this crossing was 0.8 foot higher than the elevation of the highway. The remaining 385 cubic feet per second flowed southwestward in a trench along the north side of the highway. Flow also was simulated with the culvert removed. The exact location of flood boundaries on Birch Creek could not be determined because of the highly braided channel and the many anthropogenic features (such as the trench, highway, and diversion channels) in the study area that affect flood hydraulics and flow. Because flood boundaries could not be located exactly, only a generalized flood-prone map was developed

  9. Employing Organizational Modeling and Simulation to Reduce F/A-18E/F F414 Engine Maintenance Time

    National Research Council Canada - National Science Library

    Hagan, Joel J; Slack, William G

    2006-01-01

    ...) at Naval Air Station (NAS) Lemoore, California. To achieve this goal, organizational modeling was employed to evaluate how changes to the organizational structure of the Lemoore AIMD affected engine throughput time...

  10. Re-Engineering Control Systems using Automatic Generation Tools and Process Simulation: the LHC Water Cooling Case

    CERN Document Server

    Booth, W; Bradu, B; Gomez Palacin, L; Quilichini, M; Willeman, D

    2014-01-01

    This paper presents the approach used at CERN (European Organization for Nuclear Research) to perform the re-engineering of the control systems dedicated to the LHC (Large Hadron Collider) water cooling systems.

  11. Design and Task Analysis for a Game-Based Shiphandling Simulator Using an Open Source Game Engine (DELTA3D)

    Science.gov (United States)

    2011-09-01

    Rodrigues, F. L. D. (2010).Sistema de realidade virtual para simulador visual de passadiço ( Virtual reality system for visual bridge simulator...products/shipsimulatorextremes Souza, I. (2007). Simulador de Realidade Virtual para o Treinamento de Biópsia por Agulha de Nódulos da Glândula de...Games, Shiphandling Simulator, Training, Virtual Environments, Simulation, Open Source, Brazilian Navy 16. PRICE CODE 17. SECURITY CLASSIFICATION OF

  12. Modern Trends Of Computation, Simulation, and Communication, And Their Impacts On The Progress Of Scientific And Engineering Research, Development, And Education

    International Nuclear Information System (INIS)

    Bunjamin, Muhammad

    2001-01-01

    A short report on the modern trends of computation, simulation, and communication in the 1990s is presented, along with their impacts on the progress of scientific and engineering research, development, and education. A full description of this giant issue is certainly a m ission impossible f or the author. Nevertheless, it is the author's hope that it will at least give an overall view about what is going on in this very dynamic field in the advanced countries. After t hinking globally t hru reading this report, we should then decide on w hat and how to act locally t o respond to these global trends. The main source of information reported here were the computational science and engineering journals and books issued during the 1990s as listed in the references below

  13. Discussion on boundary conditions for simplified numerical simulation of swirl velocity in a cylinder of engine; Engine nai swirl no kan`i suchi simulation ni okeru kyokai joken no kento

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, K; Tasaka, H; Tan, H [Miyazaki University, Miyazaki (Japan)

    1997-10-01

    A simplified and quantitative simulation to calculate a swirl velocity in a cylinder with short time and low cost was offered by one of the authors. But the discussion on boundary conditions for the simulation was not enough. In this paper, measurements of diminution of the swirl velocity in a vessel packed with a fluid and simulations corresponding to the measurements were carried out varying aspect ratio of the vessel. From the measurement and calculating results, boundary conditions were obtained. The validity of the obtained boundary conditions was discussed and the adequate boundary conditions were determined. 4 refs., 6 figs., 2 tabs.

  14. Unsteady Reynolds-averaged Navier-Stokes simulations of inlet distortion in the fan system of a gas-turbine aero-engine

    Science.gov (United States)

    Spotts, Nathan

    As modern trends in commercial aircraft design move toward high-bypass-ratio fan systems of increasing diameter with shorter, nonaxisymmetric nacelle geometries, inlet distortion is becoming common in all operating regimes. The distortion may induce aerodynamic instabilities within the fan system, leading to catastrophic damage to fan blades, should the surge margin be exceeded. Even in the absence of system instability, the heterogeneity of the flow affects aerodynamic performance significantly. Therefore, an understanding of fan-distortion interaction is critical to aircraft engine system design. This thesis research elucidates the complex fluid dynamics and fan-distortion interaction by means of computational fluid dynamics (CFD) modeling of a complete engine fan system; including rotor, stator, spinner, nacelle and nozzle; under conditions typical of those encountered by commercial aircraft. The CFD simulations, based on a Reynolds-averaged Navier-Stokes (RANS) approach, were unsteady, three-dimensional, and of a full-annulus geometry. A thorough, systematic validation has been performed for configurations from a single passage of a rotor to a full-annulus system by comparing the predicted flow characteristics and aerodynamic performance to those found in literature. The original contributions of this research include the integration of a complete engine fan system, based on the NASA rotor 67 transonic stage and representative of the propulsion systems in commercial aircraft, and a benchmark case for unsteady RANS simulations of distorted flow in such a geometry under realistic operating conditions. This study is unique in that the complex flow dynamics, resulting from fan-distortion interaction, were illustrated in a practical geometry under realistic operating conditions. For example, the compressive stage is shown to influence upstream static pressure distributions and thus suppress separation of flow on the nacelle. Knowledge of such flow physics is

  15. Towards a generic multi-agent engine for the simulation of spatial behavioural processes : MASQUE/SwarmCity

    NARCIS (Netherlands)

    Devisch, O.T.J.; Arentze, T.A.; Borgers, A.W.J.; Timmermans, H.J.P.; Leeuwen, van J.P.; Timmermans, H.J.P.

    2004-01-01

    SwarmCity is being developed as a micro-simulation model, simulating the location-choice behaviour of a population of households, retailers, firms, developers, etc. reacting to an urban plan. The focus of SwarmCity lies -in a first phase- on the decision-making procedures of households,

  16. Simulation Modeling and Optimization of Uniflow Scavenging System Parameters on Opposed-Piston Two-Stroke Engines

    Directory of Open Access Journals (Sweden)

    Fukang Ma

    2018-04-01

    Full Text Available Based on the introduction of opposed-piston two-stroke (OP2S gasoline direct injection (GDI engines, the OP2S-GDI engine working principle and scavenging process were analyzed. GT-Power software was employed to model the working process based on the structural style and principle of OP2S-GDI engine. The tracer gas method and OP2S-GDI engine experiment were employed for model validation at full load of 6000 rpm. The OP2S-GDI engine scavenging system parameters were optimized, including intake port height stroke ratio, intake port circumference ratio, exhaust port height stroke ratio, exhaust port circumference ratio, and opposed-piston motion phase difference. At the same time, the effect of the port height stroke ratio and opposed-piston motion phase difference on effective compression ratio and expansion ratio were considered, and the indicated work was employed as the optimization objective. A three-level orthogonal experiment was applied in the calculation process to reduce the calculation work. The influence and correlation coefficient on the scavenging efficiency and delivery ratio were investigated by the orthogonal experiment analysis of intake and exhaust port height stroke ratio and circular utilization. The effect of the scavenging system parameters on delivery ratio, scavenging efficiency and indicated work were calculated to obtain the best parameters. The results show that intake port height stroke ratio is the main factor for the delivery ratio, while exhaust port height stroke ratio is the main factor to engine delivery ratio and scavenging efficiency.

  17. Sandia National Laboratories Advanced Simulation and Computing (ASC) software quality plan. Part 1: ASC software quality engineering practices, Version 2.0.

