湍流边界层起伏压力谱和聚偏氟二乙烯薄膜(PVDF)水听器响应的实验研究

详细信息

Experimental study on spectrum of turbulent-boundary-Layer fluctuation pressure and response of a PVDF hydrophone

摘要: 利用一个 φ8 mm水听器和一个 20元阵在水洞中测量了湍流边界层起伏压力的点功率谱密度和波数频率谱密度。点功率谱密度测量结果的无量纲表示和 Bull M. K.等人风洞中的测量结果相吻合。波数频率谱的测量结果中能清楚地看到迁移峰,从而可进一步从迁移峰所在的位置求得迁移速度。同时还测量了一个接收面积为 100 mm×60 mm的 PVDF水听器对湍流边界层压力起伏的响应谱,将其结果和 φ8 mm水听器测量结果的对比,可以清楚看到 PVDF水听器对湍流边界层压力起伏的空间滤波作用。

Abstract: The point power spectrum density and the wavenumber frequency spectrum density of turbulent-boundary-layer fluctuation pressure are measured by use of a φ8 mm hydrophone and a 20-element array,respectively.The non-dimensional representation of measured point power spectrum coincides with the measured results by Bull M.K.et al.in wind tunnel.The convection peak can be seen clearly in the measured wavenumber frequency spectrum and the convection velocity can be calculated from the location of the convection peak.The response spectrum of a PVDF hydrophone,which receive area is 100 mm×60 mm,is also measured.By comparing it with the response spectrum of the φ8 mm hydrophone,it is shown that the PVDF hyrdophone has a strong wavenumber filtering effect on turbulent-boundary-layer pressure fluctuation.