激波与SF_6梯形气柱相互作用的数值模拟

基于大涡模拟,结合五阶加权基本无振荡格式以及沉浸边界法对平面入射激波与两种SF_6梯形重气柱的相互作用过程进行了数值模拟,数值结果清晰地显示了激波诱导Richtmyer-Meshkov不稳定性所导致的两种梯形重气柱的变形过程,详细分析了入射激波在两种梯形重气柱界面发生反射、折射、绕射以及折射激波与透射激波在气柱内部来回反射的过程,并研究了该过程中所产生的复杂波系结构,对两种梯形气柱变形过程中与周围空气的混合过程进行了分析;通过记录气柱界面四个特征尺寸随时间的变化对两种梯形气柱界面的不同演化过程进行了定量分析。

Richtmyer-Meshkov instability induced by the interaction between shock wave and SF6 isosceles trapezoid cylinders

Based on the large eddy simulation, combined with the 5th order weighted essentially non-oscillatory scheme and the immersed boundary method, the interaction between planar shock wave and two isosceles trapezoid SF₆ cylinders is numerically simulated. Our numerical results clearly show that the deformations of isosceles trapezoid cylinders are induced by the Richtmyer-Meshkov instability due to the interaction of shock wave with them. The reflecting, refracting and diffracting process of incident shock are discussed in detail, and the complex wave structures induced during these processes are revealed. In addition, the mixing mechanism of SF₆ gas and air is expatiated. Furthermore, the efforts are made to understand the difference in the evolution of the interface between these two isosceles trapezoid cylinders by analyzing the variation of four characteristic scales.
Keywords： Richemyer-Meshkov instability isosceles trapezia cylinder mixing wave structure