The Caltech ASC converging shock experiments (P. Dimotakis)

The converging shock experiments being conducted by P. Dimotakis are broken into three phases of increasing complexity. The converging shock is produced by means of a wedge afixed to the end of a shocktube.

• Phase 0: A single gas is used, the shock interacts with the boundary of the wedge producing shock mach stems, reflected shocks and triple points. The focusing of the shock is achieved by the successive reflection of the shock
• Phase 1: Two gases are used. The driver gas in the shocktube, and a lens gas in the wedge. The shape of the boundary (contact) between the two gases has been specially designed to curve the shock producing a circular shock centered on the apex of the wedge.
• Phase 2: A third gas is used. It is placed within the wedge after the lens. Purturbations on the contact between this gas and the lens gas will give rise to a Richtmyer-Meshkov instability, and the acceleration towards the apex will also have aspects of the Rayleigh-Taylor instablility

-- DavidHill - 2005