On the inviscid instability of the hyperbolictangent velocity profile
On the inviscid instability of the hyperbolictangent velocity profile
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DOI：
10.1017/s0022112064000908
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发表时间：
1964-08
影响因子：
3.7
通讯作者：
A. Michalke
中科院分区：
文献类型：
--
作者：
A. Michalke
针对双曲切向速度剖面的放大扰动，对无粘线性化稳定性理论的Rayleigh稳定性方程进行了数值积分。本征值和本征函数的评价其次是扰动流的流线型的讨论。在这里，在放大扰动和中性扰动之间没有发现质的区别。但考虑到扰动流的涡量分布，结果表明，在放大扰动的情况下，在一个扰动波长内出现两个涡量集中，而在中性情况下，只存在一个涡量最大值。结果进行了讨论相对于自由边界层流动的不稳定性机制。
The Rayleigh stability equation of inviscid linearized stability theory was integrated numerically for amplified disturbances of the hyperbolic-tangent velocity profile. The evaluation of the eigenvalues and eigenfunctions is followed by a discussion of the streamline pattern of the disturbed flow. Here no qualitative distinction is found between an amplified and the neutral disturbance. But considering the vorticity distribution of the disturbed flow it is shown that in the case of amplified disturbances two concentrations of vorticity occur within a disturbance wavelength, while in the neutral case only one maximum of vorticity exists. The results are discussed with respect to the instability mechanism of free boundary-layer flow.