Models for a stand-alone PV system[Photovoltaic

Energy Technology Data Exchange (ETDEWEB)

Hansen, A.D.; Soerensen, P.; Hansen, L.H.; Bindner, H.

2000-12-01

This report presents a number of models for modelling and simulation of a stand-alone photovoltaic (PV) system with a battery bank verified against a system installed at Risoe National Laboratory. The work has been supported by the Danish Ministry of Energy, as a part of the activities in the Solar Energy Centre Denmark. The study is carried out at Risoe National Laboratory with the main purpose to establish a library of simple mathematical models for each individual element of a stand-alone PV system, namely solar cells, battery, controller, inverter and load. The models for PV module and battery are based on the model descriptions found in the literature. The battery model is developed at UMASS and is known as the Kinetic Battery Model (KiBaM). The other component models in the PV system are based on simple electrical knowledge. The implementation is done using Matlab/Simulink, a simulation program that provides a graphical interface for building models as modular block diagrams. The non-linear behaviour of the battery, observed in the measurements, is investigated and compared to the KiBaM model's performance. A set of linear Black box models are estimated based on the battery measurements. The performance of the best linear Black box model is compared to the KiBaM model. A validation of each of the implemented mathematical model is performed by an interactive analysis and comparison between simulation results and measurements, acquired from the stand-alone PV system at Risoe. (au)

Connecting embedded and stand-alone peer mentoring models to enhance student engagement

Directory of Open Access Journals (Sweden)

Rhys Cooper

2018-03-01

Full Text Available This paper outlines the Trident Student Mentoring Program that runs in the College of Engineering at Victoria University, Melbourne, Australia. The program offers both embedded and stand-alone models of peer mentoring services to the same cohort of first-year students. It shows that by forming strong links between these two types of peer mentoring models, the inherent challenges of both, such as low attendance rates in stand-alone models and short periods of peer to peer time in embedded models, are mitigated.

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

Performance and Simulation of a Stand-alone Parabolic Trough Solar Thermal Power Plant

Science.gov (United States)

Mohammad, S. T.; Al-Kayiem, H. H.; Assadi, M. K.; Gilani, S. I. U. H.; Khlief, A. K.

2018-05-01

In this paper, a Simulink® Thermolib Model has been established for simulation performance evaluation of Stand-alone Parabolic Trough Solar Thermal Power Plant in Universiti Teknologi PETRONAS, Malaysia. This paper proposes a design of 1.2 kW parabolic trough power plant. The model is capable to predict temperatures at any system outlet in the plant, as well as the power output produced. The conditions that are taken into account as input to the model are: local solar radiation and ambient temperatures, which have been measured during the year. Other parameters that have been input to the model are the collector’s sizes, location in terms of latitude and altitude. Lastly, the results are presented in graphical manner to describe the analysed variations of various outputs of the solar fields obtained, and help to predict the performance of the plant. The developed model allows an initial evaluation of the viability and technical feasibility of any similar solar thermal power plant.

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)

Modified Chaos Particle Swarm Optimization-Based Optimized Operation Model for Stand-Alone CCHP Microgrid

Directory of Open Access Journals (Sweden)

Fei Wang

2017-07-01

Full Text Available The optimized dispatch of different distributed generations (DGs in stand-alone microgrid (MG is of great significance to the operation’s reliability and economy, especially for energy crisis and environmental pollution. Based on controllable load (CL and combined cooling-heating-power (CCHP model of micro-gas turbine (MT, a multi-objective optimization model with relevant constraints to optimize the generation cost, load cut compensation and environmental benefit is proposed in this paper. The MG studied in this paper consists of photovoltaic (PV, wind turbine (WT, fuel cell (FC, diesel engine (DE, MT and energy storage (ES. Four typical scenarios were designed according to different day types (work day or weekend and weather conditions (sunny or rainy in view of the uncertainty of renewable energy in variable situations and load fluctuation. A modified dispatch strategy for CCHP is presented to further improve the operation economy without reducing the consumers’ comfort feeling. Chaotic optimization and elite retention strategy are introduced into basic particle swarm optimization (PSO to propose modified chaos particle swarm optimization (MCPSO whose search capability and convergence speed are improved greatly. Simulation results validate the correctness of the proposed model and the effectiveness of MCPSO algorithm in the optimized operation application of stand-alone MG.

Modelling of synchronisation and energy performance of FBE- and LBE-based standalone LTE-U networks

Directory of Open Access Journals (Sweden)

Jiamin Li

2017-06-01

Full Text Available Without the aid of licensed channel, deploying long-term evolution (LTE networks over unlicensed spectrum (named standalone LTE-U networks faces the difficulty of establishing and maintaining synchronisation between user equipments and base stations. In this work, considering the two modes of listen-before-talk-based channel access scheme, frame-based equipment (FBE and load-based equipment (LBE, the authors propose analytical frameworks to study the successful probability of synchronisation and the energy consumption of synchronisation in a standalone LTE-U network. Specifically, for the LBE mode, the authors also propose a Lattice-Poisson algorithm-based approach to derive the distribution of the channel non-occupancy period of a standalone LTE-U network. Furthermore, the authors explore the impact of diverse protocol parameters of both FBE and LBE modes on the two studied performance metrics. Simulation results demonstrate the accuracy of the analysis, and shed some light on the selection of FBE and LBE for standalone LTE-U networks, in terms of synchronisation, energy consumption, and throughput of standalone LTE-U and Wi-Fi networks.

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.

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)

Analysis and controller design for stand-alone VSIs in synchronous reference frame

DEFF Research Database (Denmark)

Ramezani, Malek; Li, Shuhui; Golestan, Saeed

2017-01-01

-by-step graphical analysis and design approach for a three-phase stand-alone VSI system in the dq reference frame, which provides a clear systematic decoupling process to design the inner- and outer-loop current and voltage controllers, respectively. The closed-loop d- and q-axis output impedances of the stand......-alone VSI system by considering the coupling effects between axes are also formulated, modelled, and evaluated. The study investigates how the decoupling and compensating terms added in the current and voltage controllers affect the dynamic performance and output dq impedances of the VSI system. Simulation...... and hardware results verify the effectiveness of the graphic design and analysis strategy....

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)

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

Hybrid Configuration of Darrieus and Savonius Rotors for Stand-alone Power Systems

Science.gov (United States)

Wakui, Tetsuya; Tanzawa, Yoshiaki; Hashizume, Takumi; Nagao, Toshio

The suitable hybrid configuration of Darrieus lift-type and Savonius drag-type rotors for stand-alone wind turbine-generator systems is discussed using our dynamic simulation model. Two types of hybrid configurations are taken up: Type-A installs the Savonius rotor inside the Darrieus rotor and Type-B installs the Savonius rotor outside the Darrieus rotor. The computed results of the output characteristics and the dynamic behaviors of the system operated at the maximum power coefficient points show that Type-A, which has fine operating behavior to wind speed changes and can be compactly designed because of a shorter rotational shaft, is an effective way for self-controlled stand-alone small-scale systems.

Study on a computerized compact simulator of NHR-200

International Nuclear Information System (INIS)

Gao Zuying; Dong Yujie

1997-01-01

A fully computerized compact simulator is studied in accordance with the engineering practical need of NHR-200. A SUN SPARC 2 stand-alone workstation is selected as its computer system and multi-task structure of software is employed. Simulation program is derived from the RETRAN-02 code. The standard I/O devices are used as its interface equipment and the man-machine interface graphic program is coded on the basis of X Window System. Shared memory and semaphores are used for inter-task communication and a timer is used in real-time control of tasks. Its accuracy and simulation speed are verified by using several typical accident transients. The accuracy and speed are perfectly able to meet the requirements of engineering simulation. It is useful for normal and accident transient analysis, engineering study and design, reactor operation support and personnel training

Optimal expansion planning of stand-alone systems with stochastic simulations

Energy Technology Data Exchange (ETDEWEB)

Hoese, Alejandro [Instituto de Energia Electrica (IEE), Universidad Nacional de San Juan, (Argentina)

1997-12-31

Stand-alone systems in the range of 1 kW - 10 MW are taking relevance in the new (global) liberal concept of energy market. State and private investors are becoming increasingly attention on the use of renewable for these systems, but it must be shown that these non-conventional solutions are competitive with the established conventional ones. The high investment costs and the technical and economic uncertainties coupled with the use of time-dependent energy sources are the mainly inhibiting factors for the decision agents to choose these systems instead of conventional ones. In the paper a new model for optimal expansion planning of hybrid stand-alone generating systems under consideration of uncertainties is presented. This model is at present in {sup d}evelopment state{sup .} Results already obtained in the first steps of this research are promising and some of them are here presented. [Espanol] Los sistemas autocontenidos en el rango de 1 Kw a 10 MW estan tomando importancia en el nuevo (global) concepto liberal del mercado de la energia. Inversionistas privados y del Estado estan poniendo mayor atencion en el uso de energias renovables para estos sistemas, pero debe mostrarse que estas soluciones no-convencionales son competitivas con las convencionales establecidas. Los altos costos de inversion y las incertidumbres tecnicas y economicas aunadamente con el uso de fuentes de energia dependientes del tiempo son los principales factores inhibidores de los factores de decision para escoger estos sistemas en lugar de los convencionales. En este articulo se presenta un nuevo modelo de planeacion de expansion optima de sistemas hibridos autocontenidos de generacion electrica bajo la consideracion de incertidumbres. Este modelo esta actualmente en {sup e}stado de desarrollo{sup .} Los resultados ya obtenidos en las primeras etapas de esta investigacion son prometedores y se presentan algunos de ellos.

Optimal expansion planning of stand-alone systems with stochastic simulations

Energy Technology Data Exchange (ETDEWEB)

Hoese, Alejandro [Instituto de Energia Electrica (IEE), Universidad Nacional de San Juan, (Argentina)

1998-12-31

Stand-alone systems in the range of 1 kW - 10 MW are taking relevance in the new (global) liberal concept of energy market. State and private investors are becoming increasingly attention on the use of renewable for these systems, but it must be shown that these non-conventional solutions are competitive with the established conventional ones. The high investment costs and the technical and economic uncertainties coupled with the use of time-dependent energy sources are the mainly inhibiting factors for the decision agents to choose these systems instead of conventional ones. In the paper a new model for optimal expansion planning of hybrid stand-alone generating systems under consideration of uncertainties is presented. This model is at present in {sup d}evelopment state{sup .} Results already obtained in the first steps of this research are promising and some of them are here presented. [Espanol] Los sistemas autocontenidos en el rango de 1 Kw a 10 MW estan tomando importancia en el nuevo (global) concepto liberal del mercado de la energia. Inversionistas privados y del Estado estan poniendo mayor atencion en el uso de energias renovables para estos sistemas, pero debe mostrarse que estas soluciones no-convencionales son competitivas con las convencionales establecidas. Los altos costos de inversion y las incertidumbres tecnicas y economicas aunadamente con el uso de fuentes de energia dependientes del tiempo son los principales factores inhibidores de los factores de decision para escoger estos sistemas en lugar de los convencionales. En este articulo se presenta un nuevo modelo de planeacion de expansion optima de sistemas hibridos autocontenidos de generacion electrica bajo la consideracion de incertidumbres. Este modelo esta actualmente en {sup e}stado de desarrollo{sup .} Los resultados ya obtenidos en las primeras etapas de esta investigacion son prometedores y se presentan algunos de ellos.

Stand-alone wind system with Vanadium Redox Battery energy storage

DEFF Research Database (Denmark)

Teodorescu, Remus; Barote, L.; Weissbach, R.

2008-01-01

Energy storage devices are required for power balance and power quality in stand alone wind energy systems. A Vanadium Redox Flow Battery (VRB) system has many features which make its integration with a stand-alone wind energy system attractive. This paper proposes the integration of a VRB system...... with a typical stand-alone wind energy system during wind speed variation as well as transient performance under variable load. The investigated system consists of a variable speed wind turbine with permanent magnet synchronous generator (PMSG), diode rectifier bridge, buck-boost converter, bidirectional charge...... controller, transformer, inverter, ac loads and VRB (to store a surplus of wind energy and to supply power during a wind power shortage). The main purpose is to supply domestic appliances through a single phase 230V, 50Hz inverter. Simulations are accomplished in order to validate the stability of the supply....

Design and Operation Studies of A Stand-Alone PV Generation System

DEFF Research Database (Denmark)

Hu, Yanting; Chen, Zhe; Zhang, Donglai

2013-01-01

This paper discusses the modeling, design and operation of a PV powered stand-alone system, which includes a PV array, a battery bank, power electronic converters and the associated control system. The design considerations are analyzed and a design platform is presented. Furthermore the operation...... modes of the system are described. A power electronic system with the associated control scheme has been proposed and simulation models have been developed. Simulation studies have been conducted on an example system; the results have demonstrated the effectiveness of the presented methods....

Loss-of-load probabilities for stand-alone photovoltaic systems

International Nuclear Information System (INIS)

Klein, S.A.; Beckman, W.A.

1989-01-01

A general method is presented for estimating the loss-of-load probability of stand-alone photovoltaic systems. The method was developed by correlating simulation results. The simulations were driven with synthetic radiation sequences having the same statistical significance as available historical data. The methods assumes a constant nighttime load and accounts for the distribution and persistence in daily solar radiation data. It is shown that the 10 year average performance of systems having loss-of-load probabilities less than about 0.01 can vary greatly from one ten year period to the next and thereby cannot be considered realistic performance estimates of a system during its lifetime. (author). 26 refs, 15 figs, 4 tabs

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.

Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies

Science.gov (United States)

Borden, C. S.; Volkmer, K.; Cochrane, E. H.; Lawson, A. C.

1984-01-01

A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems.

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

Modeling and Control of the Distributed Power Converters in a Standalone DC Microgrid

Directory of Open Access Journals (Sweden)

Xiaodong Lu

2016-03-01

Full Text Available A standalone DC microgrid integrated with distributed renewable energy sources, energy storage devices and loads is analyzed. To mitigate the interaction among distributed power modules, this paper describes a modeling and control design procedure for the distributed converters. The system configuration and steady-state analysis of the standalone DC microgrid under study are discussed first. The dynamic models of the distributed converters are then developed from two aspects corresponding to their two operating modes, device-regulating mode and bus-regulating mode. Average current mode control and linear compensators are designed accordingly for each operating mode. The stability of the designed system is analyzed at last. The operation and control design of the system are verified by simulation results.

Study on Soft Phase Locked Method to Solving the Synchronization Problem of Active Power Filter in Stand-alone Power Grid

DEFF Research Database (Denmark)

Zhuo, Fang; Wu, Longhui; Chen, Zhe

2009-01-01

on zero-cross detection can't work effectively in small rating stand-alone power grid. Then a soft phase locked loop with additional filter is proposed. It can lock the phase angle on to the positive sequence of fundamental voltage accurately and rapidly. It ensures the performance of APF applied...... in the small rating stand-alone power grid. Moreover, the soft phase locked loop is easy to be implemented in a Digital Signal Processor (DSP). Simulation and experimental results validate that the soft phase locked loop has satisfactory performance.......Traditional LC filters can't work stably in small rating stand-alone power grid. So active power filter (APF) is becoming an important tool to solve the power quality problem in small rating stand-alone power grid. In most current detection algorithm of APF, it needs a synchronizing signal. Firstly...

Stand-Alone Microgrid Inverter Controller Design for Nonlinear, Unbalanced Load with Output Transformer

Directory of Open Access Journals (Sweden)

Jae-Uk Lim

2018-04-01

Full Text Available This paper proposes a technique that compensates for unbalance and nonlinearity in microgrid inverters with power transformers operating in stand-alone mode. When a microgrid inverter is operating in stand-alone mode, providing high-quality power is very important. When an unbalanced, nonlinear load is connected, zero sequence current and negative sequence current occur, which leads to an unbalanced output voltage. This paper examines why the zero sequence component occurs differently depending on the structure of a three-phase transformer connected to the inverter output terminal, and it proposes a method for controlling the zero sequence component. It also uses a resonant controller to remove the harmonics that correspond to the negative sequence component and the nonlinear component. The proposed elements were verified by a Powersim (PSIM simulation.

39 CFR 122.2 - Stand-alone special services.

Science.gov (United States)

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Stand-alone special services. 122.2 Section 122.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES [DOMESTIC MAIL] SERVICE STANDARDS FOR MARKET-DOMINANT SPECIAL SERVICES PRODUCTS § 122.2 Stand-alone special services. (a) The service standard...

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...

Optimization of the photovoltaic-hydrogen supply system of a stand-alone remote-telecom application

Energy Technology Data Exchange (ETDEWEB)

Gomez, Guillermo; Martinez, Graciano; Galvez, Jose L.; Cuevas, Raquel; Maellas, Jesus [National Institute for Aerospace Technology (INTA), Renewable Energy Department, Ctra. Ajalvir km 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Gila, Raul; Bueno, Emilio [Polytechnical School - Alcala de Henares University, Electronics Department, Campus Universitario, Ctra. De Madrid-Barcelona Km 33.600, Alcala de Henares, Madrid (Spain)

2009-07-15

Hydrogen is considered as the optimal carrier for the surplus energy storage from renewable resources. Although hydrogen and its application in fuel cell is considered as a high-cost energy system, some cost-efficient solutions have been found for their use in stand-alone applications, which usually depend on the variability of renewable sources that have to be oversized in order to reduce their dependence on external energy sources. This paper shows the results from the simulation of several alternatives of introducing hydrogen technologies to increase the independence of a remote-telecom application fed by photovoltaic panels. Hydrogen is obtained by electrolysis and it is used in a fuel cell when the renewable energy source is not enough to maintain the stand-alone application. TRNSYS simulation environment has been used for evaluating the proposed alternatives. The results show that the best configuration option is that considering the use of hydrogen as a way to storage the surplus of radiation and the management system can vary the number of photovoltaic panels assigned to feed the hydrogen generation, the batteries or the telecom application. (author)

The Stand-alone Heliostat

International Nuclear Information System (INIS)

Garcia Navajas, G. I.; Egea Gea, A.

2000-01-01

The first Autonomous Heliostat has been developed by CIEMAT at PSA facilities in Almeria. This heliostat is an innovative approach to reducing the civil engineering work costs in heliostat fields of central tower plants. Channels, cables and other electric elements have been eliminated in the new heliostat. Thus, one 70-nr, classical T glass/metal heliostat has been adapted to include all the new stand-alone concept components. A PV system is able to drive two sun-tracking DC motors between 5 and 24Vdc, 0 and 15A. The heliostat communicates with the control room 400-m away by using a radio-modem working at 9600 baud. An anemometer, a wind switcher, light and ambient temperature sensors have been installed on the heliostat for self-protection decision-making. A PV panel integrated into the heliostat reflecting surface, eliminates cabling and other elements required for a conventional power supply. Communication lines between master control and local control have been replaced by radio-modem. Testing has validated the technical feasibility of the prototype and quantified the real consumption and efficiencies of new elements. The extra costs produced.by the autonomous concepts are compared with the cost of civil work in conventional heliostat field. (Author) 8 refs

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.

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

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.

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.

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.

Stand-alone photovoltaic applications. Lessons learned

International Nuclear Information System (INIS)

Loois, G.; Van Hemert, B.

1999-02-01

The IEA Photovoltaic Power Systems Programme (PVPS) is one of the collaborative R and D agreements established within the IEA. The objective of Task III is to promote and facilitate the exchange of information and experiences in the field of PV Systems in Stand-alone and Island Applications (SAPV). The book focuses on the practical experiences gained, and does not aim to provide a complete manual on SAPV. When Task III started its activities in 1993, a collection of 50 'State of the art' projects was published in the book 'Examples of Stand-Alone Photovoltaic Systems'. This publication marked the base line for the work of the task. Now, in 1998, the showcases from each country demonstrate the lessons learned in five years of cooperation. The book consists of two parts. The first part contains eight chapters dealing with a specific aspect of stand-alone PV. The second part introduces 14 national showcase projects in a systematic presentation. Each chapter and showcase can be read independently from the rest of the book. Chapter 2, contributed by The Netherlands, analyses the market for stand-alone PV systems. It gives an overview of the 'traditional' application of stand-alone PV, which is the electrification of remote buildings and which has been addressed in depth in other publications. The focus is on the market niches of service applications that are also interesting for more densely populated areas, e.g. in industrialised countries. The United Kingdom illustrates the economic aspects in Chapter 3. Cost comparisons are made, but more important is the illustration of the non-financial considerations that make PV the preferred choice as a power source for many applications. Switzerland explores in Chapter 4 (financing aspects) different financing mechanisms, and financial policies used to overcome the initial cost barrier. Most of these approaches have been applied in developing countries rather than in the western world. Using various examples from all over the

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.

Neural Network based Control of SG based Standalone Generating System with Energy Storage for Power Quality Enhancement

Science.gov (United States)

Nayar, Priya; Singh, Bhim; Mishra, Sukumar

2017-08-01

An artificial intelligence based control algorithm is used in solving power quality problems of a diesel engine driven synchronous generator with automatic voltage regulator and governor based standalone system. A voltage source converter integrated with a battery energy storage system is employed to mitigate the power quality problems. An adaptive neural network based signed regressor control algorithm is used for the estimation of the fundamental component of load currents for control of a standalone system with load leveling as an integral feature. The developed model of the system performs accurately under varying load conditions and provides good dynamic response to the step changes in loads. The real time performance is achieved using MATLAB along with simulink/simpower system toolboxes and results adhere to an IEEE-519 standard for power quality enhancement.

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

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.

Feasibility and Optimal Design of a Stand-Alone Photovoltaic Energy System for the Orphanage

Directory of Open Access Journals (Sweden)

Vincent Anayochukwu Ani

2014-01-01

Full Text Available Access to electricity can have a positive psychological impact through a lessening of the sense of exclusion, and vulnerability often felt by the orphanages. This paper presented the simulation and optimization study of a stand-alone photovoltaic power system that produced the desired power needs of an orphanage. Solar resources for the design of the system were obtained from the National Aeronautics and Space Administration (NASA Surface Meteorology and Solar Energy website at a location of 6°51′N latitude and 7°35′E longitude, with annual average solar radiation of 4.92 kWh/m2/d. This study is based on modeling, simulation, and optimization of energy system in the orphanage. The patterns of load consumption within the orphanage were studied and suitably modeled for optimization. Hybrid Optimization Model for Electric Renewables (HOMER software was used to analyze and design the proposed stand-alone photovoltaic power system model. The model was designed to provide an optimal system configuration based on an hour-by-hour data for energy availability and demands. A detailed design, description, and expected performance of the system were presented in this paper.

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.

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)

Hierarchical energy management system for stand-alone hybrid system based on generation costs and cascade control

International Nuclear Information System (INIS)

Torreglosa, J.P.; García, P.; Fernández, L.M.; Jurado, F.