    Energy Technology Data Exchange (ETDEWEB)

    Sturtevant, Judith E.; Heaphy, Robert; Hodges, Ann Louise; Boucheron, Edward A.; Drake, Richard Roy; Minana, Molly A.; Hackney, Patricia; Forsythe, Christi A.; Schofield, Joseph Richard, Jr. (,; .); Pavlakos, Constantine James; Williamson, Charles Michael; Edwards, Harold Carter

    2006-09-01

    The purpose of the Sandia National Laboratories Advanced Simulation and Computing (ASC) Software Quality Plan is to clearly identify the practices that are the basis for continually improving the quality of ASC software products. The plan defines the ASC program software quality practices and provides mappings of these practices to Sandia Corporate Requirements CPR 1.3.2 and 1.3.6 and to a Department of Energy document, ASCI Software Quality Engineering: Goals, Principles, and Guidelines. This document also identifies ASC management and software project teams responsibilities in implementing the software quality practices and in assessing progress towards achieving their software quality goals.

  18. Large eddy simulations of the influence of piston position on the swirling flow in a model two-stroke diesel engine

    DEFF Research Database (Denmark)

    Obeidat, Anas Hassan MohD; Schnipper, Teis; Ingvorsen, Kristian Mark

    2014-01-01

    Purpose – The purpose of this paper is to study the effect of piston position on the in-cylinder swirling flow in a simplified model of a large two-stroke marine diesel engine. Design/methodology/approach – Large eddy simulations with four different models for the turbulent flow are used: a one...... qualitatively with port closure from a Lamb-Oseen vortex profile to a solid body rotation, while the axial velocity changes from a wake-like profile to a jet-like profile. The numerical results are compared with particle image velocimetry measurements, and in general, the authors find a good agreement. Research...

  19. Experimental development, 1D CFD simulation and energetic analysis of a 15 kw micro-CHP unit based on reciprocating internal combustion engine

    International Nuclear Information System (INIS)

    Muccillo, M.; Gimelli, A.

    2014-01-01

    Cogeneration is commonly recognized as one of the most effective solutions to achieve the increasingly stringent reduction in primary energy consumption and greenhouse emissions. This characteristic led to the adoption of specific directives promoting this technique. In addition, a strategic role in power reliability is recognized to distributed generation. The study and prototyping of cogeneration plants, therefore, has involved many research centres. This paper deals with energetic aspects of CHP referring to the study of a 15 kW micro-CHP plant based on a LPG reciprocating engine designed, built and grid connected. The plant consists of a heat recovery system characterized by a single water circuit recovering heat from exhaust gases, from engine coolant and from the energy radiated by the engine within the shell hosting the plant. Some tests were carried out at whole open throttle and the experimental data were collected. However it was needed to perform a 1D thermo-fluid dynamics simulation of the engine to completely characterize the micro-CHP. As the heat actually recovered depends on the user's thermal load, particularly from the required temperature's level, a comparison of the results for six types of users were performed: residential, hospital, office, commercial, sports, hotel. Both Italian legislative indexes IRE and LT were evaluated, as defined by A.E.E.G resolution n. 42/02 and subsequent updates, as well as the plant's total Primary Energy Saving. - Highlights: • This paper deals with energetic aspects of CHP referring to the study of a 15 kW micro-CHP plant. • The 15 kW micro-CHP plant is based on a GPL reciprocating engine designed, built and grid connected. • Some tests were carried out at whole open throttle and the experimental data were collected. • It was needed to perform a 1D thermo-fluid dynamics simulation of the engine to completely characterize the micro-CHP. • The analysed solution is particularly suited for

  20. Understanding the role of low reactivity fuel stratification in a dual fuel RCCI engine – A simulation study

    NARCIS (Netherlands)

    Mikulski, M.; Bekdemir, C.

    2017-01-01

    Natural gas - diesel, Reactivity Controlled Compression Ignition (RCCI) is currently one of the most promising combustion strategies for the next generation heavy-duty engines. A major issue to be addressed for this dual fuel concept to become practically applicable is its low combustion efficiency

  1. Bridging the Design-Science Gap with Tools: Science Learning and Design Behaviors in a Simulated Environment for Engineering Design

    Science.gov (United States)

    Chao, Jie; Xie, Charles; Nourian, Saeid; Chen, Guanhua; Bailey, Siobhan; Goldstein, Molly H.; Purzer, Senay; Adams, Robin S.; Tutwiler, M. Shane

    2017-01-01

    Many pedagogical innovations aim to integrate engineering design and science learning. However, students frequently show little attempt or have difficulties in connecting their design projects with the underlying science. Drawing upon the Cultural-Historical Activity Theory, we argue that the design tools available in a learning environment…

  2. Evaluating the Impact of Role-Playing Simulations on Global Competency in an Online Transnational Engineering Course

    Science.gov (United States)

    Wold, Kari

    2013-01-01

    Successfully interacting with those from different cultures is essential to excel in any field, particularly when global, transnational collaborations in the workplace are increasingly common. However, many higher education students in engineering are not explicitly taught how to display the global competency skills desired by future employers. To…

  3. Calibration and validation of a model for simulating thermal and electric performance of an internal combustion engine-based micro-cogeneration device

    International Nuclear Information System (INIS)

    Rosato, A.; Sibilio, S.

    2012-01-01

    The growing worldwide demand for more efficient and less polluting forms of energy production has led to a renewed interest in the use of micro-cogeneration technologies in the residential. Among the others technologies, internal combustion engine-based micro-cogeneration devices are a market-ready technology gaining an increasing appeal thanks to their high efficiency, fuel flexibility, low emissions, low noise and vibration. In order to explore and assess the feasibility of using internal combustion engine-based cogeneration systems in the residential sector, an accurate and practical simulation model that can be used to conduct sensitivity and what-if analyses is needed. A residential cogeneration device model has been developed within IEA/ECBCS Annex 42 and implemented into a number of building simulation programs. This model is potentially able to accurately predict the thermal and electrical outputs of the residential cogeneration devices, but it relies almost entirely on empirical data because the model specification uses experimental measurements contained within a performance map to represent the device specific performance characteristics coupled with thermally massive elements to characterize the device's dynamic thermal performance. At the Built Environment Control Laboratory of Seconda Università degli studi di Napoli, an AISIN SEIKI micro-cogeneration device based on natural gas fuelled reciprocating internal combustion engine is available. This unit has been intensively tested in order to calibrate and validate the Annex 42 model. This paper shows in detail the series of experiments conducted for the calibration activity and examines the validity of this model by contrasting simulation predictions to measurements derived by operating the system in electric load following control strategy. The statistical comparison was made both for the whole database and the segregated data by system mode operation. The good agreement found in the predictions of

  4. Simulation Engine for Fluid Solid Interaction Problems and its Application to the Modelling of Air Blast Hazards in Block Cave Mining.

    Science.gov (United States)

    Galindo Torres, S. A.; Scheuermann, A.; Ruest, M.

    2016-12-01

    Air blasts that may occur in a block caving mining operation represent a significant hazard for personnel as well as to mining infrastructure. Uncontrolled caving of a large volume of broken rock into a mine void causes compression of the air within, forcing it to flow at high velocities into connecting tunnels such as extraction points beneath the cave or observation points intersecting the cave. This high velocity flow of air can cause injury to personnel and significant damage to equipment. In this presentation, we introduce a simulation engine for the air blast problem. The solid material is modelled using the Discrete Element Method (DEM) and the fluid (air) is modelled using the Lattice Boltzmann Method (LBM). The combined DEM-LBM approach has been introduced by our group at the University of Queensland[1]. LBM allows us to introduce an appropriate equation of state for the air that simulates compressibility as a function of the speed of sound. Validation examples are presented to justify the use of this tool for an air blasting situation. A section view of one simulation is provided in Fig 1. An investigation into the risk of developing air pockets as a function of fragment size distribution is also conducted and described. The fragment size distribution can be assessed during mining and the risk of air pockets forming (and consequently of air blast occurring) can be deduced and mitigation measures put in place. The effect of other key variables that can be determined from geotechnical investigations, such as fracture frequency, are also systematically explored. It is expected that the results of this study can elucidate key features of the air blasting phenomenon in order to formulate safer mining protocols. references 1. Galindo-Torres, S.A., A coupled Discrete Element Lattice Boltzmann Method for the simulation of fluid-solid interaction with particles of general shapes. Computer Methods in Applied Mechanics and Engineering, 2013. 265(0): p. 107-119.

