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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Transatmospheric vehicle research

Research was conducted into the alternatives to the supersonic combustion ramjet (scramjet) engine for hypersonic flight. A new engine concept, the Oblique Detonation Wave Engine (ODWE) was proposed and explored analytically and experimentally. Codes were developed which can couple the fluid dynamics of supersonic flow with strong shock waves, with the finite rate chemistry necessary to model the detonation process. An additional study was conducted which compared the performance of a hypersonic vehicle powered by a scramjet or an ODWE. Engineering models of the overall performances of the two engines are included. This information was fed into a trajectory program which optimized the flight path to orbit. A third code calculated the vehicle size, weight, and aerodynamic characteristics. The experimental work was carried out in the Ames 20MW arc-jet wind tunnel, focusing on mixing and combustion of fuel injected into a supersonic airstream. Several injector designs were evaluated by sampling the stream behind the injectors and analyzing the mixture with an on-line mass spectrometer. In addition, an attempt was made to create a standing oblique detonation wave in the wind tunnel using hydrogen fuel. It appeared that the conditions in the test chamber were marginal for the generation of oblique detonation waves.

Adelman, Henry G.↗
NASA NTRS1962

SPACE VEHICLE RESEARCH

In this paper an outline is presented of some of our research and advanced technological activities directed at problems which must be solved if our nation is to continue as a leader in the mastery of space. In discussing technical programs it is helpful to relate them to various phases of space flight.

Spacecraft propulsion↗
NASA NTRS1972

Statistical analysis of landing contact conditions for three lifting body research vehicles

The landing contact conditions for the HL-10, M2-F2/F3, and the X-24A lifting body vehicles are analyzed statistically for 81 landings. The landing contact parameters analyzed are true airspeed, peak normal acceleration at the center of gravity, roll angle, and roll velocity. Ground measurement parameters analyzed are lateral and longitudinal distance from intended touchdown, lateral distance from touchdown to full stop, and rollout distance. The results are presented in the form of histograms for frequency distributions and cumulative frequency distribution probability curves with a Pearson Type 3 curve fit for extrapolation purposes.

Larson, R. R.↗
NASA NTRS1975

Development of a remote digital augmentation system and application to a remotely piloted research vehicle

A cost-effective approach to flight testing advanced control concepts with remotely piloted vehicles is described. The approach utilizes a ground based digital computer coupled to the remotely piloted vehicle's motion sensors and control surface actuators through telemetry links to provide high bandwidth feedback control. The system was applied to the control of an unmanned 3/8-scale model of the F-15 airplane. The model was remotely augmented; that is, the F-15 mechanical and control augmentation flight control systems were simulated by the ground-based computer, rather than being in the vehicle itself. The results of flight tests of the model at high angles of attack are discussed.

Edwards, J. W.↗
NASA NTRS1980

Backup flight control system for a highly maneuverable remotely piloted research vehicle

NASA is currently conducting flight tests of a remotely piloted subscale advanced fighter configuration as part of the Highly Maneuverable Aircraft Technology (HiMAT) program. This paper describes the initial development, user modification, and flight test experience of a back-up control system (BCS) contained within one of two onboard microprocessors. The development of the BCS proceeded in two distinct steps: the initial contractor development of control laws and logic to satisfy BCS design objectives, and user modifications required to satisfy operational requirements. A brief resume of flight qualification procedures and pilot comments is presented.

Hoyt, C. E.↗
NASA NTRS1985

Quasi non-intrusive sampling and analysis of gases associated with the boundary layer on the tethered satellite and similar supersonic and hypersonic research vehicles

The effect that one candidate inlet, an assembly of capillary openings in a thin glass plate (a multichannel plate), might have on the overall sampling process is considered. The flow characteristics of the plate, under a variety of conditions of external pressure and mass flow, is evaluated. A review of capillary flow theory is presented with some development of the pertinent equations. The predicted mass flow will be compared to that determined perimentally to assess the effect that mass flow through one capillary might have upon a neighboring capillary. Mass spectrometric measurements of mixtures flowing through the multichannel plate (MCP) is also considered. In the first part of the experiments, the flow was in a direction normal to the surface of the plate. The experimental gases were Argon and mixtures of carbon dioxide in air. Ongoing experiments are discussed which are conducted with the flow parallel to the surface of the plate, a simulation of the kind of flow that a flight vehicle would experience.

Fishel, C.↗
NASA NTRS1985

Discussion of flight experiments with an entry research vehicle

The focus of interest is the maneuvering flight of advanced entry vehicles operating at altitudes above 50 km and at velocities of 5 to 8 km/s. Information resulting in more accurate aerodynamic analysis is sought and measurement techniques that appear to be applicable are identified. Measurements discussed include: shock layer or boundary layer profiles of velocity, temperature, species mass fractions, and other gas properties associated with aerodynamic heating; surface energy transfer process; nonequilibrium flow processes and pressure distribution; separated, vortic leeside flow of nonequilibrium fluid; boundary layer transition on highly swept configurations; and shock and surface slip and gas/surface interaction. Further study should focus on evolving measurement techniques, installation requirements, and on identification of the portions of flights where successful results seem probable.

Potter, J. L.↗
NASA NTRS1988

Flight control systems development and flight test experience with the HiMAT research vehicles

Two highly maneuverable aircraft technology (HiMAT) remotely piloted vehicles were flown a total of 26 flights. These subscale vehicles were of advanced aerodynamic configuration with advanced technology concepts such as composite and metallic structures, digital integrated propulsion control, and ground (primary) and airborne (backup) relaxed static stability, digital fly-by-wire control systems. Extensive systems development, checkout, and flight qualification were required to conduct the flight test program. The design maneuver goal was to achieve a sustained 8-g turn at Mach 0.9 at an altitude of 25,000 feet. This goal was achieved, along with the acquisition of high-quality flight data at subsonic and supersonic Mach numbers. Control systems were modified in a variety of ways using the flight-determined aerodynamic characteristics. The HiMAT program was successfully completed with approximately 11 hours of total flight time.

Kempel, Robert W.↗
NASA NTRS1991

Hypersonic Research Vehicle (HRV) real-time flight test support feasibility and requirements study. Part 1: Real-time flight experiment support

The results are presented of a study to identify potential real time remote computational applications to support monitoring HRV flight test experiments along with definitions of preliminary requirements. A major expansion of the support capability available at Ames-Dryden was considered. The focus is on the use of extensive computation and data bases together with real time flight data to generate and present high level information to those monitoring the flight. Six examples were considered: (1) boundary layer transition location; (2) shock wave position estimation; (3) performance estimation; (4) surface temperature estimation; (5) critical structural stress estimation; and (6) stability estimation.

Rediess, Herman A.↗
NASA NTRS1991

Hypersonic Research Vehicle (HRV) real-time flight test support feasibility and requirements study. Part 2: Remote computation support for flight systems functions

The requirements are assessed for the use of remote computation to support HRV flight testing. First, remote computational requirements were developed to support functions that will eventually be performed onboard operational vehicles of this type. These functions which either cannot be performed onboard in the time frame of initial HRV flight test programs because the technology of airborne computers will not be sufficiently advanced to support the computational loads required, or it is not desirable to perform the functions onboard in the flight test program for other reasons. Second, remote computational support either required or highly desirable to conduct flight testing itself was addressed. The use is proposed of an Automated Flight Management System which is described in conceptual detail. Third, autonomous operations is discussed and finally, unmanned operations.

Rediess, Herman A.↗