Revisiting the strong shock problem: Converging and diverging shocks in different geometries

Abstract

Self-similar solutions to converging (implosions) and diverging (explosions) shocks have been studied before, in planar, cylindrical, or spherical symmetry. Here, we offer a unified treatment of these apparently disconnected problems. We study the flow of an ideal gas with adiabatic index γ with initial density containing a strong shock wave. We characterize the self-similar solutions in the entirety of the parameter space ω and draw the connections between the different geometries. We find that only type II self-similar solutions are valid in converging shocks, and that in some cases, a converging shock might not create a reflected shock after its convergence. Finally, we derive analytical approximations for the similarity exponent in the entirety of parameter space.