Experiments were carried out to assess the effect of rear face geometrical modifications of a wall mounted rectangular cavity on pressure fluctuations at supersonic speed. Initially, tests were conducted on a base cavity of length to depth ratio of 3.6, in a 50 × 100 mm at a Mach number of 2, and a Reynolds number of 2 × 10⁶ based on cavity length. Geometrical modifications to the rear face of the base cavity in the form of single ramp, double ramp and partial ramp circle were done to study their acoustic emission characteristics. Oil flow images revealed the complex nature of the flow inside the cavities. Time resolved flow visualization revealed attenuation of receptive interaction at the cavity leading edge, and minimized mass flux into the cavity by adopting these modifications. Unsteady measurements indicated reduction in the peak tones, broadband levels, and coherence. Among the modified geometries, double ramp configuration significantly reduced the overall sound pressure levels and the fluctuating pressures of the order of 10 dB and 50% respectively.

进行实验以评估壁挂式矩形腔体的背面几何形状修改对超声速下压力波动的影响。最初，在长径比为3.6的基本型腔中，以50×100 mm的马赫数2和雷诺数2×10 ^{6进行试验。}根据型腔长度。对基础腔体背面的几何形状进行了修改，以单斜面，双斜面和部分斜面圆的形式进行了研究，以研究其声发射特性。油流图像显示了腔体内流动的复杂性。时间分辨的流动可视化显示了在腔体前缘处感受性相互作用的衰减，并且通过采用这些修改使进入腔体的质量通量最小化。不稳定的测量表明峰值音调，宽带水平和相干性降低。在修改的几何形状中，双斜坡配置显着降低了总体声压级，并将波动压力分别降低了10 dB和50％左右。