2014-01-01

Highlights: • We present an energy management system for a stand-alone WT/PV/hydrogen/battery hybrid system. • Hierarchical control composed by master and slave control strategies. • Control assures reliable electricity support for stand-alone applications subject to technical and economic criteria. - Abstract: This paper presents an energy management system (EMS) for stand-alone hybrid systems composed by photovoltaic (PV) solar panels and a wind turbine (WT) as primary energy sources and two energy storage systems, which are a hydrogen system and a battery. The hydrogen system is composed of fuel cell (FC), electrolyzer and hydrogen storage tank. The EMS is a hierarchical control composed by a master control strategy and a slave control strategy. On the one hand, the master control generates the reference powers to meet several premises (such as to satisfy the load power demand, and to maintain the hydrogen tank level and the state of charge (SOC) of the battery between their target margins), taking also into account economic aspects to discriminate between using the battery or hydrogen system. On the other hand, the slave control modifies the reference powers generated by the master control according to the energy sources dynamic limitations, and maintains the DC bus voltage at its reference value. The models, implemented in MATLAB-Simulink environment, have been developed from commercially available components. To check the viability of the proposed EMS, two kinds of simulations were carried out: (1) A long-term simulation of 25 years (expected lifetime of the system) with a sample time of one hour to validate the master control of the EMS; and (2) A short-term simulation with sudden net power variations to validate the slave control of the EMS

Improved double integral sliding mode MPPT controller based parameter estimation for a stand-alone photovoltaic system

International Nuclear Information System (INIS)

Chatrenour, Nasrin; Razmi, Hadi; Doagou-Mojarrad, Hasan

2017-01-01

Highlights: • IDISMC based MPPT algorithm is introduced. • Hurwitz stability theorem is used for switching surface coefficients computation. • GA approach is presented for parameter estimation of the stand-alone PV system. - Abstract: In this paper, an Improved Double Integral Sliding Mode MPPT Controller (IDISMC) for a stand-alone photovoltaic (PV) system is proposed. Performance of a sliding mode controller (SMC) is greatly influenced by the choice of the sliding surface. Switching surface coefficients were selected by the use of Hurwitz stability theorem. The IDISMC not only is robust against parametric and non-parametric uncertainties, but also has a very small steady-state error, thanks to the use of double integral of tracking voltage error in the definition of its sliding surface. For realistic simulation, Genetic Algorithm (GA) method was used to estimate parameters of solar panels model. The validity of the proposed double integral SMC in maximum power point tracking was approved by comparing the simulation results obtained for a sample PV system with the results of other methods.

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

R and D into stand-alone PV systems for export

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-09-01

The current status of photovoltaic (PV) technology is reviewed for systems to provide electricity where mains supplies are unavailable, known as stand-alone PV systems. Typical applications and experiences with installed stand-alone systems are described. Economic issues and barriers to the wide use of PV systems are also examined. (UK)

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)

Techno-economic assessment of FT unit for synthetic diesel production in existing stand-alone biomass gasification plant using process simulation tool

DEFF Research Database (Denmark)

Hunpinyo, Piyapong; Narataruksa, Phavanee; Tungkamani, Sabaithip

2014-01-01

For alternative thermo-chemical conversion process route via gasification, biomass can be gasified to produce syngas (mainly CO and H2). On more applications of utilization, syngas can be used to synthesize fuels through the catalytic process option for producing synthetic liquid fuels...... such as Fischer-Tropsch (FT) diesel. The embedding of the FT plant into the stand-alone based on power mode plants for production of a synthetic fuel is a promising practice, which requires an extensive adaptation of conventional techniques to the special chemical needs found in a gasified biomass. Because...... there are currently no plans to engage the FT process in Thailand, the authors have targeted that this work focus on improving the FT configurations in existing biomass gasification facilities (10 MWth). A process simulation model for calculating extended unit operations in a demonstrative context is designed...

Structure Optimization of Stand-Alone Renewable Power Systems Based on Multi Object Function

Directory of Open Access Journals (Sweden)

Jae-Hoon Cho

2016-08-01

Full Text Available This paper presents a methodology for the size optimization of a stand-alone hybrid PV/wind/diesel/battery system while considering the following factors: total annual cost (TAC, loss of power supply probability (LPSP, and the fuel cost of the diesel generator required by the user. A new optimization algorithm and an object function (including a penalty method are also proposed; these assist with designing the best structure for a hybrid system satisfying the constraints. In hybrid energy system sources such as photovoltaic (PV, wind, diesel, and energy storage devices are connected as an electrical load supply. Because the power produced by PV and wind turbine sources is dependent on the variation of the resources (sun and wind and the load demand fluctuates, such a hybrid system must be able to satisfy the load requirements at any time and store the excess energy for use in deficit conditions. Therefore, reliability and cost are the two main criteria when designing a stand-alone hybrid system. Moreover, the operation of a diesel generator is important to achieve greater reliability. In this paper, TAC, LPSP, and the fuel cost of the diesel generator are considered as the objective variables and a hybrid teaching–learning-based optimization algorithm is proposed and used to choose the best structure of a stand-alone hybrid PV/wind/diesel/battery system. Simulation results from MATLAB support the effectiveness of the proposed method and confirm that it is more efficient than conventional methods.

Standalone BISON Fuel Performance Results for Watts Bar Unit 1, Cycles 1-3

Energy Technology Data Exchange (ETDEWEB)

Clarno, Kevin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pawlowski, Roger [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stimpson, Shane [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Jeffrey [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-03-07

The Consortium for Advanced Simulation of Light Water Reactors (CASL) is moving forward with more complex multiphysics simulations and increased focus on incorporating fuel performance analysis methods. The coupled neutronics/thermal-hydraulics capabilities within the Virtual Environment for Reactor Applications Core Simulator (VERA-CS) have become relatively stable, and major advances have been made in analysis efforts, including the simulation of twelve cycles of Watts Bar Nuclear Unit 1 (WBN1) operation. While this is a major achievement, the VERA-CS approaches for treating fuel pin heat transfer have well-known limitations that could be eliminated through better integration with the BISON fuel performance code. Several approaches are being implemented to consider fuel performance, including a more direct multiway coupling with Tiamat, as well as a more loosely coupled one-way approach with standalone BISON cases. Fuel performance typically undergoes an independent analysis using a standalone fuel performance code with manually specified input defined from an independent core simulator solution or set of assumptions. This report summarizes the improvements made since the initial milestone to execute BISON from VERA-CS output. Many of these improvements were prompted through tighter collaboration with the BISON development team at Idaho National Laboratory (INL). A brief description of WBN1 and some of the VERA-CS data used to simulate it are presented. Data from a small mesh sensitivity study are shown, which helps justify the mesh parameters used in this work. The multi-cycle results are presented, followed by the results for the first three cycles of WBN1 operation, particularly the parameters of interest to pellet-clad interaction (PCI) screening (fuel-clad gap closure, maximum centerline fuel temperature, maximum/minimum clad hoop stress, and cumulative damage index). Once the mechanics of this capability are functioning, future work will target cycles with

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.

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...

A review on sizing methodologies of photovoltaic array and storage battery in a standalone photovoltaic system

International Nuclear Information System (INIS)

Khatib, Tamer; Ibrahim, Ibrahim A.; Mohamed, Azah

2016-01-01

Highlights: • We review the current methods for sizing standalone PV systems. • We review the current criteria adapted in sizing standalone PV systems. • We review current method for sizing battery in standalone PV systems. - Abstract: The reliance of future energy demand on standalone PV system is based on its payback period and particular electrical grid parity prices. This highlights the importance for optimum and applicable methods for sizing these systems. Moreover, the designers are being more sensitive toward simple and reliable sizing models for standalone PV system. This paper proposes a review on important knowledge that needs to be taken into account while designing and implementing standalone PV systems. Such a knowledge includes configurations of standalone photovoltaic system, evaluation criteria for unit sizing, sizing methodologies. Moreover, this review provides highlights on challenges and limitations of standalone PV system size optimization techniques.

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...

Modeling, design and analysis of a stand-alone hybrid power generation system using solar/urine

International Nuclear Information System (INIS)

Wu, Wei; Zhou, Ya-Yan; Lin, Mu-Hsuan; Hwang, Jenn-Jiang

2013-01-01

Highlights: • The stand-alone hybrid power system is presented. • The urine-to-hydrogen processor is proposed. • Scenario analysis of the hybrid power dispatching and the urine/solar demands is investigated. • The design, modeling and optimization of the hybrid power system is addressed by Aspen Plus and Matlab. - Abstract: The urine turned to hydrogen as an energy conversion process is integrated into a stand-alone hybrid (PV/FC/battery) power generation system. The optimization and simulation of a new urine-to-hydrogen processor is evaluated in Aspen Plus environment. In our approach, the PV generator aims to reduce urine consumption and the lithium-ion battery can compensate the power gap due to the fuel processing delay. Based on prescribed patterns of solar irradiation and the daily load demand of a 30-persons classroom, scenario analyses of the hybrid power dispatching and operational feasibility is addressed

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

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.

Powertrain Test Procedure Development for EPA GHG Certification of Medium- and Heavy-Duty Engines and Vehicles

Energy Technology Data Exchange (ETDEWEB)

Chambon, Paul H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deter, Dean D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-07-01

xiii ABSTRACT The goal of this project is to develop and evaluate powertrain test procedures that can accurately simulate real-world operating conditions, and to determine greenhouse gas (GHG) emissions of advanced medium- and heavy-duty engine and vehicle technologies. ORNL used their Vehicle System Integration Laboratory to evaluate test procedures on a stand-alone engine as well as two powertrains. Those components where subjected to various drive cycles and vehicle conditions to evaluate the validity of the results over a broad range of test conditions. Overall, more than 1000 tests were performed. The data are compiled and analyzed in this report.

Fuzzy logic control of stand-alone photovoltaic system with battery storage

Science.gov (United States)

Lalouni, S.; Rekioua, D.; Rekioua, T.; Matagne, E.

Photovoltaic energy has nowadays an increased importance in electrical power applications, since it is considered as an essentially inexhaustible and broadly available energy resource. However, the output power provided via the photovoltaic conversion process depends on solar irradiation and temperature. Therefore, to maximize the efficiency of the photovoltaic energy system, it is necessary to track the maximum power point of the PV array. The present paper proposes a maximum power point tracker (MPPT) method, based on fuzzy logic controller (FLC), applied to a stand-alone photovoltaic system. It uses a sampling measure of the PV array power and voltage then determines an optimal increment required to have the optimal operating voltage which permits maximum power tracking. This method carries high accuracy around the optimum point when compared to the conventional one. The stand-alone photovoltaic system used in this paper includes two bi-directional DC/DC converters and a lead-acid battery bank to overcome the scare periods. One converter works as an MPP tracker, while the other regulates the batteries state of charge and compensates the power deficit to provide a continuous delivery of energy to the load. The Obtained simulation results show the effectiveness of the proposed fuzzy logic controller.

Size optimization of stand-alone photovoltaic (PV) room air conditioners

International Nuclear Information System (INIS)

Chen, Chien-Wei; Zahedi, A.

2006-01-01

Sizing of a stand-alone PV system determines the main cost of the system. PV electricity cost is determined by the amount of solar energy received, hence the actual climate and weather conditions such as solar irradiance and ambient temperature affect the size required and cost of the system. Air conditioning demand also depends on the weather conditions. Therefore, sizing a PV powered air conditioner must consider the characteristics of local climate and temperature. In this paper, sizing procedures and special considerations for air conditioning under Melbourne's climatic conditions is presented. The reliability of various PV-battery size combinations is simulated by MATLAB. As a result, excellent system performance can be predicated.(Author)

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.

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.)

System design optimization for stand-alone photovoltaic systems sizing by using superstructure model

International Nuclear Information System (INIS)

Azau, M A M; Jaafar, S; Samsudin, K

2013-01-01

Although the photovoltaic (PV) systems have been increasingly installed as an alternative and renewable green power generation, the initial set up cost, maintenance cost and equipment mismatch are some of the key issues that slows down the installation in small household. This paper presents the design optimization of stand-alone photovoltaic systems using superstructure model where all possible types of technology of the equipment are captured and life cycle cost analysis is formulated as a mixed integer programming (MIP). A model for investment planning of power generation and long-term decision model are developed in order to help the system engineer to build a cost effective system.

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)

Feasibility Analysis and Simulation of a Stand-Alone Photovoltaic Energy System for Electricity Generation and Environmental Sustainability – Equivalent to 650VA Fuel-Powered Generator – Popularly Known as “I Pass My Neighbour”

International Nuclear Information System (INIS)

Ani, Vincent Anayochukwu

2015-01-01

Photovoltaic (PV) power system can be used to replace wholly 650VA generator for electricity generation for household use in Nigeria. This paper presented the feasibility analysis of load data and simulation study of a stand-alone PV power system that produced the electrical needs of a household. This study is based on designing of PV energy system for household use. The patterns of load consumption within the household were studied and suitably modeled for simulation. The simulation study indicates that energy requirements to provide electricity, which is equivalent to 650VA generator for household use in Nigeria, can be accomplished by 520 W solar PV array, 2312 Ah nominal capacity battery, and a 1 kW DC/AC inverter. This would be suitable for deployment of 100% clean energy for environmental sustainability and uninterruptable power performance in the household. The results of this research show that, with a low-power consuming appliances, it is possible to meet the entire annual electricity demand of a single household solely through a stand-alone PV energy supply. Installing solar panels by most Nigerian home can significantly reduce home reliance on government power thereby reduce the strain on the current capacity of our power generation infrastructure. A detailed design and description of the system were presented in this paper.

Feasibility Analysis and Simulation of a Stand-Alone Photovoltaic Energy System for Electricity Generation and Environmental Sustainability – Equivalent to 650VA Fuel-Powered Generator – Popularly Known as “I Pass My Neighbour”

Energy Technology Data Exchange (ETDEWEB)

Ani, Vincent Anayochukwu, E-mail: vincent_ani@yahoo.com [Department of Electronic Engineering, University of Nigeria Nsukka, Nsukka (Nigeria)

2015-09-11

Photovoltaic (PV) power system can be used to replace wholly 650VA generator for electricity generation for household use in Nigeria. This paper presented the feasibility analysis of load data and simulation study of a stand-alone PV power system that produced the electrical needs of a household. This study is based on designing of PV energy system for household use. The patterns of load consumption within the household were studied and suitably modeled for simulation. The simulation study indicates that energy requirements to provide electricity, which is equivalent to 650VA generator for household use in Nigeria, can be accomplished by 520 W solar PV array, 2312 Ah nominal capacity battery, and a 1 kW DC/AC inverter. This would be suitable for deployment of 100% clean energy for environmental sustainability and uninterruptable power performance in the household. The results of this research show that, with a low-power consuming appliances, it is possible to meet the entire annual electricity demand of a single household solely through a stand-alone PV energy supply. Installing solar panels by most Nigerian home can significantly reduce home reliance on government power thereby reduce the strain on the current capacity of our power generation infrastructure. A detailed design and description of the system were presented in this paper.

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...

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.

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.

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)

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...

Port-O-Sim Object Simulation Application

Science.gov (United States)

Lanzi, Raymond J.

2009-01-01

Port-O-Sim is a software application that supports engineering modeling and simulation of launch-range systems and subsystems, as well as the vehicles that operate on them. It is flexible, distributed, object-oriented, and realtime. A scripting language is used to configure an array of simulation objects and link them together. The script is contained in a text file, but executed and controlled using a graphical user interface. A set of modules is defined, each with input variables, output variables, and settings. These engineering models can be either linked to each other or run as standalone. The settings can be modified during execution. Since 2001, this application has been used for pre-mission failure mode training for many Range Safety Scenarios. It contains range asset link analysis, develops look-angle data, supports sky-screen site selection, drives GPS (Global Positioning System) and IMU (Inertial Measurement Unit) simulators, and can support conceptual design efforts for multiple flight programs with its capacity for rapid six-degrees-of-freedom model development. Due to the assembly of various object types into one application, the application is applicable across a wide variety of launch range problem domains.

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....

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.

Design and Performance Analysis of a Biodiesel Engine Driven Refrigeration System for Vaccine Storage

Directory of Open Access Journals (Sweden)

K Kamsuk

2013-06-01

Full Text Available A compact, stand-alone, refrigeration module powered by a small biodiesel engine for vaccine storage in rural use was proposed. The engine was of single cylinder, four-stroke, directinjection with displacement of 0.296 cm3 and compression ratio of 20:1. The refrigeration system was modified from an automotive vapor compression system. The system performance was analytically investigated. From the simulation, it was found to have acceptable operation over a range of speeds and loads. Performance of the system in terms of fuel consumption and torque tended to decrease with an increase in engine speed. The modular system was able to operate at cooling loads above 4.6 kW, with proper speed ratio between the engine and the compressor. Overall, primary energy ratio of the refrigeration was found to be maximum at 0.54.

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.

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.

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.

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.

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.

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.

A Case Study of Control and Improved Simplified Swarm Optimization for Economic Dispatch of a Stand-Alone Modular Microgrid

Directory of Open Access Journals (Sweden)

Xianyong Zhang

2018-03-01

Full Text Available Due to the complex configuration and control framework, the conventional microgrid is not cost-effective for engineering applications with small or medium capacity. A stand-alone modular microgrid with separated AC bus and decentralized control strategy is proposed in this paper. Each module is a self-powered system, which consists of wind and solar power, a storage battery, load and three-port converter. The modules are interconnected by three-port converters to form the microgrid. Characteristics, operation principle, control of the modular microgrid and the three-port converter are analyzed in detail. Distributed storage batteries enable power exchanges among modules to enhance economic returns. Economic dispatch of the stand-alone modular microgrid is a mixed-integer programming problem. A day-ahead operation optimization model including fuel cost, battery operation cost, and power transmission cost is established. Because there are so many constraints, it is difficult to produce a feasible solution and even more difficult to have an improved solution. An improved simplified swarm optimization (iSSO method is therefore proposed. The iSSO scheme designs the new update mechanism and survival of the fittest policy. The experimental results from the demonstration project on DongAo Island reflect the effectiveness of the stand-alone modular microgrid and the economic dispatch strategy based on the iSSO method.

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.

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.

A New Approach for Optimal Sizing of Standalone Photovoltaic Systems

OpenAIRE

Khatib, Tamer; Mohamed, Azah; Sopian, K.; Mahmoud, M.

2012-01-01

This paper presents a new method for determining the optimal sizing of standalone photovoltaic (PV) system in terms of optimal sizing of PV array and battery storage. A standalone PV system energy flow is first analysed, and the MATLAB fitting tool is used to fit the resultant sizing curves in order to derive general formulas for optimal sizing of PV array and battery. In deriving the formulas for optimal sizing of PV array and battery, the data considered are based on five sites in Malaysia...

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.

Design of Stand-Alone Hybrid Power Generation System at Brumbun Beach Tulungagung East Java

Science.gov (United States)

Rahmat, A. N.; Hidayat, M. N.; Ronilaya, F.; Setiawan, A.

2018-04-01

Indonesian government insists to optimize the use of renewable energy resources in electricity generation. One of the efforts is launching Independent Energy Village plan. This program aims to fulfill the need of electricity for isolated or remote villages in Indonesia. In order to support the penetration of renewable energy resources in electricity generation, a hybrid power generation system is developed. The simulation in this research is based on the availability of renewable energy resources in Brumbun beach, Tulungagung, East Java. Initially, the electricity was supplied through stand-alone electricity generations which are installed at each house. Hence, the use of electricity between 5 p.m. – 9 p.m. requires high operational costs. Based on the problem above, this research is conducted to design a stand-alone hybrid electricity generation system, which may consist of diesel, wind, and photovoltaic. The design is done by using HOMER software to optimize the use of electricity from renewable resources and to reduce the operation of diesel generation. The combination of renewable energy resources in electricity generation resulted in NPC of 44.680, COE of 0,268, and CO2 emissions of 0,038 % much lower than the use of diesel generator only.

The Stand-alone Heliostat; El Heliostato Autonomo

Energy Technology Data Exchange (ETDEWEB)

Garcia Navajas, G.; Egea Gea, A. [Ciemat. Madrid (Spain)

2000-07-01

The first Autonomous Heliostat has been developed by CIEMAT at PSA facilities in Almeria. This heliostat is an innovative approach to reducing the civil engineering work costs in heliostat fields of central tower plants. Channels, cables and other electric elements have been eliminated in the new heliostat. Thus, one 70-m''2, classical T glass/metal heliostat has been adapted to include all the new stand-alone concept components. A PV system is able to drive two sun-tracking DC motors between 5 and 24 Vdc, 0 and 15A. The heliostat communicates with the control room 400-m away by using a radio-modern working at 9600 baud. An anemometer, a wind switcher, light and ambient temperature sensors have been installed on the heliostat for self-protection decision-making. A PV panel integrated into the heliostat reflecting surface, eliminates cabling and other elements required for a conventional power supply. Communication lines between master control and local control have been replaced by radio-modern. Testing has validated the technical feasibility of the prototype and quantified the real consumption and efficiencies of new elements. The extra costs produced by the autonomous concepts are compared with the cost of civil work in conventional heliostat field. (Author) 8 refs.

The Stand-alone Heliostat; El Heliostato Autonomo

Energy Technology Data Exchange (ETDEWEB)

Garcia Navajas, G; Egea Gea, A [Ciemat. Madrid (Spain)

2000-07-01

The first Autonomous Heliostat has been developed by CIEMAT at PSA facilities in Almeria. This heliostat is an innovative approach to reducing the civil engineering work costs in heliostat fields of central tower plants. Channels, cables and other electric elements have been eliminated in the new heliostat. Thus, one 70-m''2, classical T glass/metal heliostat has been adapted to include all the new stand-alone concept components. A PV system is able to drive two sun-tracking DC motors between 5 and 24 Vdc, 0 and 15A. The heliostat communicates with the control room 400-m away by using a radio-modern working at 9600 baud. An anemometer, a wind switcher, light and ambient temperature sensors have been installed on the heliostat for self-protection decision-making. A PV panel integrated into the heliostat reflecting surface, eliminates cabling and other elements required for a conventional power supply. Communication lines between master control and local control have been replaced by radio-modern. Testing has validated the technical feasibility of the prototype and quantified the real consumption and efficiencies of new elements. The extra costs produced by the autonomous concepts are compared with the cost of civil work in conventional heliostat field. (Author) 8 refs.

FESetup: Automating Setup for Alchemical Free Energy Simulations.

Science.gov (United States)

Loeffler, Hannes H; Michel, Julien; Woods, Christopher

2015-12-28

FESetup is a new pipeline tool which can be used flexibly within larger workflows. The tool aims to support fast and easy setup of alchemical free energy simulations for molecular simulation packages such as AMBER, GROMACS, Sire, or NAMD. Post-processing methods like MM-PBSA and LIE can be set up as well. Ligands are automatically parametrized with AM1-BCC, and atom mappings for a single topology description are computed with a maximum common substructure search (MCSS) algorithm. An abstract molecular dynamics (MD) engine can be used for equilibration prior to free energy setup or standalone. Currently, all modern AMBER force fields are supported. Ease of use, robustness of the code, and automation where it is feasible are the main development goals. The project follows an open development model, and we welcome contributions.

