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NASA Network Resource and Training Site
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Selected papers from MODSIM World 2011 Conference & Expo are contained in this NASA Conference Publication (CP). MODSIM World 2011 was held in Virginia Beach, Virginia, October 11-14, 2011. The theme of the 2011 conference & expo was "Overcoming Critical Global Challenges with Modeling & Simulation". The conference program consisted of five technical tracks - Defense, Homeland Security & First Responders; Education; Health & Medicine; The Human Dimension; and...
Topics: NASA Technical Reports Server (NTRS), COGNITION, GAME THEORY, COMPUTERIZED SIMULATION, DECISION...
Simulation and analysis of vehicle performance is essential for design of a new launch vehicle system. It is more and more demand to have an integrated, highly efficient, robust simulation tool with graphical user interface (GUI) for vehicle performance and simulations. The objectives of this project are to integrate and develop launch vehicle simulation and analysis tools in MATLAB/Simulink under PC Platform, to develop a vehicle capable of being launched on a Delta-IV Heavy Launch Vehicle...
Topics: NASA Technical Reports Server (NTRS), CARGO, FLIGHT SIMULATION, AEROSPACE VEHICLES, SYSTEMS...
NASA Network Resource and Training Site
Jun 1, 2001 NASA Technical Reports Server (NTRS)
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This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on June 19-21, 2001. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to attitude/orbit determination, prediction and control; attitude simulation; attitude sensor calibration; theoretical foundation of attitude computation; dynamics model improvements; autonomous navigation;...
Topics: NASA Technical Reports Server (NTRS), ATTITUDE (INCLINATION), GUIDANCE (MOTION), NAVIGATION, ORBIT...
NASA Network Resource and Training Site
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In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Fifth International Symposium on Magnetic Suspension Technology was held at the Radisson Hotel Santa Barbara, Santa Barbara, California, on December 1-3, 1999. The symposium included 18 sessions in which a total of 53 papers were presented. The technical sessions covered the areas of...
Topics: NASA Technical Reports Server (NTRS), CONFERENCES, MAGNETIC SUSPENSION, SUPERCONDUCTING MAGNETS,...
NASA Network Resource and Training Site
Apr 1, 1998 NASA Technical Reports Server (NTRS)
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An aerodynamic uncertainty model for the X-33 single-stage-to-orbit demonstrator aircraft has been developed at NASA Dryden Flight Research Center. The model is based on comparisons of historical flight test estimates to preflight wind-tunnel and analysis code predictions of vehicle aerodynamics documented during six lifting-body aircraft and the Space Shuttle Orbiter flight programs. The lifting-body and Orbiter data were used to define an appropriate uncertainty magnitude in the subsonic and...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, X-33 REUSABLE LAUNCH VEHICLE,...
The feasibility of simulating and synthesizing substructures by computational neural network models is illustrated by investigating a statically indeterminate beam, using both a 1-D and a 2-D plane stress modelling. The beam can be decomposed into two cantilevers with free-end loads. By training neural networks to simulate the cantilever responses to different loads, the original beam problem can be solved as a match-up between two subsystems under compatible interface conditions. The genetic...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, NETWORK SYNTHESIS, SUBSTRUCTURES,...
NASA Network Resource and Training Site
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A study of various aspects of Adjustable Speed Drives (ASD) is presented. A summary of the relative merits of different ASD systems presently in vogue is discussed. The advantages of using microcomputer based ASDs is now widely understood and accepted. Of the three most popular drive systems, namely the Induction Motor Drive, Switched Reluctance Motor Drive and Brushless DC Motor Drive, any one may be chosen. The choice would depend on the nature of the application and its requirements. The...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, MECHANICAL DRIVES, INDUCTION MOTORS,...
The proceedings of the Benchmark Problems in Computational Aeroacoustics Workshop held at NASA Langley Research Center are the subject of this report. The purpose of the Workshop was to assess the utility of a number of numerical schemes in the context of the unusual requirements of aeroacoustical calculations. The schemes were assessed from the viewpoint of dispersion and dissipation -- issues important to long time integration and long distance propagation in aeroacoustics. Also investigated...
Topics: NASA Technical Reports Server (NTRS), ACOUSTIC PROPAGATION, AEROACOUSTICS, COMPUTATIONAL FLUID...
