【摘要】 实验研究了低马赫数(1.27)激波作用air/SF6界面的RM不稳定性问题。air/SF6初始正弦界面由厚度为1～2!m的薄膜相隔得到,用阴影法测试界面演化过程。实验结果表明:由于不稳定性重流体(SF6)向轻流体(air)演化成"尖钉"结构,而轻流体演化为"气泡"结构;由于界面切向速度差的Kelvin-Helm-holtz不稳定性,"尖钉"头部翻转成蘑菇头形状;之后,蘑菇杆破碎。扰动振幅发展的实验结果与Zhang-Sohn模型和PPM数值计算的结果较吻合。更多还原

【Abstract】 In a shock tube,the air/SF6 interface was accelerated by the incident shock wave with the low Mach number of 1.27.The initial sinusoidal interface was obtained by applying the polymeric membrane with the thickness of 1~2 mm and the interface evolution was monitored by using the time-resolved shadowgraph technique.The Richtmyer-Meshkov(RM) instability of the sinusoidal initial perturbation at the air/SF6 interfaces was characterized by the "spikes" of the heavy fluid(SF6) falling into the light fluid(air) and the "bubbles" of the light fluid(air) rising into the heavy fluid(SF6).Due to the Richtmyer-Meshkov(RM) instability caused by the tangential velocity difference at the air/SF6 interfaces,the heads of the "spikes" overturned into "mushroom" shapes and subsequently the "mushroom" poles broke up.And this RM instability caused the spikes to break up.The experimental disturbance amplitude is in agreement with the results by the Zhang-Sohn model and PPM simulation.更多还原