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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Exploratory wind-tunnel investigation of a wingtip-mounted vortex turbine for vortex energy recovery

The Langley 8-foot transonic pressure tunnel was used for tests to determine the possibility of recovering, with a turbine-type device, part of the energy loss associated with the lift-induced vortex system. Tests were conducted on a semispan model with an unswept, untapered wing, with and without a wingtip-mounted vortex turbine. Three sets of turbine blades were tested to determine the effect of airfoil section shape and planform. The tests were conducted at a Mach number of 0.70 over an angle-of-attack range from 0 deg. to 4 deg. at a Reynolds number of 3.82 x 10 to the 6th power based on the wing reference chord of 13 in.

Patterson, J. C., Jr.↗
NASA NTRS1985

Exploratory flutter test in a cryogenic wind tunnel

The feasibility of flutter testing in cryogenic wind tunnels is investigated experimentally in tests on a rigid solid-metal rectangular-planform aspect-ratio-1.5 NACA 64A010 wing model with an integral flexible beam support, cantilever mounted to the wall of the 0.3-m transonic cryogenic tunnel at NASA Langley, at Mach numbers M = 0.5 and 0.8 and Reynolds numbers Re = (4.09-18.16) x 10 to the 6th. Best results are obtained when the onset of flutter (predicted by the peak-hold subcritical-response technique of Sandford et al., 1975) is approached by adjusting stagnation pressure while keeping M and the stagnation temperature constant. The data are presented in graphs and tables and discussed. It is found that Re effects on flutter cannot be separated from mass-ratio and temperature effects for a single test model and must be interpreted from analytical trends, and that the effects detected by this procedure are so small (4.0-6.5 percent) as to fall within the scatter band of the subcritical-response predictions.

Cole, S. R.↗
NASA NTRS1985

Project VESTA, exploratory mission to the asteroids: Scientific objectives and technical specifications

The VESTA project, a Franco-Soviet collaboration, is described. The VESTA probe will be launched and will pass through the asteroid belts before encountering comets. The probe will be an autonomous vehicle. The scientific objectives are to obtaining information on asteroids, comets, solar system formation, meteorites and other sources of extraterrestrial material. The surface morphology, mineral composition and internal structure of asteroids will be studied.

Source record↗
NASA NTRS1985

Exploratory low-speed wind-tunnel study of concepts designed to improve aircraft stability and control at high angles of attack

A wind tunnel investigation of concepts to improve the high angle-of-attack stability and control characteristics of a high performance aircraft was conducted. The effect of vertical tail geometry on stability and the effectiveness of several conventional and unusual control concepts was determined. These results were obtained over a large angle-of-attack range. Vertical tail location, cant angle and leading edge sweep could influence both longitudinal and lateral-directional stability. The control concepts tested were found to be effective and to provide control into the post stall angle-of-attack region.

Hahne, D. E.↗
NASA NTRS1985

Exploratory studies of physiological components of motion sickness: Cardiopulmonary differences between high and low susceptibles

A comprehensive examination of cardiovascular autonomic response to motion sickness was studied and whether differences in cardiopulmonary function exist in high and low susceptibility groups were determined. Measurement techniques were developed as was test equipment for its ability to provide accurately new measures of interest and to test the adequately of these new measures in differentiating between susceptibility groups. It was concluded that these groups can be differentiated using simple, brief stressors and measurements of cardiodynamic function.

Naifeh, K.↗
NASA NTRS1986

Exploratory wind-tunnel investigation of the stability and control characteristics of advanced general aviation configurations

Results of low-speed wind-tunnel investigations are presented for two general aviation configurations: the AVTEK canard configuration and the DeVore conventional configuration. Cooperative research programs were undertaken by industry and NASA to jointly conduct tests in the NASA Langley 12-Foot Low-Speed Wind Tunnel to explore stability and control characteristics of each configuration. A 1/5-scale AVTEK model and a 1/6-scale DeVore model were tested over an angle-of-attack range of up to 45 deg and an angle-of-sideslip range of up to 20 deg. Results from the AVTEK test are presented with an emphasis on the effects of configuration on the stall and poststall characteristics. Results from the DeVore test are presented with emphasis on the effects of wing leading-edge droop design on spin resistance characteristics.

Yip, L. P.↗
NASA NTRS1987

Exploratory evaluation of a moving-model technique for measurement of dynamic ground effects

An attempt is presently made to measure the dynamic or time-dependent ground effects that may be encountered by aircraft during approach and landing by means of a ground-based testing technique that employs a model moving horizontally over an upwardly inclined ground plane to simulate the rate of descent. Results have been thus obtained for a 60-deg delta wing and for an F-18 full configuration, with and without thrust reversal, at forward speeds of up to 100 ft/sec. An analysis of the results gathered indicates that ground effects were reduced when the rate of descent was included in the test conditions.

