Unsteady-Nonequilibrium Shock Wave/Boundary Layer Interaction with Explicit/Implicit Hybrid Approach

Abstract

The flow fields of a shock tube and a nozzle starting process for both perfect gas and flow with thermochemical nonequilibrium has been simulated. This flow is produced in high enthalpy impulse facilities such as free piston shock tunnel. The governing equations are the axisymmetric, compressible Navier-Stokes equations. For the case of thermochemical nonequilibrium, Park’s two-temperature model, where air consists of 5 species, is used for defining the thermodynamic properties of air as a driven gas. The numerical scheme employed here is the hybrid scheme of explicit and implicit methods, which was developed at our laboratory, along with AUSM + to evaluate inviscid fluxes. In the present simulation, the Mach number of an incident shock wave is set at Ms = 2:6;5:3. The results clearly show the complicated shock wave/ boundary layer interaction in the part of shock tube. These suggest that the retention of gas accounts for the growth of bifurcated shock structure. The discharge of vortex from the bifurcation surpresses the magnification of size of the bifurcation.