  5. Physical multiscale modeling and numerical simulation of electrochemical devices for energy conversion and storage from theory to engineering to practice

    CERN Document Server

    Franco, Alejandro A; Bessler, Wolfgang G

    2015-01-01

    This book reviews the use of innovative physical multiscale modeling methods to deeply understand the electrochemical mechanisms and numerically simulate the structure and properties of electrochemical devices for energy storage and conversion.

  6. Simulation Modeling Method and Experimental Investigation on the Uniflow Scavenging System of an Opposed-Piston Folded-Cranktrain Diesel Engine

    Directory of Open Access Journals (Sweden)

    Fukang Ma

    2017-05-01

    Full Text Available The scavenging process for opposed-piston folded-cranktrain (OPFC diesel engines can be described by the time evolution of the in-cylinder and exhaust chamber residual gas rates. The relation curve of in-cylinder and exhaust chamber residual gas rate is called scavenging profile, which is calculated through the changes of in-cylinder and exhaust chamber gas compositions determined by computational fluid dynamics (CFD simulation. The scavenging profile is used to calculate the scavenging process by mono-dimensional (1D simulation. The tracer gas method (TGM is employed to validate the accuracy of the scavenging profile. At the same time, the gas exchange performance under different intake and exhaust state parameters was examined based on the TGM. The results show that the scavenging process from 1D simulation and experiment match well, which means the scavenging model obtained by CFD simulation performs well and validation of its effectiveness by TGM is possible. The difference between intake and exhaust pressure has a significant positive effect on the gas exchange performance and trapped gas mass, but the pressure difference has little effect on the scavenging efficiency and the trapped air mass if the delivery ratio exceeds 1.4.

  7. Contribution to the building of an execution engine for UML models for the simulation of competitor and timed applications

    International Nuclear Information System (INIS)

    Benyahia, A.

    2012-01-01

    Model Driven Engineering (MDE) places models at the heart of the software engineering process. MDE helps managing the complexity of software systems and improving the quality of the development process. The Model Driven Architecture (MDA) initiative from the Object Management Group (OMG) defines a framework for building design flows in the context of MDE. MDA relies heavily on formalisms which are normalized by the OMG, such as UML for modeling, QVT for model transformations and so on. This work deals with the execution semantics of the UML language applied to embedded real-time applications. In this context, the OMG has a norm which defines an execution model for a subset of UML called fUML (foundational UML subset). This execution model gives a precise semantics to UML models, which can be used for analyzing models, generating code, or verifying transformations. The goal of this PhD thesis is to define and build an execution engine for UML models of embedded real-time systems, which takes into account the explicit hypothesis made by the designer about the execution semantics at a high level of abstraction, in order to be able to execute models as early as possible in the design flow of a system. To achieve this goal, we have extended the fUML execution model along three important axes with regard to embedded real-time systems: - Concurrence: fUML does not provide any mechanism for handling concurrent activities in its execution engine. We address this issue by introducing an explicit scheduler which allows us to control the execution of concurrent tasks. - Time: fUML does not provide any mean to handle time. By adding a clock to the model of execution, we can take into account the elapsed time as well as temporal constraints on the execution of activities. - Profiles: fUML does not take profiles into account, which makes it difficult to personalize the execution engine with new semantic variants. The execution engine we propose allows the use of UML models with

  8. Analysis of cyclic variations of liquid fuel-air mixing processes in a realistic DISI IC-engine using Large Eddy Simulation

    International Nuclear Information System (INIS)

    Goryntsev, D.; Sadiki, A.; Klein, M.; Janicka, J.

    2010-01-01

    Direct injection spark ignition (DISI) engines have a large potential to reduce emissions and specific fuel consumption. One of the most important problem in the design of DISI engines is the cycle-to-cycle variations of the flow, mixing and combustion processes. The Large Eddy Simulation (LES) based analysis is used to characterize the cycle-to-cycle fluctuations of the flow field as well as the mixture preparation in a realistic four-stroke internal combustion engine with variable charge motion system. Based on the analysis of cycle-to-cycle velocity fluctuations of in-cylinder flow, the impact of various fuel spray boundary conditions on injection processes and mixture preparation is pointed out. The joint effect of both cycle-to-cycle velocity fluctuations and variable spray boundary conditions is discussed in terms of mean and standard deviation of relative air-fuel ratio, velocity and mass fraction. Finally a qualitative analysis of the intensity of cyclic fluctuations below the spark plug is provided.

  9. Sandia National Laboratories Advanced Simulation and Computing (ASC) software quality plan. Part 1 : ASC software quality engineering practices version 1.0.

    Energy Technology Data Exchange (ETDEWEB)

    Minana, Molly A.; Sturtevant, Judith E.; Heaphy, Robert; Hodges, Ann Louise; Boucheron, Edward A.; Drake, Richard Roy; Forsythe, Christi A.; Schofield, Joseph Richard, Jr.; Pavlakos, Constantine James; Williamson, Charles Michael; Edwards, Harold Carter

    2005-01-01

    The purpose of the Sandia National Laboratories (SNL) Advanced Simulation and Computing (ASC) Software Quality Plan is to clearly identify the practices that are the basis for continually improving the quality of ASC software products. Quality is defined in DOE/AL Quality Criteria (QC-1) as conformance to customer requirements and expectations. This quality plan defines the ASC program software quality practices and provides mappings of these practices to the SNL Corporate Process Requirements (CPR 1.3.2 and CPR 1.3.6) and the Department of Energy (DOE) document, ASCI Software Quality Engineering: Goals, Principles, and Guidelines (GP&G). This quality plan identifies ASC management and software project teams' responsibilities for cost-effective software engineering quality practices. The SNL ASC Software Quality Plan establishes the signatories commitment to improving software products by applying cost-effective software engineering quality practices. This document explains the project teams opportunities for tailoring and implementing the practices; enumerates the practices that compose the development of SNL ASC's software products; and includes a sample assessment checklist that was developed based upon the practices in this document.

  10. Design and simulation of a two- or four-stroke free-piston engine generator for range extender applications

    International Nuclear Information System (INIS)

    Jia, Boru; Smallbone, Andrew; Zuo, Zhengxing; Feng, Huihua; Roskilly, Anthony Paul

    2016-01-01

    Highlights: • A FPE model operated in two thermodynamic cycles is presented. • The engine performance for both gas exchange cycles are described. • Power distribution with different operation parameters are provided. • Advantages and disadvantages for the two thermodynamic cycles are summarised. - Abstract: Free-piston engines (FPEs) are known to have a greater thermal efficiency (40–50%) than an equivalent and more conventional four-stroke reciprocating engines (30–40%). Modern FPEs are proposed for the generation of electric and hydraulic power, with a potential application in hybrid electric vehicles. The numerous FPE configurations considered to date have almost exclusively operated using a two-stroke thermodynamic cycle to improve the thermal efficiency, however it is well known that the application of two-stoke cycles can be limited by noise and exhaust gas emissions constraints. In this article, a numerical model is used to investigate the techno-feasibility of operating Newcastle University’s FPE prototype using a two- or four-stroke thermodynamic cycle. If operated as a four-stroke cycle, the linear generator must be used as both a motor and a generator resulting in a more irregular piston motion compared to corresponding operating in a two-stroke cycle. In four-stroke cycles, almost half the indicated power is consumed in overcoming the pumping losses of the motoring process. Whilst the heat release process is appears to be closer to a constant volume process when operated on two-stroke engine cycle, the peak cylinder pressure and compression ratio proved lower. In addition, a narrower power range is reported for a four-stroke cycle despite a corresponding higher thermal efficiency.

