The 4th International Conference on Matter and Radiation at Extremes (ICMRE 2019)

507 / 2019-03-19 09:31:14

Convergent Richtmyer-Meshkov instability on a heavy gas layer with perturbed outer surface

Richmyer-Meshkov instability; Convergent geometry

Plenary track > Interface Instabilities at Extremes

In this work, we present two-dimensional experiments of a cylindrical shock accelerating a heavy gas shell in a semi-annular converging shock tube. A soap-film technique is improved to generate gas layers with controllable inner and outer boundaries. Three SF6 layers of different thicknesses surrounded by air are successfully generated and their interactions with a cylindrical shock are recorded by a high-speed schlieren photography. Results show that the thicker the gas layer, the weaker the interface-coupling effect, and the slower the evolution of the outer interface. Induced by the distorted transmitted shock and the interface coupling, the inner interface exhibits a slow perturbation growth which can be largely suppressed by reducing the layer thickness. After the reshock, the inner perturbation increases linearly at a growth rate regardless of the initial layer thickness.