Numerical simulation of air-He shock tube flow with equilibrium air model

In this study, a compressible multicomponent Navier-Stokes flow solver with real gas effect is developed for studying the high-speed flow in an air-He shock tube. For compressible multicomponent flow simulation, a reduced five-equation model in conjunction with the Harten-Lax-van Leer scheme for contact surface approximate Riemann solver is employed. For the real gas effect, a curve-fitting approximation for equilibrium air constructed from Grabau-type transition functions is adopted. In addition, the Baldwin-Lomax turbulence model is used for turbulent flow simulation. In this work, several typical test cases will be demonstrated first. Subsequently, air-He shock tube simulations with the real gas effect will be performed by using parallel computation. Based on the present results, the real gas effect shows significant influence on the temperature behind the reflected shock. In addition, the driver gas contamination and the development of shock bifurcation are presented by flow visualization.