  11. Molecular simulation workflows as parallel algorithms: the execution engine of Copernicus, a distributed high-performance computing platform.

    Science.gov (United States)

    Pronk, Sander; Pouya, Iman; Lundborg, Magnus; Rotskoff, Grant; Wesén, Björn; Kasson, Peter M; Lindahl, Erik

    2015-06-09

    Computational chemistry and other simulation fields are critically dependent on computing resources, but few problems scale efficiently to the hundreds of thousands of processors available in current supercomputers-particularly for molecular dynamics. This has turned into a bottleneck as new hardware generations primarily provide more processing units rather than making individual units much faster, which simulation applications are addressing by increasingly focusing on sampling with algorithms such as free-energy perturbation, Markov state modeling, metadynamics, or milestoning. All these rely on combining results from multiple simulations into a single observation. They are potentially powerful approaches that aim to predict experimental observables directly, but this comes at the expense of added complexity in selecting sampling strategies and keeping track of dozens to thousands of simulations and their dependencies. Here, we describe how the distributed execution framework Copernicus allows the expression of such algorithms in generic workflows: dataflow programs. Because dataflow algorithms explicitly state dependencies of each constituent part, algorithms only need to be described on conceptual level, after which the execution is maximally parallel. The fully automated execution facilitates the optimization of these algorithms with adaptive sampling, where undersampled regions are automatically detected and targeted without user intervention. We show how several such algorithms can be formulated for computational chemistry problems, and how they are executed efficiently with many loosely coupled simulations using either distributed or parallel resources with Copernicus.

  12. MATHEMATICS EDUCATION FOR LOGISTICS ENGINEERING

    OpenAIRE

    BÉLA ILLÉS; GABRIELLA BOGNÁR

    2012-01-01

    Mathematics is a crucial language in all engineering courses and researches where mathematical modeling, simulation and manipulation are commonly used. Engineering Mathematics courses are considered difficult courses in engineering curricula. This is reflected in engineering students’ performance at the end of each semester for these courses. Our goal is to overview a few questions on mathematics as a core subject of engineering.

  13. Simulation of temporal and spatial soot evolution in an automotive diesel engine using the Moss–Brookes soot model

    International Nuclear Information System (INIS)

    Pang, Kar Mun; Ng, Hoon Kiat; Gan, Suyin

    2012-01-01

    Highlights: ► Numerical models were validated against experimental data of two diesel engines. ► Soot model constant values were calibrated to predict in-cylinder soot processes. ► Effects of split-main injection parameters on soot distributions were determined. ► Soot cloud was distributed towards cylinder wall when using large dwell period. ► Greater soot deposition expected with large dwell period and retarded injection. - Abstract: In this reported work, computational study on the formation processes of soot particles from diesel combustion is conducted using an approach where Computational Fluid Dynamics (CFD) is coupled with a chemical kinetic model. A multi-step soot model which accounts for inception, surface growth, coagulation and oxidation was applied. Model constant values in the Moss–Brookes soot formation and Fenimore–Jones soot oxidation models were calibrated, and were validated against in-cylinder soot evolution and exhaust soot density of both heavy- and light-duty diesel engines, respectively. Effects of various injection parameters such as start of injection (SOI) timing, split-main ratio and dwell period of the split-main injection strategy on in-cylinder temporal/spatial soot evolution in a light-duty diesel engine were subsequently investigated. The spatial soot distributions at each crank angle degree after start of injection were found to be insensitive to the change of values in SOI and split-main ratio when close-coupled injection was implemented. Soot cloud was also observed to be distributed towards the cylinder wall when a large separation of 20° was used, even with an advanced SOI timing of −6° after top dead centre (ATDC). The use of large separation is hence not desired for this combustion system as it potentially leads to soot deposition on surface oil film and greater tailpipe soot emissions.

  14. Adaptation and development of software simulation methodologies for cardiovascular engineering: present and future challenges from an end-user perspective.

    Science.gov (United States)

    Díaz-Zuccarini, V; Narracott, A J; Burriesci, G; Zervides, C; Rafiroiu, D; Jones, D; Hose, D R; Lawford, P V

    2009-07-13

    This paper describes the use of diverse software tools in cardiovascular applications. These tools were primarily developed in the field of engineering and the applications presented push the boundaries of the software to address events related to venous and arterial valve closure, exploration of dynamic boundary conditions or the inclusion of multi-scale boundary conditions from protein to organ levels. The future of cardiovascular research and the challenges that modellers and clinicians face from validation to clinical uptake are discussed from an end-user perspective.

  15. Identifying Structure-Property Relationships Through DREAM.3D Representative Volume Elements and DAMASK Crystal Plasticity Simulations: An Integrated Computational Materials Engineering Approach

    Science.gov (United States)

    Diehl, Martin; Groeber, Michael; Haase, Christian; Molodov, Dmitri A.; Roters, Franz; Raabe, Dierk

    2017-05-01

    Predicting, understanding, and controlling the mechanical behavior is the most important task when designing structural materials. Modern alloy systems—in which multiple deformation mechanisms, phases, and defects are introduced to overcome the inverse strength-ductility relationship—give raise to multiple possibilities for modifying the deformation behavior, rendering traditional, exclusively experimentally-based alloy development workflows inappropriate. For fast and efficient alloy design, it is therefore desirable to predict the mechanical performance of candidate alloys by simulation studies to replace time- and resource-consuming mechanical tests. Simulation tools suitable for this task need to correctly predict the mechanical behavior in dependence of alloy composition, microstructure, texture, phase fractions, and processing history. Here, an integrated computational materials engineering approach based on the open source software packages DREAM.3D and DAMASK (Düsseldorf Advanced Materials Simulation Kit) that enables such virtual material development is presented. More specific, our approach consists of the following three steps: (1) acquire statistical quantities that describe a microstructure, (2) build a representative volume element based on these quantities employing DREAM.3D, and (3) evaluate the representative volume using a predictive crystal plasticity material model provided by DAMASK. Exemplarily, these steps are here conducted for a high-manganese steel.

  16. Three Dimensional Numerical Simulation of Rocket-based Combined-cycle Engine Response During Mode Transition Events

    Science.gov (United States)

    Edwards, Jack R.; McRae, D. Scott; Bond, Ryan B.; Steffan, Christopher (Technical Monitor)

    2003-01-01

    The GTX program at NASA Glenn Research Center is designed to develop a launch vehicle concept based on rocket-based combined-cycle (RBCC) propulsion. Experimental testing, cycle analysis, and computational fluid dynamics modeling have all demonstrated the viability of the GTX concept, yet significant technical issues and challenges still remain. Our research effort develops a unique capability for dynamic CFD simulation of complete high-speed propulsion devices and focuses this technology toward analysis of the GTX response during critical mode transition events. Our principal attention is focused on Mode 1/Mode 2 operation, in which initial rocket propulsion is transitioned into thermal-throat ramjet propulsion. A critical element of the GTX concept is the use of an Independent Ramjet Stream (IRS) cycle to provide propulsion at Mach numbers less than 3. In the IRS cycle, rocket thrust is initially used for primary power, and the hot rocket plume is used as a flame-holding mechanism for hydrogen fuel injected into the secondary air stream. A critical aspect is the establishment of a thermal throat in the secondary stream through the combination of area reduction effects and combustion-induced heat release. This is a necessity to enable the power-down of the rocket and the eventual shift to ramjet mode. Our focus in this first year of the grant has been in three areas, each progressing directly toward the key initial goal of simulating thermal throat formation during the IRS cycle: CFD algorithm development; simulation of Mode 1 experiments conducted at Glenn's Rig 1 facility; and IRS cycle simulations. The remainder of this report discusses each of these efforts in detail and presents a plan of work for the next year.

