Shock collisions in 3D using an axi-symmetric regularized smoothed particle hydrodynamics code

In many shock wave problems, the assumption of cylinder symmetry is useful, and allows 3D situations to be simulated with a 2D numerical code, thereby reducing computational cost, and increasing computational speed. In this paper we use the regularized smoothed particle hydrodynamics (RSPH) description for cylinder symmetry (Omang in “A numerical study of shock reflection phenomena. Exploring the capabilities of regularized smoothed particle hydrodynamics to handle shock waves”, 2005; Omang et al. in Shock Waves 14(4):293–298, 2005; Omang et al. in J Comput Phys 213(1):391–412, 2006) to study 3D shock reflection and shock interaction phenomena. In the first example we study the shock reflection pattern resulting from a torus-shaped shock reflecting both from the symmetry axis and from an object in the flow field. At the symmetry axis a characteristic Mach reflection is formed, with a triple point, a curved Mach stem, and a weak slip layer. The shock also interacts with the object, producing additional reflected shocks. The interactions between the different shock waves, resulting for instance in strong local pressure and density peaks, are studied in closer detail.