Aeronautical Engineering: A special bibliography with indexes, supplement 67, February 1976

This bibliography lists 341 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1976

Aeronautical engineering: A continuing bibliography with indexes

This bibliography lists 425 reports, articles and other documents introduced into the NASA scientific and technical information system in January 1985

CEAS/AIAA/ICASE/NASA Langley International Forum on Aeroelasticity and Structural Dynamics 1999

These proceedings represent a collection of the latest advances in aeroelasticity and structural dynamics from the world community. Research in the areas of unsteady aerodynamics and aeroelasticity, structural modeling and optimization, active control and adaptive structures, landing dynamics, certification and qualification, and validation testing are highlighted in the collection of papers. The wide range of results will lead to advances in the prediction and control of the structural response of aircraft and spacecraft

The Effect of Pulsed Injection on Shear Layer Dynamics in a Scramjet Combustion Chamber

One of the greatest problems that scramjet research faces is fuel air mixing. The residence time for a scramjet engine, or the time it takes for a volume of air to completely pass through the engine, is on the order of 0.1 ms. In that extremely short period of time fuel must be injected and fully mirco-mixed at stoichiometric ratios with the combustion chamber airflow. The fuel-air mixture must then be combusted and expanded through the nozzle to produce thrust. The goal of this research is to develop a new more efficient method of fuel air mixing within a scramjet combustion chamber. A possible way to speed up the mixing process of parallel injection without incurring the total pressure losses that would occur in normal injection is to inject the fuel from the rear side of a backward facing step. Backward facing steps in supersonic flow produce a Prandtl-Meyer expansion fan followed by a shear layer. The instabilities in this shear layer have dominant resonant frequencies. It is believed that if fuel is injected in pulses that impinge on the shear layer at these dominant resonant frequencies that the shear layer will resonate. When the shear layer resonates the vortices that form in the shear layer will grow in magnitude, thus mixing the injected fuel with the air. To test this hypothesis a new test section was designed and built that features a one inch step under which an injector can be housed. This new test section was installed in the supersonic facility at the University of Kansas. Two injectors were also designed that each feature a face plate, one with eight injection ports arranged in a ring and one with 5 injection ports. Between the face plate and a back plate there is a cavity that houses a rotating valve that is powered by a pneumatic motor. Five valves were built: one with 8 teeth, one with 16 teeth, one with 5 teeth that are the same size as the gaps between the teeth, one with 5 teeth where the teeth are 50% larger than the gaps, and one with 5 teeth where the teeth are 50% smaller than the gaps. The 8 tooth valve and 16 tooth valve where used with the 8 port injector face plate. The 5 tooth valves were used with the 5 port injector face plate. As the valve rotates the teeth block and unblock the injection ports injecting carbon dioxide gas into the test section. The 8 port injector was tested over a range of frequencies from 1.6 kHz to 10.0 kHz. The 5 port injector was tested for each valve over a range of frequencies from 1.0 kHz to 4.0 kHz. Static pressure data was taken along the upper and lower walls of the test section by means of an array of pressure sensors. The pressure data from the test section was compared to results generated using a three dimensional CFD simulation of the test section. Overall the pressure data on the lower wall agreed reasonably well with the CFD simulation. The vorticity and turbulence contours generated by the STAR-CCM+ simulation suggest that as a pulse is injected into the test section from the step it causes the shear layer to curve outward near the point of injection. After the pulse the shear layer returns to the state it was in before injection. The shear layer showed no resonance behavior as a result of pulsed injection. A spectral analysis was performed on the wall static pressure data. The results of this analysis showed no indication of resonance behavior of the shear layer in the wind tunnel tests

Aeronautical Engineering: A continuing bibliography with indexes, supplement 128, November 1980

This bibliography lists 419 reports, articles, and other documents introduced into the NASA scientific and technical information system in October 1980

Acoustics Division recent accomplishments and research plans

The research program currently being implemented by the Acoustics Division of NASA Langley Research Center is described. The scope, focus, and thrusts of the research are discussed and illustrated for each technical area by examples of recent technical accomplishments. Included is a list of publications for the last two calendar years. The organization, staff, and facilities are also briefly described

Aeronautical engineering: A continuing bibliography with indexes (supplement 322)

This bibliography lists 719 reports, articles, and other documents introduced into the NASA scientific and technical information system in Oct. 1995. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Aeronautical engineering: A continuing bibliography with indexes (supplement 254)

This bibliography lists 538 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Aeronautical engineering: A continuing bibliography with indexes (supplement 269)

This bibliography lists 539 reports, articles, and other documents introduced into the NASA scientific and technical information system in August, 1991. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Aeronautical Engineering: A continuing bibliography with indexes, supplement 174

This bibliography lists 466 reports, articles and other documents introduced into the NASA scientific and technical information system in April 1984