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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9

All sources NASA NTRS DOE OSTI

NASA NTRS1979

Near-term hybrid vehicle program, phase 1. Appendix B: Design trade-off studies

The relative attractiveness of various hybrid/electric power train configurations and electrical and mechanical drive-line components was studied. The initial screening was concerned primarily with total vehicle weight and economic factors and identified the hybrid power train combinations which warranted detailed evaluation over various driving cycles. This was done using a second-by-second vehicle simulation program which permitted the calculations of fuel economy, electricity usage, and emissions as a function of distance traveled in urban and highway driving. Power train arrangement possibilities were examined in terms of their effect on vehicle handling, safety, serviceability, and passenger comfort. A dc electric drive system utilizing a separately excited motor with field control and battery switching was selected for the near term hybrid vehicle. Hybrid vehicle simulations showed that for the first 30 mi (the electric range of the vehicle) in urban driving, the fuel economy was 80 mpg using a gasoline engine and 100 mpg using a diesel engine. In urban driving the hybrid would save about 75% of the fuel used by the conventional vehicle and in combined urban/highway driving the fuel saving is about 50%.

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NASA NTRS1980

Engineering test facility design definition

The Engineering Test Facility (ETF) is the major focus of the Department of Energy (DOE) Magnetohydrodynamics (MHD) Program to facilitate commercialization and to demonstrate the commercial operability of MHD/steam electric power. The ETF will be a fully integrated commercial prototype MHD power plant with a nominal output of 200 MW sub e. Performance of this plant is expected to meet or surpass existing utility standards for fuel, maintenance, and operating costs; plant availability; load following; safety; and durability. It is expected to meet all applicable environmental regulations. The current design concept conforming to the general definition, the basis for its selection, and the process which will be followed in further defining and updating the conceptual design.

Bercaw, R. W.↗

NASA NTRS1991

Final design of a free-piston hydraulic advanced Stirling conversion system

Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

Wallace, D. A.↗

NASA NTRS1978

OAST space power technology program

The current research and technology (R and T) base program is first described, then special attention is directed toward outlining a new system technology specifically oriented toward providing the utility power plant technology base for semi-permanent earth orbital facilities expected to be needed in the middle to late 1980's. The R and T program involves five areas of research: (1) photovoltaic energy conversion; (2) chemical energy conversion and storage; (3) thermal-to-electric conversion; (4) environment interactions; and (5) power systems management and distribution. The general objectives and planned direction of efforts in each of these areas is summarized.

Mullin, J. P.↗

NASA NTRS1984

A review of electric propulsion systems and mission applications

The satisfaction of growing demands for access to space resources will require new developments related to advanced propulsion and power technologies. A key technology in this context is concerned with the utilization of electric propulsion. A brief review of the current state of development of electric propulsion systems on an international basis is provided, taking into account advances in the USSR, the U.S., Japan, West Germany, China and Brazil. The present investigation, however, is mainly concerned with the U.S. program. The three basic types of electric thrusters are considered along with the intrinsic differences between chemical and electric propulsion, the resistojet, the augmented hydrazine thruster, the arcjet, the ion auxiliary propulsion system flight test, the pulsed plasma thruster, magnetoplasmadynamic propulsion, a pulsed inductive thruster, and rail accelerators. Attention is also given to the applications of electric propulsion.

Vondra, R.↗

NASA NTRS2012

Jet Noise Reduction Potential from Emerging Variable Cycle Technologies

Henderson, Brenda↗

NASA NTRS2012

Jet Noise Reduction Potential From Emerging Variable Cycle Technologies

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NASA NTRS2006

Performance of Solar Electric Powered Deep Space Missions Using Hall Thruster Propulsion