NASA LeRC is currently developing a FORTRAN based computer model of a complete nuclear electric propulsion (NEP) vehicle that can be used for piloted and cargo missions to the Moon or Mars. Proposed designs feature either a Brayton or a K-Rankine power conversion cycle to drive a turbine coupled with rotary alternators. Both ion and magnetoplasmodynamic (MPD) thrusters will be considered in the model. In support of the NEP model, Rocketdyne is developing power conversion, heat rejection, and...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, HEAT PIPES, NUCLEAR ELECTRIC...
NASA Network Resource and Training Site
Nov 1, 1992 NASA Technical Reports Server (NTRS)
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The role of multistage turbomachinery simulation in the development of propulsion system models is discussed. Particularly, the need for simulations with higher fidelity and faster turnaround time is highlighted. It is shown how such fast simulations can be used in engineering-oriented environments. The use of parallel processing to achieve the required turnaround times is discussed. Current work by several researchers in this area is summarized. Parallel turbomachinery CFD research at the NASA...
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, COMPUTERIZED SIMULATION,...
NASA Network Resource and Training Site
Feb 1, 1992 NASA Technical Reports Server (NTRS)
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The Planet Surface Systems Office at the NASA Johnson Space Center has participated in an analysis of the Space Exploration Initiative architectures described in the Synthesis Group report. This effort involves a Systems Engineering and Integration effort to define point designs for evolving lunar and Mars bases that support substantial science, exploration, and resource production objectives. The analysis addresses systems-level designs; element requirements and conceptual designs; assessments...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, EXTRATERRESTRIAL RESOURCES, LUNAR...
NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefiting other supercomputer centers...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE ENGINEERING, COMPUTATIONAL FLUID DYNAMICS,...
NASA Network Resource and Training Site
Sep 1, 1991 NASA Technical Reports Server (NTRS)
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MPD (MagnetoPlasmaDynamic) thrusters demonstrated between 2000 and 7000 seconds specific impulse at efficiencies approaching 40 percent, and were operated continuously at power levels over 500 kW. These demonstrated capabilities, combined with the simplicity and robustness of the thruster, make them attractive candidates for application to both unmanned and manned orbit raising, lunar, and planetary missions. To date, however, only a limited number of thruster configurations, propellants, and...
Topics: NASA Technical Reports Server (NTRS), ELECTRIC ROCKET ENGINES, MAGNETOPLASMADYNAMICS, NUCLEAR...
A collection of papers presented at the Fourth NASA Workshop on Computational Control of Flexible Aerospace Systems is given. The papers address modeling, systems identification, and control of flexible aircraft, spacecraft and robotic systems.
Topics: NASA Technical Reports Server (NTRS), AEROSPACE SYSTEMS, AIRCRAFT CONTROL, CONFERENCES, DYNAMIC...
NASA Network Resource and Training Site
Aug 15, 1990 NASA Technical Reports Server (NTRS)
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The topics of volume 2 of First CLIPS Conference are associated with following applications: quality control; intelligent data bases and networks; Space Station Freedom; Space Shuttle and satellite; user interface; artificial neural systems and fuzzy logic; parallel and distributed processing; enchancements to CLIPS; aerospace; simulation and defense; advisory systems and tutors; and intelligent control.
Topics: NASA Technical Reports Server (NTRS), ARTIFICIAL INTELLIGENCE, C (PROGRAMMING LANGUAGE),...
Given here are selected scientific results from the Numerical Aerodynamic Simulation (NAS) Program's third year of operation. During this year, the scientific community was given access to a Cray-2 and a Cray Y-MP supercomputer. Topics covered include flow field analysis of fighter wing configurations, large-scale ocean modeling, the Space Shuttle flow field, advanced computational fluid dynamics (CFD) codes for rotary-wing airloads and performance prediction, turbulence modeling of separated...
Topics: NASA Technical Reports Server (NTRS), ACOUSTICS, COMPUTATIONAL FLUID DYNAMICS, COMPUTERIZED...
NASA scientific and technical information (STI) programs are discussed. Topics include management of information in a research and development agency, the new space and Earth science information systems at NASA's archive, scientific and technical information management, and technology transfer of NASA aerospace technology to other industries.
Topics: NASA Technical Reports Server (NTRS), AEROSPACE TECHNOLOGY TRANSFER, DATA BASES, INFORMATION...
