摘要
本文进一步研究了起伏边界条件下层结流体剪切流的不稳定性质,论述了圆频率（或相速度）在复平面上的分布规律。结果发现,起伏边界使扰动不稳定的充分条件更加苛刻。不稳定扰动的圆频率被限制在复平面上一个内接于Howard半圆的半椭圆内。该半椭圆的长轴重合于Howard半圆的直径,而短轴则与波数、最小 Richardson数、自由边界值以及基本流的垂直切变和波动方向与基流切变矢量的夹角有关。
The instability of heterogeneous orthogonal shear flow is investigated with free surface boundary condition in this paper,and the distribution law of frequency (or phase speed) on the complex frequency (or phase speed) coodinated plane is also given. The result shows that the existense of free surface make it difficult to satisfy the sufficient condition for instability and furthermore the complex frequency is limited in a semi-ellipse inside the Howard semicircle, with its maximum axis coinciding on the diameter of Howard semicircle, while the minimum axis depending upon the wave number,free surface condition,flow shear and the angle between the shear vector and the wave number vector.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
1997年第1期38-46,共9页
Chinese Journal of Hydrodynamics
