Experimental Investigation On Shock Wave Induced Richtmyer-Meshkov Instability At Multilayered Fluids Interfaces

When two fluid interfaces with different Density were instantaneous accelerated by shock wave, they will get a limited speed, in the course of this a small initial disturbance will get developed and enlarged which will lead to Richtmyer-Meshkov (RM) instabilityin the end, that is a strong mixing phenomenon caused by two totally immiscible fluids. It has widely application background and important research value for Inertial confinement thermonuclear fusion (ICF), Supernova dynamics and so on. This article try to do research on Multiphase fluid interface through Rectangular shock tube and High Speed PhotographyThe experiment mentioned in text will be organized inside Rectangular shock tube, shock wave will be gained through impact from High-pressure gas to aluminum film and it has a top-down direction. Two Multiphase fluid interface are used in the experiment which are"air- Silicone oil-water"and"air-alcohol-silicone oil", so that the Atwood-Number realized in the same experiment from 0 to 1. silicone oil and alcohol are colored with Ethyl acetate solution with No.140 blue and blue ink, in order to get clear interface by High-speed photography.The following conclusions can be made: High-viscosity liquids will block the development of interface, so that the phenomenon of turbulent mixing of RM is not going to appear or it will be delayed; the interface with smaller Atwood-No. will have a priority by development compared with interface with bigger Atwood-No.The spike which has been observed is Single-mode structure, the bubble with different wavelength have similar growing speed, and there are no annex from bigger bubbles to the smaller. The thickness of the silicone-oil is also one of the factors which will influence the unstable development of RM. For oil interface which has thickness between 4-5mm will separate from water media and could be mangled by airflow when it is unstable.If the Atwood-No. is 1, the depth of bubble is in direct ratio to the time, if Atwood-No. is 0, the depth of bubble is in direct ratio to the quadric of time, and the height of spike is in direct ratio of time, and there is a linear relationship between Mixing zone width and time; the mixture goes more fiercely when function direction of shock wave consistent with the Gradient direction of the Viscosity. Besides this text has compared the unstable RM phenomenon between"air-silicone oil"and"air-water".