V.A.Voskoboinick, A.V.Voskoboinick, A.A.Voskoboinick Pressure fluctuations inside and nearby the pair of oval dimples on a flat plate |
Acoustic bulletin, Vol. 17 ¹ 1, (2015) |
| This paper deals with presenting of experimental results for characteristic features of the flow around the pair of oval dimples on a hydraulically smooth flat plate. The profiles of longitudinal velocity fluctuations are obtained and fields of the dynamic and wall-pressure fluctuations are studied inside and on the streamlined surface of the pair of oval dimples inclined at the angle of 30 degrees to the streamline, as well as in their vicinity. The intensities and frequency spectra of the dynamic and wall-pressure fluctuations are obtained above and on the streamlined dimple surfaces and in their vicinity. The maximum wall-pressure fluctuation levels are pointed out on the aft walls of the dimples. The tonal components corresponding to oscillation frequencies of vortical flow inside the dimples and ejection frequencies of the large-scale vortical structures outside the dimples are observed in pressure fluctuation spectra. In a middle section between the oval dimples at the distance up to two their diameters, there was observed no interaction of the vortical structures ejected from each of the dimples. With a deletion from the pair of oval dimples, the intensity of tonal frequency oscillations in wall-pressure fluctuation spectra typical for the vortex flow inside the oval dimples is diminishing and boundary layer is gradually restoring. |
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KEY WORDS: pair of oval dimples, vortex flow, pressure sensors, dynamic pressure fluctuations, wall-pressure fluctuations, pressure fluctuation spectra, tonal oscillations |
| TEXT LANGUAGE: Ukrainian |