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.

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

AOF: standalone test results of GALACSI

Science.gov (United States)

La Penna, P.; Aller Carpentier, E.; Argomedo, J.; Arsenault, R.; Conzelmann, R. D.; Delabre, B.; Donaldson, R.; Gago, F.; Gutierrez-Cheetam, P.; Hubin, N.; Jolley, P.; Kiekebusch, M.; Kirchbauer, J. P.; Klein, B.; Kolb, J.; Kuntschner, H.; Le Louarn, M.; Lizon, J.-L.; Madec, P.-Y.; Manescau, A.; Mehrgan, L.; Oberti, S.; Quentin, J.; Sedghi, B.; Ströbele, S.; Suárez Valles, M.; Soenke, C.; Tordo, S.; Vernet, J.

2016-07-01

GALACSI is the Adaptive Optics (AO) module that will serve the MUSE Integral Field Spectrograph. In Wide Field Mode it will enhance the collected energy in a 0.2"×0.2" pixel by a factor 2 at 750 nm over a Field of View (FoV) of 1'×1' using the Ground Layer AO (GLAO) technique. In Narrow Field Mode, it will provide a Strehl Ratio of 5% (goal 10%) at 650 nm, but in a smaller FoV (7.5"×7.5" FoV), using Laser Tomography AO (LTAO). Before being ready for shipping to Paranal, the system has gone through an extensive testing phase in Europe, first in standalone mode and then in closed loop with the DSM in Europe. After outlining the technical features of the system, we describe here the first part of that testing phase and the integration with the AOF ASSIST (Adaptive Secondary Setup and Instrument Stimulator) testbench, including a specific adapter for the IRLOS truth sensor. The procedures for the standalone verification of the main system performances are outlined, and the results of the internal functional tests of GALACSI after full integration and alignment on ASSIST are presented.

GROSS- GAMMA RAY OBSERVATORY ATTITUDE DYNAMICS SIMULATOR

Science.gov (United States)

Garrick, J.

1994-01-01

The Gamma Ray Observatory (GRO) spacecraft will constitute a major advance in gamma ray astronomy by offering the first opportunity for comprehensive observations in the range of 0.1 to 30,000 megaelectronvolts (MeV). The Gamma Ray Observatory Attitude Dynamics Simulator, GROSS, is designed to simulate this mission. The GRO Dynamics Simulator consists of three separate programs: the Standalone Profile Program; the Simulator Program, which contains the Simulation Control Input/Output (SCIO) Subsystem, the Truth Model (TM) Subsystem, and the Onboard Computer (OBC) Subsystem; and the Postprocessor Program. The Standalone Profile Program models the environment of the spacecraft and generates a profile data set for use by the simulator. This data set contains items such as individual external torques; GRO spacecraft, Tracking and Data Relay Satellite (TDRS), and solar and lunar ephemerides; and star data. The Standalone Profile Program is run before a simulation. The SCIO subsystem is the executive driver for the simulator. It accepts user input, initializes parameters, controls simulation, and generates output data files and simulation status display. The TM subsystem models the spacecraft dynamics, sensors, and actuators. It accepts ephemerides, star data, and environmental torques from the Standalone Profile Program. With these and actuator commands from the OBC subsystem, the TM subsystem propagates the current state of the spacecraft and generates sensor data for use by the OBC and SCIO subsystems. The OBC subsystem uses sensor data from the TM subsystem, a Kalman filter (for attitude determination), and control laws to compute actuator commands to the TM subsystem. The OBC subsystem also provides output data to the SCIO subsystem for output to the analysts. The Postprocessor Program is run after simulation is completed. It generates printer and CRT plots and tabular reports of the simulated data at the direction of the user. GROSS is written in FORTRAN 77 and

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)

Engineering in translational medicine

CERN Document Server

2014-01-01

This book covers a broad area of engineering research in translational medicine. Leaders in academic institutions around the world contributed focused chapters on a broad array of topics such as: cell and tissue engineering (6 chapters), genetic and protein engineering (10 chapters), nanoengineering (10 chapters), biomedical instrumentation (4 chapters), and theranostics and other novel approaches (4 chapters). Each chapter is a stand-alone review that summarizes the state-of-the-art of the specific research area. Engineering in Translational Medicine gives readers a comprehensive and in-depth overview of a broad array of related research areas, making this an excellent reference book for scientists and students both new to engineering/translational medicine and currently working in this area.

Stand-alone XLIF

DEFF Research Database (Denmark)

Hansen, E. J.; Simony, A.; Hummel, Stefan

2015-01-01

and clinical/radiological results in 22 patients treated with XLIF procedure for DS or degenerative disc disease (DDD). Material and methods: 22 consecutive patients with DS underwent surgery with the XLIF stand-alone procedure, with follow-up of 24 months. Clinical outcome scores were collected. Complications......Introduction: Adult thoracolumbar degeneration is an increasing challenge in the aging population. With age the progressive degeneration of the discs leads to an asymmetric collapse and a thoracolumbar coronal plane deformity, a degenerative scoliosis (DS). Aim: To evaluate the complication rate......-year follow-up, with a 31.8% revision rate. Due to the high revision rate we recommend supplementary posterior instrumentation, to achieve a higher fusion rate. When considering XLIF-stand-alone procedure for DS or DDD without supplemental posterior instrumentation, only single-level disease should...

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.

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...

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...

Clinical outcome of stand-alone ALIF compared to posterior instrumentation for degenerative disc disease

DEFF Research Database (Denmark)

Udby, Peter M.; Bech-Azeddine, Rachid

2015-01-01

The objective of the article was to: a) present results from a case cohort pilot study comparing stand-alone ALIF and TLIF and, b) review the literature on studies comparing the clinical outcome of stand-alone ALIF with posterior instrumentation including TLIF or PLIF, in patients with disabling...... low back pain resulting from degenerative disc disease. ALIF surgery has previously been linked with certain high risk complications and unfavorable long term fusion results. Newer studies suggest that stand-alone ALIF can possibly be advantageous compared to other types of posterior instrumented...

Procedures for Determining the Performance of Stand-Alone Photovoltaic Systems; TOPICAL

International Nuclear Information System (INIS)

DeBlasio, R.; Durand, S.; Hansen, R.; Hutchinson, P.; Kroposki, B.; McNutt, P.; Rosenthal, A.; Thomas, M.

1999-01-01

This document provides the procedures for determining the performance of stand-alone PV systems. The procedures in this document provide a common approach for evaluating whether a given PV system is suitable to perform the function for which it was designed and manufactured to accomplish, and whether it will provide adequate power to run the load. These procedures cover small stand-alone PV systems. They cover complete outdoor system testing. Test results are valid only for the system that is tested

Stand-alone photovoltaic systems in the Netherlands. Evaluation of the market introduction

International Nuclear Information System (INIS)

Cloin, J.; Van Dijk, A.L.; Westra, C.A.

1999-08-01

The policy followed for stand-alone PV systems in the Netherlands is evaluated for the period 1997-1998. The world-wide powerful growth of the PV industry is not being followed by the increase in volume of implemented stand-alone PV systems in the Netherlands. This leads to the question whether the Dutch policy to stimulate stand-alone PV systems is effective. Recommendations on the use of communication as a strategic instrument are given, including the drawing up of a marketing plan. Other recommendations include increased transparency in the application for subsidies and a pro-active role of the Netherlands Agency for Energy and the Environment (Novem) in the contact with relevant market parties. The increased focus on product development aimed at the environmental benefits and general reliability of PV systems is recommended. 38 refs

The neutron instrument simulation package, NISP

International Nuclear Information System (INIS)

Seeger, P.A.; Daemen, L.L.

2004-01-01

The Neutron Instrument Simulation Package (NISP) performs complete source-to-detector simulations of neutron instruments, including neutrons that do not follow the expected path. The original user interface (MC( ) Web) is a web-based application, http://strider.lansce.lanl.gov/NISP/Welcome.html. This report describes in detail the newer standalone Windows version, NISP( ) Win. Instruments are assembled from menu-selected elements, including neutron sources, collimation and transport elements, samples, analyzers, and detectors. Magnetic field regions may also be specified for the propagation of polarized neutrons including spin precession. Either interface writes a geometry file that is used as input to the Monte Carlo engine (MC( ) Run) in the user's computer. Both the interface and the engine rely on a subroutine library, MCLIB. The package is completely open source. New features include capillary optics, temperature dependence of Al and Be, revised source files for ISIS, and visualization of neutron trajectories at run time. Also, a single-crystal sample type has been successfully imported from McStas (with more generalized geometry), demonstrating the capability of including algorithms from other sources, and NISP( ) Win may render the instrument in a virtual reality file. Results are shown for two instruments under development.

A control strategy for PV stand-alone applications

International Nuclear Information System (INIS)

Slouma, S; Baccar, H

2015-01-01

This paper proposes a stand-alone photovoltaic (PV) system study in domestic applications. Because of the decrease in power of photovoltaic module as a consequence of changes in solar radiation and temperature which affect the photovoltaic module performance, the design and control of DC-DC buck converter was proposed for providing power to the load from a photovoltaic source.In fact, the control of this converter is carried out with integrated MPPT (Maximum Power Point Tracking) algorithm which ensures a maximum energy generated by the PV arrays. Moreover, the output stage is composed by a battery energy storage system, dc-ac inverter, LCL filter which enables higher efficiency, low distortion ac waveforms and low leakage currents. The control strategy adopted is cascade control composed by two regulation loops.Simulations performed with PSIM software were able to validate the control system.The realization and testing of the photovoltaic system were achieved in the Photovoltaic laboratory of the Centre for Research and Energy Technologies at the Technopark Borj Cedria. Experimental results verify the effeciency of the proposed system

A control strategy for PV stand-alone applications

Science.gov (United States)

Slouma, S.; Baccar, H.

2015-04-01

This paper proposes a stand-alone photovoltaic (PV) system study in domestic applications. Because of the decrease in power of photovoltaic module as a consequence of changes in solar radiation and temperature which affect the photovoltaic module performance, the design and control of DC-DC buck converter was proposed for providing power to the load from a photovoltaic source.In fact, the control of this converter is carried out with integrated MPPT (Maximum Power Point Tracking) algorithm which ensures a maximum energy generated by the PV arrays. Moreover, the output stage is composed by a battery energy storage system, dc-ac inverter, LCL filter which enables higher efficiency, low distortion ac waveforms and low leakage currents. The control strategy adopted is cascade control composed by two regulation loops.Simulations performed with PSIM software were able to validate the control system.The realization and testing of the photovoltaic system were achieved in the Photovoltaic laboratory of the Centre for Research and Energy Technologies at the Technopark Borj Cedria. Experimental results verify the effeciency of the proposed system.

JAERI Fuel Cleanup System (J-FCU) stand-alone tritium test at the TSTA

International Nuclear Information System (INIS)

Konishi, Satoshi; Hayashi, Takumi; Inoue, Masahiko

1993-03-01

JAERI designed, fabricated, and installed the JAERI Fuel Cleanup System (J-FCU) as a subsystem of simulated fusion fuel loop at the TSTA. The main function of the J-FCU is to purify and to recover hydrogen isotopes from simulated plasma exhaust while exhausting tritium free impurities. After a lot of deuterium tests, a first tritium test of the J-FCU was performed with one gram of tritium at the TSTA on June 1991. Main purpose of this test was to evaluate the total integrity and function of the J-FCU system with a DT mixture. Through this test, the J-FCU was operated well and its function with tritium was demonstrated. This report describes the detail test results of the J-FCU first tritium test and discuss its functions by stand-alone mode. Residual tritium inventory of the J-FCU system was also discussed. (author)

Stand-Alone Photovoltaic System Operation with Energy Management and Fault Tolerant

International Nuclear Information System (INIS)

Jmashidpour, Ehsan; Poure, Philippe; Gholipour, E.; Saadate, Shahrokh

2017-01-01

This paper presents a stand-alone photovoltaic (PV) system with a fault tolerant operation capability. An energy management method is provided to keep the balance between produced and consumed energy instantaneously. As the storage element, an Ultra-Capacitor (UC) pack is used for facing high frequency variation of the load/source, and batteries are in charge of slow load /source variations. A Maximum Power Point Tracking (MPPT) algorithm is applied to control the boost converter of the PV source to achieve the maximum power. In order to improve the micro-grid service continuity and reliability, a fast fault diagnosis method based on the converter current shape for PV source is applied. Finally, the validity of the proposed energy management and the fault diagnosis method is confirmed by the simulation and experimental results. (author)

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)

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)

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.

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

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.

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.

Study of Stand-Alone Microgrid under Condition of Faults on Distribution Line

Science.gov (United States)

Malla, S. G.; Bhende, C. N.

2014-10-01

The behavior of stand-alone microgrid is analyzed under the condition of faults on distribution feeders. During fault since battery is not able to maintain dc-link voltage within limit, the resistive dump load control is presented to do so. An inverter control is proposed to maintain balanced voltages at PCC under the unbalanced load condition and to reduce voltage unbalance factor (VUF) at load points. The proposed inverter control also has facility to protect itself from high fault current. Existing maximum power point tracker (MPPT) algorithm is modified to limit the speed of generator during fault. Extensive simulation results using MATLAB/SIMULINK established that the performance of the controllers is quite satisfactory under different fault conditions as well as unbalanced load conditions.

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.

Stand-alone induction generators for small water power schemes

Energy Technology Data Exchange (ETDEWEB)

Harvey, Adam [Intermediate Technology Development Group, Rugby (United Kingdom); Smith, Nigel [Smith Associates, Nottingham (United Kingdom)

1996-04-01

Conventional technology for isolated power generation is the synchronous generator. Using stand-alone induction generators has proved to have tremendous advantages in remote regions of developing countries, where electricity has significant social benefits. (author)

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)

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.

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.

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.

A review on recent size optimization methodologies for standalone solar and wind hybrid renewable energy system

International Nuclear Information System (INIS)

Al-falahi, Monaaf D.A.; Jayasinghe, S.D.G.; Enshaei, H.

2017-01-01

Highlights: • Possible combinations and configurations for standalone PV-WT HES were discussed. • Most recently used assessment parameters for standalone PV-WT HES were explained. • Optimization algorithms and software tools were comprehensively reviewed. • The recent trend of using hybrid algorithms over single algorithms was discussed. • Optimization algorithms for sizing standalone PV-WT HES were critically compared. - Abstract: Electricity demand in remote and island areas are generally supplied by diesel or other fossil fuel based generation systems. Nevertheless, due to the increasing cost and harmful emissions of fossil fuels there is a growing trend to use standalone hybrid renewable energy systems (HRESs). Due to the complementary characteristics, matured technologies and availability in most areas, hybrid systems with solar and wind energy have become the popular choice in such applications. However, the intermittency and high net present cost are the challenges associated with solar and wind energy systems. In this context, optimal sizing is a key factor to attain a reliable supply at a low cost through these standalone systems. Therefore, there has been a growing interest to develop algorithms for size optimization in standalone HRESs. The optimal sizing methodologies reported so far can be broadly categorized as classical algorithms, modern techniques and software tools. Modern techniques, based on single artificial intelligence (AI) algorithms, are becoming more popular than classical algorithms owing to their capabilities in solving complex optimization problems. Moreover, in recent years, there has been a clear trend to use hybrid algorithms over single algorithms mainly due to their ability to provide more promising optimization results. This paper aims to present a comprehensive review on recent developments in size optimization methodologies, as well as a critical comparison of single algorithms, hybrid algorithms, and software tools

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.

Performance evaluation of a stand-alone solar dish Stirling system for power generation suitable for off-grid rural electrification

International Nuclear Information System (INIS)

Kadri, Y.; Hadj Abdallah, H.

2016-01-01

Highlights: • Estimation of the output temperature reached by 2 m parabolic dish. • Output power estimation for uncontrollable load was done using Matlab®. • Validation of the proposed system under Tunisian conditions for rural electrification. - Abstract: The development of green power generation such as solar systems that have become a great interest for several countries especially for Tunisia as it presents a significant solar potential. For this purpose, this research has investigated the feasibility and the performance of standalone solar dish/Stirling micro generation plant for rural electrification. The considered hybrid system includes solar dish/Stirling engine, permanent magnet synchronous generator and a storage battery. To start with, thermal modeling and simulation have been carried out using Matlab® for the solar-driven Stirling heat engine system composed of an Alpha Stirling engine, a solar collector and a receiver, in which the radiation, convection, conduction and radiation heat loss have been taken into consideration for the selected design. For numerical validation of the receiver’s thermal model, simulation results were compared with experimental measurements reported for the EURODISH system with a reasonable degree of agreement. Second, the generated torque driving the generator has been estimated by the Adiabatic model of URIELI based on the classical fourth-order Runge-Kutta. In order for an autonomous control, the dish generator is connected to the load via power electronic converters where the bidirectional power flow is possible by the use of two voltage source converters in a back-to-back configuration. They are referred to as Stirling/generator side converter and load side inverter, both are oriented control by space vector pulse width modulation. In this context, the Stirling side converter is used to adjust the synchronous generator while the inverter controls the power flow between the direct current bus and the

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

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.

Sensorless direct voltage control of the stand-alone brushless doubly-fed generator

DEFF Research Database (Denmark)

Liu, Yi; Xu, Wei; Xiong, Fei

2017-01-01

The conventional stand-alone brushless doubly-fed generator (BDFG) control strategies need the feedback from the rotor position or speed sensors, which can reduce system reliability and increase the cost and axial volume of the machine. In this paper, a sensorless direct voltage control (DVC) str......) strategy is presented for the stand-alone BDFG. The satisfactory dynamic performance is verified by experimental results under four kinds of typical operation conditions. Besides, the proposed control strategy is robust due to no generator parameters being required....

A soil-canopy scheme for use in a numerical model of the atmosphere: 1D stand-alone model

Science.gov (United States)

Kowalczyk, E. A.; Garratt, J. R.; Krummel, P. B.

We provide a detailed description of a soil-canopy scheme for use in the CSIRO general circulation models (GCMs) (CSIRO-4 and CSIRO-9), in the form of a one-dimensional stand-alone model. In addition, the paper documents the model's ability to simulate realistic surface fluxes by comparison with mesoscale model simulations (involving more sophisticated soil and boundary-layer treatments) and observations, and the diurnal range in surface quantities, including extreme maximum surface temperatures. The sensitivity of the model to values of the surface resistance is also quantified. The model represents phase 1 of a longer-term plan to improve the atmospheric boundary layer (ABL) and surface schemes in the CSIRO GCMs.

Introducing GEOPHIRES v2.0: Updated Geothermal Techno-Economic Simulation Tool

Energy Technology Data Exchange (ETDEWEB)

Beckers, Koenraad J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); McCabe, Kevin [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-02-14

This paper presents an updated version of the geothermal techno-economic simulation tool GEOPHIRES (GEOthermal energy for Production of Heat and electricity ('IR') Economically Simulated). GEOPHIRES combines engineering models of the reservoir, wellbores, and surface plant facilities of a geothermal plant with an economic model to estimate the capital and operation and maintenance costs, lifetime energy production, and overall levelized cost of energy. The available end-use options are electricity, direct-use heat, and cogeneration. The main updates in the new version include conversion of the source code from FORTRAN to Python, the option to import temperature data (e.g., measured or from stand-alone reservoir simulator), updated cost correlations, and more flexibility in selecting the time step and number of injection and production wells. In this paper, we provide an overview of all the updates and two case studies to illustrate the tool's new capabilities.

Stand-alone solutions, computer networks and extern communications

International Nuclear Information System (INIS)

Tarschisch, H.

1988-01-01

The advantages of local networks over stand-alone solutions are presented. Of the local networks (LAN), two are presently at the center of attention: the bus and the ring. ETHERNET and the IBM-Token-Ring are described as typical examples. Access to public networks, especially TELEPAC and ISDN, is discussed. 12 figs

Standalone General Purpose Data Logger Design and Implementation

African Journals Online (AJOL)

This paper describes the design of a general purpose data logger that is compatible with a variety of transducers, potentially permitting the measurement and recording of a wide range of phenomena. The recorded data can be retrieved to a PC via an RS-232 serial port. The standalone general purpose data logger ...

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

A New Approach for Optimal Sizing of Standalone Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Tamer Khatib

2012-01-01

Full Text Available This paper presents a new method for determining the optimal sizing of standalone photovoltaic (PV system in terms of optimal sizing of PV array and battery storage. A standalone PV system energy flow is first analysed, and the MATLAB fitting tool is used to fit the resultant sizing curves in order to derive general formulas for optimal sizing of PV array and battery. In deriving the formulas for optimal sizing of PV array and battery, the data considered are based on five sites in Malaysia, which are Kuala Lumpur, Johor Bharu, Ipoh, Kuching, and Alor Setar. Based on the results of the designed example for a PV system installed in Kuala Lumpur, the proposed method gives satisfactory optimal sizing results.

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

A compact seven switches topology and reduced DC-link capacitor size for single-phase stand-alone PV system with hybrid energy storages

DEFF Research Database (Denmark)

Liu, Xiong; Wang, Peng; Loh, Poh Chiang

2011-01-01

Single-phase stand-alone PV system is suitable for household applications in remote area. Hybrid battery/ultra-capacitor energy storage can reduce charge and discharge cycles and avoid deep discharges of battery. This paper proposes a compact seven switches structure for stand-alone PV system......, which otherwise needs nine switches configuration, inclusive of one switch for boost converter, four switches for single-phase inverter and four switches for two DC/DC converters of battery and ultra-capacitor. It is well-known that a bulky DC-link capacitor is always required to absorb second......-order harmonic current caused by single-phase inverter. In the proposed compact topology, a small size DC-link capacitor can achieve the same function through charging/discharging control of ultra-capacitor to mitigate second-order ripple current. Simulation results are provided to validate the effectiveness...

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...

COCOA: Simulating Observations of Star Cluster Simulations

Science.gov (United States)

Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Dalessandro, Emanuele

2017-03-01

COCOA (Cluster simulatiOn Comparison with ObservAtions) creates idealized mock photometric observations using results from numerical simulations of star cluster evolution. COCOA is able to present the output of realistic numerical simulations of star clusters carried out using Monte Carlo or N-body codes in a way that is useful for direct comparison with photometric observations. The code can simulate optical observations from simulation snapshots in which positions and magnitudes of objects are known. The parameters for simulating the observations can be adjusted to mimic telescopes of various sizes. COCOA also has a photometry pipeline that can use standalone versions of DAOPHOT (ascl:1104.011) and ALLSTAR to produce photometric catalogs for all observed stars.

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…

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.

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

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.

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.

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.

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.

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

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...

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

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)

Solar pv fed stand-alone excitation system of a synchronous machine for reactive power generation

Science.gov (United States)

Sudhakar, N.; Jain, Siddhartha; Jyotheeswara Reddy, K.

