On the jump in the frequency of acoustic oscillations in supersonic flows over rectangular cavity
On the jump in the frequency of acoustic oscillations in supersonic flows over rectangular cavity
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DOI：
10.1063/1.3081560
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发表时间：
2009-02
影响因子：
4.6
通讯作者：
T. Handa;M. Masuda
中科院分区：
文献类型：
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作者：
T. Handa;M. Masuda
在这项研究中，我们分析了在超声速流中观察到的矩形空腔的声振荡频率的跳跃。频率跳变以前曾在实验中观察到，当腔体的长深比逐渐变化时。然而，其发生的原因尚未得到很好的理解。为了解释频率跳变的发生，我们改进了经典的声振荡模型，考虑了腔壁处的声反射。使用我们的分析模型得到的结果被发现同意与实验结果的频率跳跃和频率的变化与长度-深度比。在解析模型的基础上，还提出了一个简单模型，在简单模型中，假设腔体内的声波是一维波。这个简单的模型可以清楚地解释空腔中声振荡频率发生跳变的根本原因。
In this study, we analyze the jump in the frequency of acoustic oscillations that is observed in supersonic flows over a rectangular cavity. Frequency jumps have previously been observed in experiments when the length-to-depth ratio of a cavity is gradually varied. However, the reason for their occurrence has not been well understood. In order to explain the occurrence of the frequency jump, we improved the classical acoustic oscillation model by taking the acoustic reflections at the cavity walls into account. The results obtained using our analytical model are found to agree with experimental results with respect to both the frequency jump and the variation in frequency with the length-to-depth ratio. On the basis of the analytical model, a simple model is also proposed; in the simple model, it is assumed that the acoustic waves in the cavity are one-dimensional waves. This simple model can provide clearly the fundamental reason for the occurrence of the jump in the frequency of acoustic oscillations in the cavity.