Experimental Method for a Double-pulse Laserdriven Flyer and Flyer Motion Simulation
D-S. Geng, L. Chen J-Y. Lu, J-Y. Wu and K. Yang
Flyer velocity is an important indicator to measure the impact initiation ability of laser-driven flyer. In this paper an experimental method of flyer drive by double-pulse is presented. A high speed Schlieren photography system is designed to observe the flyer and shock wave. A one-dimensional (1-D) numerical calculation model is established, which considered phase transition, absorption of laser energy, and dynamic mechanical response. The flyer motion is simulated by using the weighted essentially non-oscillatory (WENO) finite difference method (FDM), level set equation and ghost fluid method. It is found that the double-pulse laser can effectively increase the flyer velocity and energy efficiency. At the end of laser irradiation, the aluminium film exhibits three regions: gas phase, gas-solid mixture phase and solid phase. During the acceleration process, the flyer undergoes intense compression and tension.
Keywords: Nd:YAG laser, aluminium film, flyer, plasma, double-pulse, high speed Schlieren photography weighted essentially non-oscillatory (WENO), finite difference method (FDM)