2017-11-01

This paper presents a model of a stand-alone solar energy conversion system based on synchronous machine working as a synchronous condenser in overexcited state. The proposed model consists of a Synchronous Condenser, a DC/DC boost converter whose output is fed to the field of the SC. The boost converter is supplied by the modelled solar panel and a day time variable irradiance is fed to the panel during the simulation time. The model also has one alternate source of rechargeable batteries for the time when irradiance falls below a threshold value. Also the excess power produced when there is ample irradiance is divided in two parts and one is fed to the boost converter while other is utilized to recharge the batteries. A simulation is done in MATLAB-SIMULINK and the obtained results show the utility of such modelling for supplying reactive power is feasible.

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....

The stand-alone test and decreasing serial cost sharing

DEFF Research Database (Denmark)

Hougaard, Jens Leth; Thorlund-Petersen, Lars

2000-01-01

The rule of decreasing serial cost sharing defined in de Frutos [1] over the class of concave cost functions may violate the important stand-alone test. Sufficient conditions for the test to be satisfied are given, in terms of individual rationality as well as coalitional stability...

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....

Stand-alone version of the 11kW Gaia wind turbine

Energy Technology Data Exchange (ETDEWEB)

Bindner, H.; Rosas, P.A.C.; Teodorescu, R.; Blaabjerg, F.

2004-09-15

This report describes the development of a stand-alone version of the 11kW Gaia wind turbine. Various possible configurations are investigated and a configuration using a back-to-back converter is chosen. A model is developed for controller design of the fast controllers of the unit. Controllers are designed and a prototype is built for testing. The report documents the performance of the prototype through measurements done on the full scale prototype installed in a test facility where it has been tested both as a standalone unit and in parallel with a diesel genset. For system wide power quality assessment and controller design a dynamic performance assessment model has been developed. (au)

Harmonics reduction in standalone DFIG-DC system by shunt active ...

Indian Academy of Sciences (India)

Himanshu Misra

2018-05-22

May 22, 2018 ... Doubly fed induction generator; standalone; DC voltage regulation; shunt active filter; harmonics ... Operation and design issue of DFIG in DC-net interface is ...... control systems for the operation of DFIGs in wind energy.

Security and computer forensics in web engineering education

OpenAIRE

Glisson, W.; Welland, R.; Glisson, L.M.

2010-01-01

The integration of security and forensics into Web Engineering curricula is imperative! Poor security in web-based applications is continuing to cost organizations millions and the losses are still increasing annually. Security is frequently taught as a stand-alone course, assuming that security can be 'bolted on' to a web application at some point. Security issues must be integrated into Web Engineering processes right from the beginning to create secure solutions and therefore security shou...

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

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.

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.

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.

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.

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

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)

Monitoring of standalone photovoltaic systems applied to rural electrification areas; Avaliacao de desempenho e identificacao de falhas em sistemas fotovoltaicos isolados aplicados a eletrificacao rural

Energy Technology Data Exchange (ETDEWEB)

Machado-Neto, L. V. B.; Cabral, C. V. T.; Oliveira-Filho, D.; Diniz, A. s. A. C.

2004-07-01

The sustainability of standalone photovoltaic systems passes through an accompaniment of the systems installed in the field. To subsidize this accompaniment it had been developed procedures for monitoring a similar system in laboratory. The standalone photovoltaic system monitored is similar to the systems installed by Companhia Energetica de Minas Gerais - CEMIG in the schools of isolated communities, inside the Solar Light Program. The system was simulated and the aims were to optimize the project and carry out a comparative study with the monitored results. The assembly procedure of the facility consisted of the implantation of the sensors, installation of acquisition boards and development of the monitoring program. The results presented here will allow the development of a program of preventive maintenance of the systems installed by CEMIG. (Author)

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.

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

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

Modelling of fluid-solid interaction using two stand-alone codes

CSIR Research Space (South Africa)

Grobler, Jan H

2010-01-01

Full Text Available A method is proposed for the modelling of fluid-solid interaction in applications where fluid forces dominate. Data are transferred between two stand-alone codes: a dedicated computational fluid dynamics (CFD) code capable of free surface modelling...

Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems

Energy Technology Data Exchange (ETDEWEB)

1980-07-01

This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

Environmental/Climatic Effect on Stand-Alone Solar Energy Supply ...

African Journals Online (AJOL)

This paper investigates the climatic eects and environmental variations on the performance of a stand-alone photovoltaic system. The eects of partial shading with dierent climate conditions and load resistance variations were examined. A survey of some of the work done in this eld of environmental eect on solar panel was ...

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.

Biomechanical comparison of a new stand-alone anterior lumbar interbody fusion cage with established fixation techniques – a three-dimensional finite element analysis

Directory of Open Access Journals (Sweden)

Hsieh Pang-Hsing

2008-06-01

Full Text Available Abstract Background Initial promise of a stand-alone interbody fusion cage to treat chronic back pain and restore disc height has not been realized. In some instances, a posterior spinal fixation has been used to enhance stability and increase fusion rate. In this manuscript, a new stand-alone cage is compared with conventional fixation methods based on the finite element analysis, with a focus on investigating cage-bone interface mechanics and stress distribution on the adjacent tissues. Methods Three trapezoid 8° interbody fusion cage models (dual paralleled cages, a single large cage, or a two-part cage consisting of a trapezoid box and threaded cylinder were created with or without pedicle screws fixation to investigate the relative importance of the screws on the spinal segmental response. The contact stress on the facet joint, slip displacement of the cage on the endplate, and rotational angle of the upper vertebra were measured under different loading conditions. Results Simulation results demonstrated less facet stress and slip displacement with the maximal contact on the cage-bone interface. A stand-alone two-part cage had good slip behavior under compression, flexion, extension, lateral bending and torsion, as compared with the other two interbody cages, even with the additional posterior fixation. However, the two-part cage had the lowest rotational angles under flexion and torsion, but had no differences under extension and lateral bending. Conclusion The biomechanical benefit of a stand-alone two-part fusion cage can be justified. This device provided the stability required for interbody fusion, which supports clinical trials of the cage as an alternative to circumferential fixations.

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.

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

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.

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)

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...

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)

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)

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.

Availability model of stand-alone photovoltaic system

Science.gov (United States)

Mazurek, G.

2017-08-01

In this paper we present a simple, empirical model of stand-alone photovoltaic power system availability. The model is a final result of five-year long studies and ground measurements of solar irradiation carried out in Central Europe. The obtained results facilitate sizing of PV modules that have to be installed with taking into account system's availability level in each month of a year. The model can be extended to different geographical locations, with help of local meteorological data or solar irradiation datasets derived from satellite measurements.

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.

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.

Energy management system for stand-alone diesel-wind-biomass microgrid with energy storage system

International Nuclear Information System (INIS)

Wang, Chengshan; Liu, Yixin; Li, Xialin; Guo, Li; Qiao, Lei; Lu, Hai

2016-01-01

An energy management system for stand-alone microgrid composed of diesel generators, wind turbine generator, biomass generator and an ESS (energy storage system) is proposed in this paper. Different operation objectives are achieved by a hierarchical control structure with different time scales. Firstly, the optimal schedules of the diesel generators, wind turbine generator, biomass generator and ESS are determined fifteen minutes ahead according to the super short-term forecast of load and wind speed in the optimal scheduling layer. Comprehensive analysis which takes the uncertainty of load and wind speed into account is conducted in this layer to minimize the operation cost of the system and ensure a desirable range of the state of charge of the ESS. Secondly, the operation points of each unit are regulated dynamically to guarantee real-time power balance and safety range of diesel generation in the real-time control layer, based on which the response capability when suffering significant forecast deviation and other emergency issues, e.g. sudden load-up can be improved. Finally, the effectiveness of the proposed energy management strategy is verified on an RT-Lab based real-time simulation platform, and the economic performances with different types of ESS are analyzed as well. - Highlights: • A hierarchical control strategy is proposed for a stand-alone microgrid. • The uncertainties of load and wind speed have been considered. • Better economic performance and high reliability of the system can be achieved. • The influences of different energy storage systems have been analyzed.

Dual-fuel natural gas/diesel engines: Technology, performance, and emissions

Science.gov (United States)

Turner, S. H.; Weaver, C. S.

1994-11-01

An investigation of current dual-fuel natural gas/diesel engine design, performance, and emissions was conducted. The most pressing technological problems associated with dual-fuel engine use were identified along with potential solutions. It was concluded that dual-fuel engines can achieve low NO(sub x) and particulate emissions while retaining fuel-efficiency and BMEP levels comparable to those of diesel engines. The investigation also examined the potential economic impact of dual-fuel engines in diesel-electric locomotives, marine vessels, farm equipment, construction, mining, and industrial equipment, and stand-alone electricity generation systems. Recommendations for further additional funding to support research, development, and demonstration in these applications were then presented.

The Method of a Standalone Functional Verifying Operability of Sonar Control Systems

Directory of Open Access Journals (Sweden)

A. A. Sotnikov

2014-01-01

Full Text Available This article describes a method of standalone verifying sonar control system, which is based on functional checking of control system operability.The main features of realized method are a development of the valid mathematic model for simulation of sonar signals at the point of hydroacoustic antenna, a valid representation of the sonar control system modes as a discrete Markov model, providing functional object verification in real time mode.Some ways are proposed to control computational complexity in case of insufficient computing resources of the simulation equipment, namely the way of model functionality reduction and the way of adequacy reduction.Experiments were made using testing equipment, which was developed by department of Research Institute of Information Control System at Bauman Moscow State Technical University to verify technical validity of industrial sonar complexes.On-board software was artificially changed to create malfunctions in functionality of sonar control systems during the verifying process in order to estimate verifying system performances.The method efficiency was proved by the theory and experiment results in comparison with the basic methodology of verifying technical systems.This method could be also used in debugging of on-board software of sonar complexes and in development of new promising algorithms of sonar signal processing.

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

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

Technical Study of a Standalone Photovoltaic-Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia.

Science.gov (United States)

Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

2015-01-01

Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions.

Technical Study of a Standalone Photovoltaic–Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia

Science.gov (United States)

Samrat, Nahidul Hoque; Ahmad, Norhafizan; Choudhury, Imtiaz Ahmed; Taha, Zahari

2015-01-01

Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions. PMID:26121032

Technical Study of a Standalone Photovoltaic-Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia.

Directory of Open Access Journals (Sweden)

Nahidul Hoque Samrat

Full Text Available Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions.

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.

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.

X-ray microbeam stand-alone facility for cultured cells irradiation

Energy Technology Data Exchange (ETDEWEB)

Bożek, Sebastian, E-mail: sebastian.bozek@yahoo.com [Jagiellonian University Medical College, Department of Pharmaceutical Biophysics, Krakow (Poland); Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M. [Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow (Poland)

2017-03-01

Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

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.

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.

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 ...

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.

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.

Numerical Simulation of the Effect of 3D Needle Movement on Cavitation and Spray Formation in a Diesel Injector

Science.gov (United States)

Mandumpala Devassy, B.; Edelbauer, W.; Greif, D.

2015-12-01

Cavitation and its effect on spray formation and its dispersion play a crucial role in proper engine combustion and controlled emission. This study focuses on these effects in a typical common rail 6-hole diesel injector accounting for 3D needle movement and flow compressibility effects. Coupled numerical simulations using 1D and 3D CFD codes are used for this investigation. Previous studies in this direction have already presented a detailed structure of the adopted methodology. Compared to the previous analysis, the present study investigates the effect of 3D needle movement and cavitation on the spray formation for pilot and main injection events for a typical diesel engine operating point. The present setup performs a 3D compressible multiphase simulation coupled with a standalone 1D high pressure flow simulation. The simulation proceeds by the mutual communication between 1D and 3D solvers. In this work a typical common rail injector with a mini-sac nozzle is studied. The lateral and radial movement of the needle and its effect on the cavitation generation and the subsequent spray penetration are analyzed. The result indicates the effect of compressibility of the liquid on damping the needle forces, and also the difference in the spray penetration levels due to the asymmetrical flow field. Therefore, this work intends to provide an efficient and user-friendly engineering tool for simulating a complete fuel injector including spray propagation.

Numerical Simulation of the Effect of 3D Needle Movement on Cavitation and Spray Formation in a Diesel Injector

International Nuclear Information System (INIS)

Devassy, B Mandumpala; Edelbauer, W; Greif, D

2015-01-01

Cavitation and its effect on spray formation and its dispersion play a crucial role in proper engine combustion and controlled emission. This study focuses on these effects in a typical common rail 6-hole diesel injector accounting for 3D needle movement and flow compressibility effects. Coupled numerical simulations using 1D and 3D CFD codes are used for this investigation. Previous studies in this direction have already presented a detailed structure of the adopted methodology. Compared to the previous analysis, the present study investigates the effect of 3D needle movement and cavitation on the spray formation for pilot and main injection events for a typical diesel engine operating point. The present setup performs a 3D compressible multiphase simulation coupled with a standalone 1D high pressure flow simulation. The simulation proceeds by the mutual communication between 1D and 3D solvers. In this work a typical common rail injector with a mini-sac nozzle is studied. The lateral and radial movement of the needle and its effect on the cavitation generation and the subsequent spray penetration are analyzed. The result indicates the effect of compressibility of the liquid on damping the needle forces, and also the difference in the spray penetration levels due to the asymmetrical flow field. Therefore, this work intends to provide an efficient and user-friendly engineering tool for simulating a complete fuel injector including spray propagation. (paper)

Stand-alone and Interdisciplinary Course Design for Engineering Education for Sustainable Development

DEFF Research Database (Denmark)

Arsat, M.; Holgaard, Jette Egelund; de Graaff, Erik

discipline or to fit across programmes. At Aalborg University (AAU), Denmark, which has a long tradition of problem based learning (PBL), a comprehensive sustainability course has been introduced to fit all students not at least across programmes but also across faculties of engineering, humanities...

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.

Stand-alone power systems for the future: Optimal design, operation and control of solar-hydrogen energy systems

Energy Technology Data Exchange (ETDEWEB)

Ulleberg, Oeystein

1998-12-31

This thesis gives a systematic review of the fundamentals of energy systems, the governing physical and chemical laws related to energy, inherent characteristics of energy system, and the availability of the earth`s energy. It shows clearly why solar-hydrogen systems are one of the most viable options for the future. The main subject discussed is the modelling of SAPS (Stand-Alone Power Systems), with focus on photovoltaic-hydrogen energy systems. Simulation models for a transient simulation program are developed for PV-H{sub 2} components, including models for photovoltaics, water electrolysis, hydrogen storage, fuel cells, and secondary batteries. A PV-H{sub 2} demonstration plant in Juelich, Germany, is studied as a reference plant and the models validated against data from this plant. Most of the models developed were found to be sufficiently accurate to perform short-term system simulations, while all were more than accurate enough to perform long-term simulations. Finally, the verified simulation models are used to find the optimal operation and control strategies of an existing PV-H{sub 2} system. The main conclusion is that the simulation methods can be successfully used to find optimal operation and control strategies for a system with fixed design, and similar methods could be used to find alternative system designs. 148 refs., 78 figs., 31 tabs.

Stand-alone power systems for the future: Optimal design, operation and control of solar-hydrogen energy systems

Energy Technology Data Exchange (ETDEWEB)

Ulleberg, Oeystein

1999-12-31

This thesis gives a systematic review of the fundamentals of energy systems, the governing physical and chemical laws related to energy, inherent characteristics of energy system, and the availability of the earth`s energy. It shows clearly why solar-hydrogen systems are one of the most viable options for the future. The main subject discussed is the modelling of SAPS (Stand-Alone Power Systems), with focus on photovoltaic-hydrogen energy systems. Simulation models for a transient simulation program are developed for PV-H{sub 2} components, including models for photovoltaics, water electrolysis, hydrogen storage, fuel cells, and secondary batteries. A PV-H{sub 2} demonstration plant in Juelich, Germany, is studied as a reference plant and the models validated against data from this plant. Most of the models developed were found to be sufficiently accurate to perform short-term system simulations, while all were more than accurate enough to perform long-term simulations. Finally, the verified simulation models are used to find the optimal operation and control strategies of an existing PV-H{sub 2} system. The main conclusion is that the simulation methods can be successfully used to find optimal operation and control strategies for a system with fixed design, and similar methods could be used to find alternative system designs. 148 refs., 78 figs., 31 tabs.

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.

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.

Environmental impacts of producing bioethanol and biobased lactic acid from standalone and integrated biorefineries using a consequential and an attributional life cycle assessment approach

DEFF Research Database (Denmark)

Parajuli, Ranjan; Knudsen, Marie Trydeman; Birkved, Morten

2017-01-01

: a standalone system producing bioethanol from winter wheat-straw (system A), a standalone system producing biobased lactic acid from alfalfa (system B), and an integrated biorefinery system (system C) combining the two standalone systems and producing both bioethanol and lactic acid. The synergy...

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.

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.

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.

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.

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.

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.

A Three-Port Topology Comparison for a Low Power Stand-Alone Photovoltaic System

DEFF Research Database (Denmark)

Mira Albert, Maria del Carmen; Knott, Arnold; Andersen, Michael A. E.

2014-01-01

Three-port converter (TPC) topologies for renewable energy systems aim to provide higher efficiency and power density than conventional cascaded structures. This work proposes an analytical comparison of different TPC topologies for a photovoltaic LED lamp stand-alone system. A comparison using c...... component stress factor (CSF) is performed, which gives a quantitative measure of the performance of the converter. The candidate topologies are compared to each other according to a defined LED lighting strategy and a solar irradiation profile.......Three-port converter (TPC) topologies for renewable energy systems aim to provide higher efficiency and power density than conventional cascaded structures. This work proposes an analytical comparison of different TPC topologies for a photovoltaic LED lamp stand-alone system. A comparison using...

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…

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

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...

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.

A maximum power point tracking scheme for a 1kw stand-alone ...

African Journals Online (AJOL)

A maximum power point tracking scheme for a 1kw stand-alone solar energy based power supply. ... Nigerian Journal of Technology ... A method for efficiently maximizing the output power of a solar panel supplying a load or battery bus under ...

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.

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.

Effects of Medical Device Regulations on the Development of Stand-Alone Medical Software: A Pilot Study.

Science.gov (United States)

Blagec, Kathrin; Jungwirth, David; Haluza, Daniela; Samwald, Matthias

2018-01-01

Medical device regulations which aim to ensure safety standards do not only apply to hardware devices but also to standalone medical software, e.g. mobile apps. To explore the effects of these regulations on the development and distribution of medical standalone software. We invited a convenience sample of 130 domain experts to participate in an online survey about the impact of current regulations on the development and distribution of medical standalone software. 21 respondents completed the questionnaire. Participants reported slight positive effects on usability, reliability, and data security of their products, whereas the ability to modify already deployed software and customization by end users were negatively impacted. The additional time and costs needed to go through the regulatory process were perceived as the greatest obstacles in developing and distributing medical software. Further research is needed to compare positive effects on software quality with negative impacts on market access and innovation. Strategies for avoiding over-regulation while still ensuring safety standards need to be devised.

Control of a Stand-Alone Variable Speed Wind Energy Supply System †

Directory of Open Access Journals (Sweden)

Mohamed M. Hamada

2013-04-01

Full Text Available This paper presents a simple control strategy for the operation of a variable speed stand-alone wind turbine with a permanent magnet synchronous generator (PMSG. The PMSG is connected to a three phase resistive load through a switch mode rectifier and a voltage source inverter. Control of the generator side converter is used to achieve maximum power extraction from the available wind power. Control of the DC-DC bidirectional buck-boost converter, which is connected between batteries bank and DC-link voltage, is used to maintain the DC-link voltage at a constant value. It is also used to make the batteries bank stores the surplus of wind energy and supplies this energy to the load during a wind power shortage. The load side voltage source inverter uses a relatively complex vector control scheme to control the output load voltage in terms of amplitude and frequency. The control strategy works under wind speed variation as well as with variable load. Extensive simulation results have been performed using MATLAB/SIMULINK.

Stand-alone excitation synchronous wind power generators with power flow management strategy

Directory of Open Access Journals (Sweden)

Tzuen-Lih Chern

2014-09-01

Full Text Available This study presents a stand-alone excitation synchronous wind power generator (SESWPG with power flow management strategy (PFMS. The rotor speed of the excitation synchronous generator tracks the utility grid frequency by using servo motor tracking technologies. The automatic voltage regulator governs the exciting current of generator to achieve the control goals of stable voltage. When wind power is less than the needs of the consumptive loading, the proposed PFMS increases motor torque to provide a positive power output for the loads, while keeping the generator speed constant. Conversely, during the periods of wind power greater than output loads, the redundant power of generator production is charged to the battery pack and the motor speed remains constant with very low power consumption. The advantage of the proposed SESWPG is that the generator can directly output stable alternating current (AC electricity without using additional DC–AC converters. The operation principles with software simulation for the system are described in detail. Experimental results of a laboratory prototype are shown to verify the feasibility of the system.

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%.

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.

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...

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

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.

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

A practical multi-objective design approach for optimum exhaust heat recovery from hybrid stand-alone PV-diesel power systems

International Nuclear Information System (INIS)

Yousefi, Moslem; Kim, Joong Hoon; Hooshyar, Danial; Yousefi, Milad; Sahari, Khairul Salleh Mohamed; Ahmad, Rodina Binti

2017-01-01

Highlights: • Heat recovery exchanger is designed based on practical conditions of a hybrid power system. • Off-the-grid electricity system modeling and analysis using micro-grid analysis software HOMER. • NSGA-II is used for the multi-objective design optimization task. • A new local search is proposed to incorporate the engineering knowledge in NSGA-II. • The proposed approach outperforms the existing ones. - Abstract: Integration of solar power and diesel generators (DGs) together with battery storage has proven to be an efficient choice for stand-alone power systems (SAPS). For higher energy efficiency, heat recovery from exhaust gas of the DG can also be employed to supply all or a portion of the thermal energy demand. Although the design of such heat recovery systems (HRSs) has been studied, the effect of solar power integration has not been taken into account. In this paper, a new approach for practical design of these systems based on varying engine loads is presented. Fast and elitist non-dominated sorting genetic algorithm (NSGA-II) equipped with a novel local search was used for the design process, considering conflicting objectives of annual energy recovery and total cost of the system, and six design variables. An integrated power system, designed for a remote SAPS, was used to evaluate the design approach. The optimum power supply system was first designed using the commercial software Hybrid Optimization of Multiple Energy Resources (HOMER), based on power demand and global solar energy in the region. Heat recovery design was based on the outcome of HOMER for DG hourly load, considering different power scenarios. The proposed approach improves the annual heat recovery of the PV/DG/battery system by 4%, PV/battery by 1.7%, and stand-alone DG by 1.8% when compared with a conventional design based on nominal DG load. The results prove that the proposed approach is effective and that load calculations should be taken into account prior to

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

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].

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.

Optimal sizing method for stand-alone photovoltaic power systems

Energy Technology Data Exchange (ETDEWEB)

Groumpos, P P; Papageorgiou, G

1987-01-01

The total life-cycle cost of stand-alone photovoltaic (SAPV) power systems is mathematically formulated. A new optimal sizing algorithm for the solar array and battery capacity is developed. The optimum value of a balancing parameter, M, for the optimal sizing of SAPV system components is derived. The proposed optimal sizing algorithm is used in an illustrative example, where a more economical life-cycle cost has bene obtained. The question of cost versus reliability is briefly discussed.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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.