  17. Design and Testing of an H2/O2 Predetonator for a Simulated Rotating Detonation Engine Channel

    Science.gov (United States)

    2013-03-01

    Abstract A study is presented on the relationship between a pre-detonator and a detonation channel of an RDE . Testing was conducted on a straight...narrow channel made of clear polycarbonate windows connected to an H2/O2 pre-detonator to simulate the RDE initiation scheme and allow for flow...25 2.5 RDE Initiation Schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 vi Page 2.5.1 Blasting Wire

  18. New Approach to Simulation of Heat State of Compartments from Lattice Composite Shells for Space Engineering Products

    Directory of Open Access Journals (Sweden)

    Razin Alexander F.

    2017-01-01

    Full Text Available A new approach to the simulation of the heat state of the compartment of lattice polymer composite materials (PCM, not providing for the use of known commercial software packages, has been proposed. The simulation has been performed using the PCM interstage of the Proton rocket as an example with due account of aerodynamic heating, solar radiation and acting of jets of auxiliary propulsion units. At the first stage of numerical analysis, a problem of unsteady heat conduction in the system “skin-air gap-heat insulation” has been solved. An effect of changing a pressure inside a compartment on thermal conductivity of heat insulation was taken into account. The effective thermal conductivity in gaps was used. An effect of a temperature of equipment on a value of radiant heat flux was also taken into account. At the second stage, the heat state of the system “skin-rib” was analyzed. A mathematical model in the form of a system of nonlinear equations for heat balance of control elements on which a rib and a skin section were partitioned, including an information about a temperature of heat insulation received at the first stage of the simulation, was used.

  19. Crystal engineering of ibuprofen compounds: From molecule to crystal structure to morphology prediction by computational simulation and experimental study

    Science.gov (United States)

    Zhang, Min; Liang, Zuozhong; Wu, Fei; Chen, Jian-Feng; Xue, Chunyu; Zhao, Hong

    2017-06-01

    We selected the crystal structures of ibuprofen with seven common space groups (Cc, P21/c, P212121, P21, Pbca, Pna21, and Pbcn), which was generated from ibuprofen molecule by molecular simulation. The predicted crystal structures of ibuprofen with space group P21/c has the lowest total energy and the largest density, which is nearly indistinguishable with experimental result. In addition, the XRD patterns for predicted crystal structure are highly consistent with recrystallization from solvent of ibuprofen. That indicates that the simulation can accurately predict the crystal structure of ibuprofen from the molecule. Furthermore, based on this crystal structure, we predicted the crystal habit in vacuum using the attachment energy (AE) method and considered solvent effects in a systematic way using the modified attachment energy (MAE) model. The simulation can accurately construct a complete process from molecule to crystal structure to morphology prediction. Experimentally, we observed crystal morphologies in four different polarity solvents compounds (ethanol, acetonitrile, ethyl acetate, and toluene). We found that the aspect ratio decreases of crystal habits in this ibuprofen system were found to vary with increasing solvent relative polarity. Besides, the modified crystal morphologies are in good agreement with the observed experimental morphologies. Finally, this work may guide computer-aided design of the desirable crystal morphology.

  20. Sandia National Laboratories Advanced Simulation and Computing (ASC) software quality plan part 2 mappings for the ASC software quality engineering practices, version 2.0.

    Energy Technology Data Exchange (ETDEWEB)

    Heaphy, Robert; Sturtevant, Judith E.; Hodges, Ann Louise; Boucheron, Edward A.; Drake, Richard Roy; Minana, Molly A.; Hackney, Patricia; Forsythe, Christi A.; Schofield, Joseph Richard, Jr. (,; .); Pavlakos, Constantine James; Williamson, Charles Michael; Edwards, Harold Carter

    2006-09-01

    The purpose of the Sandia National Laboratories Advanced Simulation and Computing (ASC) Software Quality Plan is to clearly identify the practices that are the basis for continually improving the quality of ASC software products. The plan defines the ASC program software quality practices and provides mappings of these practices to Sandia Corporate Requirements CPR001.3.2 and CPR001.3.6 and to a Department of Energy document, ''ASCI Software Quality Engineering: Goals, Principles, and Guidelines''. This document also identifies ASC management and software project teams' responsibilities in implementing the software quality practices and in assessing progress towards achieving their software quality goals.

  1. Use of superplastic tin lead alloy to simulate the behavior of engineering materials in design of systems for occupant protection during car accident collision

    International Nuclear Information System (INIS)

    Zaid, A.I.O.; Abu-Mallouh, R.M.; Al-Habbali, S.M.

    2003-01-01

    In every collision, the collision energy and forces developed during an accident have to be absorbed by someway to protect car occupants and reduce car damage. Different systems and devices have been designed and used for this purpose. The aim is to dissipate the kinetic energy irreversibly rather than convert it and store it elastically. Devices used are usually one shot items i.e. once having been deformed, they are discarded and replaced. The development and detail design of these mechanical devices and systems for dissipating the collision energy in controlled and predetermined rate is a prerequisite. The literature on these devices is voluminous but most of it deals with the problem under quasi-static rate condition due to the unavailability of equipment and complication of the testing under dynamic or high strain rate conditions. It is now well-established that the behavior of materials under dynamic loading is somewhat different from their behavior under the quasi-static condition. Therefore, a material having a rate sensitivity in the quasi-static range will be very useful in simulating the behavior of engineering materials at the high strain rate condition. In this paper superplastic tin-lead alloy which is rate sensitive in the range from 10/sup -2/ to 10/sup -1/ Is was used to simulate the behavior of steel and other engineering materials, in absorbing the collision energy by allowing a cylindrical billet to be extruded through circular cross sectional die with a high extrusion ratio. The testing was carried out at three different strain rates, the force and energy consumed in the plastic work for the extrusion process were determined experimentally and compared with those predicted from the mechanical behavior of the alloy at the corresponding strain rate using Johnson formulae for forward extrusion. The experimental results were found in good agreement with the predicted values. (author)

  2. Computational fluid dynamics simulation of the combustion process, emission formation and the flow field in an in-direct injection diesel engine

    Directory of Open Access Journals (Sweden)

    Barzegar Ramin

    2013-01-01

    Full Text Available In the present paper, the combustion process and emission formation in the Lister 8.1 I.D.I Diesel engine have been investigated using a Computational Fluid Dynamics (CFD code. The utilized model includes detailed spray atomization, mixture formation and distribution model which enable modeling the combustion process in spray/wall and spray/swirl interactions along with flow configurations. The analysis considers both part load and full load states. The global properties are presented separately resolved for the swirl chamber (pre-chamber and the main chamber. The results of model verify the fact that the equal amount of the fuel is burned in the main and pre-chamber at full load state while at part load the majority of the fuel is burned in the main chamber. Also, it is shown that the adherence of fuel spray on the pre-chamber walls is due to formation of a stagnation zone which prevents quick spray evaporation and plays an important role in the increase of soot mass fractions at this zone at full load conditions. The simulation results, such as the mean in-cylinder pressure, heat release rate and exhaust emissions are compared with the experimental data and show good agreement. This work also demonstrates the usefulness of multidimensional modeling for complex chamber geometries, such as in I.D.I Diesel engines, to gain more insight into the flow field, combustion process and emission formation.

