Numerical simulation of weak steady shock reflections

The reflection of weak shocks constitutes an interesting problem from a modeling point of view. The discussion about the von Neumann paradox and the Guderley’s triple shock wave solution are an example of this interest. In the present paper the attention is focused on those steady state reflections where the Von Neumann theory fails or does not provide the “classical” solution with incident and reflected shocks belonging to opposite families. Contrarily to the theory, numerical solutions of these problems show a Mach reflection similar to von Neumann triple point solution, provided that the computed shocks have a physical or numerical thickness. These special cases of Mach reflections are discussed with the help of numerical solutions obtained by different approaches based on shock capturing and shock fitting, respectively.