强度介质的Richtmyer-Meshkov扰动增长规律研究

The Richtmyer-Meshkov (RM) flow in medias with strength is the key issue of the state diagnostics of implosion and the physical understanding of the ejecta and mixing. As a research object originally, the scope of hydrodynamics instability study has expanded to be a research tool for the study of dynamic properties of materials under extreme conditions. Based on the linear model of perturbation growth, this project is proposed to build a theoretical model that is able to describe the correlation mechanism between the growth of RM flow and material strength. The shock compression of the medias and the release process after the shock breakout will be considered to analysis the reverse yielding control mechanism on the plastic deformation of perturbed surface. The experimental feasibility of using the RM flow to infer the strength of materials is another research objective in this proposal.

强度介质的Richtmyer-Meshkov流动不稳定性问题不仅是判断内爆压缩性能和理解微喷混合过程的关键物理问题，也是研究材料在极端条件下动力学性质的研究工具。本项目基于扰动增长的线性模型，考虑冲击波对强度介质的压缩效应，分析冲击波自由面卸载后介质反向屈服对扰动面演化的控制机理，建立扰动增长与材料性质的关联性理论模型，为研究材料的动力学性质探索新的实验技术途径。

冲击波作用下，强度介质界面的扰动增长可能导致表面的物质微喷射、轻重介质混合等复杂物理现象，是材料动力学行为、复杂物理系统和ICF相关研究中的难点问题，长期以来一直受到国内外研究者的关注。本项目针对冲击波加载的强度介质界面Richtmyer-Meshkov (RM)扰动增长问题，从理论和数值模拟两方面重点研究了界面扰动增长的规律，以冲击波加载扰动界面的动力学过程理论分析为基础，建立了描述初始扰动、加载压力、材料可压缩性与强度对扰动增长影响的关联关系，给出了扰动增长由线性向非线性过渡的物理判据，利用关联关系分析了金属材料的扰动增长实验，获得了铜、铝和铈材料在高应变率条件下的强度数据，希望为材料在高应变率条件下的强度实验研究提供不同的技术途径。