Numerical and theoretical investigations of shock-induced material ejection and ejecta-gas mixing

When a strong shock wave releases from material surface, material ejection usually takes place where a great amount of high-speed particles can be ejected from the material surface. This phenomenon is called micro-ejection and the ejected particles is named as ejecta. In gas environment, the interaction between ejecta and gas can lead to the formation of a layer of gas-ejecta mixture and this process is called mixing. Micro-ejection and mixing are of great importance in many fields such as inertial confinement fusion and implosive dynamics, and have attracted intense research activities both experimentally and theoretically in the past several decades. The author and collaborators have been studying the microejection and mixing phenomena for years, and some valuable achievements have been obtained. In the present review, we introduce some of our theoretical works on the two main mechanisms of micro-ejection (i.e., micro-jetting and microspallation) as well as the gas-ejecta mixing process, including mechanisms of micro-jetting and micro-spallation and their dominant factors, modeling of micro-jetting based on the Richtmyer-Meshkov theory in elastic-plastic solids, and some dynamic characteristics of mixing.