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

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

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.

Leadership in Dental Hygiene Degree Completion Programs: A Pilot Study Comparing Stand-Alone Leadership Courses and Leadership-Infused Curricula.

Science.gov (United States)

Smith, Michelle L; Gurenlian, JoAnn R; Freudenthal, Jacqueline J; Farnsworth, Tracy J

2016-05-01

The aim of this study was to define the extent to which leadership and leadership skills are taught in dental hygiene degree completion programs by comparing stand-alone leadership courses/hybrid programs with programs that infuse leadership skills throughout the curricula. The study involved a mixed-methods approach using qualitative and quantitative data. Semi-structured interviews were conducted with program directors and faculty members who teach a stand-alone leadership course, a hybrid program, or leadership-infused courses in these programs. A quantitative comparison of course syllabi determined differences in the extent of leadership content and experiences between stand-alone leadership courses and leadership-infused curricula. Of the 53 U.S. dental hygiene programs that offer degree completion programs, 49 met the inclusion criteria, and 19 programs provided course syllabi. Of the program directors and faculty members who teach a stand-alone leadership course or leadership-infused curriculum, 16 participated in the interview portion of the study. The results suggested that competencies related to leadership were not clearly defined or measurable in current teaching. Reported barriers to incorporating a stand-alone leadership course included overcrowded curricula, limited qualified faculty, and lack of resources. The findings of this study provide a synopsis of leadership content and gaps in leadership education for degree completion programs. Suggested changes included defining a need for leadership competencies and providing additional resources to educators such as courses provided by the American Dental Education Association and the American Dental Hygienists' Association.

Integral type small PWR with stand-alone safety

International Nuclear Information System (INIS)

Makihara, Yoshiaki

2001-01-01

A feasibility study is achieved on an integral type small PWR with stand-alone safety. It is designed to have the following features. (1) The coolant does not leak out at any accidental condition. (2) The fuel failure does never occur while it is supposed on the large scale PWR at the design base accident. (3) At any accidental condition the safety is secured without any support from the outside (stand-alone safety secure). (4) It has self-regulating characteristics and easy controllability. The above features can be satisfied by integrate the steam generator and CRDM in the reactor vessel while the pipe line break has to be considered on the conventional PWR. Several counter measures are planned to satisfy the above features. The economy feature is also attained by several simplifications such as (1) elimination of main coolant piping and pressurizer by the integration of primary cooling system and self-pressurizing, (2) elimination of RCP by application of natural circulating system, (3) elimination of ECCS and accumulator by application of static safety system, (4) large scale volume reduction of the container vessel by application of integrated primary cooling system, (5) elimination of boric acid treatment by deletion of chemical shim. The long operation period such as 10 years can be attained by the application of Gd fuel in one batch refueling. The construction period can be shortened by the standardizing the design and the introduction of modular component system. Furthermore the applicability of the reduced modulation core is also considered. (K. Tsuchihashi)

Stand-Alone Personalized Normative Feedback for College Student Drinkers: A Meta-Analytic Review, 2004 to 2014.

Directory of Open Access Journals (Sweden)

Keri B Dotson

Full Text Available Norms clarification has been identified as an effective component of college student drinking interventions, prompting research on norms clarification as a single-component intervention known as Personalized Normative Feedback (PNF. Previous reviews have examined PNF in combination with other components but not as a stand-alone intervention.To investigate the degree to which computer-delivered stand-alone personalized normative feedback interventions reduce alcohol consumption and alcohol-related harms among college students and to compare gender-neutral and gender-specific PNF.Electronic databases were searched systematically through November 2014. Reference lists were reviewed manually and forward and backward searches were conducted.Outcome studies that compared computer-delivered, stand-alone PNF intervention with an assessment only, attention-matched, or active treatment control and reported alcohol use and harms among college students.Between-group effect sizes were calculated as the standardized mean difference in change scores between treatment and control groups divided by pooled standard deviation. Within-group effect sizes were calculated as the raw mean difference between baseline and follow-up divided by pooled within-groups standard deviation.Eight studies (13 interventions with a total of 2,050 participants were included. Compared to control participants, students who received gender-neutral (dbetween = 0.291, 95% CI [0.159, 0.423] and gender-specific PNF (dbetween = 0.284, 95% CI [0.117, 0.451] reported greater reductions in drinking from baseline to follow-up. Students who received gender-neutral PNF reported 3.027 (95% CI [2.171, 3.882] fewer drinks per week at first follow-up and gender-specific PNF reported 3.089 (95% CI [0.992, 5.186] fewer drinks. Intervention effects were small for harms (dbetween = 0.157, 95% CI [0.037, 0.278].Computer-delivered PNF is an effective stand-alone approach for reducing college student

Stand-Alone Personalized Normative Feedback for College Student Drinkers: A Meta-Analytic Review, 2004 to 2014.

Science.gov (United States)

Dotson, Keri B; Dunn, Michael E; Bowers, Clint A

2015-01-01

Norms clarification has been identified as an effective component of college student drinking interventions, prompting research on norms clarification as a single-component intervention known as Personalized Normative Feedback (PNF). Previous reviews have examined PNF in combination with other components but not as a stand-alone intervention. To investigate the degree to which computer-delivered stand-alone personalized normative feedback interventions reduce alcohol consumption and alcohol-related harms among college students and to compare gender-neutral and gender-specific PNF. Electronic databases were searched systematically through November 2014. Reference lists were reviewed manually and forward and backward searches were conducted. Outcome studies that compared computer-delivered, stand-alone PNF intervention with an assessment only, attention-matched, or active treatment control and reported alcohol use and harms among college students. Between-group effect sizes were calculated as the standardized mean difference in change scores between treatment and control groups divided by pooled standard deviation. Within-group effect sizes were calculated as the raw mean difference between baseline and follow-up divided by pooled within-groups standard deviation. Eight studies (13 interventions) with a total of 2,050 participants were included. Compared to control participants, students who received gender-neutral (dbetween = 0.291, 95% CI [0.159, 0.423]) and gender-specific PNF (dbetween = 0.284, 95% CI [0.117, 0.451]) reported greater reductions in drinking from baseline to follow-up. Students who received gender-neutral PNF reported 3.027 (95% CI [2.171, 3.882]) fewer drinks per week at first follow-up and gender-specific PNF reported 3.089 (95% CI [0.992, 5.186]) fewer drinks. Intervention effects were small for harms (dbetween = 0.157, 95% CI [0.037, 0.278]). Computer-delivered PNF is an effective stand-alone approach for reducing college student drinking and

Thermal Analysis of the Receiver of a Standalone Pilot Solar Dish–Stirling System

Directory of Open Access Journals (Sweden)

Ehsan Gholamalizadeh

2018-06-01

Full Text Available Recent developments in solar thermal systems have aroused considerable interest in several countries with high solar potential. One of the most promising solar driven technologies is the solar thermal dish-Stirling system. One of the main issues of the solar dish–Stirling system is thermal losses from its components. The majority of the thermal losses of the system occur through its receiver before the thermal energy is converted to electrical energy by the Stirling engine. The goal of this investigation is to analyze the thermal performance of the receiver of a standalone pilot solar dish–Stirling system installed in Kerman City, Iran, to be used in remote off-grid areas of the Kerman Province. An analytical model was developed to predict the input energy, thermal losses, and thermal efficiency of the receiver. The receiver thermal model was first validated by comparing simulation results to experimental measurements for the EuroDish project. Then, the incident flux intensity intercepted by the receiver aperture, the thermal losses through the receiver (including conduction, convection, and radiation losses, and the power output during daytime hours (average day of each month for a year were predicted. The results showed that the conduction loss was small, while the convection and radiation losses played major roles in the total thermal losses through the receiver. The convection loss is dominant during the early morning and later evening hours, while radiation loss reaches its highest value near midday. Finally, the thermal efficiency of the receiver and the power output for each working hour throughout the year were calculated. The maximum performance of the system occurred at midday in the middle of July, with a predicted power output of 850 W, and a receiver efficiency of about 60%. At this time, a conduction loss of about 266 W, a convection loss of 284 W, and a radiation loss of about 2000 W were estimated.

Simulation of stand alone PV systems; Dokuritsugata taiyoko hatsuden system no simulation

Energy Technology Data Exchange (ETDEWEB)

Tsuda, I.; Sakuta, K. [Electrotechnical Laboratory, Tsukuba (Japan); Oshiro, T. [Japan Quality Assurance Organization, Tokyo (Japan); Kurokawa, K. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

1997-11-25

Studies are performed to develop a simulation program for a stand-alone photovoltaic power generation system equipped with a lead acid battery. In this stand-alone photovoltaic power generation system, the load is connected in shunt with the solar cell array output through the intermediary of a lead acid battery and inverter. The program is a model in which the solar cell model is built taking parallel resistance into account, and the temperature-dependence of the constants is described using approximations experimentally obtained by Solar Techno Center of JQA (Japan Quality Assurance Organization), Hamamatsu. Insolation data for the model is described using METPV compiled by Japan Weather Association, and load data is described using data actually measured at Shizuoka. This program is compared with the data of operation at Hamamatsu, and the result is almost satisfactory. Simulations are conducted at five typical locations in Japan using this program, and it is found that the array load matching correction factor is dependent on seasonal changes rather than locality, that the battery contribution rate does not change much throughout the year, and that it is not dependent on locality. 5 refs., 7 figs., 3 tabs.

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.

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

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.

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)

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

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.

New control strategy of stand-alone brushless doubly-fed induction generator for supplying unbalanced loads in ship shaft power generation system

DEFF Research Database (Denmark)

Liu, Yi; Xu, Wei; Xiong, Fei

2017-01-01

The ship shaft power generation system based on a stand-alone brushless doubly-fed induction generator (BDFIG) have demonstrated excellent saving-energy performance. This paper presents a new control scheme of the stand-alone BDFIG for supplying unbalanced loads in the ship shaft power generation...

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.

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.

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)

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

A New Vector Control of Brushless Doubly-Fed Inductor Generator With Transient Current Compensation for Stand-Alone Power Generation Applications

DEFF Research Database (Denmark)

Liu, Yi; Xu, Wei; Yu, Kailiang

2018-01-01

The stand-alone brushless doubly-fed induction generator (BDFIG) with the conventional control strategies suffers heavily from poor dynamic performance especially under heavy load disturbance. This paper presents a new vector control strategy of BDFIG for stand-alone power generation applications...... control strategies, and the results verify the satisfactory dynamic performance of the proposed strategy....

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...

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.

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)

A Standalone Solar Photovoltaic Power Generation using Cuk Converter and Single Phase Inverter

Science.gov (United States)

Verma, A. K.; Singh, B.; Kaushika, S. C.

2013-03-01

In this paper, a standalone solar photovoltaic (SPV) power generating system is designed and modeled using a Cuk dc-dc converter and a single phase voltage source inverter (VSI). In this system, a dc-dc boost converter boosts a low voltage of a PV array to charge a battery at 24 V using a maximum power point tracking control algorithm. To step up a 24 V battery voltage to 360 V dc, a high frequency transformer based isolated dc-dc Cuk converter is used to reduce size, weight and losses. The dc voltage of 360 V is fed to a single phase VSI with unipolar switching to achieve a 230 Vrms, 50 Hz ac. The main objectives of this investigation are on efficiency improvement, reduction in cost, weight and size of the system and to provide an uninterruptible power to remotely located consumers. The complete SPV system is designed and it is modeled in MATLAB/Simulink. The simulated results are presented to demonstrate its satisfactory performance for validating the proposed design and control algorithm.

Robust Frequency and Voltage Stability Control Strategy for Standalone AC/DC Hybrid Microgrid

Directory of Open Access Journals (Sweden)

Furqan Asghar

2017-05-01

Full Text Available The microgrid (MG concept is attracting considerable attention as a solution to energy deficiencies, especially in remote areas, but the intermittent nature of renewable sources and varying loads cause many control problems and thereby affect the quality of power within a microgrid operating in standalone mode. This might cause large frequency and voltage deviations in the system due to unpredictable output power fluctuations. Furthermore, without any main grid support, it is more complex to control and manage the system. In past, droop control and various other coordination control strategies have been presented to stabilize the microgrid frequency and voltages, but in order to utilize the available resources up to their maximum capacity in a positive way, new and robust control mechanisms are required. In this paper, a standalone microgrid is presented, which integrates renewable energy-based distributed generations and local loads. A fuzzy logic-based intelligent control technique is proposed to maintain the frequency and DC (direct current-link voltage stability for sudden changes in load or generation power. Also from a frequency control perspective, a battery energy storage system (BESS is suggested as a replacement for a synchronous generator to stabilize the nominal system frequency as a synchronous generator is unable to operate at its maximum efficiency while being controlled for stabilization purposes. Likewise, a super capacitor (SC and BESS is used to stabilize DC bus voltages even though maximum possible energy is being extracted from renewable generated sources using maximum power point tracking. This newly proposed control method proves to be effective by reducing transient time, minimizing the frequency deviations, maintaining voltages even though maximum power point tracking is working and preventing generators from exceeding their power ratings during disturbances. However, due to the BESS limited capacity, load switching

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

Stand-alone version of the 11kW Gaia wind turbine

DEFF Research Database (Denmark)

Bindner, H.; Rosas, P.A.C.; Teodorescu, R.

2004-01-01

This report describes the development of a stand-alone version of the 11kW Gaia wind turbine. Various possible configurations are investigated and a configuration using a back-to-back converter is chosen. A model is developed for controller design of thefast controllers of the unit. Controllers...... assessment and controller design a dynamic performance assessment model has been developed....

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.

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.

Evaluating a Pre-Session Homework Exercise in a Standalone Information Literacy Class

Science.gov (United States)

Goetz, Joseph E.; Barber, Catherine R.

2015-01-01

In this study, researchers evaluate a homework exercise assigned before a standalone information literacy session. Students in a Master of Education program completed a worksheet using the ERIC database thesaurus. The researchers conducted pre- and posttests within a single library session to assess student learning, using a control group for…

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…

A Novel Method for Fast Configuration of Energy Storage Capacity in Stand-Alone and Grid-Connected Wind Energy Systems

Directory of Open Access Journals (Sweden)

Haixiang Zang

2016-12-01

Full Text Available In this paper, a novel method is proposed and applied to quickly calculate the capacity of energy storage for stand-alone and grid-connected wind energy systems, according to the discrete Fourier transform theory. Based on practical wind resource data and power data, which are derived from the American Wind Energy Technology Center and HOMER software separately, the energy storage capacity of a stand-alone wind energy system is investigated and calculated. Moreover, by applying the practical wind power data from a wind farm in Fujian Province, the energy storage capacity for a grid-connected wind system is discussed in this paper. This method can also be applied to determine the storage capacity of a stand-alone solar energy system with practical photovoltaic power data.

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.

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.

Impact of Battery’s Model Accuracy on Size Optimization Process of a Standalone Photovoltaic System

Directory of Open Access Journals (Sweden)

Ibrahim Anwar Ibrahim

2016-09-01

Full Text Available This paper presents a comparative study between two proposed size optimization methods based on two battery’s models. Simple and complex battery models are utilized to optimally size a standalone photovoltaic system. Hourly meteorological data are used in this research for a specific site. Results show that by using the complex model of the battery, the cost of the system is reduced by 31%. In addition, by using the complex battery model, the sizes of the PV array and the battery are reduced by 5.6% and 30%, respectively, as compared to the case which is based on the simple battery model. This shows the importance of utilizing accurate battery models in sizing standalone photovoltaic systems.

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.

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...

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

Optimum autonomous stand-alone photovoltaic system design on the basis of energy pay-back analysis

International Nuclear Information System (INIS)

Kaldellis, J.K.; Zafirakis, D.; Kondili, E.

2009-01-01

Stand-alone photovoltaic (PV) systems comprise one of the most promising electrification solutions for covering the demand of remote consumers. However, such systems are strongly questioned due to extreme life-cycle (LC) energy requirements. For similar installations to be considered as environmentally sustainable, their LC energy content must be compensated by the respective useful energy production, i.e. their energy pay-back period (EPBP) should be found less than their service period. In this context, an optimum sizing methodology is currently developed, based on the criterion of minimum embodied energy. Various energy autonomous stand-alone PV-lead-acid battery systems are examined and two different cases are investigated; a high solar potential area and a medium solar potential area. By considering that the PV-battery (PV-Bat) system's useful energy production is equal to the remote consumer's electricity consumption, optimum cadmium telluride (CdTe) based systems yield the minimum EPBP (15 years). If achieving to exploit the net PV energy production however, the EPBP is found less than 20 years for all PV types. Finally, the most interesting finding concerns the fact that in all cases examined the contribution of the battery component exceeds 27% of the system LC energy requirements, reflecting the difference between grid-connected and stand-alone configurations.

Magnetic field measurements near stand-alone transformer stations.

Science.gov (United States)

Kandel, Shaiela; Hareuveny, Ronen; Yitzhak, Nir-Mordechay; Ruppin, Raphael

2013-12-01

Extremely low-frequency (ELF) magnetic field (MF) measurements around and above three stand-alone 22/0.4-kV transformer stations have been performed. The low-voltage (LV) cables between the transformer and the LV switchgear were found to be the major source of strong ELF MFs of limited spatial extent. The strong fields measured above the transformer stations support the assessment method, to be used in future epidemiological studies, of classifying apartments located right above the transformer stations as highly exposed to MFs. The results of the MF measurements above the ground around the transformer stations provide a basis for the assessment of the option of implementing precautionary procedures.

Enhanced current and voltage regulators for stand-alone applications

DEFF Research Database (Denmark)

Federico, de Bosio; Pastorelli, Michele; Antonio DeSouza Ribeiro, Luiz

2016-01-01

State feedback decoupling permits to achieve a better dynamic response for Voltage Source in stand-alone applications. The design of current and voltage regulators is performed in the discrete-time domain since it provides better accuracy and allows direct pole placement. As the attainable...... bandwidth of the current loop is mainly limited by computational and PWM delays, a lead compensator structure is proposed to overcome this limitation. The design of the voltage regulator is based on the Nyquist criterion, verifying to guarantee a high sensitivity peak. Discrete-time domain implementation...

A critical evaluation of deterministic methods in size optimisation of reliable and cost effective standalone hybrid renewable energy systems

International Nuclear Information System (INIS)

Maheri, Alireza

2014-01-01

Reliability of a hybrid renewable energy system (HRES) strongly depends on various uncertainties affecting the amount of power produced by the system. In the design of systems subject to uncertainties, both deterministic and nondeterministic design approaches can be adopted. In a deterministic design approach, the designer considers the presence of uncertainties and incorporates them indirectly into the design by applying safety factors. It is assumed that, by employing suitable safety factors and considering worst-case-scenarios, reliable systems can be designed. In fact, the multi-objective optimisation problem with two objectives of reliability and cost is reduced to a single-objective optimisation problem with the objective of cost only. In this paper the competence of deterministic design methods in size optimisation of reliable standalone wind–PV–battery, wind–PV–diesel and wind–PV–battery–diesel configurations is examined. For each configuration, first, using different values of safety factors, the optimal size of the system components which minimises the system cost is found deterministically. Then, for each case, using a Monte Carlo simulation, the effect of safety factors on the reliability and the cost are investigated. In performing reliability analysis, several reliability measures, namely, unmet load, blackout durations (total, maximum and average) and mean time between failures are considered. It is shown that the traditional methods of considering the effect of uncertainties in deterministic designs such as design for an autonomy period and employing safety factors have either little or unpredictable impact on the actual reliability of the designed wind–PV–battery configuration. In the case of wind–PV–diesel and wind–PV–battery–diesel configurations it is shown that, while using a high-enough margin of safety in sizing diesel generator leads to reliable systems, the optimum value for this margin of safety leading to a

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...

Maintenance of Segmental Lordosis and Disk Height in Stand-alone and Instrumented Extreme Lateral Interbody Fusion (XLIF).

Science.gov (United States)

Malham, Gregory M; Ellis, Ngaire J; Parker, Rhiannon M; Blecher, Carl M; White, Rohan; Goss, Ben; Seex, Kevin A

2017-03-01

A prospective single-surgeon nonrandomized clinical study. To evaluate the radiographic and clinical outcomes, by fixation type, in extreme lateral interbody fusion (XLIF) patients and provide an algorithm for determining patients suitable for stand-alone XLIF. XLIF may be supplemented with pedicle screw fixation, however, since stabilizing structures remain intact, it is suggested that stand-alone XLIF can be used for certain indications. This eliminates the associated morbidity, though subsidence rates may be elevated, potentially minimizing the clinical benefits. A fixation algorithm was developed after evaluation of patient outcomes from the surgeon's first 30 cases. This algorithm was used prospectively for 40 subsequent patients to determine the requirement for supplemental fixation. Preoperative, postoperative, and 12-month follow-up computed tomography scans were measured for segmental and global lumbar lordosis and posterior disk height. Clinical outcome measures included back and leg pain (visual analogue scale), Oswestry Disability Index (ODI), and SF-36 physical and mental component scores (PCS and MCS). Preoperatively to 12-month follow-up there were increases in segmental lordosis (7.9-9.4 degrees, P=0.0497), lumbar lordosis (48.8-55.2 degrees, P=0.0328), and disk height (3.7-5.5 mm, P=0.0018); there were also improvements in back (58.6%) and leg pain (60.0%), ODI (44.4%), PCS (56.7%), and MCS (16.1%) for stand-alone XLIF. For instrumented XLIF, segmental lordosis (7.6-10.5 degrees, P=0.0120) and disk height (3.5-5.6 mm, Plordosis decreased (51.1-45.8 degrees, P=0.2560). Back (49.8%) and leg pain (30.8%), ODI (32.3%), PCS (37.4%), and MCS (2.0%) were all improved. Subsidence occurred in 3 (7.5%) stand-alone patients. The XLIF treatment fixation algorithm provided a clinical pathway to select suitable patients for stand-alone XLIF. These patients achieved positive clinical outcomes, satisfactory fusion rates, with sustained correction of lordosis and

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.

SIMULATE-3 K coupled code applications

Energy Technology Data Exchange (ETDEWEB)

Joensson, Christian [Studsvik Scandpower AB, Vaesteraas (Sweden); Grandi, Gerardo; Judd, Jerry [Studsvik Scandpower Inc., Idaho Falls, ID (United States)

2017-07-15

This paper describes the coupled code system TRACE/SIMULATE-3 K/VIPRE and the application of this code system to the OECD PWR Main Steam Line Break. A short description is given for the application of the coupled system to analyze DNBR and the flexibility the system creates for the user. This includes the possibility to compare and evaluate the result with the TRACE/SIMULATE-3K (S3K) coupled code, the S3K standalone code (core calculation) as well as performing single-channel calculations with S3K and VIPRE. This is the typical separate-effect-analyses required for advanced calculations in order to develop methodologies to be used for safety analyses in general. The models and methods of the code systems are presented. The outline represents the analysis approach starting with the coupled code system, reactor and core model calculation (TRACE/S3K). This is followed by a more detailed core evaluation (S3K standalone) and finally a very detailed thermal-hydraulic investigation of the hot pin condition (VIPRE).

