不同界面组分分布对Richtmyer-Meshkov不稳定性的影响  

Influence of different interface component distributions on Richtmyer-Meshkov instability

作　　者：张升博 张焕好[1] 陈志华[1] 郑纯 Zhang Sheng-Bo;Zhang Huan-Hao;Chen Zhi-Hua;Zheng Chun(Key Laboratory of Transient Physics,Nanjing University of Science&Technology,Nanjing 210094,China;School of Mechanical Engineering,Nanjing University of Science&Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学,瞬态物理国家重点实验室,南京210094 [2]南京理工大学机械工程学院,南京210094

出　　处：《物理学报》2023年第10期242-255,共14页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12072162,12102196);江苏省自然科学基金(批准号:BK20210322);中国博士后科学基金(批准号:2022M711642);江苏省研究生科研与实践创新计划项目(批准号:KYCX22_0492)资助的课题。

摘　　要：基于二维非定常Euler方程,对平面激波与不同界面组分分布下氦气气柱作用过程所引起的Richtmyer-Meshkov不稳定性现象进行了数值模拟,探讨了激波冲击轻质气柱后气柱界面形态的演变及流场波系结构,定量分析了气柱特征尺度(气柱长度、高度和中轴宽度)和气柱体积压缩率随时间变化.此外,结合流场压强、速度、环量和气体混合率,多角度分析了激波驱动界面气体混合的流动机制,获得了不同界面组分分布对界面不稳定性的影响.结果表明,随着气柱界面从完全扩散界面向间断界面的过渡,界面两侧的声反射系数随之增大,使入射激波与气柱界面的作用由常规透射转变为非常规透射,反射激波逐渐加强,透射激波逐渐减弱,使得Richtmyer-Meshkov不稳定性随之增强;同时,界面两侧阿特伍德数的增大,加强了Rayleigh-Taylor不稳定性和Kelvin-Helmholtz不稳定性的发展.此外,界面不稳定性的加强使得流场环量增大,导致气体混合率的增长速率随之升高.In this paper,the Richtmyer-Meshkov instability is studied numerically by using the high-resolution Roe scheme based on the two-dimensional unsteady Euler equation,which is caused by the interaction between shock wave and the helium circular light gas cylinder with different component distributions.The numerical results are used to further discuss the deformation process of the gas cylinder and the wave structure of the flow field,and also to quantitatively analyze the characteristic dimensions(length,height and central axial width)of the gas cylinder,the time-dependent volume compression ratio of the cylinder.In addition,the flow mechanism of shock-driven interface gas mixing is analyzed from multiple perspectives by combining the flow field pressure,velocity,circulation and gas mixing rate.Then the effects of different initial component distribution conditions on interface instability are investigated.The results show that when the diffusion interface transforms into the sharp interface,the reflection coefficient gradually increases on both sides of interface.When the incident shock wave interacts with the cylinder,the transmission of the shock wave will transform from conventional transmission into unconventional transmission.At the same time,the reflected shock wave is gradually strengthened and the transmitted shock wave is gradually weakened,which leads the Richtmyer-Meshkov instability to be strengthened.Moreover,the Atwood numbers on both sides of the interface also increase as the diffusion interface transforms into the sharp interface,which leads the Rayleigh-Taylor instability and the Kelvin-Helmholtz instability to be strengthened.Therefore,the increase of instability will cause the circulation to increase,resulting in the increase of the growth rate of gas mixing rate.

关 键 词：RICHTMYER-MESHKOV不稳定性 间断界面 扩散界面 氦气柱 激波 

分 类 号：O354.5[理学—流体力学]