Richtmyer-Meshkov不稳定性扰动增长率冲击模型的微尺度效应

On the microscale effect of Richtmyer-Meshkov instability on perturbation growth rate of impact model

本文通过考虑流体介质输运性质对激波理论的影响,针对微型激波管中的RichtmyerMeshkov(RM)不稳定性,分析了微尺度效应对三种冲击模型扰动增长率的影响。一维气体动力学计算结果表明:流动尺度对于Richtmyer模型、Meyer-Blewett(M-B)模型和Vandenboomgaerde-Mügler-Gauthier(V-M-G)模型中的线性扰动增长率有显著影响。当流动尺度由宏观状态逐渐减小至微尺度时,三种模型的扰动增长率均会经历从少量增长到明显下降,然后迅速上升的过程。微尺度条件下,V-M-G模型的扰动增长率相比宏观尺度有显著提高。与其他两种模型相比,修正后的V-M-G模型更合理地描述了微尺度效应对于线性扰动增长率的影响。此外,对于修正后的V-M-G模型,当入射激波马赫数较低时,扰动增长率受微尺度效应的影响更为明显。

In this paper,taking into account the effect of fluid transport properties on shock wave theory,the influence of microscale effect on perturbation growth rate of three impulsive models is analyzed in view of Richtmyer-Meshkov instability in micro shock tube.Results of one dimensional gas dynamics calculation show that the flow scale has a significant influence on the linear growth rate of the perturbation in the Richtmyer model,the Meyer-Blewett (M-B)model and the Vandenboomgaerde-Mugler-Gauthier (V-M-G)model.As the flow scales decrease from macroscale to microscale,the amplitude growth rates of these three models will undergo a process of littile growth, evident decrease and rapid increase.Compared with the situation in macroscale,there has been a notable rise in the amplitude growth rate of V-M-G model in microscale.By contrast,this fixed model describes the effect of microscale on linear amplitude growth rate of Richtmyer-Meshkov instability more reasonably.In addition,as the Math number of the incident shock is smaller,the influence of the microscale on the amplitude growth rate is more remarkable in the fixed V-M-G model.