タイトル | Cavity Unsteady-Pressure Measurements at Subsonic and Transonic Speeds |
本文(外部サイト) | http://hdl.handle.net/2060/19980008833 |
著者(英) | Plentovich, E. B.; Tracy, Maureen B. |
著者所属(英) | NASA Langley Research Center |
発行日 | 1997-12-01 |
言語 | eng |
内容記述 | An experimental investigation was conducted in the Langley 8-Foot Transonic Pressure Tunnel to determine the flow characteristics of rectangular cavities with varying relative dimensions at subsonic and transonic speeds. Cavities were tested with width-to-depth ratios of 1, 4, 8, and 16 for length-to-depth ratios l/h of 1 through 17.5. The maximum cavity depth was 2.4 in., and the turbulent boundary layer approaching the cavity was approximately 0.5 in. thick. Unsteady- and mean static-pressure measurements were made at free-stream Mach numbers from 0.20 to 0.95 at a unit Reynolds number per foot of approximately 3 x 10(exp 6); however, only unsteady-pressure results are presented in this paper. Results indicate that as l/h increases, cavity flows changed from resonant to nonresonant with resonant amplitudes decreasing gradually. Resonant spectra are obtained largely in cavities with mean static-pressure distributions characteristic of open and transitional flows. Resonance sometimes occurred for closed flow. Increasing cavity width or decreasing cavity depth while holding l/h fixed had the effect of increasing resonant amplitudes and sometimes induced resonance. The effects due to changes in width are more pronounced. Decreasing Mach number has the effect of broadening the resonances. |
NASA分類 | Aerodynamics |
レポートNO | NASA-TP-3669 L-17560 NAS 1.60:3669 |
権利 | No Copyright |
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