Power limited, low-thrust trajectories were assessed for missions to Jupiter, Saturn, and Neptune utilizing a single Venus Gravity Assist (VGA) and a primary propulsion system based on either a 3-kW high voltage Hall thruster, of the type being developed by the NASA In-Space Propulsion Technology Program, or an 8-kW variant of this thruster. These Hall thrusters operate with specific impulses below 3,000 seconds. A trade study was conducted to examine mission parameters that include: net delivered mass (NDM), beginning-of-life (BOL) solar array power, heliocentric transfer time, required launch vehicle, number of operating thrusters, and throttle profile. The top performing spacecraft configuration was defined to be the one that delivered the highest mass for a range of transfer times. In order to evaluate the potential future benefit of using next generation Hall thrusters as the primary propulsion system, comparisons were made with the advanced state-of-the-art (ASOA), 7-kW, 4,100 second NASA's Evolutionary Xenon Thruster (NEXT) for the same mission scenarios. For the BOL array powers considered in this study (less than 30 kW), the results show that the performance of the Hall thrusters, relative to NEXT, is largely dependant on the performance capability of the launch vehicle, and that at least a 10 percent performance gain, equating to at least an additional 200 kg dry mass at each target planet, is achieved over the higher specific impulse NEXT when launched on an Atlas 551.

Witzberger, Kevin E.↗

NASA NTRS1974

Application of a numerical differencing analyzer computer program to a Modular Integrated Utility System

This paper describes the application of a numerical differencing analyzer computer program to the thermal analyzation of a MIUS model. The MIUS model which was evaluated is one which would be required to support a 648-unit Garden Apartment Complex. This computer program was capable of predicting the thermal performance of this MIUS from the impressed electrical, heating, and cooling loads.

Brandli, A. E.↗

NASA NTRS1980

SPS program review transportation perspective

The delivery of cargo and space workers to the SPS construction site requires the development of two different systems, one to handle large cargo deliveries and a smaller system to accommodate crew. The overall scenario of the transportation system is shown. Eight major elements comprise the transportation system: personnel launch vehicle (PLV) or shuttle; personnel orbital transfer vehicle (POTV); the heavy lift launch vehicle (HLLV); the electric orbital transfer vehicle (EOTV); intra orbit transfer vehicle (IOTV); LEO support facility; GEO support facility and a shuttle derived HLLV (SDHLLV) for supporting the early SPS Demonstration Program. The HLLV and EOTV represent the cargo carriers while the PLV and POTV represent the people carriers. The IOTV is utilized to ferry people and cargo modules over short distances in the vicinity of its station.

Wales, W. W., Jr.↗

NASA NTRS2003

Promising More Information

When NASA needed a real-time, online database system capable of tracking documentation changes in its propulsion test facilities, engineers at Stennis Space Center joined with ECT International, of Brookfield, Wisconsin, to create a solution. Through NASA's Dual-Use Program, ECT developed Exdata, a software program that works within the company's existing Promise software. Exdata not only satisfied NASA s requirements, but also expanded ECT s commercial product line. Promise, ECT s primary product, is an intelligent software program with specialized functions for designing and documenting electrical control systems. An addon to AutoCAD software, Promis e generates control system schematics, panel layouts, bills of material, wire lists, and terminal plans. The drawing functions include symbol libraries, macros, and automatic line breaking. Primary Promise customers include manufacturing companies, utilities, and other organizations with complex processes to control.

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NASA NTRS2012

Advanced Jet Noise Exhaust Concepts in NASA's N+2 Supersonics Validation Study and the Environmentally Responsible Aviation Project's Upcoming Hybrid Wing Body Acoustics Test

Acoustic and flow-field experiments were conducted on exhaust concepts for the next generation supersonic, commercial aircraft. The concepts were developed by Lockheed Martin (LM), Rolls-Royce Liberty Works (RRLW), and General Electric Global Research (GEGR) as part of an N+2 (next generation forward) aircraft system study initiated by the Supersonics Project in NASA s Fundamental Aeronautics Program. The experiments were conducted in the Aero-Acoustic Propulsion Laboratory at the NASA Glenn Research Center. The exhaust concepts presented here utilized lobed-mixers and ejectors. A powered third-stream was implemented to improve ejector acoustic performance. One concept was found to produce stagnant flow within the ejector and the other produced discrete-frequency tones (due to flow separations within the model) that degraded the acoustic performance of the exhaust concept. NASA's Environmentally Responsible Aviation (ERA) Project has been investigating a Hybrid Wing Body (HWB) aircraft as a possible configuration for meeting N+2 system level goals for noise, emissions, and fuel burn. A recently completed NRA led by Boeing Research and Technology resulted in a full-scale aircraft design and wind tunnel model. This model will be tested acoustically in NASA Langley's 14-by 22-Foot Subsonic Tunnel and will include dual jet engine simulators and broadband engine noise simulators as part of the test campaign. The objectives of the test are to characterize the system level noise, quantify the effects of shielding, and generate a valuable database for prediction method development. Further details of the test and various component preparations are described.

