马赫数对等离子体碰撞冲击波结构的影响——全动理学模拟研究  

Influence of Mach Number on Structure of Collisional Plasma Shock Waves: Fully Kinetic Simulations

作　　者：张文帅 蔡洪波[1] 张恩浩 杜报 邹士阳[1] 朱少平[1,2] ZHANG Wenshuai;CAI Hongbo;ZHANG Enhao;DU Bao;ZOU Shiyang;ZHU Shaoping(Institute of Applied Physics and Computational Mathematics,Beijing 100094,China;Graduate School,China Academy of Engineering Physics,Beijing 100088,China)

机构地区：[1]北京应用物理与计算数学研究所,北京100094 [2]中国工程物理研究院研究生院,北京100088收稿日期:2022-08-22修回日期:2022-11-04发布日期:2023

出　　处：《计算物理》2023年第2期199-209,共11页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(11905015,11975055)资助项目。

摘　　要：利用全动理学粒子(PIC)模拟研究不同马赫(Mach)数条件下等离子体碰撞冲击波的结构。研究发现:在低Mach数条件下,冲击波波阵面位置物理量的分布较为平缓(努森数较小),等离子体的粘性和热流可由经典输运理论描述,这种情况下数值求解双流体方程组得到的冲击波结构与PIC模拟一致。随着冲击波Mach数的增加,冲击波波阵面位置物理量的分布变陡,努森数增加,动理学效应对等离子体输运的影响变得显著。高Mach数条件下,动理学效应主要体现在“先驱离子”对离子粘性和热流的增强以及电子非局域输运对电子热流的影响。通过影响等离子体输运行为,动理学效应可以显著影响冲击波的结构特征。Fully kinetic Particle-in-cell(PIC)simulations are performed to study the structure of collisional plasma shock waves with different Mach numbers.It is found that for low-Mach shocks,the spatial gradient of physical quantities near the shock front is gentle,corresponding to small Knudsen numbers,and the plasma transport properties(e.g.viscosity,heat flux)are well described by the classical transport theory.The simulated shock structure is consistent with that obtained from the numerical solution of the two-fluid equations.With increasing Mach numbers,the spatial gradient of physical quantities near the shock front becomes steep(i.e.the Knudsen number is increased),and the influence of kinetic effects on plasma transport properties become significant.For high-Mach shocks,kinetics effects come into play mainly in the following two aspects:(1)enhanced ion viscosity and heat flux due to the precursor ions and(2)nonlocal transport effects on the electron heat flux.Kinetic effects can significantly influence the shock wave structure by changing the plasma transport properties.

关 键 词：等离子体冲击波 粘性与热流 动理学模拟 双流体方程组 

分 类 号：O469[理学—凝聚态物理]