中文摘要：

为了探索平面混合层发展过程中大尺度结构与压力脉动之间的关系，加深对混合过程的认识，文中采用大涡模拟方法对二维带板厚超声速平面混合层进行数值模拟研究。计算结果显示了涡的配对与合并过程，与实验结果相符。通过对记录点的压力变化进行傅里叶转换，观察分析频谱，得出了在周期运动假设条件下，转捩点后任一瞬时拟序涡的频率即为其通过该点的压力波动频谱上的峰值频率。

英文摘要：

In order to investigate the reciprocity between large-scale structures and pressure oscillation for better understanding the process of mixing deeply, LES simulation was used to investigate the evolution of 2D supersonic planar mixing layer in this paper. The numerical results show the merging process of vortices conforms well with the relative experimental results . Through observing the Fourier transform of the pressure at a spatial point, the results show that under the hypothesis of periodic motion of vortexes, at any time, the frequency of large vortex that behind the crunch is just the peak value of the frequency of the pressure.