Physics of the amplification of vortex disturbances in shear flows
Physics of the amplification of vortex disturbances in shear flows
复制标题
剪切流中涡旋扰动放大的物理学
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
D. G. Lominadze
中科院分区：
文献类型：
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作者：
G. Chagelishvili;R. Chanishvili;D. G. Lominadze
本文描述了剪切流中涡扰动放大的线性机制的物理性质，这是由于线性动力学中问题的本征函数的非正交性造成的。为了获得最清晰和最简单的图片，一个平行的线速度剪切流进行了研究，涡扰动表示的平面波的形式-空间傅立叶谐波。在这个层次上，我们的物理方法与剪切流线性过程的非模态数学分析是一致的，这在过去几年中得到了积极的培养。提出的物理解释了在线性演化阶段涡旋扰动随时间的非单调增长。此外，作为普遍的，在这项工作中采用的“语言”也可以用来描述潜在的（声学）干扰的放大。
The physics of the linear mechanism of the amplification of vortex disturbances in shear flows, which is due to the nonorthogonality of the eigenfunctions of the problem in the linear dynamics, is described. To obtain the clearest and simplest picture, a parallel flow with a linear velocity shear is studied, and the vortex disturbances are represented in the form of plane waves — spatial Fourier harmonics. On this level our physical approach is consonant with the nonmodal mathematical analysis of linear processes in shear flows, which has been actively cultivated in the last few years. The physics presented explains the non-monotonic growth of vortex disturbances in time at the linear stage of evolution. Moreover, being universal, the “language” employed in this work can also be used to describe the amplification of potential (acoustic) disturbances.