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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Design integration and noise studies for jet STOL aircraft. Task 7C: Augmentor wing cruise blowing valveless system. Volume 2: Small-scale development testing of augmentor wing critical ducting components

Augmentor wing ducting system studies conducted on a valveless system configuration that provides cruise thrust from the augmentor nozzles have shown that most of the duct system pressure loss would occur in the strut-wing duct y-junction and the wing duct-augmentor lobe nozzles. These components were selected for development testing over a range of duct Mach numbers and pressure ratios to provide a technical basis for predicting installed wing thrust loading and for evaluating design wing loading of a particular wing aspect ratios. The flow characteristics of ducting components with relatively high pressure loss coefficients were investigated. The turbulent pressure fluctuations associated with flows at high Mach numbers were analyzed to evaluate potential duct fatigue problems.

Runnels, J. N.↗
NASA NTRS1975

Cold-flow acoustic evaluation of a small scale, divergent, lobed nozzle for supersonic jet noise suppression

A supersonic jet noise suppressor was tested with cold flow for acoustic and thrust characteristics at nozzle- to atmospheric-pressure ratios of 1.5 to 4.0. Jet noise suppression and spectral characteristics of the divergent, lobed, suppressor (DLS) nozzle with and without an ejector are presented. Suppression was obtained at nozzle pressure ratios of 2.5 to 4.0. The largest, maximum-lobe, sound pressure level suppression with a hard-wall ejector was 14.6 decibels at a nozzle pressure ratio of 3.5. The thrust loss was 2 percent. In general, low-frequency jet noise was suppressed, leaving higher frequencies essentially unchanged. Without the ejector the nozzle showed a thrust loss of 11 percent together with slightly poorer noise suppression.

Huff, R. G.↗
NASA NTRS1975

Cartographic research in EREP program for small scale mapping

The author has identified the following significant results. Skylab photography is suitable for producing planimetric maps with graphical representation of landform at scales up to 1:100,000. It cannot supply all the detail necessary for maps at this scale, but it may be used to produce a sound framework which can be completed by detail from other sources. Its principal cartographic use is for original mapping of undeveloped areas of the world, but it would also be useful for the revision of existing maps and for monitoring extensive urban changes.

Mott, P. G.↗
NASA NTRS1975

Small-scale imagery: A useful tool for mapping geological features in the Texas Gulf Coastal plain

A sample of satellite imagery includes photographs and multispectral scanner imagery from the Apollo, LANDSAT, and Skylab spacecraft over an area west of Houston, Texas. Large circular features and lineaments can readily be mapped. One of the circular features identified by drainage, vegetation, and soil-tone anomalies, occurs in Fort Bend County, Texas, and covers an area about 25 miles in diameter. Another circular feature lies to the north, immediately west of Houston, and is about 15 miles in diameter. These features represent the surface expression of deeply-buried positive structures. It is recommended that regional geological studies begin with photointerpretations of high-altitude aircraft and synoptic space imagery, space imagery provides the synoptic view of rapid evaluation of large-scale features, and, at enlarged scales, the resolution required for detailed study of selected areas of structures.

Amsbury, D. L.↗