We study the evolution of the single-mode Richtmyer–Meshkov instability for a wide range of Atwood numbers, shock strengths and perturbation amplitudes using Youngs’ hydrodynamical simulation code TURMOIL. We compare our results to previously published analytic models for the impulsively-driven growth rate, and propose a modification to them to treat the reduction of growth found at high initial perturbation amplitudes and high Mach numbers. It is known that the overall asymmetry between bubbles and spikes and their eventual deceleration can be interpreted as the result of nonlinear coupling to higher harmonic modes. However, we find that for light-to-heavy interfaces at moderate to high impinging shock Mach numbers, the shape of the growing bubbles varies in time, with the initial curved bubble surfaces flattening and inverting to generate a second low velocity jet. For high shock Mach numbers and low initial surface amplitudes, the process of inversion can recur on numerous occasions. We interpret this as being the result of vorticity deposited by the transmitted shock in the bulk of the heavy material, away from the initial interface.

我们使用杨氏流体力学仿真代码TURMOIL研究了大范围Atwood数，冲击强度和摄动幅度的单模Richtmyer-Meshkov不稳定性的演化。我们将我们的结果与先前发布的脉冲驱动增长率的分析模型进行比较，并提出对它们的修改，以处理在高初始扰动幅度和高马赫数下发现的增长下降。众所周知，气泡和尖峰之间的整体不对称及其最终的减速可以解释为非线性耦合至高次谐波模式的结果。但是，我们发现，对于中到高冲击马赫数的轻到重的界面，气泡的形状会随时间变化，初始弯曲的气泡表面变平并反转以生成第二个低速射流。对于高冲击马赫数和低初始表面振幅，反演过程会在许多情况下重复出现。我们将其解释为是由于传播的冲击在远离初始界面的大部分重质材料中传递的震动所造成的涡旋的结果。