Henderson, Brenda S.↗

NASA NTRS1987

Dedicated robotic servicing for the space station

The concept of a series of dedicated robotics manipulators that would be resident in the subsystems of the Space Station is presented. These would be used to do Orbital Replacement Unit (ORU) exchanges, inspection of the components, and in certain cases subsystem assembly. By performing these well-definded tasks automatically, higher crew productivity would be achieved. In order to utilize the robots effectively, ORU's must be designed to allow remote release and quick disconnection of the electrical, fluid, and thermal connections. The robot must be of a modular design for ease of maintenance and must have an adaptive control capability to make-up for slight errors in programming.

Thompson, R. F.↗

NASA NTRS1992

The 1991-1992 walking robot design

The University of Maryland Walking Machine team designed and constructed a robot. This robot was completed in two phases with supervision and suggestions from three professors and one graduate teaching assistant. Bob was designed during the Fall Semester 1991, then machined, assembled, and debugged in the Spring Semester 1992. The project required a total of 4,300 student hours and cost under $8,000. Mechanically, Bob was an exercise in optimization. The robot was designed to test several diverse aspects of robotic potential, including speed, agility, and stability, with simplicity and reliability holding equal importance. For speed and smooth walking motion, the footpath contained a long horizontal component; a vertical aspect was included to allow clearance of obstacles. These challenges were met with a leg design that utilized a unique multi-link mechanism which traveled a modified tear-drop footpath. The electrical requirements included motor, encoder, and voice control circuitry selection, manual controller manufacture, and creation of sensors for guidance. Further, there was also a need for selection of the computer, completion of a preliminary program, and testing of the robot.

Azarm, Shapour↗

NASA NTRS1997

Multi-Disciplinary System Reliability Analysis

The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code developed under the leadership of NASA Lewis Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multi-disciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

Mahadevan, Sankaran↗

NASA NTRS2001

Multidisciplinary System Reliability Analysis

The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code, developed under the leadership of NASA Glenn Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multidisciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

Mahadevan, Sankaran↗

NASA NTRS1995

(abstract) Cassini MLI Balnkets High-Temperature Exposure Tests

The trajectory required for the Cassini spacecraft to reach Saturn will subject the spacecraft to a 0.61 AU temperature environment at perihelion. Temperatures on some sunlit blanket surfaces at 0.61 AU can reach levels that are beyond the service capability of the conventional Mylar/Dacron net MLI. The majority of the blanket surfaces, however, will experience temperatures with an upper bound of 250(deg) C. The maximum allowable temperature for Mylar/Dacron net is determined to be 220(deg)C. Kapton can withstand temperatures in excess of 400(deg) C; however, the high cost of embossed Kapton relative to Mylar/Dacron net requires a baseline design which includes a standard layup and a high-temperature layup. The high-temperature layup is utilized at a limited number of locations, while at least 90% of the blankets are of the standard layup. The verification of both layups' capability to meet all temperature requirements has been accomplished by a comprehensive test program which addressed their high-temperature survivability, effective emittance, and optical and electrical properties. This paper focuses on the high-temperature exposure tests which helped define the hybrid standard layup, and which demonstrated the adequacy of both layups in withstanding their respective thermal environments.

temperature control insulation Cassini↗

NASA NTRS1992

Energy loss analysis of an integrated space power distribution system

The results of studies related to conceptual topologies of an integrated utility-like space power system are described. The system topologies are comparatively analyzed by considering their transmission energy losses as functions of mainly distribution voltage level and load composition. The analysis is expedited by use of a Distribution System Analysis and Simulation (DSAS) software. This recently developed computer program by the Electric Power Research Institute (EPRI) uses improved load models to solve the power flow within the system. However, present shortcomings of the software with regard to space applications, and incompletely defined characteristics of a space power system make the results applicable to only the fundamental trends of energy losses of the topologies studied. Accountability, such as included, for the effects of the various parameters on the system performance can constitute part of a planning tool for a space power distribution system.

Kankam, M. David↗