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分析了不同来流边界层厚度与空腔深度比(δ/D)对长深比(L/D)为8的开式空腔内不同测点的声压级分布和声压频谱特性的影响。试验马赫数是0.6和1.5,相应的Re为1.23×107和2.26×107(基于每米)。结果表明,δ/D减小,导致开式空腔内不同测点声压级均有不同程度的增大;导致空腔上方剪切层与腔内流动或腔后壁相互作用能量增加,引起腔内同一测点不同离散频率对应的声压级增大。可见,δ/D减小,腔内流动自激振荡更易引起空腔自身结构和腔内储藏物结构振动和疲劳破坏。
The effect of different boundary layer thickness and cavity depth ratio (δ / D) on sound pressure level distribution and sound pressure spectrum characteristics at different measuring points in an open cavity with L / D ratio of 8 was analyzed. . The test Mach numbers are 0.6 and 1.5 and the corresponding Re is 1.23x107 and 2.26x107 (on a per meter basis). The results show that the decrease of δ / D results in the increase of sound pressure level at different measuring points in open cavity to some extent; the energy of the interaction between the shear layer above the cavity and the cavity or the posterior wall increases The sound pressure level corresponding to different discrete frequencies of the same measuring point in the cavity increases. It can be seen that the δ / D decreases and the self-oscillating flow in the cavity more easily causes the self-structure of the cavity and the vibration and fatigue of the storage structure in the cavity.