Parallel direct simulation monte carlo of two-phase gas-droplet laser plume expansion from the bottom of a cylindrical cavity into an ambient gas

Abstract

A combined computational model for simulation of the expansion of two-phase laser plumes is developed. The model includes a two-dimensional thermal model of the irradiated target, Direct Simulation Monte Carlo method for flow of multi-component gas mixture in the plume, and a Lagrangian scheme for tracking of trajectories of individual sub-micron droplets generated on the irradiated surface. The model is implemented in a parallel computational code and applied for simulations of the plume expansion into an ambient gas, which is induced by a nanosecond laser pulse irradiating the bottom of a cylindrical cavity on the target surface. Simulations reveal the significant physical effects of the ambient gas chemical composition on the motion of laser ablated submicron debris in the vicinity of the target. © 2011 Springer-Verlag Berlin Heidelberg.