Molecular Dynamics Simulation Research on the Transport, Breakup and Reaction Dynamics of Shock-induced Ejecta in Gas Environment

The metal-gases interface instability evolution and subsequent transport process of micro-ejecta in gases has recently begun to attract attention and research interest. Here, we have conducted a series of studies on shock-induced ejection with molecular dynamics simulation, including ejecta transport, breakup and reaction dynamics in gases. We find that ejected microjets experience progressively aggravated deceleration with increasing gas density, and particle flows ahead of jet tips are suppressed. Further, with the presence of gases, the size distribution of ejected particles is altered with an outstanding feature of enhanced formation of atomic particles. Further simulations of ejecta transport in reactive gases revealed that the reactions will quickly increase the temperature of the mixing zone, followed by the deceleration of spikes and a greater shock intensity in the compressed gases, compared with the ejection in inert gases. When ejecta transport in reactive gases, the chemical interactions cause higher temperature in mixed zone and more metal atoms to evaporate from the surface of larger particles, thus forming smaller fragments and more atomic particles.