Experimental Investigation on Flowing Soap Film Gaseous Interface and its Evolution Accelerated by a Cylindrical Converging Shock Wave
流动肥皂膜气体界面及其在柱状汇聚激波作用下演化的实验研究

In the study of Richtmyer-Meshkov (RM) instability experiment, the formation of initial perturbation on the interface between two fluids with different densities is an essential precondition and key problem. A flowing soap film method for generating gaseous interface is proposed in this paper, in which a guiding frame made up of filaments passes through the shock tube test section. Soap liquid moves from the top of guiding frame due to the gravitation and forms a flowing soap film within the guiding frame. If on the both sides of film are filled with different gases, then a steady gaseous interface is formed. According to different configurations of guiding frame, various shapes of interface can be obtained, including planar, prismy, piecewise smooth, curved and multilayer structures. Results indicate that the flowing soap film interface is thin, easy to form specified shapes, able to match the shock tube test section and to maintain enough long time. Interaction of a cylindrical converging shock wave with a vertical interface was investigated experimentally. The shape change of cylindrical converging shock wave and the development process of RM instability of vertical SF6/air interface were observed based on high-speed schlieren photography.