可压缩空间发展混合层亚谐扰动作用分析简

基于线性稳定性理论，建立了可压缩空间发展混合层亚谐扰动作用的唯象分析图，用以分析并判定亚谐扰动相差对基频涡卷非线性演化类型的影响，据此导出了基频涡卷各类非线性演化的定量的相差唯象模型. 研究发现，当亚谐扰动波长较小时，对于单一亚谐扰动，基频涡卷的演化类型共4 类，分别是撕裂、中心对称群并、第1 类非对称群并和第2 类非对称群并现象. 撕裂与中心对称群并为特殊现象，对应特定的相差点；非对称群并为常见现象，对应除这些相差点之外的相差区间. 当亚谐扰动波长较大时，由于扰动幅值随空间指数增长，只存在非对称群并现象.

SUBHARMONIC INTERACTION OF SPATIALLY-DEVELOPING COMPRESSIBLE MIXING LAYERS

A phenomenological model of collective interaction of primary vortex of mixing layers is built on the linear stability theory. The model can be used to determine the influence of the phase shift of the subharmonic disturbance wave on the nonlinear evolving process of the primary vortex. The results indicate that there are three classes of subharmonic interaction to the short subharmonic wavelength, which are tearing, symmetric collective interaction and asymmetrical collective interaction, respectively. And to the long subharmonic wavelength, there always occurs asymmetrical collective interaction.