<title>Visualization of interfacial instability induced by initially disturbed converging shock waves</title>

Abstract

The paper reports an experimental study of the interaction of initially disturbed converging and diverging cylindrical shock waves with cylindrical interfaces and the resulting Richtmyer- Meshkov instability. Experiments were conducted in an annular vertical diaphragmless shock tube, in which cylindrical soap bubbles filled with He and SF6 were placed co-axially in its test section. In order to the clarify effects of initial disturbances, 10 mm dia. pins were installed in the annular section, 92 mm from the shock tube's test section and before the 90 degree smooth bend at the top of the shock tube. The inner ends of the pins were rounded to ensure completel sealing with the inner wall of the low pressure channel. Weak disturbances in the converging cylindrical shock waves were produced by inserting the pins. Double exposure holographic interferometry was used for quantitative visualization of the interfacial instability and the subsequent mixing between the interface gases. It is known that the lower mode numbers of disturbances are dominant near the converging center, therefore experiments with mode eight and mode four disturbed converging shock waves were performed and the effects of weak waves behind the shock wave on the interfacial growth rates were clarified.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.