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

International Nuclear Information System (INIS)

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

2006-01-01

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

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.

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...

Control strategy of wind turbine based on permanent magnet synchronous generator and energy storage for stand-alone systems

DEFF Research Database (Denmark)

Deng, Fujin; Liu, Dong; Chen, Zhe

2017-01-01

This paper investigates a variable speed wind turbine based on permanent magnet synchronous generator and a full-scale power converter in a stand-alone system. An energy storage system(ESS) including battery and fuel cell-electrolyzer combination is connected to the DC link of the full-scale power...... converter through the power electronics interface. Wind is the primary power source of the system, the battery and FC-electrolyzer combination is used as a backup and a long-term storage system to provide or absorb power in the stand-alone system, respectively. In this paper, a control strategy is proposed...... for the operation of this variable speed wind turbine in a stand-alone system, where the generator-side converter and the ESS operate together to meet the demand of the loads. This control strategy is competent for supporting the variation of the loads or wind speed and limiting the DC-link voltage of the full...

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

Initialization of high resolution surface wind simulations using NWS gridded data

Science.gov (United States)

J. Forthofer; K. Shannon; Bret Butler

2010-01-01

WindNinja is a standalone computer model designed to provide the user with simulations of surface wind flow. It is deterministic and steady state. It is currently being modified to allow the user to initialize the flow calculation using National Digital Forecast Database. It essentially allows the user to downscale the coarse scale simulations from meso-scale models to...

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...

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...

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.

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.

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.

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.

Nuclear power plant simulation using advanced simulation codes through a state-of-the-art workstation

International Nuclear Information System (INIS)

Laats, E.T.; Hagen, R.N.

1985-01-01

The Nuclear Plant Analyzer (NPA) currently resides in a Control Data Corporation 176 mainframe computer at the Idaho National Engineering Laboratory (INEL). The NPA user community is expanding to include worldwide users who cannot consistently access the INEL mainframe computer from their own facilities. Thus, an alternate mechanism is needed to enable their use of the NPA. Therefore, a feasibility study was undertaken by EG and G Idaho to evaluate the possibility of developing a standalone workstation dedicated to the NPA

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)

Use of Super-Capacitor to Enhance Charging Performance of Stand-Alone Solar PV System

KAUST Repository

Huang, B. J.; Hsu, P. C.; Ho, P. Y

2011-01-01

Introduction: The battery charging performance in a stand-alone solar PV system affects the PV system efficiency and the load operating time. The New Energy Center of National Taiwan University has been devoted to the development of a PWM charging

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

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.

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...

Methanol production via pressurized entrained flow biomass gasification – Techno-economic comparison of integrated vs. stand-alone production

International Nuclear Information System (INIS)

Andersson, Jim; Lundgren, Joakim; Marklund, Magnus

2014-01-01

The main objective with this work was to investigate techno-economically the opportunity for integrated gasification-based biomass-to-methanol production in an existing chemical pulp and paper mill. Three different system configurations using the pressurized entrained flow biomass gasification (PEBG) technology were studied, one stand-alone plant, one where the bark boiler in the mill was replaced by a PEBG unit and one with a co-integration of a black liquor gasifier operated in parallel with a PEBG unit. The cases were analysed in terms of overall energy efficiency (calculated as electricity-equivalents) and process economics. The economics was assessed under the current as well as possible future energy market conditions. An economic policy support was found to be necessary to make the methanol production competitive under all market scenarios. In a future energy market, integrating a PEBG unit to replace the bark boiler was the most beneficial case from an economic point of view. In this case the methanol production cost was reduced in the range of 11–18 Euro per MWh compared to the stand-alone case. The overall plant efficiency increased approximately 7%-units compared to the original operation of the mill and the non-integrated stand-alone case. In the case with co-integration of the two parallel gasifiers, an equal increase of the system efficiency was achieved, but the economic benefit was not as apparent. Under similar conditions as the current market and when methanol was sold to replace fossil gasoline, co-integration of the two parallel gasifiers was the best alternative based on received IRR. - Highlights: • Techno-economic results regarding integration of methanol synthesis processes in a pulp and paper mill are presented. • The overall energy efficiency increases in integrated methanol production systems compared to stand-alone production units. • The economics of the integrated system improves compared to stand-alone alternatives. • Tax

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.

Assessment of renewable energy resources potential for large scale and standalone applications in Ethiopia

NARCIS (Netherlands)

Tucho, Gudina Terefe; Weesie, Peter D.M.; Nonhebel, Sanderine

2014-01-01

This study aims to determine the contribution of renewable energy to large scale and standalone application in Ethiopia. The assessment starts by determining the present energy system and the available potentials. Subsequently, the contribution of the available potentials for large scale and

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)

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.

Parametric sensitivity study for solar-assisted heat-pump systems

Science.gov (United States)

White, N. M.; Morehouse, J. H.

1981-07-01

The engineering and economic parameters affecting life-cycle costs for solar-assisted heat pump systems are investigted. The change in energy usage resulting from each engineering parameter varied was developed from computer simulations, and is compared with results from a stand-alone heat pump system. Three geographical locations are considered: Washington, DC, Fort Worth, TX, and Madison, WI. Results indicate that most engineering changes to the systems studied do not provide significant energy savings. The most promising parameters to ary are the solar collector parameters tau (-) and U/sub L/ the heat pump capacity at design point, and the minimum utilizable evaporator temperature. Costs associated with each change are estimated, and life-cycle costs computed for both engineering parameters and economic variations in interest rate, discount rate, tax credits, fuel unit costs and fuel inflation rates. Results indicate that none of the feasibile engineering changes for the system configuration studied will make these systems economically competitive with the stand-alone heat pump without a considerable tax credit.

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

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

Coordination Control Strategy for AC/DC Hybrid Microgrids in Stand-Alone Mode

Directory of Open Access Journals (Sweden)

Dwi Riana Aryani

2016-06-01

Full Text Available Interest in DC microgrids is rapidly increasing along with the improvement of DC power technology because of its advantages. To support the integration process of DC microgrids with the existing AC utility grids, the form of hybrid AC/DC microgrids is considered for higher power conversion efficiency, lower component cost and better power quality. In the system, AC and DC portions are connected through interlink bidirectional AC/DC converters (IC with a proper control system and power management. In the stand-alone operation mode of AC/DC hybrid microgrids, the control of power injection through the IC is crucial in order to maintain the system security. This paper mainly deals with a coordination control strategy of IC and a battery energy storage system (BESS converter under stand-alone operation. A coordinated control strategy for the IC, which considers the state of charge (SOC level of BESS and the load shedding scheme as the last resort, is proposed to obtain better power sharing between AC and DC subgrids. The scheme will be tested with a hybrid AC/DC microgrid, using the tool of the PSCAD/EMTDC software.

Modeling and Experimental Test of Grid-Tied Photovoltaic Cell Emulating System in the Stand-alone Mode

Directory of Open Access Journals (Sweden)

Vu Minh Phap

2017-06-01

Full Text Available In recent decades, generation of electricity from solar arrays has been increased to meet the world's growing energy demand. However, the utilization rate of the power conditioner in the grid-tied solar power system is low because the operation of solar panels is dependent on sunlight. Thus, we studied the method that the small scale wind power generating system in size from a few hundred watts to two or three kilowatts can be connected to the grid-tied power conditioner of the solar power system for residential applications with low power ratings (single phase, size is limited to 10kW by emulating characteristic of the solar panel. In this paper, we introduce the application of the grid-tied PV cell emulating system in the stand-alone mode to improve the utilization rate of the power conditioner. The simulation and experimental test results verify that the PV cell emulating system can operate the power conditioner of the gridtied solar power system.

Seismic stability of a standalone glove box structure

Energy Technology Data Exchange (ETDEWEB)

Saraswat, A., E-mail: anupams@barc.gov.in [Bhabha Atomic Research Centre, Mumbai (India); Reddy, G.R. [Bhabha Atomic Research Centre, Mumbai (India); Ghosh, S. [Indian Institute of Technology Bombay, Mumbai (India); Ghosh, A.K.; Kumar, Arun [Bhabha Atomic Research Centre, Mumbai (India)

2014-09-15

Highlights: • Glove box is a leak tight, safety related structure used for handling radiotoxic materials. • To study the seismic performance of a freestanding glove box, extensive shake table testing has been carried out. • Glove box maintained structural integrity and leak tightness up to design basis earthquake loading. • Detailed three-dimensional finite element model of the structure is developed and analyzed by using direct time integration methods. • Simplified numerical method is proposed and successfully applied, to quickly estimate sliding displacement and determine upper bounds for it. - Abstract: In a nuclear fuel cycle facility, radiotoxic materials are being handled in freestanding leak tight enclosures called glove boxes (GBs). These glove boxes act as a primary confinement for the radiotoxic materials. Glove boxes are designed as per codal requirements for class I component. They are designed to withstand extreme level of earthquake loading with a return period of 10,000 years. To evaluate seismic performance of the glove box, there is a need to check the stability (sliding and overturning), structural integrity (stresses and strains) and leak tightness under earthquake loading. Extensive shake table experiments were conducted on a single standalone glove box. Actual laboratory conditions were simulated during testing to check the response. After extensive shake table testing, glove box structure was also analyzed using finite element (FE) software. Detailed three-dimensional model of glove box structure was developed and analyzed using nonlinear time history method. It was observed that finite element methods could be utilized to accurately predict dynamic response of glove box structure. This paper discusses the details and results of shake table testing and methodology used for modelling and analysing freestanding glove box structure under seismic loading. In addition, simplified numerical procedure, developed using energy conservation

Seismic stability of a standalone glove box structure

International Nuclear Information System (INIS)

Saraswat, A.; Reddy, G.R.; Ghosh, S.; Ghosh, A.K.; Kumar, Arun

2014-01-01

Highlights: • Glove box is a leak tight, safety related structure used for handling radiotoxic materials. • To study the seismic performance of a freestanding glove box, extensive shake table testing has been carried out. • Glove box maintained structural integrity and leak tightness up to design basis earthquake loading. • Detailed three-dimensional finite element model of the structure is developed and analyzed by using direct time integration methods. • Simplified numerical method is proposed and successfully applied, to quickly estimate sliding displacement and determine upper bounds for it. - Abstract: In a nuclear fuel cycle facility, radiotoxic materials are being handled in freestanding leak tight enclosures called glove boxes (GBs). These glove boxes act as a primary confinement for the radiotoxic materials. Glove boxes are designed as per codal requirements for class I component. They are designed to withstand extreme level of earthquake loading with a return period of 10,000 years. To evaluate seismic performance of the glove box, there is a need to check the stability (sliding and overturning), structural integrity (stresses and strains) and leak tightness under earthquake loading. Extensive shake table experiments were conducted on a single standalone glove box. Actual laboratory conditions were simulated during testing to check the response. After extensive shake table testing, glove box structure was also analyzed using finite element (FE) software. Detailed three-dimensional model of glove box structure was developed and analyzed using nonlinear time history method. It was observed that finite element methods could be utilized to accurately predict dynamic response of glove box structure. This paper discusses the details and results of shake table testing and methodology used for modelling and analysing freestanding glove box structure under seismic loading. In addition, simplified numerical procedure, developed using energy conservation

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.

Efficiency of hydrogen gas production in a stand-alone solar hydrogen system

International Nuclear Information System (INIS)

Singh, K.; Tamakloe, R.Y.

2003-01-01

Many photovoltaic systems operate in a decentralised electricity producing system, or stand-alone mode and the total energy demand is met by the output of the photovoltaic array. The output of the photovoltaic system fluctuates and is unpredictable for many applications making some forms of energy storage system necessary. The role of storage medium is to store the excess energy produced by the photovoltaic arry, to absorb momentary power peaks and to supply energy during sunless periods. One of the storage modes is the use of electrochemical techniques, with batteries and water electrolysis as the most important examples. The present study includes three main parts: the first one is the hydrogen production form the electrolysis of water depending on the DC output current of the photovoltaic (PV) energy source and the charging of the battery. The second part presents the influence of various parameters on the efficiency of hydrogen gas production. The final part includes simulation studies with focus on solar hydrogen efficiency under the influence of various physical and chemical parameters. For a 50W panel-battery-electrolyser system, the dependence of volume of hydrogen gas on voltage, current and power yielded a maximum efficiency of 13.6% (author)

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.

Modelling toolkit for simulation of maglev devices

Science.gov (United States)

Peña-Roche, J.; Badía-Majós, A.

2017-01-01

A stand-alone App1 has been developed, focused on obtaining information about relevant engineering properties of magnetic levitation systems. Our modelling toolkit provides real time simulations of 2D magneto-mechanical quantities for superconductor (SC)/permanent magnet structures. The source code is open and may be customised for a variety of configurations. Ultimately, it relies on the variational statement of the critical state model for the superconducting component and has been verified against experimental data for YBaCuO/NdFeB assemblies. On a quantitative basis, the values of the arising forces, induced superconducting currents, as well as a plot of the magnetic field lines are displayed upon selection of an arbitrary trajectory of the magnet in the vicinity of the SC. The stability issues related to the cooling process, as well as the maximum attainable forces for a given material and geometry are immediately observed. Due to the complexity of the problem, a strategy based on cluster computing, database compression, and real-time post-processing on the device has been implemented.

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…

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...

International market assessment of stand-alone photovoltaic power systems for cottage industry applications

Science.gov (United States)

Philippi, T. M.

1981-01-01

The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

International market assessment of stand-alone photovoltaic power systems for cottage industry applications

Science.gov (United States)

Philippi, T. M.

1981-11-01

The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

Future UK markets for stand-alone renewable energy systems

International Nuclear Information System (INIS)

Paish, O.

1999-01-01

A study to identify and quantify the market for stand-alone renewable energy supplies of power (photovoltaics, wind and micro-hydro electricity systems) was described. The study focused on small systems, generally less than a few kW installed capacity. It was suggested that in the UK, the emphasis on grid-connected renewable energy technologies (RETs) has blurred the fact that it is 'off-grid' renewable systems that can offer more immediate real commercial markets for the renewables business. With the likelihood of a significant increase in demand for renewables world wide over the next ten years, the UK needs to make a special effort to become involved

Assessment of Stand-Alone Displays for Time Management in a Creativity-Driven Learning Environment

DEFF Research Database (Denmark)

Frimodt-Møller, Søren

2017-01-01

This paper considers the pros and cons of stand-alone displays, analog (e.g. billboards, blackboards, whiteboards, large pieces of paper etc.) as well as digital (e.g. large shared screens, digital whiteboards or similar), as tools for time management processes in a creativity-driven learning...

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.

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

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.

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.

Performance and driveline analyses of engine capacity in range extender engine hybrid vehicle

Science.gov (United States)

Praptijanto, Achmad; Santoso, Widodo Budi; Nur, Arifin; Wahono, Bambang; Putrasari, Yanuandri

2017-01-01

In this study, range extender engine designed should be able to meet the power needs of a power generator of hybrid electrical vehicle that has a minimum of 18 kW. Using this baseline model, the following range extenders will be compared between conventional SI piston engine (Baseline, BsL), engine capacity 1998 cm3, and efficiency-oriented SI piston with engine capacity 999 cm3 and 499 cm3 with 86 mm bore and stroke square gasoline engine in the performance, emission prediction of range extender engine, standard of charge by using engine and vehicle simulation software tools. In AVL Boost simulation software, range extender engine simulated from 1000 to 6000 rpm engine loads. The highest peak engine power brake reached up to 38 kW at 4500 rpm. On the other hand the highest torque achieved in 100 Nm at 3500 rpm. After that using AVL cruise simulation software, the model of range extended electric vehicle in series configuration with main components such as internal combustion engine, generator, electric motor, battery and the arthemis model rural road cycle was used to simulate the vehicle model. The simulation results show that engine with engine capacity 999 cm3 reported the economical performances of the engine and the emission and the control of engine cycle parameters.

Robust Power Management Control for Stand-Alone Hybrid Power Generation System

International Nuclear Information System (INIS)

Kamal, Elkhatib; Adouane, Lounis; Aitouche, Abdel; Mohammed, Walaa

2017-01-01

This paper presents a new robust fuzzy control of energy management strategy for the stand-alone hybrid power systems. It consists of two levels named centralized fuzzy supervisory control which generates the power references for each decentralized robust fuzzy control. Hybrid power systems comprises: a photovoltaic panel and wind turbine as renewable sources, a micro turbine generator and a battery storage system. The proposed control strategy is able to satisfy the load requirements based on a fuzzy supervisor controller and manage power flows between the different energy sources and the storage unit by respecting the state of charge and the variation of wind speed and irradiance. Centralized controller is designed based on If-Then fuzzy rules to manage and optimize the hybrid power system production by generating the reference power for photovoltaic panel and wind turbine. Decentralized controller is based on the Takagi-Sugeno fuzzy model and permits us to stabilize each photovoltaic panel and wind turbine in presence of disturbances and parametric uncertainties and to optimize the tracking reference which is given by the centralized controller level. The sufficient conditions stability are formulated in the format of linear matrix inequalities using the Lyapunov stability theory. The effectiveness of the proposed Strategy is finally demonstrated through a SAHPS (stand-alone hybrid power systems) to illustrate the effectiveness of the overall proposed method. (paper)

Linguistic and Structural Analyses of Stand-Alone Literature Reviews: Seventy-Five Years of Change

Science.gov (United States)

Wright, Heidi Rachel

2016-01-01

The purpose of this dissertation is to offer a multifaceted overview of stand-alone literature reviews. These texts, literature reviews published unattached to research articles, have existed for centuries but remained largely unstudied by linguists. Thus, the goal of this project is to present these reviews' situational, grammatical, and…

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.

Analysis and control of induction generator supplying stand-alone AC loads employing a Matrix Converter

Directory of Open Access Journals (Sweden)

Sumedha Mahajan

2017-04-01

Full Text Available This paper proposes a Capacitor Excited Induction Generator (CEIG-Matrix Converter (MC system for feeding stand-alone AC loads. The variable output voltage magnitude and frequency from CEIG is converted into a constant voltage magnitude and frequency at the load terminals by controlling MC using Space Vector Modulation (SVM technique. This single-stage MC is turned up as a good alternative for the proposed system against commonly used AC/DC/AC two stage power converters. The configuration and implementation of the closed-loop control scheme employing dSPACE 1103 real time controller have been fully described in the paper. The proposed closed-loop controller regulates the AC load voltage irrespective of changes in the prime mover speed and load. A method for predetermining the steady-state performance of the proposed system has been developed and described with relevant analytical expressions. The effectiveness of the proposed system is exemplified through simulation results for various operating conditions. The proposed control technique is further validated using an experimental setup developed in the laboratory.

Minimum cost solution of wind–photovoltaic based stand-alone power systems for remote consumers

International Nuclear Information System (INIS)

Kaldellis, J.K.; Zafirakis, D.; Kavadias, K.

2012-01-01

Renewable energy sources (RES) based stand-alone systems employing either wind or solar power and energy storage comprise a reliable energy alternative, on top of conventional diesel-electric generator sets, commonly used by remote consumers. However, such systems usually imply the need for oversizing and considerable energy storage requirements leading to relatively high costs. On the other hand, hybrid configurations that may exploit both wind and solar potential of a given area may considerably reduce energy storage capacity and improve the economic performance of the system. In this context, an integrated techno-economic methodology for the evaluation of hybrid wind–photovoltaic stand-alone power systems is currently developed, aiming at the designation of optimum configurations for a typical remote consumer, using economic performance criteria. For the problem investigation, the developed evaluation model is applied to four representative areas of the Greek territory with different wind potential characteristics in order to obtain optimum configurations on the basis of minimum initial investment, 10-year and 20-year total cost. According to the results obtained, the proposed solution is favorably compared with all other stand-alone energy alternatives, reflecting the ability of hybrid systems to adjust even in areas where the local RES potential is not necessarily of high quality. - Highlights: ► Wind- and PV-stand alone systems often imply use of extreme battery capacity. ► Hybrid wind–PV systems may reduce energy storage requirements and associated costs. ► An optimization methodology is developed, based on economic performance criteria. ► Methodology is applied to four Greek regions of different wind potential. ► Results obtained reflect the hybrid solution's advantages over other alternatives.

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

MOSFET Loss Evaluation for a Low-Power Stand-Alone Photovoltaic-LED System

DEFF Research Database (Denmark)

Mira Albert, Maria del Carmen; Knott, Arnold; Andersen, Michael A. E.

2015-01-01

This paper presents a performance evaluation and comparison of state-of-the-art low voltage Si MOSFETs for a stand-alone photovoltaic-LED Light to Light (LtL) system. The complete system is formed by two cascaded converters that will be optimized for a determined solar irradiation and LED...... illumination profiles. The comparison is performed based on dynamic characterization and evaluation of the devices energy loss at different current levels....

Comparison of three ice cloud optical schemes in climate simulations with community atmospheric model version 5

Science.gov (United States)

Zhao, Wenjie; Peng, Yiran; Wang, Bin; Yi, Bingqi; Lin, Yanluan; Li, Jiangnan

2018-05-01

A newly implemented Baum-Yang scheme for simulating ice cloud optical properties is compared with existing schemes (Mitchell and Fu schemes) in a standalone radiative transfer model and in the global climate model (GCM) Community Atmospheric Model Version 5 (CAM5). This study systematically analyzes the effect of different ice cloud optical schemes on global radiation and climate by a series of simulations with a simplified standalone radiative transfer model, atmospheric GCM CAM5, and a comprehensive coupled climate model. Results from the standalone radiative model show that Baum-Yang scheme yields generally weaker effects of ice cloud on temperature profiles both in shortwave and longwave spectrum. CAM5 simulations indicate that Baum-Yang scheme in place of Mitchell/Fu scheme tends to cool the upper atmosphere and strengthen the thermodynamic instability in low- and mid-latitudes, which could intensify the Hadley circulation and dehydrate the subtropics. When CAM5 is coupled with a slab ocean model to include simplified air-sea interaction, reduced downward longwave flux to surface in Baum-Yang scheme mitigates ice-albedo feedback in the Arctic as well as water vapor and cloud feedbacks in low- and mid-latitudes, resulting in an overall temperature decrease by 3.0/1.4 °C globally compared with Mitchell/Fu schemes. Radiative effect and climate feedback of the three ice cloud optical schemes documented in this study can be referred for future improvements on ice cloud simulation in CAM5.

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.

Methodology for the design of a stand-alone photovoltaic power supply

OpenAIRE

López Seguel, Julio; Seleme Junior, Seleme Isaac; Donoso-Garcia, Pedro F; Ferreira Morais, Lenin Martins; Cabaleiro Cortizo, Porfirio; Severo Mendes, Marcos A

2013-01-01

This paper presents a complete methodology for the design of an autonomous photovoltaic system to maximize the use of solar energy. It is a method that prioritizes the best cost-effective choice at every step of the project. In order to ensure the proper use and extended battery life time, a control strategy for charging the batteries is proposed. Experimental results are provided for a stand-alone photovoltaic system with low electrical power, intended primarily for the illumination and basi...

