Modified shock velocity in heterogeneous wetted foams in the strong shock limit

Abstract

Shock propagation in wetted foams described by a regular square alignment of fibers of heavy medium immersed in a light medium is studied. A two-dimensional Eulerian adaptative mesh refinement code is used. The equation of state is assumed to be that of perfect gases. The variation of the presence ratio of fibers—the ratio of the dry-foam density to the solid density—leads to an increase in the shock velocity in comparison to the speed that the shock would have in a homogeneous medium with the same average density. This departure from the homogeneous case exhibits a maximum when the presence ratio is roughly 70%. Only three independent parameters seem to have an effect on the shock velocity: the presence ratio, the density ratio between both fluids, and the adiabatic exponent. The numerical results seem to be consistent with a thermodynamic description of turbulence.