超声速自由来流条件下,开式空腔流动表现出剧烈的自持振荡现象.非定常的流动会在空腔内部诱发强烈的气动噪声.采用分离涡模拟方法(DES)对流场进行了数值模拟,结果表明空腔内部产生了强烈的反馈声波.空腔内部反馈声波与剪切层之间相互作用使剪切层表现出剧烈的不稳定性,剪切层的纵向运动会在空腔前缘诱发出交替出现的压缩波和膨胀波,数值模拟得到了一个周期内前缘出现压缩波和膨胀波的间歇因子.%Under the condition of supersonic flow,the open cavity shows violent self-sustained oscillation. This unsteady flow will induce a strong aerodynamic noise within the cavity. A numerical simulation of the flow field by a detached eddy simulation(DES) is carried out,and the results show that the acoustic wave is generated in the cavity. Shear layer shows severe instability due to interaction between internal waves and shear layer, longitudinal motion in the shear layer trigger alternately compression wave and expansion wave in the leading edge. The inter-mittent factor of compression wave and expansion wave are illustrated.
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