绕射激波和反射激波作用下N_2/SF_6界面R-M不稳定性实验研究  

EXPERIMENTALLY STUDY OF THE RICHTMYER-MESHKOV INSTABILITY AT N_2/SF_6 FLAT INTERFACES BY DIFFRACTED INCIDENT SHOCK WAVES AND RESHOCK

作　　者：刘金宏[1] 邹立勇[1] 曹仁义[1] 廖深飞 王彦平[1] 

机构地区：[1]中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室,绵阳621900

出　　处：《力学学报》2014年第3期475-479,共5页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金资助项目(11302201;11172278)~~

摘　　要：利用高速纹影测试实验研究低马赫数入射激波绕圆柱体后冲击N2/SF6平面界面,以及来自固壁的反射激波再冲击过程的(Richmyer--Meshkov,R--M)不稳定性特征.与平面激波作用不同的是,绕射后的激波会在界面处生成局部扰动.实验结果显示,入射激波作用下界面宽度增长缓慢,而反射激波再冲击后,局部扰动会产生大的"尖钉"和"气泡"结构;以及反射激波与边界层相互作用产生壁面涡,它们会加剧湍流混合区的增长;实验中反射激波过后混合区增长率不十分依赖于波前状态,增长规律同Mikaelian模型较吻合;来自尾部固壁的反射稀疏波会再次加剧湍流混合区的增长.The developments of Richtmyer-Meshkov instability at gas interface subjected to a diffracted incident shock wave of low Mach number and reshock wave have been experimentally studied using the high-speed schlieren photog- raphy. The planar shock wave diffracted over a cylindrical column produces local perturbation at the gas interface. It has been demonstrated that the thickness of the interface grows slowly under the incident shock wave, while spike and bubble are clearly observed upon reshock. Moreover, the interaction between the reshock wave and the boundary layer generates wall vortices, which accelerates the development of turbulence mixing zone （TMZ）. The post-reshock growth rate of TMZ is almost independent of pre-reshock conditions and in good agreement with the prediction of Mikaelian model. The reflected rarefaction wave from wall-end also accelerates the development of TMZ.

关 键 词：Richmyer--Meshkov不稳定性 湍流混合 激波管 

分 类 号：O357.5[理学—流体力学]