Investigations of a novel boundary condition approach for the accurate prediction of hypersonic oblique shocks in mesh-free Lagrangian simulations

Abstract

The mesh-free Smoothed-particle hydrodynamic (SPH) method, with boundary condition and artificial viscosity modifications, is used to model oblique shock waves in inviscid, compressible (super- and hypersonic) flow. The boundary modifications include simple particle reflection at walls and the artificial viscosity modifications include a novel compression switch. It is shown the Lagrangian SPH particle method can be used to accurately capture not only the shock angle but also the jump conditions of the flow across the oblique shock, including post-shock temperature, density, pressure, Mach, and velocity. The validation shown includes compression corner angles for air, at M = 5, at 10-25 degrees—those possibly found in real hypersonic flight—as well as stretch cases of supersonic (M = 2) flow and CO2 as the working fluid.