An Experimental Investigation of Cavity Flow Oscillations and Tones of an In-Flow Microphone
| Autor: | Jin Tso, Richard S. Fields, Paul T. Soderman |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Physics
020301 aerospace & aeronautics Acoustics and Ultrasonics Anechoic chamber Microphone business.industry Acoustics Aerospace Engineering 02 engineering and technology 01 natural sciences 010305 fluids & plasmas Nose cone symbols.namesake Optics 0203 mechanical engineering Flow velocity 0103 physical sciences symbols Trailing edge Strouhal number Sound pressure business Wind tunnel |
| Zdroj: | International Journal of Aeroacoustics. 5:173-191 |
| ISSN: | 2048-4003 1475-472X |
| DOI: | 10.1260/147547206777629844 |
| Popis: | An experiment was conducted to investigate the flow-induced nose-cone cavity oscillations of a B&K in-flow microphone. A 38.1-mm-diameter scale model of the B&K 12.7-mm UA 0386 nose cone was constructed and tested in a 177.8-mm-round free-jet in the Anechoic Chamber Wind Tunnel at NASA Ames Research Center at ReD up to 1.1 × 105. The results indicated that the B&K nose-cone cavity behaves much like a cavity without a screen. Detailed flow velocity measurements over the cavity screen have shown inflection points in the mean velocity profiles and high disturbance intensities in the vicinity of the cavity trailing edge. These results and the high coherence between the strong velocity and acoustic pressure oscillations at the cavity trailing edge implied that the cavity acoustic tones are the consequence of the cavity shear-layer impingement on the cavity trailing edge. The effect of cavity screen appears to be secondary in the velocity range tested. The screen seems mainly to modulate the Strouhal numbers of the higher acoustic modes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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