【摘要】 根据流动稳定性理论 ,将不稳定波的一个周期作为相干结构的初值 ,采用直接数值模拟方法对有压力梯度湍流边界层中相干结构的演化进行了研究 ,得出其各种特性的变化与实验观测到的结果一致 .更多还原

【Abstract】 By using the method of direct numerical simulation(DNS), evolution of coherent structures in the wall region of a turbulent boundary layer with three different pressure gradients was studied. Initial values of the coherent structures in the wall region were obtained on the basis of the idea of resonant triad in the theory of hydrodynamic stability. It was found that the results of DNS match with those of the experiments very well in many aspects. The effects of pressure gradient on coherent structure were obtained by comparing the results of three different cases.更多还原