Transitional shock-wave/boundary-layer interactions in hypersonic flow
Transitional shock-wave/boundary-layer interactions in hypersonic flow
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DOI：
10.1017/jfm.2014.333
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发表时间：
2014-07
影响因子：
3.7
通讯作者：
N. Sandham;E. Schülein;A. Wagner;S. Willems;J. Steelant
中科院分区：
文献类型：
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作者：
N. Sandham;E. Schülein;A. Wagner;S. Willems;J. Steelant
激波与边界层的强烈相互作用导致流动分离和传热速率的提高。当接近的边界层是高超音速的和过渡的问题是特别具有挑战性的，需要更可靠的数据，以评估流动和表面热传递的变化，并开发简化的模型。本文比较了马赫数为6时，三种不同实验设备使用同一仪表板插入件时平板上过渡干扰的结果。这些设施包括一个路德维希管（RWG），一个开放式喷气风洞（H2K）和一个高焓自由活塞驱动的反射激波风洞（HEG）。实验测量包括阴影和红外热成像以及传热和压力传感器。直接数值模拟（DNS）进行比较与选定的实验流动条件。结合的方法可以评估单位雷诺数，扰动振幅，冲击位置和壁面冷却的影响。壁面热通量的基础上提出的措施，允许在再附着制度的斯坦顿数的峰值映射在一系列的接近边界层的不稳定性状态，与完全湍流的相互作用相比，过渡的相互作用发现更高的超调。过渡过程中发现，从第二（Mack）模式不稳定性叠加在流向条纹。
Abstract Strong interactions of shock waves with boundary layers lead to flow separations and enhanced heat transfer rates. When the approaching boundary layer is hypersonic and transitional the problem is particularly challenging and more reliable data is required in order to assess changes in the flow and the surface heat transfer, and to develop simplified models. The present contribution compares results for transitional interactions on a flat plate at Mach 6 from three different experimental facilities using the same instrumented plate insert. The facilities consist of a Ludwieg tube (RWG), an open-jet wind tunnel (H2K) and a high-enthalpy free-piston-driven reflected shock tunnel (HEG). The experimental measurements include shadowgraph and infrared thermography as well as heat transfer and pressure sensors. Direct numerical simulations (DNS) are carried out to compare with selected experimental flow conditions. The combined approach allows an assessment of the effects of unit Reynolds number, disturbance amplitude, shock impingement location and wall cooling. Measures of intermittency are proposed based on wall heat flux, allowing the peak Stanton number in the reattachment regime to be mapped over a range of intermittency states of the approaching boundary layer, with higher overshoots found for transitional interactions compared with fully turbulent interactions. The transition process is found to develop from second (Mack) mode instabilities superimposed on streamwise streaks.