SHOCK-INDUCED RICHTMYER-MESHKOV INSTABILITY IN THE PRESENCE OF A WALLBOUNDARY-LAYER

An experimental investigation on gaseous mixing zones originated from the Richtmyer-Meshkov instability has been undertaken in a square cros s section shock tube. Mass concentration fields, of one of the two mix ing constituents, have been determined within the mixing zone when the shock wave passes from the heavy gas to the light one, from one gas t o an other of close density, and from the light gas to the heavy one. Results have been obtained before and after the coming back of the ref lected shock wave. The diagnostic method is based on the infrared abso rption of one of the two constituents of the mixing zone. It is shown that the mixing zone is strongly deformed by the wall boundary layer. The consequence is the presence of strong gradients of concentration i n the direction perpendicular to the shock wave propagation. Finally, it is pointed out that the mixing goes more homogeneous when the Atwoo d number tends to zero.