  3. Establishing design criteria for crankshaft thrust bearings in gasoline and diesel engines by computer simulations and experiments. Crankshaft thrust bearing design - final report; Auslegungskriterien fuer Kurbelwellenaxiallager in Otto- und Dieselmotoren durch rechnergestuetzte Simulation und experimentelle Untersuchungen. Axialgleitlagerauslegung - Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hunsicker, W. [Fachhochschule Mannheim (Germany). Inst. fuer Tribologie; Backhaus, K. [Univ. GH Kassel (Germany). Inst. fuer Maschinenelemente und Konstruktionstechnik; Schubert, W. [KS Gleitlager GmbH, Papenburg (Germany)

    2004-07-01

    Aim of the research-project was it to increase the calculation safety of crank shaft thrust bearings in combustion engines. The project was divided in two parts: (1) A simulation program to analyze the load bearing capacity of axial bearings under mixed lubrication has been developed at the Institut fuer Maschinenelemente und Konstruktionstechnik, University of Kassel. This part of the research-project has been presented at the FVV Herbsttagung in 2003. (2) The test runs with original parts were carried out on a newly designed thrust bearing test rig at the Institut fuer Tribologie, University of Applied Sciences in Mannheim. The following presentation shows the results of part 2. The experimental results show the influence of rotational frequency, load, bearing material, lateral run-out of the tread of the crankshaft and groove pattern. These test runs will help to dimension thrust bearings more efficiently. (orig.)

  4. Operating function tests of the PWR type RHR pump for engineering safety system under simulated strong ground excitation

    International Nuclear Information System (INIS)

    Uga, Takeo; Shiraki, Kazuhiro; Homma, Toshiaki; Inazuka, Hisashi; Nakajima, Norifumi.

    1979-08-01

    Results are described of operating function verification tests of a PWR RHR pump during an earthquake. Of the active reactor components, the PWR residual heat removal pump was chosen from view points of aseismic classification, safety function, structural complexity and past aseismic tests. Through survey of the service conditions and structure of this pump, seismic test conditions such as acceleration level, simulated seismic wave form and earthquake duration were decided for seismicity of the operating pump. Then, plans were prepared to evaluate vibration chracteristics of the pump and to estimate its aseismic design margins. Subsequently, test facility and instrumentation system were designed and constructed. Experimental results could thus be acquired on vibration characteristics of the pump and its dynamic behavior during different kinds and levels of simulated earthquake. In conclusion: (1) Stiffeners attached to the auxiliary system piping do improve aseismic performance of the pump. (2) The rotor-shaft-bearing system is secure unless it is subjected to transient disturbunces having high frequency content. (3) The motor and pump casing having resonance frequencies much higher than frequency content of the seismic wave show only small amplifications. (4) The RHR pump possesses an aseismic design margin more than 2.6 times the expected ultimate earthquake on design basis. (author)

  5. A comparison of CHENATH, the Nationwide House Energy Rating Scheme Simulation Engine, with measured test cell data

    Energy Technology Data Exchange (ETDEWEB)

    Delsante, A.E. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Highett, VIC (Australia). Div. of Building Construction and Engineering

    1995-12-31

    The Nationwide House Energy Rating Scheme (NatHERS) uses a simulation program as its reference tool to evaluate the energy demand of buildings. The Commonwealth Scientific Industrial Research Organisation (CSIRO) developed software called CHENATH, is a significantly enhanced version of the CHEETAH simulation program. As part of the NatHERS development process, it was considered important to subject CHENATH to further testing. Two separate evaluation projects were undertaken. This paper describes one of these projects. CHENATH was compared with measured data from three test cells with single glazing, double glazing and no glazing. The solar radiation comparisons led to an improved model that accounts for anisotropic diffuse radiation. CHENATH significantly under-predicted the heating energy, but conclusions are difficult to draw because the actual heater used was very different from that assumed by the program. Temperature comparisons in the free running single-glazed cell showed that CHENATH`s new glazing model preformed significantly better than the old model. This exercise has reinforced the need for extreme care in designing, monitoring and describing test cells and for modellers to interpret the data supplied correctly. (author). 4 tabs., 3 figs., 4 refs.

  6. Simulating the Range Expansion of Spartina alterniflora in Ecological Engineering through Constrained Cellular Automata Model and GIS

    Directory of Open Access Journals (Sweden)

    Zongsheng Zheng

    2015-01-01

    Full Text Available Environmental factors play an important role in the range expansion of Spartina alterniflora in estuarine salt marshes. CA models focusing on neighbor effect often failed to account for the influence of environmental factors. This paper proposed a CCA model that enhanced CA model by integrating constrain factors of tidal elevation, vegetation density, vegetation classification, and tidal channels in Chongming Dongtan wetland, China. Meanwhile, a positive feedback loop between vegetation and sedimentation was also considered in CCA model through altering the tidal accretion rate in different vegetation communities. After being validated and calibrated, the CCA model is more accurate than the CA model only taking account of neighbor effect. By overlaying remote sensing classification and the simulation results, the average accuracy increases to 80.75% comparing with the previous CA model. Through the scenarios simulation, the future of Spartina alterniflora expansion was analyzed. CCA model provides a new technical idea and method for salt marsh species expansion and control strategies research.

  7. Application of a Detailed Emission Model for Heavy Duty Diesel Engine Simulations Application d'un modèle détaillé d'émissions pour la simulation de gros moteurs diesel

    Directory of Open Access Journals (Sweden)

    Magnusson I.

    2006-12-01

    Full Text Available A detailed chemical model describing the formation of soot and NO is applied to simulate emission formation in a heavy duty diesel engine. Cylinder flow and spray development is simulated using an engine CFD code - Speedstar. Combustion is described using a simple eddy break-up model. Modeling of the emission-chemistry/turbulent-flow interaction is based on a flamelet approach. Contrary to a typical flamelet concept, transport equations are solved for mass fractions of soot and NO. The reason being that these major emission constituencies are assumed to change slowly in comparison to typical time scales for chemical processes or transport processes important for combustion. Chemical reactions leading to production and destruction of soot and NO are, however, assumed to be fast. Soot and NO source terms are therefore evaluated from a flamelet library using a presumed probability density function and integrating over mixture fraction space. Results from simulations are compared to engine measurements inform of exhaust emission data and cylinder pressure. Un modèle avec chimie détaillée décrivant la formation des suies et du NO est appliqué à la simulation de la formation des polluants dans un gros moteur Diesel. L'écoulement et le spray sont modélisés avec le code de calcul Speedstar. La combustion est représentée par le modèle eddy break-up . La modélisation de l'interaction entre l'écoulement turbulent et la chimie des polluants est basée sur une approche de type flamelet . Cependant, à la différence d'autres travaux, des équations de transport pour les fractions massiques de suies et de NO sont résolues. Cela est justifié par la supposition que les temps caractéristiques de formation de ces composés sont longs comparés à ceux associés aux phénomènes de transport et aux réactions chimiques associées à la combustion. Cependant, les vitesses de réaction se rapportant aux suies et au NO sont supposées rapides. Cela

  8. Enhancement of the Open National Combustion Code (OpenNCC) and Initial Simulation of Energy Efficient Engine Combustor

    Science.gov (United States)

    Miki, Kenji; Moder, Jeff; Liou, Meng-Sing

    2016-01-01

    In this paper, we present the recent enhancement of the Open National Combustion Code (OpenNCC) and apply the OpenNCC to model a realistic combustor configuration (Energy Efficient Engine (E3)). First, we perform a series of validation tests for the newly-implemented advection upstream splitting method (AUSM) and the extended version of the AUSM-family schemes (AUSM+-up). Compared with the analytical/experimental data of the validation tests, we achieved good agreement. In the steady-state E3 cold flow results using the Reynolds-averaged Navier-Stokes(RANS), we find a noticeable difference in the flow fields calculated by the two different numerical schemes, the standard Jameson- Schmidt-Turkel (JST) scheme and the AUSM scheme. The main differences are that the AUSM scheme is less numerical dissipative and it predicts much stronger reverse flow in the recirculation zone. This study indicates that two schemes could show different flame-holding predictions and overall flame structures.

