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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 1,189 records · Page 66
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Sea level static calibration of a compact multimission aircraft propulsion simulator with inlet flow distortion

Wind tunnel tests of propulsion-integrated aircraft models have identified inlet flow distortion as a major source of compressor airflow measurement error in turbine-powered propulsion simulators. Consequently, two Compact Multimission Aircraft Propulsion Simulator (CMAPS) units were statically tested at sea level ambient conditions to establish simulator operating performance characteristics and to calibrate the compressor airflow against an accurate bellmouth flowmeter in the presence of inlet flow distortions. The distortions were generated using various-shaped wire mesh screens placed upstream of the compressor. CMAPS operating maps and performance envelopes were obtained for inlet total pressure distortions (ratio of the difference between the maximum and minimum total pressures to the average total pressure) up to 35 percent, and were compared to baseline simulator operating characteristics for a uniform inlet. Deviations from CMAPS baseline performance were attributed to the coupled variation of both compressor inlet-flow distortion and Reynolds number index throughout the simulator operating envelope for each screen configuration. Four independent methods were used to determine CMAPS compressor airflow; direct compressor inlet and discharge measurements, an entering/exiting flow-balance relationships, and a correlation between the mixer pressure and the corrected compressor airflow. Of the four methods, the last yielded the least scatter in the compressor flow coefficient, approximately + or - 3 percent over the range of flow distortions.

Won, Mark J.↗
NASA NTRS1990

Enhancing space transportation: The NASA program to develop electric propulsion

The NASA Office of Aeronautics, Exploration, and Technology (OAET) supports a research and technology (R and T) program in electric propulsion to provide the basis for increased performance and life of electric thruster systems which can have a major impact on space system performance, including orbital transfer, stationkeeping, and planetary exploration. The program is oriented toward providing high-performance options that will be applicable to a broad range of near-term and far-term missions and vehicles. The program, which is being conducted through the Jet Propulsion Laboratory (JPL) and Lewis Research Center (LeRC) includes research on resistojet, arcjets, ion engines, magnetoplasmadynamic (MPD) thrusters, and electrodeless thrusters. Planning is also under way for nuclear electric propulsion (NEP) as part of the Space Exploration Initiative (SEI).

Bennett, Gary L.↗
NASA NTRS1990

The NASA-Lewis program on fusion energy for space power and propulsion, 1958-1978

An historical synopsis is provided of the NASA-Lewis research program on fusion energy for space power and propulsion systems. It was initiated to explore the potential applications of fusion energy to space power and propulsion systems. Some fusion related accomplishments and program areas covered include: basic research on the Electric Field Bumpy Torus (EFBT) magnetoelectric fusion containment concept, including identification of its radial transport mechanism and confinement time scaling; operation of the Pilot Rig mirror machine, the first superconducting magnet facility to be used in plasma physics or fusion research; operation of the Superconducting Bumpy Torus magnet facility, first used to generate a toroidal magnetic field; steady state production of neutrons from DD reactions; studies of the direct conversion of plasma enthalpy to thrust by a direct fusion rocket via propellant addition and magnetic nozzles; power and propulsion system studies, including D(3)He power balance, neutron shielding, and refrigeration requirements; and development of large volume, high field superconducting and cryogenic magnet technology.

Schulze, Norman R.↗
NASA NTRS1991

NASA aeropropulsion research in support of propulsion systems of the 21st century

A review is given of the NASA's ongoing and planned research and technology programs leading to advanced air breathing propulsion systems of the next century. The primary focus is on efforts being performed or sponsored by NASA-Lewis, with emphasis on civil, subsonic, and supersonic transportation systems which should begin to enter service within 10 to 20 years. Subsonic transport propulsion program elements, including ducted UltraHigh Bypass (UHB) engines and high efficiency cores are discussed in terms of goals, technical issues and problems, approaches and plans. Similarly, The Supersonic Cruise Propulsion Program is reviewed via discussion of near term and far term goals; barrier issues such as NOx and noise reduction and the consequent Phase 1 (near term) research plans are described; and finally, emerging technologies such as the supersonic through-flow fan are considered for their potential long term impact.

