Numerical Simulation of Laser Ablation Propulsion Performance for Spherical Capsule

The purpose of this research is to study the performance of laser ablation propulsion with a numerical method based on computational fluid dynamics (CFD). We focus on the propulsion performance when pulsed laser beam is irradiated on a 10-mm-diameter spherical model. In this paper, 1.3 mm pulsed laser beam and a so-called donut-mode laser beam were both done to validate a simple numerical method without laser ablation model under 10 kPa – 100 kPa ambient pressure. The flow field quantities were solved with three-dimensional Euler equation by finite volume method. Blast wave energy conversion efficiency η _bw and momentum coupling coefficient C _m were both investigated by comparing between numerical simulation and experiment. Specifically, a so-called explosion source model is used to simplify laser ablation process and estimate blast wave energy conversion efficiency η _bw in this numerical method. Relatively good results of η _bw and C _m are obtained with this method. Finally, results of donut-mode laser beam simulation are presented about blast wave expansion andC _m.