ABSTRACT The effects of non-uniformity of flows and initial disturbance intensity of the incident shock wave on Richtmyer–Meshkov instability (RMI) when a sinusoidal shock wave with Ma = 1.25 impinging an unperturbed interface are numerically investigated. The interface morphology, turbulent mixing zone width (TMZW), Y-integrated vorticity, circulation, and turbulent kinetic energy (TKE) are qualitatively and quantitatively compared before and after reshock. The numerical results indicate that the non-uniformity of flows and initial disturbance intensity of sinusoidal shock wave are significant factors of RMI evolution. On the one hand, the TMZW and its growth rate increase with the decrease of the parameter of non-uniformity before reshock; while, those discrepancies are reduced after reshock. On the other hand, the increase of the initial disturbance intensity of sinusoidal shock wave leads to the increase of the vorticity, circulation and TKE, the TMZW and it growth rate increase accordingly, all the time. Further analysis points out that the TMZW evolves with time as a power law before reshock, and the value of θ is sensitive to the initial conditions. After reshock and the first reflected rarefaction wave, the TMZW grows in time as a negative exponential law , but t* is different for the two stages.

中文翻译：

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非均匀流动中非平面冲击波引起的 Richtmyer-Meshkov 不稳定性的数值研究

摘要 当 Ma = 1.25 的正弦冲击波撞击未受干扰的界面时，流动的非均匀性和入射冲击波的初始扰动强度对 Richtmyer-Meshkov 不稳定性（RMI）的影响进行了数值研究。对再震前后的界面形态、湍流混合区宽度（TMZW）、Y-积分涡度、环流和湍流动能（TKE）进行了定性和定量比较。数值结果表明，流动的不均匀性和正弦冲击波的初始扰动强度是RMI演化的重要因素。一方面，TMZW及其增长率随着再震前非均匀性参数的减小而增大；而这些差异在再冲击后会减少。另一方面，正弦激波初始扰动强度的增加导致涡度、环流和TKE的增加，TMZW及其增长率也相应增加。进一步分析指出，TMZW在再激波前作为幂律随时间演化，θ值对初始条件敏感。在再冲击和第一次反射稀疏波之后，TMZW 随时间呈负指数规律增长，但两个阶段的 t* 不同。