超声速流边界层中的壁面正、负压力脉动  

Positive and negative wall-pressure fluctuations beneath a supersonic turbulent boundary laye

作　　者：尹琰鑫 吴勇军 王润 任冲 屈强 张青青 刘晋 Yanxin Yin;Yongjun Wu;Run Wang;Chong Ren;Qiang Qu;Qingqing Zhang;Jin Liu(School of Mechanical Engineering,Tianjin University,Tianjin 300072,China;China Academy of Launch Vehicle Technology,Bejing 100076,China)

机构地区：[1]School of Mechanical Engineering,Tianjin University,Tianjin 300072,China [2]China Academy of Launch Vehicle Technology,Bejing 100076,China

出　　处：《Acta Mechanica Sinica》2023年第2期114-125,共12页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.NSFC-52172079).

摘　　要：本文对来流马赫数2.25、基于动量厚度的雷诺数4000的平板湍流边界层开展了直接数值模拟,通过聚类连通法和条件相关研究了壁面正、负压力脉动.负脉动比正脉动的特征长度小,但是二者特征时间接近.正脉动的对流速度略大.壁面压力脉动结构的空间距离是自相似的,即空间距离与特征长度成正比.同类壁面压力结构在展向成串出现,正、负壁面压力脉动在流向成对。流向壁面剪切脉动大致在壁面压力脉动的下游,而展向壁面剪切脉动则与壁面压力脉动成对角线方式分布,二者的相关函数成“四极子”形式,其中壁面压力脉动与其上游的展向壁面剪切相关系数大于下游.In this work,a supersonic turbulent boundary layer with freestream Mach number 2.25 and Reynolds number based on the momentum thickness around 4000 is obtained by a direct numerical simulation.The wall-pressure fluctuations are split into positive and negative families by the conditional correlation and clustering method.The negative wall-pressure fluctuation has smaller integral length scales than the positive one.But they have comparable integral time scales.Positive wall-pressure fluctuation is convected slightly faster than the negative one.Statistically,wall-pressure clusters are self-similarly packed on the wall,i.e.,the absolute distance between two wall-pressure clusters is proportional to their sizes.Closest pairs of wall-pressure clusters of the same sign are largely spanwise aligned.While wall-pressure clusters of the opposite signs are streamwise paired.Wall-pressure fluctuations are non-locally associated with wall shear stresses.The streamwise wall shear stress is largely downstream of the wall-pressure fluctuations.While the spanwise wall shear stress and wall-pressure are diagonally aligned in two opposite directions,their cross-correlation is a quadrupole with the two correlation lobes upstream of wall-pressure fluctuations being dominant.

关 键 词：Supersonic turbulent boundary layer Wall pressure fluctuation Negative and positive events 

分 类 号：O357[理学—流体力学]