摘要
激波冲击双气柱既包含了激波与界面的相互作用又包含了界面之间的相互作用,是探索实际应用中Richtmyer-Meshkov(RM)不稳定性演化的很好的桥梁.利用高分辨率的粒子图像测速(PIV)技术获得了4种不同初始中心间距的双椭圆气柱在平面激波冲击下的速度场、涡量场和环量,定量表征了界面相互作用对RM不稳定性演化的影响.界面相互作用较弱时,双椭圆气柱的演化由两对涡对结构主导,内涡弱于外涡,且随着中心间距的减小内涡的弱化愈加显著;界面相互作用较强时,双椭圆气柱演化模式发生转变,内涡消失,只由一对涡对结构主导,外涡随中心间距的减小而增强.界面相互作用导致双椭圆气柱的演化行为与单椭圆气柱的演化行为不同,典型的特征是内涡的削弱及涡对结构的旋转运动.双椭圆气柱演化行为与双圆气柱演化行为也存在差别,表现为强界面相互作用时外涡随中心间距的减小而增强.
The interaction of a shock wave and double gas cylinders provides a good way to study the Richtmyer-Meshkov（RM） instability in practical applications, since it includes not only the interaction of a shock wave with interface but also the interface-interface interaction. The velocity and vorticity fields as well as circulations of four cases of doubleelliptic-cylinders with different center-to-center spacing impacted by a planar shock are obtained using highresolution particle image velocimetry（PIV）. These results quantitatively characterize the effect of interface-interface interaction on the evolution of the RM instability. It is demonstrated that when the interaction is weak, two vortex pairs dominate the evolution of the double elliptic gas cylinders. The inner vortices are weaker than the outer ones and become significantly weaker as the center-to-center spacing decreases. When the interaction is strong, a mode transition of the evolution of the cylinders occurs. The inner vortices disappear and only one vortex pair dominates the evolution. The outer vortices appear stronger as the center-to-center spacing decreases. As a result of the interface-interface interaction, the evolution of the double elliptic gas cylinders differs from that of the single elliptic gas cylinder and has two typical features, i.e. the weakening of the inner vortices and the rotation of the vortex pair. The evolution of the double elliptic gas cylinders also differs from that of the double circular gas cylinders and shows that the outer vortices become stronger as the center-to-center spacing is reduced in the strong interaction case.
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2016年第3期46-55,共10页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金(批准号:11172278,11472253,11302201)
中国工程物理研究院科学技术发展基金(编号:2014B0201017)资助项目
