极端环境中材料力学特性对流体力学不稳定性演化行为影响的研究

高能量密度物理环境中Rayleigh-Taylor (RT) 和Richtmyer-Meshkov (RM) 不稳定性的演化行为研究已经成为国内外关注热点。惯性约束聚变物理中RT和RM不稳定性是影响点火成功与否的关键因素；RT和RM不稳定性可诊断材料在极端环境中的物态方程。然而，当粘性、弹性、塑性等多种因素共同作用和相互耦合时，目前的理论研究还不能描述RT和RM不稳定性在高能量密度物质中的精确行为，从而制约了进一步的理论研究。申请人1）拟通过Helmholtz分解理论，得到RT和RM不稳定性精确的色散关系，研究粘性、弹性、塑性等因素对流体力学不稳定性的作用；2）结合数值模拟和理论研究，得到界面扰动初始速度与激波强度的依赖关系。在极端力学环境中，结合1）和2），得到界面的真实行为。此方法为研究极端环境中材料的力学特性以及控制不稳定性的演化行为奠定理论基础，为此方面数值模拟研究提供指导。

Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities play essential roles in a wide range of fields, from materials science, weapon physics, high energy density physics, to inertial confinement fusion. RT and RM instabilities limit the compression ratio of the imploding target, which is the key factor to reach fusion; on the other hand, RT and RM instabilities have become useful tools to diagnose constitutive properties of materials under extreme conditions. The behaviors of RT and RM instabilities in extreme conditions are highly complicated since it involves fine descriptions of the equation of state. However, most of the current theoretical researches focus on the effects of specific factors on RT and RM instabilities instead of the highly coupled situations by employing the potential flow theory. In this report, we intend to study the effects of materials properties under extreme conditions to study RT and RM instabilities by numerical simulations and theoretical formulations, in order to study the mechanical properties of materials of interests under high energy density situations and to control the detrimental growth of RT and RM instabilities to deteriorate the experimental performance. This method also offers a way to understand the dominant factors on the growth rates of the interface and provide a benchmark for future numerical simulations.