  9. Analytical evaluation on loss of off-side electric power simulation of the High Temperature Engineering Test Reactor

    International Nuclear Information System (INIS)

    Takeda, Takeshi; Nakagawa, Shigeaki; Tachibana, Yukio; Takada, Eiji; Kunitomi, Kazuhiko

    2000-03-01

    A rise-to-power test of the high temperature engineering test reactor (HTTR) started on September 28 in 1999 for establishing and upgrading the technological basis for the high temperature gas-cooled reactor (HTGR). A loss of off-site electric power test of the HTTR from the normal operation under 15 and 30 MW thermal power will be carried out in the rise-to-power test. Analytical evaluations on transient behaviors of the reactor and plant during the loss of off-site electric power were conducted. These estimations are proposed as benchmark problems for the IAEA coordinated research program on 'Evaluation of HTGR Performance'. This report describes an event scenario of transient during the loss of off-site electric power, the outline of major components and system, detailed thermal and nuclear data set for these problems and pre-estimation results of the benchmark problems by an analytical code 'ACCORD' for incore and plant dynamics of the HTGR. (author)

  10. Learning physical biology via modeling and simulation: A new course and textbook for science and engineering undergraduates

    Science.gov (United States)

    Nelson, Philip

    To a large extent, undergraduate physical-science curricula remain firmly rooted in pencil-and-paper calculation, despite the fact that most research is done with computers. To a large extent, undergraduate life-science curricula remain firmly rooted in descriptive approaches, despite the fact that much current research involves quantitative modeling. Not only does our pedagogy not reflect current reality; it also creates a spurious barrier between the fields, reinforcing the narrow silos that prevent students from connecting them. I'll describe an intermediate-level course on ``Physical Models of Living Systems.'' The prerequisite is first-year university physics and calculus. The course is a response to rapidly growing interest among undergraduates in a broad range of science and engineering majors. Students acquire several research skills that are often not addressed in traditional undergraduate courses: •Basic modeling skills; •Probabilistic modeling skills; •Data analysis methods; •Computer programming using a general-purpose platform like MATLAB or Python; •Pulling datasets from the Web for analysis; •Data visualization; •Dynamical systems, particularly feedback control. Partially supported by the NSF under Grants EF-0928048 and DMR-0832802.

  11. Development and Implementation of a Transport Method for the Transport and Reaction Simulation Engine (TaRSE) based on the Godunov-Mixed Finite Element Method

    Science.gov (United States)

    James, Andrew I.; Jawitz, James W.; Munoz-Carpena, Rafael

    2009-01-01

    A model to simulate transport of materials in surface water and ground water has been developed to numerically approximate solutions to the advection-dispersion equation. This model, known as the Transport and Reaction Simulation Engine (TaRSE), uses an algorithm that incorporates a time-splitting technique where the advective part of the equation is solved separately from the dispersive part. An explicit finite-volume Godunov method is used to approximate the advective part, while a mixed-finite element technique is used to approximate the dispersive part. The dispersive part uses an implicit discretization, which allows it to run stably with a larger time step than the explicit advective step. The potential exists to develop algorithms that run several advective steps, and then one dispersive step that encompasses the time interval of the advective steps. Because the dispersive step is computationally most expensive, schemes can be implemented that are more computationally efficient than non-time-split algorithms. This technique enables scientists to solve problems with high grid Peclet numbers, such as transport problems with sharp solute fronts, without spurious oscillations in the numerical approximation to the solution and with virtually no artificial diffusion.

  12. Unsteady analysis of a bottoming Organic Rankine Cycle for exhaust heat recovery from an Internal Combustion Engine using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Zhang, Tao; Zhu, Tong; An, Wei; Song, Xu; Liu, Liuchen; Liu, Hao

    2016-01-01

    Highlights: • An optimization model of ORC for the recovery of ICE exhaust heat is established. • Three unsteady parameters are considered for the design of ICE-ORC system. • The unsteady performances of ICE-ORC are illustrated using Monte Carlo simulation. - Abstract: An optimization model is developed to maximize the net power output of a bottoming Organic Rankine Cycle (ORC) with ten working fluids for exhaust heat recovery from an Internal Combustion Engine (ICE) theoretically. The ICE-ORC system is influenced by several unsteady parameters which make it difficult to determine the optimal design parameters. Therefore, we introduce probability density functions in order to investigate the impacts of the ICE power output, the sink temperature and the pinch point temperature difference on the ORC performances. Each unsteady parameter is illustrated to analyze the performances of the ICE-ORC system. Furthermore, Monte Carlo simulation is introduced to investigate the role played by the unsteady parameters, each of which obeys different probability distributions. By these methods, we obtained the convergence values, the frequency distributions and the cumulative probability distributions of various performance parameters. These results can provide valuable suggestions for the design of ICE-ORC system.

  13. Molecular dynamics simulations and docking enable to explore the biophysical factors controlling the yields of engineered nanobodies

    Science.gov (United States)

    Soler, Miguel A.; De Marco, Ario; Fortuna, Sara

    2016-10-01

    Nanobodies (VHHs) have proved to be valuable substitutes of conventional antibodies for molecular recognition. Their small size represents a precious advantage for rational mutagenesis based on modelling. Here we address the problem of predicting how Camelidae nanobody sequences can tolerate mutations by developing a simulation protocol based on all-atom molecular dynamics and whole-molecule docking. The method was tested on two sets of nanobodies characterized experimentally for their biophysical features. One set contained point mutations introduced to humanize a wild type sequence, in the second the CDRs were swapped between single-domain frameworks with Camelidae and human hallmarks. The method resulted in accurate scoring approaches to predict experimental yields and enabled to identify the structural modifications induced by mutations. This work is a promising tool for the in silico development of single-domain antibodies and opens the opportunity to customize single functional domains of larger macromolecules.

  14. Study of the rheological properties of water and Martian soil simulant mixtures for engineering applications on the red planet

    Science.gov (United States)

    Taylor, Lewis; Alberini, Federico; Sullo, Antonio; Meyer, Marit E.; Alexiadis, Alessio

    2018-03-01

    The rheological properties of mixtures of water and the Martian soil simulant JSC-Mars-1A are investigated by preparing and testing samples at various solids concentrations. The results indicate that the dispersion is viscoelastic and, at small timescales (∼0.1 s), reacts to sudden strain as an elastic solid. At longer timescales the dispersion behaves like a Bingham fluid and exhibits a yield stress. Hysteresis loops show that rapid step-changes (2 s duration) of shear-rate result in thixotropic behaviour, but slower changes (>10 s duration) can result in rheopexy. These observations are explained with the breakdown and recovery of the packing structure under stress. The rheological information is used to generate practical tools, such as the system curve and the Moody chart that can be used for designing piping systems, and calculating pump sizes and pressure requirements.

  15. A Mesoscopic Simulation for the Early-Age Shrinkage Cracking Process of High Performance Concrete in Bridge Engineering

    Directory of Open Access Journals (Sweden)

    Guodong Li

    2017-01-01

    Full Text Available On a mesoscopic level, high performance concrete (HPC was assumed to be a heterogeneous composite material consisting of aggregates, mortar, and pores. The concrete mesoscopic structure model had been established based on CT image reconstruction. By combining this model with continuum mechanics, damage mechanics, and fracture mechanics, a relatively complete system for concrete mesoscopic mechanics analysis was established to simulate the process of early-age shrinkage cracking in HPC. This process was based on the dispersion crack model. The results indicated that the interface between the aggregate and mortar was the crack point caused by shrinkage cracks in HPC. The locations of early-age shrinkage cracks in HPC were associated with the spacing and the size of the aggregate particle. However, the shrinkage deformation size of the mortar was related to the scope of concrete cracking and was independent of the crack position. Whereas lower water to cement ratios can improve the early strength of concrete, this ratio cannot control early-age shrinkage cracks in HPC.

