磁场对激波冲击R22重气柱作用过程影响的数值模拟  

Influence of magnetic field on interaction of shock wave with R22 heavy gas column

作　　者：林震亚 张焕好[1] 陈志华[1] 刘迎[1] 

机构地区：[1]南京理工大学瞬态物理国家重点实验室,江苏南京210094

出　　处：《爆炸与冲击》2017年第4期748-758,共11页Explosion and Shock Waves

基　　金：国家自然科学基金项目(11272156);中国博士后科学基金项目(2015M571757)

摘　　要：为研究平面入射激波与磁化R22重质圆形气柱的作用过程,首先通过数值方法得到了不同初始条件下激波诱导R22气柱的Kelvin-Helmholtz(KH)及Richtmyer-Meshkov(RM)不稳定性导致的重气柱变形过程,并详细讨论了不同情况下透射激波在气柱内聚焦诱导射流的过程;然后在加入磁场的情况下,采用CTU+CT算法进行数值模拟,以保证数值结果满足任意时刻磁场的散度为零。计算结果表明:磁场对激波诱导R22气柱不稳定性具有抑制作用;法向磁场和流向磁场都可以很好地抑制RM不稳定性;对于KH不稳定性,法向磁场的控制效果更好,不仅可以抑制界面上涡串的卷起,还可以阻止主涡的发展,而流向磁场做不到后者;磁场对射流影响不大,射流处的磁能量可以一定程度上抑制射流的衰减,同时法向磁场可以减小聚焦时压力及速度峰值。To study the interaction process of the plane incident shock wave with the magnetized R2 2 heavy gas column,we numerically simulated the deformation process of the shock-wave-induced R2 2 heavy gas column resulting from Kelvin-Helmholtz （KH） and Richtmyer-Meshkov （RM） instabilities under different initial conditions,and analyzed the jet focusing and inducing process by the transmit-ted shock wave. When the magnetic field was taken into consideration？ the CTU ＋ CT algorithm sat-isfying the divergence equation of the magnetic field at any time was adopted in the numerical simula-tion. The results show that the magnetic field is capable of restraining the wave-induced R2 2 gas column. Both the normal magnetic field （vertical to the flow direction） and the tangential magnetic field （parallel to the flow direction） can inhibit the RM instability. However, the restraining of the normal magnetic field is more effective than that of the tangential one with regard to the KH instability,as it can not only inhibit the vortex train rolling up on the interface but also pre-vent the bound vortex from developing. Besides,it is found that the magnetic field has little influence on the jet,and the magnetic energy at the jet point can suppress the jet attenuation to some extent while the normal magnetic field can reduce the peak pressure and velocity when the transmitted shock wave is focused.

关 键 词：磁化气体 磁流体动力学 磁场 不稳定性 激波 

分 类 号：O354.5[理学—流体力学]