Molecular Dynamics Simulations on Internal Structures of Normal Shock Waves in Lennard-Jones Liquids

Abstract

The present paper describes a highly efficient method for simulating the generation of shock waves in liquids by using the periodic-shell boundary condition, which is an outer boundary condition for molecular dynamics simulations. This method is used to simulate normal shock waves in Lennard-Jones liquids, clarifying the internal structures of shock fronts and the dependence of shock thicknesses on the shock Mach number. The present method significantly decreases computation times because it enables us to simulate only the shock fronts. Some of the main results derived by these simulations of molecular dynamics are that an overshoot in the profile of longitudinal temperature arises in liquid shock waves as well as in gas shock waves, that the thickness of shock front decreases with increasing Mach number, and that this thickness is about two times the diameter of molecules when the Mach number is 4.