  16. Nanofibrous Chitosan-Polyethylene Oxide Engineered Scaffolds: A Comparative Study between Simulated Structural Characteristics and Cells Viability

    Directory of Open Access Journals (Sweden)

    Mohammad Kazemi Pilehrood

    2014-01-01

    Full Text Available 3D nanofibrous chitosan-polyethylene oxide (PEO scaffolds were fabricated by electrospinning at different processing parameters. The structural characteristics, such as pore size, overall porosity, pore interconnectivity, and scaffold percolative efficiency (SPE, were simulated by a robust image analysis. Mouse fibroblast cells (L929 were cultured in RPMI for 2 days in the presence of various samples of nanofibrous chitosan/PEO scaffolds. Cell attachments and corresponding mean viability were enhanced from 50% to 110% compared to that belonging to a control even at packed morphologies of scaffolds constituted from pores with nanoscale diameter. To elucidate the correlation between structural characteristics within the depth of the scaffolds’ profile and cell viability, a comparative analysis was proposed. This analysis revealed that larger fiber diameters and pore sizes can enhance cell viability. On the contrary, increasing the other structural elements such as overall porosity and interconnectivity due to a simultaneous reduction in fiber diameter and pore size through the electrospinning process can reduce the viability of cells. In addition, it was found that manipulation of the processing parameters in electrospinning can compensate for the effects of packed morphologies of nanofibrous scaffolds and can thus potentially improve the infiltration and viability of cells.

  17. Adaptable Web Modules to Stimulate Active Learning in Engineering Hydrology using Data and Model Simulations of Three Regional Hydrologic Systems

    Science.gov (United States)

    Habib, E. H.; Tarboton, D. G.; Lall, U.; Bodin, M.; Rahill-Marier, B.; Chimmula, S.; Meselhe, E. A.; Ali, A.; Williams, D.; Ma, Y.

    2013-12-01

    The hydrologic community has long recognized the need for broad reform in hydrologic education. A paradigm shift is critically sought in undergraduate hydrology and water resource education by adopting context-rich, student-centered, and active learning strategies. Hydrologists currently deal with intricate issues rooted in complex natural ecosystems containing a multitude of interconnected processes. Advances in the multi-disciplinary field include observational settings such as Critical Zone and Water, Sustainability and Climate Observatories, Hydrologic Information Systems, instrumentation and modeling methods. These research advances theory and practices call for similar efforts and improvements in hydrologic education. The typical, text-book based approach in hydrologic education has focused on specific applications and/or unit processes associated with the hydrologic cycle with idealizations, rather than the contextual relations in the physical processes and the spatial and temporal dynamics connecting climate and ecosystems. An appreciation of the natural variability of these processes will lead to graduates with the ability to develop independent learning skills and understanding. This appreciation cannot be gained in curricula where field components such as observational and experimental data are deficient. These types of data are also critical when using simulation models to create environments that support this type of learning. Additional sources of observations in conjunction with models and field data are key to students understanding of the challenges associated with using models to represent such complex systems. Recent advances in scientific visualization and web-based technologies provide new opportunities for the development of active learning techniques utilizing ongoing research. The overall goal of the current study is to develop visual, case-based, data and simulation driven learning experiences to instructors and students through a web

  18. Reliability and safety engineering

    CERN Document Server

    Verma, Ajit Kumar; Karanki, Durga Rao

    2016-01-01

    Reliability and safety are core issues that must be addressed throughout the life cycle of engineering systems. Reliability and Safety Engineering presents an overview of the basic concepts, together with simple and practical illustrations. The authors present reliability terminology in various engineering fields, viz.,electronics engineering, software engineering, mechanical engineering, structural engineering and power systems engineering. The book describes the latest applications in the area of probabilistic safety assessment, such as technical specification optimization, risk monitoring and risk informed in-service inspection. Reliability and safety studies must, inevitably, deal with uncertainty, so the book includes uncertainty propagation methods: Monte Carlo simulation, fuzzy arithmetic, Dempster-Shafer theory and probability bounds. Reliability and Safety Engineering also highlights advances in system reliability and safety assessment including dynamic system modeling and uncertainty management. Cas...

  19. Tissue engineering of cartilage using a mechanobioreactor exerting simultaneous mechanical shear and compression to simulate the rolling action of articular joints.

    Science.gov (United States)

    Shahin, Kifah; Doran, Pauline M

    2012-04-01

    The effect of dynamic mechanical shear and compression on the synthesis of human tissue-engineered cartilage was investigated using a mechanobioreactor capable of simulating the rolling action of articular joints in a mixed fluid environment. Human chondrocytes seeded into polyglycolic acid (PGA) mesh or PGA-alginate scaffolds were precultured in shaking T-flasks or recirculation perfusion bioreactors for 2.5 or 4 weeks prior to mechanical stimulation in the mechanobioreactor. Constructs were subjected to intermittent unconfined shear and compressive loading at a frequency of 0.05 Hz using a peak-to-peak compressive strain amplitude of 2.2% superimposed on a static axial compressive strain of 6.5%. The mechanical treatment was carried out for up to 2.5 weeks using a loading regime of 10 min duration each day with the direction of the shear forces reversed after 5 min and release of all loading at the end of the daily treatment period. Compared with shaking T-flasks and mechanobioreactor control cultures without loading, mechanical treatment improved the amount and quality of cartilage produced. On a per cell basis, synthesis of both major structural components of cartilage, glycosaminoglycan (GAG) and collagen type II, was enhanced substantially by up to 5.3- and 10-fold, respectively, depending on the scaffold type and seeding cell density. Levels of collagen type II as a percentage of total collagen were also increased after mechanical treatment by up to 3.4-fold in PGA constructs. Mechanical treatment had a less pronounced effect on the composition of constructs precultured in perfusion bioreactors compared with perfusion culture controls. This work demonstrates that the quality of tissue-engineered cartilage can be enhanced significantly by application of simultaneous dynamic mechanical shear and compression, with the greatest benefits evident for synthesis of collagen type II. Copyright © 2011 Wiley Periodicals, Inc.

  20. From Usability Testing to Clinical Simulations: Bringing Context into the Design and Evaluation of Usable and Safe Health Information Technologies. Contribution of the IMIA Human Factors Engineering for Healthcare Informatics Working Group.

    Science.gov (United States)

    Kushniruk, A; Nohr, C; Jensen, S; Borycki, E M

    2013-01-01

    The objective of this paper is to explore human factors approaches to understanding the use of health information technology (HIT) by extending usability engineering approaches to include analysis of the impact of clinical context through use of clinical simulations. Methods discussed are considered on a continuum from traditional laboratory-based usability testing to clinical simulations. Clinical simulations can be conducted in a simulation laboratory and they can also be conducted in real-world settings. The clinical simulation approach attempts to bring the dimension of clinical context into stronger focus. This involves testing of systems with representative users doing representative tasks, in representative settings/environments. Application of methods where realistic clinical scenarios are used to drive the study of users interacting with systems under realistic conditions and settings can lead to identification of problems and issues with systems that may not be detected using traditional usability engineering methods. In conducting such studies, careful consideration is needed in creating ecologically valid test scenarios. The evidence obtained from such evaluation can be used to improve both the usability and safety of HIT. In addition, recent work has shown that clinical simulations, in particular those conducted in-situ, can lead to considerable benefits when compared to the costs of running such studies. In order to bring context of use into the testing of HIT, clinical simulation, involving observing representative users carrying out tasks in representative settings, holds considerable promise.