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.

Integrating interface slicing into software engineering processes

Science.gov (United States)

Beck, Jon

1993-01-01

Interface slicing is a tool which was developed to facilitate software engineering. As previously presented, it was described in terms of its techniques and mechanisms. The integration of interface slicing into specific software engineering activities is considered by discussing a number of potential applications of interface slicing. The applications discussed specifically address the problems, issues, or concerns raised in a previous project. Because a complete interface slicer is still under development, these applications must be phrased in future tenses. Nonetheless, the interface slicing techniques which were presented can be implemented using current compiler and static analysis technology. Whether implemented as a standalone tool or as a module in an integrated development or reverse engineering environment, they require analysis no more complex than that required for current system development environments. By contrast, conventional slicing is a methodology which, while showing much promise and intuitive appeal, has yet to be fully implemented in a production language environment despite 12 years of development.

Current Hitachi knowledge engineering systems: an overview

Energy Technology Data Exchange (ETDEWEB)

Masui, S; Maeda, A; Masuishi, T [Hitachi, Ltd., Tokyo (Japan)

1992-02-01

In order to bring the knowledge engineering technology up to the practical phase, Hitachi has provided several knowledge engineering system products, including expert system building tools, knowledge acquisition tools, and many kinds of stand-alone and build-in expert systems in both the business and process control fields. In this review article, an overview of Hitachi{prime}s recent knowledge systems is described, which includes a trend analysis on recent market recognition. In addition, to introduce the Hitachi{prime}s current activities, a new product, a user interface building tool, and a new method of tuning fuzzy membership functions using a neuro-computing algorithm are also described. Furthermore, it is pointed out that not only practical tools and methodologies, but also a practical development team, including a planning section, a cooperating expert, a user section, and experienced knowledge engineers, is needed to achieve practical expert systems. 20 refs., 10 figs., 1 tab.

prfectBLAST: a platform-independent portable front end for the command terminal BLAST+ stand-alone suite.

Science.gov (United States)

Santiago-Sotelo, Perfecto; Ramirez-Prado, Jorge Humberto

2012-11-01

prfectBLAST is a multiplatform graphical user interface (GUI) for the stand-alone BLAST+ suite of applications. It allows researchers to do nucleotide or amino acid sequence similarity searches against public (or user-customized) databases that are locally stored. It does not require any dependencies or installation and can be used from a portable flash drive. prfectBLAST is implemented in Java version 6 (SUN) and runs on all platforms that support Java and for which National Center for Biotechnology Information has made available stand-alone BLAST executables, including MS Windows, Mac OS X, and Linux. It is free and open source software, made available under the GNU General Public License version 3 (GPLv3) and can be downloaded at www.cicy.mx/sitios/jramirez or http://code.google.com/p/prfectblast/.

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.

Analyzing grid extension and stand-alone photovoltaic systems for the cost-effective electrification of Kenya

NARCIS (Netherlands)

Zeyringer, Marianne; Pachauri, Shonali; Schmid, Erwin; Schmidt, Johannes; Worrell, Ernst|info:eu-repo/dai/nl/106856715; Morawetz, Ulrich B.

2015-01-01

The declaration of 2014-2024 as the Decade of Sustainable Energy for All has catalyzed actions towards achieving universal electricity access. The high costs of building electric infrastructure are a major impediment to improved access, making stand-alone photovoltaic (PV) systems an attractive

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

PVSOFT99 - Photovoltaic (PV) System Sizing And Simulation Software

African Journals Online (AJOL)

A computer program (PVSOFT99) has been developed for sizing and simulation of stand-alone photovoltaic (PV) systems. Two distinct PV sizing algorithms, one based on the worst case and the other on the reliability concept, have been incorporated in the program. The reliability concept is generalized in that variation of ...

Wind Energy Workforce Development: Engineering, Science, & Technology

Energy Technology Data Exchange (ETDEWEB)

Lesieutre, George A.; Stewart, Susan W.; Bridgen, Marc

2013-03-29

Broadly, this project involved the development and delivery of a new curriculum in wind energy engineering at the Pennsylvania State University; this includes enhancement of the Renewable Energy program at the Pennsylvania College of Technology. The new curricula at Penn State includes addition of wind energy-focused material in more than five existing courses in aerospace engineering, mechanical engineering, engineering science and mechanics and energy engineering, as well as three new online graduate courses. The online graduate courses represent a stand-alone Graduate Certificate in Wind Energy, and provide the core of a Wind Energy Option in an online intercollege professional Masters degree in Renewable Energy and Sustainability Systems. The Pennsylvania College of Technology erected a 10 kilowatt Xzeres wind turbine that is dedicated to educating the renewable energy workforce. The entire construction process was incorporated into the Renewable Energy A.A.S. degree program, the Building Science and Sustainable Design B.S. program, and other construction-related coursework throughout the School of Construction and Design Technologies. Follow-on outcomes include additional non-credit opportunities as well as secondary school career readiness events, community outreach activities, and public awareness postings.

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.

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...

Multi-Objective Optimal Design of Stand-Alone Hybrid Energy System Using Entropy Weight Method Based on HOMER

Directory of Open Access Journals (Sweden)

Jiaxin Lu

2017-10-01

Full Text Available Implementation of hybrid energy system (HES is generally considered as a promising way to satisfy the electrification requirements for remote areas. In the present study, a novel decision making methodology is proposed to identify the best compromise configuration of HES from a set of feasible combinations obtained from HOMER. For this purpose, a multi-objective function, which comprises four crucial and representative indices, is formulated by applying the weighted sum method. The entropy weight method is employed as a quantitative methodology for weighting factors calculation to enhance the objectivity of decision-making. Moreover, the optimal design of a stand-alone PV/wind/battery/diesel HES in Yongxing Island, China, is conducted as a case study to validate the effectiveness of the proposed method. Both the simulation and optimization results indicate that, the optimization method is able to identify the best trade-off configuration among system reliability, economy, practicability and environmental sustainability. Several useful conclusions are given by analyzing the operation of the best configuration.

Probabilistic modelling and analysis of stand-alone hybrid power systems

International Nuclear Information System (INIS)

Lujano-Rojas, Juan M.; Dufo-López, Rodolfo; Bernal-Agustín, José L.

2013-01-01

As a part of the Hybrid Intelligent Algorithm, a model based on an ANN (artificial neural network) has been proposed in this paper to represent hybrid system behaviour considering the uncertainty related to wind speed and solar radiation, battery bank lifetime, and fuel prices. The Hybrid Intelligent Algorithm suggests a combination of probabilistic analysis based on a Monte Carlo simulation approach and artificial neural network training embedded in a genetic algorithm optimisation model. The installation of a typical hybrid system was analysed. Probabilistic analysis was used to generate an input–output dataset of 519 samples that was later used to train the ANNs to reduce the computational effort required. The generalisation ability of the ANNs was measured in terms of RMSE (Root Mean Square Error), MBE (Mean Bias Error), MAE (Mean Absolute Error), and R-squared estimators using another data group of 200 samples. The results obtained from the estimation of the expected energy not supplied, the probability of a determined reliability level, and the estimation of expected value of net present cost show that the presented model is able to represent the main characteristics of a typical hybrid power system under uncertain operating conditions. - Highlights: • This paper presents a probabilistic model for stand-alone hybrid power system. • The model considers the main sources of uncertainty related to renewable resources. • The Hybrid Intelligent Algorithm has been applied to represent hybrid system behaviour. • The installation of a typical hybrid system was analysed. • The results obtained from the study case validate the presented model

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.

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

POLARIS: Agent-based modeling framework development and implementation for integrated travel demand and network and operations simulations

Energy Technology Data Exchange (ETDEWEB)

Auld, Joshua; Hope, Michael; Ley, Hubert; Sokolov, Vadim; Xu, Bo; Zhang, Kuilin

2016-03-01

This paper discusses the development of an agent-based modelling software development kit, and the implementation and validation of a model using it that integrates dynamic simulation of travel demand, network supply and network operations. A description is given of the core utilities in the kit: a parallel discrete event engine, interprocess exchange engine, and memory allocator, as well as a number of ancillary utilities: visualization library, database IO library, and scenario manager. The overall framework emphasizes the design goals of: generality, code agility, and high performance. This framework allows the modeling of several aspects of transportation system that are typically done with separate stand-alone software applications, in a high-performance and extensible manner. The issue of integrating such models as dynamic traffic assignment and disaggregate demand models has been a long standing issue for transportation modelers. The integrated approach shows a possible way to resolve this difficulty. The simulation model built from the POLARIS framework is a single, shared-memory process for handling all aspects of the integrated urban simulation. The resulting gains in computational efficiency and performance allow planning models to be extended to include previously separate aspects of the urban system, enhancing the utility of such models from the planning perspective. Initial tests with case studies involving traffic management center impacts on various network events such as accidents, congestion and weather events, show the potential of the system.

COMBINATION THERAPIES OR STANDALONE INTERVENTIONS? INNOVATION OPTIONS FOR PHARMACEUTICAL FIRMS FIGHTING CANCER

OpenAIRE

GUNJAN BHARDWAJ; ANSHIT AGRAWAL; RUPESH TYAGI

2015-01-01

Innovation is key to the pharma model, from an initial discovery to the final development of a marketable drug. Here, we explore the innovation options in the fiercely contested therapeutic area of Oncology. We studied clinical development of drugs targeting PD-1 and PD-L1 pathway. In this interesting contest, companies seem to be focusing on standalone interventions (exploratory innovation) and combination therapy (exploitative innovation) in clinical development. Merck Sharp and Dohme, havi...

Optimum Availability of Standalone Photovoltaic Power Systems for Remote Housing Electrification

Directory of Open Access Journals (Sweden)

Tamer Khatib

2014-01-01

Full Text Available The availability of PV systems is discussed to determine the optimum availability at which standalone PV systems must be designed. Optimization methods and PV systems software, such as HOMER and PV.MY, were used for this purpose. Six PV systems with six availability levels were analyzed, in terms of wasted energy, cost of energy, battery usage, and power shortages, using real meteorological data. Results show that PV systems with 99% availability are recommended, because of their high reliability and favorably wasted energy.

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

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%.

Design of a Stand-Alone Photovoltaic Model for Home Lightings and Clean Environment

Energy Technology Data Exchange (ETDEWEB)

Ani, Vincent Anayochukwu, E-mail: vincent_ani@yahoo.com [Department of Electronic Engineering, University of Nigeria, Nsukka (Nigeria)

2016-01-11

This paper gives a well-documented health risk of fuel-based lighting (kerosene lamps and fuel-powered generators) and proposed a design of a stand-alone solar PV system for sustainable home lightings in rural Nigerian area. The design was done in three different patterns of electricity consumptions with energy efficient lightings (EELs) using two different battery types (Rolls Surrette 6CS25PS and Hoppecke 10 OpzS 1000) on; (i) judicious power consumption, (ii) normal power consumption, and (iii) excess power consumption; and compared them with the incandescent light bulb consumption. The stand-alone photovoltaic energy systems were designed to match the rural Nigerian sunlight and weather conditions to meet the required lightings of the household. The objective function and constraints for the design models were formulated and optimization procedures were used to demonstrate the best solution (reliability at the lowest lifecycle cost). Initial capital costs as well as annualized costs over 5, 10, 15, 20, and 25 years were quantified and documented. The design identified the most cost-effective and reliable solar and battery array among the patterns of electricity consumption with EEL options (judicious power consumption, normal power consumption, and excess power consumption).

Design of a Stand-Alone Photovoltaic Model for Home Lightings and Clean Environment

International Nuclear Information System (INIS)

Ani, Vincent Anayochukwu

2016-01-01

This paper gives a well-documented health risk of fuel-based lighting (kerosene lamps and fuel-powered generators) and proposed a design of a stand-alone solar PV system for sustainable home lightings in rural Nigerian area. The design was done in three different patterns of electricity consumptions with energy efficient lightings (EELs) using two different battery types (Rolls Surrette 6CS25PS and Hoppecke 10 OpzS 1000) on; (i) judicious power consumption, (ii) normal power consumption, and (iii) excess power consumption; and compared them with the incandescent light bulb consumption. The stand-alone photovoltaic energy systems were designed to match the rural Nigerian sunlight and weather conditions to meet the required lightings of the household. The objective function and constraints for the design models were formulated and optimization procedures were used to demonstrate the best solution (reliability at the lowest lifecycle cost). Initial capital costs as well as annualized costs over 5, 10, 15, 20, and 25 years were quantified and documented. The design identified the most cost-effective and reliable solar and battery array among the patterns of electricity consumption with EEL options (judicious power consumption, normal power consumption, and excess power consumption).

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.

Design of a reliable and low-cost stand-alone micro hydropower station

Energy Technology Data Exchange (ETDEWEB)

Kusakana, K.; Munda, J.L. [Tshwane Univ. of Technology, Pretoria (South Africa)

2008-07-01

A stand-alone micro-hydropower station was presented. The plant was comprised of a squirrel cage induction machine coupled to a Kaplan water turbine. Power converters were used to control the variable frequency and voltage outputs of the generator caused by variations in water flow. The hydropower plant was installed a farm in the Kwazulu-Natal region of South Africa, and was designed to provide electricity in relation to the low power demand of users in the region as well as according to the site's hydrology and topology. Load forecasts for the 8 houses using the system were conducted. A generator with a higher output than the average power needed to feed the load was selected in order to ensure load supply during peak demand. The system was designed to shore energy generated during off-peak periods in batteries. An AC-DC-AC converter was used as an interface between the generator and the load in order to ensure voltage and frequency stabilization. Simulations of plant components were conducted to demonstrate output power supply during water flow variations. Results of the modelling study indicated that power converters are needed to stabilize generator outputs. The hydropower design is a cost-effective means of supplying power to low-income households. 10 refs., 2 tabs., 7 figs.

Enhancement of a stand-alone photovoltaic system's performance: Reduction of soft and hard shading

Energy Technology Data Exchange (ETDEWEB)

Lamont, Lisa A.; El Chaar, Lana [Petroleum Institute, Electrical Engineering Department, P.O. Box 2533, Abu Dhabi (United Arab Emirates)

2011-04-15

A stand-alone photovoltaic (PV) system is the most promising solution to supply electric power to meet energy demand in isolated locations. This technology can offer an interesting alternative to other currently existing sources of energy. Due to space constraint in the remote offshore oil and gas industry, a stand-alone system is used for cathodic protection, telemetry and valve control. However in such an environment, dust accumulation and bird droppings have been critical issues to the operation of off-grid solar devices. These factors do not only reduce the available power of the modules but also makes the cost of solar devices ineffective since cleaning, especially on well-head towers, is very expensive due to the location. Hence this paper presents two technical solutions that have shown promising results in reducing the impact of these factors. (author)

A sizing method for stand-alone PV installations with variable demand

Energy Technology Data Exchange (ETDEWEB)

Posadillo, R. [Grupo de Investigacion en Energias y Recursos Renovables, Dpto. de Fisica Aplicada, E.P.S., Universidad de Cordoba, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Lopez Luque, R. [Grupo de Investigacion de Fisica Para las Energias y Recursos Renovables, Dpto. de Fisica Aplicada, Edificio C2 Campus de Rabanales, 14071 Cordoba (Spain)

2008-05-15

The practical applicability of the considerations made in a previous paper to characterize energy balances in stand-alone photovoltaic systems (SAPV) is presented. Given that energy balances were characterized based on monthly estimations, the method is appropriate for sizing installations with variable monthly demands and variable monthly panel tilt (for seasonal estimations). The method presented is original in that it is the only method proposed for this type of demand. The method is based on the rational utilization of daily solar radiation distribution functions. When exact mathematical expressions are not available, approximate empirical expressions can be used. The more precise the statistical characterization of the solar radiation on the receiver module, the more precise the sizing method given that the characterization will solely depend on the distribution function of the daily global irradiation on the tilted surface H{sub g{beta}}{sub i}. This method, like previous ones, uses the concept of loss of load probability (LLP) as a parameter to characterize system design and includes information on the standard deviation of this parameter ({sigma}{sub LLP}) as well as two new parameters: annual number of system failures (f) and the standard deviation of annual number of system failures ({sigma}{sub f}). This paper therefore provides an analytical method for evaluating and sizing stand-alone PV systems with variable monthly demand and panel inclination. The sizing method has also been applied in a practical manner. (author)

Design and fabrication of a meso-scale stirling engine and combustor.

Energy Technology Data Exchange (ETDEWEB)

Echekki, Tarek (Sandia National Laboratories, Livermore, CA); Haroldsen, Brent L. (Sandia National Laboratories, Livermore, CA); Krafcik, Karen L. (Sandia National Laboratories, Livermore, CA); Morales, Alfredo Martin (Sandia National Laboratories, Livermore, CA); Mills, Bernice E. (Sandia National Laboratories, Livermore, CA); Liu, Shiling (Sandia National Laboratories, Livermore, CA); Lee, Jeremiah C. (Sandia National Laboratories, Livermore, CA); Karpetis, Adionos N. (Sandia National Laboratories, Livermore, CA); Chen, Jacqueline H. (Sandia National Laboratories, Livermore, CA); Ceremuga, Joseph T. (Sandia National Laboratories, Livermore, CA); Raber, Thomas N. (Sandia National Laboratories, Livermore, CA); Hekmuuaty, Michelle A. (Sandia National Laboratories, Livermore, CA)

2005-05-01

prototypes to verify the design. A final high precision engine was created via LIGA. The micro-combustor was based on an excess enthalpy concept. Development of a micro-combustor included both modeling and experiments. We developed a suite of simulation tools both in support of the design of the prototype combustors, and to investigate more fundamental aspects of combustion at small scales. Issues of heat management and integration with the micro-scale Stirling engine were pursued using CFD simulations. We found that by choice of the operating conditions and channel dimensions energy conversion occurs by catalysis-dominated or catalysis-then-homogeneous phase combustion. The purpose of the experimental effort in micro-combustion was to study the feasibility and explore the design parameters of excess enthalpy combustors. The efforts were guided by the necessity for a practical device that could be implemented in a miniature power generator, or as a stand-alone device used for heat generation. Several devices were fabricated and successfully tested using methane as the fuel.

Dynamic performance improvement of standalone battery integrated PMSG wind energy system using proportional resonant controller

Directory of Open Access Journals (Sweden)

Dileep Kumar Varma Sagiraju

2017-08-01

Full Text Available The load voltage and frequency should be controlled under steady state and transient conditions in off grid applications. Power quality and power management is very important task for rural communities under erratic wind and load conditions. This paper presents a coordinated Proportional resonant (PR and battery energy controller for enhancement of power quality and power management in direct drive standalone wind energy system. The dynamic performance of standalone direct drive Permanent Magnet Synchronous Generator (PMSG is investigated with the proposed control scheme under various operating conditions such as fluctuating wind with step increase and decrease in wind velocity, balanced and unbalanced load conditions. The proposed PR control strategy with battery energy controller also ensures effective power balance between wind and battery source in order to fulfill the load demand. The superiority of the proposed control strategy is confirmed by comparing with the traditional vector control strategy under fluctuating wind and load conditions through MATLAB/SIMULINK platform.

Discrete-Time Domain Modelling of Voltage Source Inverters in Standalone Applications

DEFF Research Database (Denmark)

Federico, de Bosio; de Sousa Ribeiro, Luiz Antonio; Freijedo Fernandez, Francisco Daniel

2017-01-01

modelling of the LC plant with consideration of delay and sample-and-hold effects on the state feedback cross-coupling decoupling is derived. From this plant formulation, current controllers with wide bandwidth and good relative stability properties are developed. Two controllers based on lead compensation......The decoupling of the capacitor voltage and inductor current has been shown to improve significantly the dynamic performance of voltage source inverters in standalone applications. However, the computation and PWM delays still limit the achievable bandwidth. In this paper a discrete-time domain...

A fully integrated standalone portable cavity ringdown breath acetone analyzer

Science.gov (United States)

Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

2015-09-01

Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

A fully integrated standalone portable cavity ringdown breath acetone analyzer.

Science.gov (United States)

Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

2015-09-01

Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

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.

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.

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.

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

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.

Standalone visualization tool for three-dimensional DRAGON geometrical models

International Nuclear Information System (INIS)

Lukomski, A.; McIntee, B.; Moule, D.; Nichita, E.

2008-01-01

DRAGON is a neutron transport and depletion code able to solve one-, two- and three-dimensional problems. To date DRAGON provides two visualization modules, able to represent respectively two- and three-dimensional geometries. The two-dimensional visualization module generates a postscript file, while the three dimensional visualization module generates a MATLAB M-file with instructions for drawing the tracks in the DRAGON TRACKING data structure, which implicitly provide a representation of the geometry. The current work introduces a new, standalone, tool based on the open-source Visualization Toolkit (VTK) software package which allows the visualization of three-dimensional geometrical models by reading the DRAGON GEOMETRY data structure and generating an axonometric image which can be manipulated interactively by the user. (author)

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%.

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.

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.

The Multi-Agent Transport Simulation MATSim

OpenAIRE

Horni Andreas; Nagel Kai; Axhausen Kay W.

2016-01-01

"The MATSim (Multi-Agent Transport Simulation) software project was started around 2006 with the goal of generating traffic and congestion patterns by following individual synthetic travelers through their daily or weekly activity programme. It has since then evolved from a collection of stand-alone C++ programs to an integrated Java-based framework which is publicly hosted, open-source available, automatically regression tested. It is currently used by about 40 groups throughout the world. T...

Wind Energy System Time-domain (WEST) analyzers using hybrid simulation techniques

Science.gov (United States)

Hoffman, J. A.

1979-01-01

Two stand-alone analyzers constructed for real time simulation of the complex dynamic characteristics of horizontal-axis wind energy systems are described. Mathematical models for an aeroelastic rotor, including nonlinear aerodynamic and elastic loads, are implemented with high speed digital and analog circuitry. Models for elastic supports, a power train, a control system, and a rotor gimbal system are also included. Limited correlation efforts show good comparisons between results produced by the analyzers and results produced by a large digital simulation. The digital simulation results correlate well with test data.

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)

A simple and effective method for construction of Escherichia coli strains proficient for genome engineering.

Directory of Open Access Journals (Sweden)

Young Shin Ryu

Full Text Available Multiplex genome engineering is a standalone recombineering tool for large-scale programming and accelerated evolution of cells. However, this advanced genome engineering technique has been limited to use in selected bacterial strains. We developed a simple and effective strain-independent method for effective genome engineering in Escherichia coli. The method involves introducing a suicide plasmid carrying the λ Red recombination system into the mutS gene. The suicide plasmid can be excised from the chromosome via selection in the absence of antibiotics, thus allowing transient inactivation of the mismatch repair system during genome engineering. In addition, we developed another suicide plasmid that enables integration of large DNA fragments into the lacZ genomic locus. These features enable this system to be applied in the exploitation of the benefits of genome engineering in synthetic biology, as well as the metabolic engineering of different strains of E. coli.