Ziemianski, Joseph A.↗
NASA NTRS1991

Stacking the odds in favor of a space propulsion jackpot

When faced with a variety of technical options to solve a problem, program planners often try to identify one potential winner, then channel their resources into this option. The more scarce their resources are perceived to be, the more likely they are to fall into this trap of illogic. The real ideal solution could well be an optimum combination of options, not just one. Many propulsion opportunities are tantalizing solutions to the potentially high cost of travelling to other planets. Among these opportunities, nuclear thermal rockets (NTR), nuclear electric propulsion (NEP), and asteroid derived propellants stand out as high-payoff modest-challenge options, as near term as they are resolved to be made. But which to choose? Or should higher risk higher payoff technology be opted for, such as fusion? The approach advocated here, technoflex, is one that addresses NTR, NEP, and asteroid propellants in harmony rather than in isolation. Technoflex is technology rich, and option flexible. Technoflex should cost roughly the same as a classic phased technology elimination approach. The synergistic benefits amongst these three options, how they can be efficiently pursued together, and how they can fit with longer range technologies are stressed. Even if no single option reaches its highest expectations, the combinations of any two partial winners would still give big dividends. These combinations are cheap propellants in space, dual mode high thrust/low thrust, or versatile propellant NTR. The triple payoff is excellent, even if all three options would pan out below expectations. If only one option reaches its potential, it could make the other two still worth their investment. If all three options meet full expectations, the triple payoff is a space propulsion jackpot which makes concern about the initial investment ludicrous as well as open up the solar system to expedient exploration.

Willoughby, Alan J.↗
NASA NTRS1991

Optimum rocket propulsion for energy-limited transfer

In order to effect large-scale return of extraterrestrial resources to Earth orbit, it is desirable to optimize the propulsion system to maximize the mass of payload returned per unit energy expended. This optimization problem is different from the conventional rocket propulsion optimization. A rocket propulsion system consists of an energy source plus reaction mass. In a conventional chemical rocket, the energy source and the reaction mass are the same. For the transportation system required, however, the best system performance is achieved if the reaction mass used is from a locally available source. In general, the energy source and the reaction mass will be separate. One such rocket system is the nuclear thermal rocket, in which the energy source is a reactor and the reaction mass a fluid which is heated by the reactor and exhausted. Another energy-limited rocket system is the hydrogen/oxygen rocket where H2/O2 fuel is produced by electrolysis of water using a solar array or a nuclear reactor. The problem is to choose the optimum specific impulse (or equivalently exhaust velocity) to minimize the amount of energy required to produce a given mission delta-v in the payload. The somewhat surprising result is that the optimum specific impulse is not the maximum possible value, but is proportional to the mission delta-v. In general terms, at the beginning of the mission it is optimum to use a very low specific impulse and expend a lot of reaction mass, since this is the most energy efficient way to transfer momentum. However, as the mission progresses, it becomes important to minimize the amount of reaction mass expelled, since energy is wasted moving the reaction mass. Thus, the optimum specific impulse will increase with the mission delta-v. Optimum I(sub sp) is derived for maximum payload return per energy expended for both the case of fixed and variable I(sub sp) engines. Sample missions analyzed include return of water payloads from the moons of Mars and of Saturn.

Zuppero, Anthony↗
NASA NTRS1991

The NASA Lewis integrated propulsion and flight control simulator

A new flight simulation facility was developed at NASA-Lewis. The purpose of this flight simulator is to allow integrated propulsion control and flight control algorithm development and evaluation in real time. As a preliminary check of the simulator facility capabilities and correct integration of its components, the control design and physics models for a short take-off and vertical landing fighter aircraft model were shown, with their associated system integration and architecture, pilot vehicle interfaces, and display symbology. The initial testing and evaluation results show that this fixed based flight simulator can provide real time feedback and display of both airframe and propulsion variables for validation of integrated flight and propulsion control systems. Additionally, through the use of this flight simulator, various control design methodologies and cockpit mechanizations can be tested and evaluated in a real time environment.

Bright, Michelle M.↗
NASA NTRS1991

Expendable launch vehicle propulsion

The current status is reviewed of the U.S. Expendable Launch Vehicle (ELV) fleet, the international competition, and the propulsion technology of both domestic and foreign ELVs. The ELV propulsion technology areas where research, development, and demonstration are most needed are identified. These propulsion technology recommendations are based on the work performed by the Commercial Space Transportation Advisory Committee (COMSTAC), an industry panel established by the Dept. of Transportation.

Fuller, Paul N.↗
NASA NTRS1991

A review of liquid rocket propulsion programs in Japan

An assessment of Japan's current capabilities in the areas of space and transatmospheric propulsion is presented. The primary focus is upon Japan's programs in liquid rocket propulsion and in space plane and related transatmospheric areas. Brief reference is also made to their solid rocket programs, as well as to their supersonic air breathing propulsion efforts that are just getting underway.

Merkle, Charles L.↗
NASA NTRS1991

Overview of European and other non-US/USSR/Japan launch vehicle and propulsion technology programs

The following subject areas are covered: majority of propulsion technology development work is directly related to the ESA's Ariane 5 program and heavily involves SEP (Societe Europeenne de Propulsion) in all areas; Hermes; advanced work on magnetic bearings for turbomachinery; electric propulsion using Cs and Xe propellants done by SEP in France, MBB ERNO in West Germany, and by Culham Lab in UK; successfully tested fired H/O composite nozzle exit cone on 3rd stage of Ariane; turbine blades made of composites to allow increase in gas temperature and improvement in efficiency; combined cycle (turboramjet-rocket) engine analysis work done by Hyperspace; and ESA advanced program studies.

