Experimental investigation of starting characteristics and wave propagation from a shallow open cavity and its acoustic emission at supersonic speed
Experimental investigation of starting characteristics and wave propagation from a shallow open cavity and its acoustic emission at supersonic speed
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DOI：
10.1063/1.5006813
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发表时间：
2018-01
影响因子：
4.6
通讯作者：
S. Pandian;S. Desikan;S. Niranjan
中科院分区：
文献类型：
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作者：
S. Pandian;S. Desikan;S. Niranjan
在超声速马赫数（M = 1.8）下，对一个L/D = 5的浅开口空腔进行了实验研究，以了解其瞬态起动特性、一个旋涡脱落周期内空腔内外的波传播以及声发射。启动特性和波的传播通过时间分辨纹影图像可视化，而声发射通过非定常压力测量捕获。结果表明，在起动过程中，激波系统是一个复杂的系统，包括分叉激波系统的特点，激波串，流动分离，激波边界层相互作用。在一个旋涡脱落循环中，观察到了从凹腔前缘到凹腔后缘的旋涡对流。凹腔外的流动特征表明，由于凹腔前缘激波与旋涡激波的相互作用，凹腔尾部剪切层冲击波的产生，导致λ激波的形成和向下游运动。
Experiments were carried out on a shallow open cavity (L/D = 5) at a supersonic Mach number (M = 1.8) to understand its transient starting characteristics, wave propagation (inside and outside the cavity) during one vortex shedding cycle, and acoustic emission. Starting characteristics and wave propagation were visualized through time resolved schlieren images, while acoustic emissions were captured through unsteady pressure measurements. Results showed a complex shock system during the starting process which includes characteristics of the bifurcated shock system, shock train, flow separation, and shock wave boundary layer interaction. In one vortex shedding cycle, vortex convection from cavity leading edge to cavity trailing edge was observed. Flow features outside the cavity demonstrated the formation and downstream movement of a λ-shock due to the interaction of shock from the cavity leading edge and shock due to vortex and generation of waves on account of shear layer impingement at the cavity traili...