On the turbulence amplification in shock-wave/turbulent boundary layer interaction
On the turbulence amplification in shock-wave/turbulent boundary layer interaction
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DOI：
10.1017/jfm.2020.350
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发表时间：
2020-06
影响因子：
3.7
通讯作者：
J. Fang;A. A. Zheltovodov-A.;Yufeng Yao;C. Moulinec;D. Emerson
中科院分区：
文献类型：
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作者：
J. Fang;A. A. Zheltovodov-A.;Yufeng Yao;C. Moulinec;D. Emerson
对激波/边界层干扰中的湍流放大机制进行了综述，并在对马赫数为2.25的斜激波/平板边界层干扰直接数值模拟数据分析的基础上，提出了一种新的湍流放大机制。在相互作用区的上游部分，湍流的放大本质上不是剪切驱动的，而是由平均流的减速与流向速度波动的相互作用引起的，这导致近壁区湍流强度的快速增加。在相互作用区的下游部分，高湍流强度主要是由于在相互作用区中产生的自由剪切层。在湍流放大的初始阶段，壁湍流的特性，包括紧凑的速度条纹，流向涡和各向异性的雷诺应力，保存良好。提出的机制解释了在一些实验和数值模拟中观察到的近壁区的高水平的湍流。
The mechanism of turbulence amplification in shock-wave/boundary layer interactions is reviewed, and a new turbulence amplification mechanism is proposed based on the analysis of data from direct numerical simulation of an oblique shock-wave/flat-plate boundary layer interaction at Mach 2.25. In the upstream part of the interaction zone, the amplification of turbulence is not essentially shear driven, but induced by the interaction of the deceleration of mean flow with streamwise velocity fluctuations, which causes a rapid increase of turbulence intensity in the near-wall region. In the downstream part of the interaction zone, the high turbulence intensity is mainly due to the free shear layer generated in the interaction zone. During the initial stage of turbulence amplification, the characteristics of wall turbulence, including compact velocity streaks, streamwise vortices and an anisotropic Reynolds stress, are well preserved. The mechanism proposed explains the high level of turbulence in the near-wall region observed in some experiments and numerical simulations.