Rice, Eric E.↗
NASA NTRS1991

Space Transportation Propulsion Technology Symposium. Volume 3: Panel Session Summaries and Presentations

The Space Transportation Propulsion Technology Symposium was held at the Pennsylvania State University on June 25 to 29, 1990. Emphasis was placed on propulsion requirements and initiatives to support current, next generation, and future space transportation systems, with the primary objectives of discerning whether proposed designs truly meet future transportation needs and identifying possible technology gaps, overlaps and other programmatic deficiencies. Key space transportation propulsion issues are addressed through four panels with government, industry, and academia membership. The panel focused on systems engineering and integration; development, manufacturing, and certification; operational efficiency; program development; and cultural issues.

Source record↗
NASA NTRS1991

Propulsion system ground testing

The objective is to provide management visibility relative to the roles of simulation and propulsion system testing for future development programs through assessment of current propulsion related simulation capabilities and review of contributions from propulsion system test programs. The presentation is represented by viewgraphs.

Wood, Charles C.↗
NASA NTRS1991

Nondestructive evaluation tools and experimental studies for monitoring the health of space propulsion systems

An overview is given of background and information on space propulsion systems on both the programmatic and technical levels. Feasibility experimental studies indicate that nondestructive evaluation tools such as ultrasonic, eddy current and x-ray may be successfully used to monitor the life limiting failure mechanisms of space propulsion systems. Encouraging results were obtained for monitoring the life limiting failure mechanisms for three space propulsion systems; the degradation of tungsten arcjet and magnetoplasmadynamic electrodes; presence and thickness of spallable electrically conducting molybdenum films in ion thrusters; and the degradation of the catalyst in hydrazine thrusters.

Generazio, Edward R.↗
NASA NTRS1991

Lightning protection for shuttle propulsion elements

The results of lightning protection analyses and tests are weighed against the present set of waivers to the NASA lightning protection specification. The significant analyses and tests are contrasted with the release of a new and more realistic lightning protection specification, in September 1990, that resulted in an inordinate number of waivers. A variety of lightning protection analyses and tests of the Shuttle propulsion elements, the Solid Rocket Booster, the External Tank, and the Space Shuttle Main Engine, were conducted. These tests range from the sensitivity of solid propellant during shipping to penetration of cryogenic tanks during flight. The Shuttle propulsion elements have the capability to survive certain levels of lightning strikes at certain times during transportation, launch site operations, and flight. Changes are being evaluated that may improve the odds of withstanding a major lightning strike. The Solid Rocket Booster is the most likely propulsion element to survive if systems tunnel bond straps are improved. Wiring improvements were already incorporated and major protection tests were conducted. The External Tank remains vulnerable to burn-through penetration of its skin. Proposed design improvements include the use of a composite nose cone and conductive or laminated thermal protection system coatings.

Goodloe, Carolyn C.↗
NASA NTRS1990

Establishing a center for advanced space propulsion

The goals and the concept of NASA-sponsored Centers for the Commercial Development of Space (CCDSs) are presented. The Center for Advanced Space Propulsion (CASP), its research projects, and the prognosis for their success are discussed. The establishment of CCDSs is recognized as an experiment to bring together university and industry researchers to maintain and improve the internationally competitive position of the United States in space. Increasing private investment in space-related technology and developing new commercial products are the basic requirements for success. CASP is the only CCDS that focuses on propulsion technology, which is critical to ensuring continued U.S. leadership in space. CASP is expected to become a recognized center for propulsion research and commercialization within the next five years.

Garrison, George W.↗
NASA NTRS1991

Experimental investigation of a unique airbreathing pulsed laser propulsion concept

Investigations were conducted into unique methods of converting pulsed laser energy into propulsive thrust across a flat impulse surface under atmospheric conditions. The propulsion experiments were performed with a 1-micron neodymium-glass laser at the Space Plasma Branch of the Naval Research Laboratory. Laser-induced impulse was measured dynamically by ballistic pendulums and statically using piezoelectric pressure transducers on a stationary impulse surface. The principal goal was to explore methods for increasing the impulse coupling performance of airbreathing laser-propulsion engines. A magnetohydrodynamic thrust augmentation effect was discovered when a tesla-level magnetic field was applied perpendicular to the impulse surface. The impulse coupling coefficient performance doubled and continued to improve with increasing laser-pulse energies. The resultant performance of 180 to 200 N-s/MJ was found to be comparable to that of the earliest afterburning turbojets.

Myrabo, L. N.↗
NASA NTRS1991

Main propulsion system test simulator project

In the past, only component and subsystem testing was available during development. Full-scale propulsion system testing was performed for final verification using specialized test articles and test facilities. Following test program completion, the test article was discarded and the test facility deactivated. This left operational systems with no test bed to support anomaly simulation and evaluation. This paper discusses an approach that would provide large scale propulsion system testing for both new system design and development, and of the operational Space Shuttle main propulsion system.

Anderson, David M.↗