激光引致激波传播规律的数值研究

Numerical study on the propagation properties of laser-induced shock wave

关键词:  激光引致激波  激波传播  光线追踪法  能量源项

Key words:  Laser-induced shock wave  Shock wave propagation  Ray tracking method  Energy source

摘要:

空气光学击穿的激波流场结构的研究是激光与物质相互作用研究领域中的重要组成部分。利用光线追踪法,采用解耦的辐射输运方程,数值求解含能量源项的流体控制方程,对空气光学击穿诱导激波的传播过程和随时间演化规律进行了研究。通过线形拟合,给出了激波传播的后期阶段激波半径随时间的变化关系。流场中的超压波形有几个峰值,由多列压缩-稀疏波组成,并且强度越来越弱。研究结果可为激光应用技术提供一定的理论支持。

Abstract:

In the investigation of laser material interaction,the proper description of the shock wave flow structure after air optical breakdown plays an important role. With the ray tracking method,the decoupled radiation transfer equation is used to study the propagation process and the change law of the laser-induced shock wave by numerically solving the control equations containing energy source term. The function relationship of the shock wave radius with respect to time in the later period has been obtained by linear fitting. The temporal overpressure wave form shows that it contains more than one peak points and it comprises many compression-expansion waves,which decay slowly. The results may provide some theoretical support for laser application technology.