NASA Network Resource and Training Site
1990 NASA Technical Reports Server (NTRS)
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An overview is given of research activity on the application of computational fluid dynamics (CDF) for hypersonic propulsion systems. After the initial consideration of the highly integrated nature of air-breathing hypersonic engines and airframe, attention is directed toward computations carried out for the components of the engine. A generic inlet configuration is considered in order to demonstrate the highly three dimensional viscous flow behavior occurring within rectangular inlets....
Topics: NASA Technical Reports Server (NTRS), AIR BREATHING ENGINES, AIRFRAMES, COMPUTATIONAL FLUID...
This report contains numerous color illustrations to describe the NASA programs in aeronautics. The basic ideas involved are explained in brief paragraphs. The seven chapters deal with Subsonic aircraft, High-speed transport, High-performance military aircraft, Hypersonic/Transatmospheric vehicles, Critical disciplines, National facilities and Organizations & installations. Some individual aircraft discussed are : the SR-71 aircraft, aerospace planes, the high-speed civil transport (HSCT),...
Topics: NASA Technical Reports Server (NTRS), AERONAUTICS, AEROSPACE PLANES, COMPUTATIONAL FLUID DYNAMICS,...
This volume of the conference proceedings contain papers and discussions in the following topical areas: Parallel processing; Emerging integrated capabilities; Low order controllers; Real time simulation; Multibody component representation; User environment; and Distributed parameter techniques.
Topics: NASA Technical Reports Server (NTRS), COMPUTER NETWORKS, COMPUTERIZED SIMULATION, CONFERENCES,...
The Simulation Computer System (SCS) concept document describes and establishes requirements for the functional performance of the SCS system, including interface, logistic, and qualification requirements. The SCS is the computational communications and display segment of the Marshall Space Flight Center (MSFC) Payload Training Complex (PTC). The PTC is the MSFC facility that will train onboard and ground operations personnel to operate the payloads and experiments on board the international...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, GROUND OPERATIONAL SUPPORT SYSTEM,...
NASA Network Resource and Training Site
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This three-part document contains a collection of technical papers presented at the Second NASA/Air Force Symposium on Recent Advances in Multidisciplinary Analysis and Optimization, held September 28-30, 1988 in Hampton, Virginia. The topics covered include: helicopter design, aeroelastic tailoring, control of aeroelastic structures, dynamics and control of flexible structures, structural design, design of large engineering systems, application of artificial intelligence, shape optimization,...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT DESIGN, COMPUTATIONAL FLUID DYNAMICS, COMPUTER AIDED...
The primary objective was to develop conceptual designs of two pilot plants to produce oxygen from lunar materials. A lunar pilot plant will be used to generate engineering data necessary to support an optimum design of a larger scale production plant. Lunar oxygen would be of primary value as spacecraft propellant oxidizer. In addition, lunar oxygen would be useful for servicing nonregenerative fuel cell power systems, providing requirements for life support, and to make up oxygen losses from...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, LUNAR SOIL, OXYGEN PRODUCTION, PILOT...
NASA Network Resource and Training Site
Jun 13, 1988 NASA Technical Reports Server (NTRS)
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Spin and despin requirements; sequence of activities required to assemble the Variable Gravity Research Facility (VGRF); power systems technology; life support; thermal control systems; emergencies; communication systems; space station applications; experimental activities; computer modeling and simulation of tether vibration; cost analysis; configuration of the crew compartments; and tether lengths and rotation speeds are discussed.
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, EARTH GRAVITATION, EXPERIMENT...
NASA Network Resource and Training Site
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NASA Lewis Research Center and its prime contractor are responsible for developing the electrical power system on the space station. The power system will be controlled by a network of distributed processors. Control software will be verified, validated, and tested in hardware and software test beds. Current plans for the software test bed involve using real time and nonreal time simulations of the power system. This paper will discuss the general simulation objectives and configurations,...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, PERFORMANCE TESTS, PROVING, SPACE...
NASA Network Resource and Training Site
Nov 1, 1987 NASA Technical Reports Server (NTRS)
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This bibliography lists 967 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1987 and June 30, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly...
Topics: NASA Technical Reports Server (NTRS), MISSION PLANNING, SPACE STATION POWER SUPPLIES, SPACE STATION...
A laboratory facility for the study of control laws for large flexible spacecraft is described. The facility fulfills the requirements of the Spacecraft Control Laboratory Experiment (SCOLE) design challenge for a laboratory experiment, which will allow slew maneuvers and pointing operations. The structural apparatus is described in detail sufficient for modelling purposes. The sensor and actuator types and characteristics are described so that identification and control algorithms may be...