Passive cooling of standalone flat PV module with cotton wick structures

International Nuclear Information System (INIS)

Chandrasekar, M.; Suresh, S.; Senthilkumar, T.; Ganesh karthikeyan, M.

2013-01-01

Highlights: • A simple passive cooling system is developed for standalone flat PV modules. • 30% Reduction in module temperature is observed with developed cooling system. • 15.61% Increase in output power of PV module is found with developed cooling system. • Module efficiency is increased by 1.4% with cooling arrangement. • Lower thermal degradation due to narrow range of temperature characteristics. - Abstract: In common, PV module converts only 4–17% of the incoming solar radiation into electricity. Thus more than 50% of the incident solar energy is converted as heat and the temperature of PV module is increased. The increase in module temperature in turn decreases the electrical yield and efficiency of the module with a permanent structural damage of the module due to prolonged period of thermal stress (also known as thermal degradation of the module). An effective way of improving efficiency and reducing the rate of thermal degradation of a PV module is to reduce the operating temperature of PV module. This can be achieved by cooling the PV module during operation. Hence in the present work, a simple passive cooling system with cotton wick structures is developed for standalone flat PV modules. The thermal and electrical performance of flat PV module with cooling system consisting of cotton wick structures in combination with water, Al 2 O 3 /water nanofluid and CuO/water nanofluid are investigated experimentally. The experimental results are also compared with the thermal and electrical performance of flat PV module without cooling system

FRIEND Engine Framework: a real time neurofeedback client-server system for neuroimaging studies

Science.gov (United States)

Basilio, Rodrigo; Garrido, Griselda J.; Sato, João R.; Hoefle, Sebastian; Melo, Bruno R. P.; Pamplona, Fabricio A.; Zahn, Roland; Moll, Jorge

2015-01-01

In this methods article, we present a new implementation of a recently reported FSL-integrated neurofeedback tool, the standalone version of “Functional Real-time Interactive Endogenous Neuromodulation and Decoding” (FRIEND). We will refer to this new implementation as the FRIEND Engine Framework. The framework comprises a client-server cross-platform solution for real time fMRI and fMRI/EEG neurofeedback studies, enabling flexible customization or integration of graphical interfaces, devices, and data processing. This implementation allows a fast setup of novel plug-ins and frontends, which can be shared with the user community at large. The FRIEND Engine Framework is freely distributed for non-commercial, research purposes. PMID:25688193

FRIEND Engine Framework: A real time neurofeedback client-server system for neuroimaging studies

Directory of Open Access Journals (Sweden)

Rodrigo eBasilio

2015-01-01

Full Text Available In this methods article, we present a new implementation of a recently reported FSL-integrated neurofeedback tool, the standalone version of Functional Real-time Interactive Endogenous Modulation and Decoding (FRIEND. We will refer to this new implementation as the FRIEND Engine Framework. The framework comprises a client-server cross-platform solution for real time fMRI and fMRI/EEG neurofeedback studies, enabling flexible customization or integration of graphical interfaces, devices and data processing. This implementation allows a fast setup of novel plug-ins and frontends, which can be shared with the user community at large. The FRIEND Engine Framework is freely distributed for non-commercial, research purposes.

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)

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

Evaluating a Pre-session Exercise in a Standalone Information Literacy Class

Directory of Open Access Journals (Sweden)

Joseph E. Goetz

2015-12-01

Full Text Available In this study, researchers evaluate a homework exercise assigned before a standalone information literacy session. Students in a Master of Education program completed a worksheet using the ERIC database thesaurus. The researchers conducted pre- and posttests within a single library session to assess student learning, using a control group for comparison. The treatment group did not demonstrate better thesaurus skills than students who had regular library instruction alone, but results pointed the way to targeted improvements of pre-session learning materials. This approach could inform other information literacy homework applications such as flipping the classroom.

A behavioral simulator for switched-capacitor sigma-delta modulator analog-to-digital converter

International Nuclear Information System (INIS)

San, H. Y.; Rezaul Hasan, S. M.

1998-01-01

In this paper, a PC-based simulator for state of the art oversampled switched-capacitor sigma-delta analog-to-digital converters is presented. The proposed simulator employs behavioral model of switched-capacitor integrator and non-linear quantizer to stimulate the system. The behavioral simulation of the integrator is also verified with SPICE. The simulator is fully integrated and standalone. It integrates an input netlist file interpreter, a behavioral simulator, a generic part library and a powerful post-processor to evaluate the SNR, SDR And TSNR. Both passive and active sensitivities can be investigated by the proposed simulator. The simulator is coded in C++, and is very fast

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.

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.

Development of a Closed Loop Simulator for Poloidal Field Control in DIII-D

International Nuclear Information System (INIS)

J.A. Leuer; M.L. Walker; D.A. Humphreys; J.R. Ferron; A. Nerem; B.G. Penaflor

1999-01-01

The design of a model-based simulator of the DIII-D poloidal field system is presented. The simulator is automatically configured to match a particular DIII-D discharge circuit. The simulator can be run in a data input mode, in which prior acquired DIII-D shot data is input to the simulator, or in a stand-alone predictive mode, in which the model operates in closed loop with the plasma control system. The simulator is used to design and validate a multi-input-multi-output controller which has been implemented on DIII-D to control plasma shape. Preliminary experimental controller results are presented

Use of Super-Capacitor to Enhance Charging Performance of Stand-Alone Solar PV System

KAUST Repository

Huang, B. J.

2011-01-01

Introduction: The battery charging performance in a stand-alone solar PV system affects the PV system efficiency and the load operating time. The New Energy Center of National Taiwan University has been devoted to the development of a PWM charging technique to continue charging the lead-acid battery after the overcharge point to increase the battery storage capacity by more than 10%. The present study intends to use the super-capacitor to further increase the charge capacity before the overcharge point of the battery. The super-capacitor is connected in parallel to the lead-acid battery. This will reduce the overall charging impedance during the charge and increase the charging current, especially in sunny weather. A system dynamics model of the lead-acid battery and super-capacitor was derived and the control system simulation was carried out to predict the charging performance for various weathers. It shows that the overall battery impedance decreases and charging power increases with increasing solar radiation. An outdoor comparative test for two identical PV systems with and without supercapacitor was carried out. The use of super-capacitor is shown to be able to increase the lead-acid charging capacity by more than 25% at sunny weather and 10% in cloudy weather. © Springer-Verlag Berlin Heidelberg 2011.

Future engineers: the intrinsic technology motivation of secondary school pupils

Science.gov (United States)

Jones, Lewis C. R.; McDermott, Hilary J.; Tyrer, John R.; Zanker, Nigel P.

2018-07-01

The supply of students motivated to study engineering in higher education is critical to the sector. Results are presented from the 'Mindsets STEM Enhancement Project'. Fifty-seven new resources packs, designed to improve STEM education in Design and Technology, were given to schools across London. A modified Intrinsic Motivation Inventory questionnaire measured pupils' (n = 458) motivation towards technology. The results show that although pupils have positive reactions to the technology content within Design and Technology lessons, the type of STEM resources and lessons created through the project had made no significant difference on pupils' interest/enjoyment towards technology. This suggests stand-alone resources do not improve pupil motivation. The impact of this work to engineering higher education is that the existing levels and the inability to improve pupil motivation in technology at school could be a factor affecting the pursuit of a technology or engineering related education or career.

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...

A feasibility study of a stand-alone hybrid solar–wind–battery system for a remote island

International Nuclear Information System (INIS)

Ma, Tao; Yang, Hongxing; Lu, Lin

2014-01-01

Highlights: • A feasibility study of a hybrid solar–wind–battery system is carried out. • Techno-economic evaluation is conducted for this proposed system. • Thousands of cases are simulated to achieve an optimal system configuration. • The performance of the proposed system is analyzed in detail. • A sensitivity analysis on its load and renewable energy resource is performed. - Abstract: This paper presents a detailed feasibility study and techno-economic evaluation of a standalone hybrid solar–wind system with battery energy storage for a remote island. The solar radiation and wind data on this island in 2009 was recorded for this study. The HOMER software was employed to do the simulations and perform the techno-economic evaluation. Thousands of cases have been carried out to achieve an optimal autonomous system configuration, in terms of system net present cost (NPC) and cost of energy (COE). A detailed analysis, description and expected performance of the proposed system were presented. Moreover, the effects of the PV panel sizing, wind turbine sizing and battery bank capacity on the system’s reliability and economic performance were examined. Finally, a sensitivity analysis on its load consumption and renewable energy resource was performed to evaluate the robustness of economic analysis and identify which variable has the greatest impact on the results. The results demonstrate the techno-economic feasibility of implementing the solar–wind–battery system to supply power to this island

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."

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

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

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.

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)

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...

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.

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

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.

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.

Professional Ethics of Software Engineers: An Ethical Framework.

Science.gov (United States)

Lurie, Yotam; Mark, Shlomo

2016-04-01

The purpose of this article is to propose an ethical framework for software engineers that connects software developers' ethical responsibilities directly to their professional standards. The implementation of such an ethical framework can overcome the traditional dichotomy between professional skills and ethical skills, which plagues the engineering professions, by proposing an approach to the fundamental tasks of the practitioner, i.e., software development, in which the professional standards are intrinsically connected to the ethical responsibilities. In so doing, the ethical framework improves the practitioner's professionalism and ethics. We call this approach Ethical-Driven Software Development (EDSD), as an approach to software development. EDSD manifests the advantages of an ethical framework as an alternative to the all too familiar approach in professional ethics that advocates "stand-alone codes of ethics". We believe that one outcome of this synergy between professional and ethical skills is simply better engineers. Moreover, since there are often different software solutions, which the engineer can provide to an issue at stake, the ethical framework provides a guiding principle, within the process of software development, that helps the engineer evaluate the advantages and disadvantages of different software solutions. It does not and cannot affect the end-product in and of-itself. However, it can and should, make the software engineer more conscious and aware of the ethical ramifications of certain engineering decisions within the process.

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.

State Feedback Decoupling with In-Loop Lead Compensator in Stand-Alone VSIs

DEFF Research Database (Denmark)

Federico, de Bosio; Pastorelli, Michele; de Sousa Ribeiro, Luiz Antonio

2016-01-01

The performance of current and voltage regulators during transients and steady-state is of primary concern for power converters intended for stand-alone applications. Dynamics performance and command tracking capability are enhanced by actively decoupling the controlled states variables. To further...... widen the current loop bandwidth while still preserving a well-damped system a lead compensator structure on the forward loop is proposed. A 3 kHz bandwidth with 0.707 damping factor is achieved for the inner current controller. Accordingly, also the voltage regulator bandwidth can be widen, thus...

Design and standalone characterisation of a capacitively coupled HV-CMOS sensor chip for the CLIC vertex detector

Science.gov (United States)

Kremastiotis, I.; Ballabriga, R.; Campbell, M.; Dannheim, D.; Fiergolski, A.; Hynds, D.; Kulis, S.; Peric, I.

2017-09-01

The concept of capacitive coupling between sensors and readout chips is under study for the vertex detector at the proposed high-energy CLIC electron positron collider. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is an active High-Voltage CMOS sensor, designed to be capacitively coupled to the CLICpix2 readout chip. The chip is implemented in a commercial 180 nm HV-CMOS process and contains a matrix of 128×128 square pixels with 25μm pitch. First prototypes have been produced with a standard resistivity of ~20 Ωcm for the substrate and tested in standalone mode. The results show a rise time of ~20 ns, charge gain of 190 mV/ke- and ~40 e- RMS noise for a power consumption of 4.8μW/pixel. The main design aspects, as well as standalone measurement results, are presented.

Stand-Alone Ethics, Social Responsibility, and Sustainability Course Requirements: A Snapshot from Australia and New Zealand

Science.gov (United States)

Rundle-Thiele, Sharyn R.; Wymer, Walter

2010-01-01

This article analyzes the extent to which Australian and New Zealand marketing educators use dedicated or stand-alone courses to equip students with alternative views of business. A census of marketing programs in degree-granting universities was conducted. Program brochures were obtained via the Internet and were content analyzed. This study…

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.

Development of a microprocessor controller for stand-alone photovoltaic power systems

Science.gov (United States)

Millner, A. R.; Kaufman, D. L.

1984-01-01

A controller for stand-alone photovoltaic systems has been developed using a low power CMOS microprocessor. It performs battery state of charge estimation, array control, load management, instrumentation, automatic testing, and communications functions. Array control options are sequential subarray switching and maximum power control. A calculator keypad and LCD display provides manual control, fault diagnosis and digital multimeter functions. An RS-232 port provides data logging or remote control capability. A prototype 5 kW unit has been built and tested successfully. The controller is expected to be useful in village photovoltaic power systems, large solar water pumping installations, and other battery management applications.

The integration of two stand-alone codes to simulate fluid-structure interaction in breakwaters / Jan Hendrik Grobler

OpenAIRE

Grobler, Jan Hendrik

2013-01-01

Harbours play a vital role in the economies of most countries since a significant amount of international trade is conducted through them. Ships rely on harbours for the safe loading and unloading of cargo and the harbour infrastructure relies on breakwaters for protection. As a result, the design and analysis of breakwaters receives keen interest from the engineering community. Coastal engineers need an easy-to-use tool that can model the way in which waves interact with large ...

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.

Search Improvement Process-Chaotic Optimization-Particle Swarm Optimization-Elite Retention Strategy and Improved Combined Cooling-Heating-Power Strategy Based Two-Time Scale Multi-Objective Optimization Model for Stand-Alone Microgrid Operation

Directory of Open Access Journals (Sweden)

Fei Wang

2017-11-01

Full Text Available The optimal dispatching model for a stand-alone microgrid (MG is of great importance to its operation reliability and economy. This paper aims at addressing the difficulties in improving the operational economy and maintaining the power balance under uncertain load demand and renewable generation, which could be even worse in such abnormal conditions as storms or abnormally low or high temperatures. A new two-time scale multi-objective optimization model, including day-ahead cursory scheduling and real-time scheduling for finer adjustments, is proposed to optimize the operational cost, load shedding compensation and environmental benefit of stand-alone MG through controllable load (CL and multi-distributed generations (DGs. The main novelty of the proposed model is that the synergetic response of CL and energy storage system (ESS in real-time scheduling offset the operation uncertainty quickly. And the improved dispatch strategy for combined cooling-heating-power (CCHP enhanced the system economy while the comfort is guaranteed. An improved algorithm, Search Improvement Process-Chaotic Optimization-Particle Swarm Optimization-Elite Retention Strategy (SIP-CO-PSO-ERS algorithm with strong searching capability and fast convergence speed, was presented to deal with the problem brought by the increased errors between actual renewable generation and load and prior predictions. Four typical scenarios are designed according to the combinations of day types (work day or weekend and weather categories (sunny or rainy to verify the performance of the presented dispatch strategy. The simulation results show that the proposed two-time scale model and SIP-CO-PSO-ERS algorithm exhibit better performance in adaptability, convergence speed and search ability than conventional methods for the stand-alone MG’s operation.

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.

Grid parity analysis of stand-alone hybrid microgrids: A comparative study of Germany, Pakistan, South Africa and the United States

Science.gov (United States)

Siddiqui, Jawad M.

Grid parity for alternative energy resources occurs when the cost of electricity generated from the source is lower than or equal to the purchasing price of power from the electricity grid. This thesis aims to quantitatively analyze the evolution of hybrid stand-alone microgrids in the US, Germany, Pakistan and South Africa to determine grid parity for a solar PV/Diesel/Battery hybrid system. The Energy System Model (ESM) and NREL's Hybrid Optimization of Multiple Energy Resources (HOMER) software are used to simulate the microgrid operation and determine a Levelized Cost of Electricity (LCOE) figure for each location. This cost per kWh is then compared with two distinct estimates of future retail electricity prices at each location to determine grid parity points. Analysis results reveal that future estimates of LCOE for such hybrid stand-alone microgrids range within the 35-55 cents/kWh over the 25 year study period. Grid parity occurs earlier in locations with higher power prices or unreliable grids. For Pakistan grid parity is already here, while Germany hits parity between the years 2023-2029. Results for South Africa suggest a parity time range of the years 2040-2045. In the US, places with low grid prices do not hit parity during the study period. Sensitivity analysis results reveal the significant impact of financing and the cost of capital on these grid parity points, particularly in developing markets of Pakistan and South Africa. Overall, the study helps conclude that variations in energy markets may determine the fate of emerging energy technologies like microgrids. However, policy interventions have a significant impact on the final outcome, such as the grid parity in this case. Measures such as eliminating uncertainty in policies and improving financing can help these grids overcome barriers in developing economies, where they may find a greater use much earlier in time.

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.

Design of a Stand-Alone Photovoltaic (PV Models for Home Lightings and Clean Environment

Directory of Open Access Journals (Sweden)

Vincent Anayochukwu Ani

2016-01-01

Full Text Available This paper gives a well-documented health risks of fuel-based lighting (kerosene lamps and fuel-powered generators and proposed a design of a stand-alone solar PV system for sustainable home lightings in rural Nigerian area. The design was done in three different patterns of electricity consumptions with energy efficient lightings (EELs using two different battery types (Rolls Surrette 6CS25PS and hoppecke 10 OpzS 1000 on; i judicious power consumption, ii normal power consumption, iii excess power consumption; and compared them with the incandescent light bulb consumption. The stand-alone photovoltaic energy systems were designed to match the rural Nigerian sunlight and weather conditions to meet the required lightings of the household. The objective function and constraints for the design models were formulated and optimization procedure were used to demonstrate the best solution (reliability at the lowest lifecycle cost. Initial capital costs as well as annualized costs over 5, 10, 15, 20, and 25 years were quantified and documented. The design identified the most cost-effective and reliable solar and battery array among the patterns of electricity consumption with energy efficient lighting options (judicious power consumption, normal power consumption, and excess power consumption.

Standalone computer-aided detection compared to radiologists' performance for the detection of mammographic masses

International Nuclear Information System (INIS)

Hupse, Rianne; Samulski, Maurice; Imhof-Tas, Mechli W.; Karssemeijer, Nico; Lobbes, Marc; Boetes, Carla; Heeten, Ard den; Beijerinck, David; Pijnappel, Ruud

2013-01-01

We developed a computer-aided detection (CAD) system aimed at decision support for detection of malignant masses and architectural distortions in mammograms. The effect of this system on radiologists' performance depends strongly on its standalone performance. The purpose of this study was to compare the standalone performance of this CAD system to that of radiologists. In a retrospective study, nine certified screening radiologists and three residents read 200 digital screening mammograms without the use of CAD. Performances of the individual readers and of CAD were computed as the true-positive fraction (TPF) at a false-positive fraction of 0.05 and 0.2. Differences were analysed using an independent one-sample t-test. At a false-positive fraction of 0.05, the performance of CAD (TPF = 0.487) was similar to that of the certified screening radiologists (TPF = 0.518, P = 0.17). At a false-positive fraction of 0.2, CAD performance (TPF = 0.620) was significantly lower than the radiologist performance (TPF = 0.736, P <0.001). Compared to the residents, CAD performance was similar for all false-positive fractions. The sensitivity of CAD at a high specificity was comparable to that of human readers. These results show potential for CAD to be used as an independent reader in breast cancer screening. (orig.)

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

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

Proposed Framework for the Evaluation of Standalone Corpora Processing Systems: An Application to Arabic Corpora

Directory of Open Access Journals (Sweden)

Abdulmohsen Al-Thubaity

2014-01-01

Full Text Available Despite the accessibility of numerous online corpora, students and researchers engaged in the fields of Natural Language Processing (NLP, corpus linguistics, and language learning and teaching may encounter situations in which they need to develop their own corpora. Several commercial and free standalone corpora processing systems are available to process such corpora. In this study, we first propose a framework for the evaluation of standalone corpora processing systems and then use it to evaluate seven freely available systems. The proposed framework considers the usability, functionality, and performance of the evaluated systems while taking into consideration their suitability for Arabic corpora. While the results show that most of the evaluated systems exhibited comparable usability scores, the scores for functionality and performance were substantially different with respect to support for the Arabic language and N-grams profile generation. The results of our evaluation will help potential users of the evaluated systems to choose the system that best meets their needs. More importantly, the results will help the developers of the evaluated systems to enhance their systems and developers of new corpora processing systems by providing them with a reference framework.

Proposed framework for the evaluation of standalone corpora processing systems: an application to Arabic corpora.

Science.gov (United States)

Al-Thubaity, Abdulmohsen; Al-Khalifa, Hend; Alqifari, Reem; Almazrua, Manal

2014-01-01

Despite the accessibility of numerous online corpora, students and researchers engaged in the fields of Natural Language Processing (NLP), corpus linguistics, and language learning and teaching may encounter situations in which they need to develop their own corpora. Several commercial and free standalone corpora processing systems are available to process such corpora. In this study, we first propose a framework for the evaluation of standalone corpora processing systems and then use it to evaluate seven freely available systems. The proposed framework considers the usability, functionality, and performance of the evaluated systems while taking into consideration their suitability for Arabic corpora. While the results show that most of the evaluated systems exhibited comparable usability scores, the scores for functionality and performance were substantially different with respect to support for the Arabic language and N-grams profile generation. The results of our evaluation will help potential users of the evaluated systems to choose the system that best meets their needs. More importantly, the results will help the developers of the evaluated systems to enhance their systems and developers of new corpora processing systems by providing them with a reference framework.

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.

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.

A Simple Sizing Algorithm for Stand-Alone PV/Wind/Battery Hybrid Microgrids

Directory of Open Access Journals (Sweden)

Jing Li

2012-12-01

Full Text Available In this paper, we develop a simple algorithm to determine the required number of generating units of wind-turbine generator and photovoltaic array, and the associated storage capacity for stand-alone hybrid microgrid. The algorithm is based on the observation that the state of charge of battery should be periodically invariant. The optimal sizing of hybrid microgrid is given in the sense that the life cycle cost of system is minimized while the given load power demand can be satisfied without load rejection. We also report a case study to show the efficacy of the developed algorithm.

Process support for Opticam: a concurrent engineering approach

Science.gov (United States)

Czajkowski, Walter C.; Tipps, Joe D., Jr.

1992-12-01

Although the principles of concurrent engineering and rapid product cycles are not new concepts in the industrial sector, the optics manufacturing industry has witnessed few technological advances since the 1940's. At present the optics industry maintains outdated stand-alone manufacturing equipment and systems that do little to foster integration or communications. 'Islands of Technology', spawned from the latest offerings of CNC controlled equipment, are generally stand alone systems incapable of supporting communication with other process equipment, not to mention the total business enterprise. This approach increases the cost in design and manufacture of optical systems while negatively impacting competitiveness in the global marketplace.

Cycle Engine Modelling Of Spark Ignition Engine Processes during Wide-Open Throttle (WOT) Engine Operation Running By Gasoline Fuel

International Nuclear Information System (INIS)

Rahim, M F Abdul; Rahman, M M; Bakar, R A