交变暨静态剪切流对湍流抑制的互斥性分析

把剪切流对湍流抑制的解析理论应用于同时包含静态剪切流和周期交变剪切流的情况。所得到的结果表明：当两者单独存在时对湍流有定量上大体相同的抑制效应；当两者同时存在时对湍流的抑制效应不仅不是简单的迭加，反而在很大的区域上呈现互相削弱的趋势，特别是这种互斥性在两种剪切流强度相等时为最大。这与Maeyama等人的数值模拟结果相符合-。采用的渐近理论平均法表明导致两种剪切流在抑制湍流上不对等是由交变剪切流与它所诱发的交变相对位移之间的耦合所造成。

On mutual exclusiveness between time-varying and static shear flow in turbulence suppression

The analytical theory of turbulence suppression by shear flow is applied to analyze the effects from time-varying as well as static component. It is found that each component may yield the same suppression level when appearing alone. However, when both the components co-exist, one tends to diminish the suppression caused by the other in fairly wide parameter ranges, which agrees with the Maeyama’s simulation results published recently, in particular, the mutual exclusiveness is maximized as the strengths of the two components have the nearly same size. The adopted averaging method of asymptotic theory reveals that it is the coupling between the time-varying shear flow and the induced time-varying relative orbit motion that causes the asymmetry of the two components in turbulence suppression.