Kemmerly, Guy T.↗
NASA NTRS1987

Exploratory studies of actuated forebody strakes for yaw control at high angles of attack

Wind-tunnel studies have been conducted to evaluate the potential of actuated forebody strakes to provide increased levels of yaw control on fighter aircraft at extremely high angles of attack where conventional aerodynamic controls are ineffective. The studies involved low-speed wind-tunnel tests of actuated forebody strake concepts applied to a generic fighter model and included circumferential pressure and flow visualization surveys on an isolated forebody. Results showed that the actuated forebody strake concept can provide high levels of yaw control over wide ranges of angle-of-attack and sideslip. However, when lifting surfaces were placed in close proximity to the forebody/strake combination, significant interaction effects occurred which reduced the yaw control effectiveness of the strakes and induced coupled rolling and pitching moments.

Murri, Daniel G.↗
NASA NTRS1989

[NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 1, part 1:] Technical communications in aeronautics: Results of an exploratory study

A study was undertaken that explored several aspects of technical communications in aeronautics. The study, which utilized survey research in the form of a self-administered questionnaire, was sent to 2,000 randomly selected members of the American Institute of Aeronautics and Astronautics. Six hundred and six usable questionnaires (30.3 percent) were received by the established cut off date. The study had five objectives. The first was to solicit the opinions of aeronautical engineers and scientists regarding the importance of technical communications to their profession; second, to determine their use and production of technical communications; third, to seek their views on the content of an undergraduate course in technical communications; fourth, to determine their use of libraries/technical information centers; and finally, to determine the use and importance of computer and information technology to them. The findings add considerable information to the knowledge of technical communications practices among aeronautical engineers and scientists and reinforce some of the conventional wisdom about technical communications and question other widely-held notions.

Pinelli, Thomas E.↗
NASA NTRS1989

[NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 1, part 2:] Technical communications in aeronautics: Results of an exploratory study

A study was undertaken that explored several aspects of technical communications in aeronautics. The study, which utilized survey research in the form of a self-administered questionnaire, was sent to 2,000 randomly selected members of the American Institute of Aeronautics and Astronautics. Six hundred and six usable questionnaires (30.3 percent) were received by the established cut off date. Part 2 of this study lists appendices to part 1, including survey instrument, aggregate totals, cross tabulations, and open-ended comments.

Pinelli, Thomas E.↗
NASA NTRS1988

Exploratory study of temperature oscillations related to transient operation of a Capillary Pumped Loop heat pipe

An analytical study has been conducted for better understanding of a peculiar transient behavior which was displayed in testing of a Capillary Pumped Loop (CPL) heat pipe system. During several test runs of this CPL system varying degrees of surface temperature oscillations occurred in the inlet line of the evaporators. Although several theories have been forwarded to explain this observed phenomenon, a satisfactory understanding of causes of these oscillations is still missing. The present investigation derives the conditions which lead to such oscillatory temperature behavior in evaporator inlet section of the mentioned CPL system. Stability characteristics of these temperature oscillations were investigated.

Kiper, A. M.↗
NASA NTRS1989

Technical communication in aeronautics - Results of an exploratory study

A study was undertaken that explored several aspects of technical communications in aeronautics. The study utilized survey research. A self-administered mail questionnaire was sent to 2,000 randomly selected members of the American Institute of Aeronautics and Astronautics (AIAA) in the U.S. with academic, government, or industrial affiliations. Six hundred and six (606) usable questionnaires were received. The findings add considerable information to the knowledge of technical communications among aeronautical engineers and scientists; reinforce some of the conventional wisdom about technical communications and question other widely-held notions; and hold significant implications for technical communicators, information managers, research and development managers, and curriculum developers.

Pinelli, Thomas E.↗
NASA NTRS1990

Exploratory wind tunnel investigation of the stability and control characteristics of a three-surface, forward-swept wing advanced turboprop model

The purpose of the present investigation was to parametrically study the stability and control characteristics of a forward-swept wing three-surface turboprop model through an extended angle of attack range, including the deep-stall region. As part of a joint research program between North Carolina State University and NASA Langley Research Center, a low-speed wind tunnel investigation was conducted with a three-surface, forward-swept wing, aft-mounted, twin-pusher propeller, model, representative of an advanced turboprop configuration. The tests were conducted in the NASA Langley 12-Foot Low-Speed Wind Tunnel. The model parameters varied in the test were horizontal tail location, canard size, sweep and location, and wing position. The model was equipped with air turbines, housed within the nacelles and driven by compressed air, to model turboprop power effects. A three-surface, forward-swept wing configuration that provided satisfactory static longitudinal and lateral/directional stability was identified. The three-surface configuration was found to have greater longitudinal control and increased center of gravity range relative to a conventional (two-surface) design. The test showed that power had a large favorable effect on stability and control about all three axis in the post-stall regime.

Coe, Paul L., Jr.↗
NASA NTRS1991

An exploratory study of a three-dimensional shock wave turbulent boundary layer interaction in a corner

Three-dimensional shock wave turbulent boundary layer interactions in a corner have been studied at M about 3. The first phase, detailed mean wall static pressure distributions, has shown the interaction of a two-dimensional flow on one wall with the three-dimensional flow generated by a fin. Major three-dimensional effects on both flows were observed, extending from the interaction of the initial region of the three-dimensional flow and the corner. A large part of the resulting corner flow has little resemblance to either the two-dimensional or three-dimensional interacting flows.

Bogdonoff, S. M.↗