Richtmyer-Meshkov instability of a flat interface subjected to a rippled shock wave.
Richtmyer-Meshkov instability of a flat interface subjected to a rippled shock wave.
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DOI：
10.1103/physreve.95.013107
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
L. Zou;Jin-hong Liu;S. Liao;Xian-xu Zheng;Z. Zhai;Xisheng Luo
中科院分区：
文献类型：
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作者：
L. Zou;Jin-hong Liu;S. Liao;Xian-xu Zheng;Z. Zhai;Xisheng Luo
在垂直激波管中，利用纹影摄影和雾显诊断技术，对波纹激波作用下名义平坦界面（N2/SF6）的Richtmyer-Meshkov（RM）不稳定性进行了实验研究。非平面入射激波是由平面激波绕刚性圆柱绕射产生的，而平面界面是由无膜技术产生的。考虑了三种不同的距离η（从圆柱到界面的间距与圆柱直径的比值）。纹影图像表明，非平面入射激波可以分为三个不同的段，由两个三相点分开。Fog可视化图像显示界面结构整体呈“Λ”形，中心有一个N {2}空腔，两侧有两个界面台阶。随着无因次时间的增加，无因次界面振幅和空泡的穿透深度均增加，且在不同η数下，两曲线均呈现合理的塌陷。通过将波纹激波的前界面扰动与波纹界面的前激波扰动等效，发现这种不稳定性的增长率明显小于标准RM不稳定性的增长率。
The Richtmyer-Meshkov (RM) instability of a nominally flat interface (N_{2}/SF_{6}) subjected to a rippled shock, as the counterpart of a corrugated interface interacting with a planar shock, is studied experimentally in a vertical shock tube using both schlieren photography and fog visualization diagnostics. The nonplanar incident shock wave is produced by a planar shock diffracting around a rigid cylinder, and the flat interface is created by a membraneless technique. Three different distances η (the ratio of spacing from cylinder to interface over cylinder diameter) are considered. Schlieren images indicate that the nonplanar incident shock can be divided into three different segments separated by two triple points. Fog visualization pictures show the formation of overall "Λ" shaped interface structures and a N_{2} cavity at the center and two interface steps at both sides. With the increase of the dimensionless time, the dimensionless interface amplitude increases as well as the penetration depth of the cavity, and both curves exhibit reasonable collapse for different η numbers. Through equating the preinterface perturbation of the rippled shock with a preshock perturbation of a corrugated interface, the growth rate of this instability is found to be noticeably smaller than that of the standard RM instability.