空腔流激振荡的简化模型分析及振荡频率预估

本文由矩形空腔后缘声振动反馈激励腔口自由剪切层不稳定波的观点出发，把空腔流动振荡问题构造成一个关于空腔内外扰动波的非齐次边值问题，应用Ｆｏｕｒｉｅｒ－Ｌａｐｌａｃｅ变换技术求解，可以预估振荡频率，对Ｌ／Ａ＝Ａ亚声速空腔流动的预估结果与实验符合很好，揭示了此类空腔流动振荡的机理。

Analysis and Frequency Estimation of Flow Induced Cavity Oscillation

The perturbed wave of both inside and outside the cavity is formulated mathematically as an inhomogeneous boundary value problem based on the coupling between shear layer instabilities and the rear edge acoustic feedback.The Fourier Laplace transform technique is used to solve the problem,and then the oscillating frequencies can be determined.Good agreement is found between predicted frequencies and experimental measurements for the case of L/D =4,thus improving the understanding of physical mechanisms for the cavity flow oscillation.