Interaction of an entropy spot with a shock

The problem of a shock wave interacting with a two-dimensional and an axisy mmetric entropy or temperature spot is addressed. The problem is posed in t he framework of the Euler equations, which are solved by a sixth-order accu rate shock-fitting algorithm. The results indicate that such an interaction squishes the spot in the direction of convection and engenders a pair of c ounter-rotating vortices along with an acoustic wave, which propagates away from the center of the vortical system. The acoustic front steepens, leadi ng to secondary shocks for sufficiently high shock Mach numbers. The enstro phy and dilatation budgets are discussed. The quantitative differences betw een the hot and cold spot cases are brought out, as well as those between t he two-dimensional and the axisymmetric cases. The emphasis is on the nonli near aspects of the interaction process.