2000NewA....5..327C

We argue that the nonlinear interaction of a strong shock front with a dense gas cloud is characterized by the formation of a regular gasdynamical pattern which includes a reflected shock, a tangential discontinuity, and two Mach fronts. The pattern has the same gasdynamical nature as the Courant-Friedrichs pattern of the shock-shock interaction and contains the same dynamical elements. In shock-cloud interaction pattern, these elements are arranged in a different configuration, and the number of the elements is different. The pattern is nonstationary and evolves with the transformation of its topological structure.