Silicon Pressure Transducers used to Determine the Longitudinal Correlation Coefficient in a Flat Plate Boundary Layer
Silicon Pressure Transducers used to Determine the Longitudinal Correlation Coefficient in a Flat Plate Boundary Layer
复制标题
用于确定平板边界层纵向相关系数的硅压力传感器
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
G. Stemme
中科院分区：
文献类型：
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作者：
L. Löfdahl;Edvard Kälvesten;G. Stemme
硅基压力传感器已被用于测量二维平板边界层中的湍流壁面压力波动。___.膜片的边长为___和___，边界层厚度与膜片边长之比约为240，波数小于10个粘性单位的涡流分辨率。测量了13 Hz < f < 13 kHz频率范围内的功率谱。在外部和内部变量中缩放，示出了频谱的中频部分和高频部分之间的明显重叠区域。在这个重叠区域，斜率为_，而在高频部分，斜率为_。在纵向和横向的相关测量进行了比较，与其他调查。纵向时空相关性，包括高频率范围，表明平流速度的顺序的一半的自由流速度。纵向相关性的宽带滤波表明，频谱的高频部分与来自边界层内部的较小涡流有关，导致相关性降低。
Silicon based pressure sensors have been used to measure turbulent wall-pressure fluctuations in a two-dimensional flat plate boundary layer. ___. The side lengths of the diaphragm were ___ and ___, giving a ratio of the boundary layer thickness to the diaphragm side length of the order of 240 and a resolution of eddies with wave numbers less than ten viscous units. Power spectra were measured for the frequency range13 Hz < f < 13 kHz. Scaled in outer and inner variables a clear overlap region between the mid and high frequency parts of the spectrum is shown. In this overlap region the slope was found to be ___, while in the high frequency part it was ___. Correlation measurements in both the longitudinal and transversal directions were performed and compared to other investigations. Longitudinal space time correlations, including the high frequency range, indicated an advection velocity of the order of half the free stream velocity. A broad band filtering of the longitudinal correlation showed that the high frequency part of the spectrum is associated with the smaller eddies from the inner part of the boundary layer, resulting in a reduction of the correlation.