Strong interaction of a turbulent spot with a shock-induced separation bubble
Strong interaction of a turbulent spot with a shock-induced separation bubble
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DOI：
10.1063/1.2432158
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发表时间：
2007-01
影响因子：
4.6
通讯作者：
L. Krishnan;N. Sandham
中科院分区：
文献类型：
--
作者：
L. Krishnan;N. Sandham
本文采用直接数值模拟的方法研究了湍流斑通过激波诱导分离泡的过程。局部吹扫用于使激波冲击上游的边界层脱离，从而在冲击处形成成熟的紊流斑，其长度与分离区的长度相当。在自由流马赫数为2和4时，模拟了等温（热）壁边界条件下的相互作用。斑点的核心被视为隧道通过分离泡，导致流动的瞬时再附着。恢复时间很长，这是由于光斑后面的平静区域的影响。在相互作用过程中，斑点的拖尾界面的传播速度降低，并且观察到斑点的横向扩展的大幅增加。一个概念模型的基础上增长的横向剪切层附近的翼尖的斑点被用来解释横向增长率的变化。
Direct numerical simulations have been conducted to study the passage of a turbulent spot through a shock-induced separation bubble. Localized blowing is used to trip the boundary layer well upstream of the shock impingement, leading to mature turbulent spots at impingement, with a length comparable to the length of the separation zone. Interactions are simulated at free stream Mach numbers of two and four, for isothermal (hot) wall boundary conditions. The core of the spot is seen to tunnel through the separation bubble, leading to a transient reattachment of the flow. Recovery times are long due to the influence of the calmed region behind the spot. The propagation speed of the trailing interface of the spot decreases during the interaction and a substantial increase in the lateral spreading of the spot was observed. A conceptual model based on the growth of the lateral shear layer near the wingtips of the spot is used to explain the change in lateral growth rate.