中文摘要：

文中直接数值模拟了来流马赫数（M∞）为2．25的空间发展的可压缩平板湍流边界层。研究了可压缩平板湍流边界层内的拟序结构的形成过程。指出在粘性底层出现低速条带是触发拟序结构的第一个信息。条带升起，开始发生振动，然后破裂，并伴随着产生强烈的湍流脉动，这便形成了湍流的猝发过程。因此壁湍流拟序结构的重要意义在于它是生成湍流的重要机制。条带的破裂还伴随着上抛和下扫现象，这是壁湍能生成和耗散的关键。

英文摘要：

A Direct numerical simulation of a spatially evolving compressible flat-plate turbulent boundary layer with incoming Mach number （M∞） of 2.25 was performed in this paper. The coherent structure forming process is studied. The low-speed strip appearing in the viscous sublayer is the first information to trig coherent structure. Strip rises, begin to vibrate, and rupture, and accompanied by strong turbulence, which will form the turbulent bursting process. Therefore the wall turbulent coherent structure is significant in that it is the important mechanism to generate turbulence. Strip rupture accompanied by up and down sweep phenomenon, it is the key of wall turbulent energy generation and dissioation.