Theoretical analysis and numerical simulation of laser driven multi-layered flyer

Abstract

AbstractA flyer with high velocity and good integrity can be obtained by laser driven multi-layered film. In order to deeply study the action mechanism, a calculation model of laser driven multi-layered flyer has been established, taking into account the effect of multi-layered on flyer velocity increase. Multi-layered flyer velocity driven by laser pulse beam has been calculated to decide film configuration capable of forming a high velocity flyer. Taking this film configuration as object, an intense laser driven multi-layered flyer experiment has been conducted to obtain flyer velocity and verify calculation model. In order to analyze flyer motion details, a two-dimensional axisymmetric computation model of laser driven flyer has been established. In this study, laser energy spatial-temporal distribution, film ablation, and plasma absorption laser to drive flyer have been considered. Saha ionization equilibrium equation is adopted to calculate film ionization degree and give plasma state equation. Dynamic mesh algorithm is used to calculate flyer motion. Coupled numerical simulation of laser ablation, laser interaction with plasma and plasma driven flyer has been achieved. Results show that flyer velocity firstly increases and then decreases with the increase of ablation layer thickness. Ablation layer has an optical laser absorption depth for different layer materials. Plasma velocity distribution is linear in axial when flyer accelerates. Insulation layer can decrease flyer temperature effectively to keep flyer integrity.