Topics: NASA Technical Reports Server (NTRS), FLEXIBLE SPACECRAFT, LARGE SPACE STRUCTURES, RESEARCH...
NASA Network Resource and Training Site
Dec 1, 1984 NASA Technical Reports Server (NTRS)
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High chamber pressure expander cycles proposed for orbit transfer vehicles depend primarily on the heat energy transmitted from the combustion products through the thrust wall chamber wall. The heat transfer to the nozzle wall is affected by such variables as wall roughness, relamarization, and the presence of particles in the flow. Motor performance loss for these nozzles with thick boundary layers is inaccurate using the existing procedure coded BLIMPJ. Modifications and innovations to the...
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYERS, COMPUTERIZED SIMULATION, ENGINE DESIGN,...
Predictions of a free-piston Stirling engine model are compared with RE1000 engine test data taken at NASA-Lewis Research Center. The model validation and the engine testing are being done under a joint interagency agreement between the Department of Energy's Oak Ridge National Laboratory and NASA-Lewis. A kinematic code developed at Lewis was upgraded to permit simulation of free-piston engine performance; it was further upgraded and modified at Lewis and is currently being validated. The...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, MATHEMATICAL MODELS, PERFORMANCE...
NASA Network Resource and Training Site
May 14, 1982 NASA Technical Reports Server (NTRS)
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The aerosol generator and the charge flow devices (CFD) chamber which were designed for zero-gravity operation was analyzed. Characteristics of the CFD chamber and aerosol generator which would be useful for cloud physics experimentation in a one-g as well as a zero-g environment are documented. The Collision type of aerosol generator is addressed. Relationships among the various input and output parameters are derived and subsequently used to determine the requirements on the controls of the...
Topics: NASA Technical Reports Server (NTRS), AEROSOLS, CHARGE FLOW DEVICES, CLOUD PHYSICS, WEIGHTLESSNESS,...
NASA Network Resource and Training Site
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A functional prototype of an electric vehicle ac propulsion system was built consisting of a 18.65 kW rated ac induction traction motor, pulse width modulated (PWM) transistorized inverter, two speed mechanically shifted automatic transmission, and an overall drive/vehicle controller. Design developmental steps, and test results of individual components and the complex system on an instrumented test frame are described. Computer models were developed for the inverter, motor and a representative...
Topics: NASA Technical Reports Server (NTRS), ALTERNATING CURRENT, ELECTRIC MOTOR VEHICLES, INVERTERS,...
NASA Network Resource and Training Site
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Seventeen propulsion system concepts for electric vehicles were compared to determine the differences in components and battery pack to achieve the basic performance level. Design tradeoffs were made for selected configurations to find the optimum component characteristics required to meet all performance goals. The anticipated performance when using nickel-zinc batteries rather than the standard lead-acid batteries was also evaluated. The two systems selected for the final conceptual design...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, ELECTRIC MOTOR VEHICLES, PROPULSION...
A mathematical model was developed and computerized simulations were obtained for a brushless dc motor. Experimentally obtained oscillograms of the machine phase currents are presented and the corresponding current and voltage waveforms for various modes of operation of the motor are presented and discussed.
Topics: NASA Technical Reports Server (NTRS), ELECTRIC MOTORS, ENGINE DESIGN, ENGINE TESTS, MATHEMATICAL...
The LOVES computer code developed to investigate the concept of space servicing operational satellites as an alternative to replacing expendable satellites or returning satellites to earth for ground refurbishment is presented. In addition to having the capability to simulate the expendable satellite operation and the ground refurbished satellite operation, the program is designed to simulate the logistics of space servicing satellites using an upper stage vehicle and/or the earth to orbit...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, MANNED SPACECRAFT, SPACE MAINTENANCE,...
NASA Network Resource and Training Site
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The droplet coalescence kinetics at 0 g and 1 g were considered for two systems which contained liquid droplets in a host liquid. One of these (Al-In) typified a system containing a liquid phase miscibility gap and the order (oil-water) a mixture of two essentially insoluble liquids. A number of coalescence mechanisms potentially prominent at low g in this system were analyzed and explanations are presented for the observed unusual stability of the emulsion. Ground base experiments were...
Topics: NASA Technical Reports Server (NTRS), LIQUID PHASES, MICROGRAVITY, SOLUBILITY, COMPUTERIZED...