Simulation of high-speed flows by an unstructured grid implicit method including real gas effects

摘要

The incorporation of real gas effects into an efficient dual-time implicit method is presented for numerical simulation of high-speed flows. Two-dimensional compressible Navier-Stokes equations are discretized by an implicit approach in a real-time basis. The resulting set of implicit nonlinear equations is then solved iteratively in pseudo-time using a Runge-Kutta scheme. A control-volume central difference approach is used for spatial discretization on unstructured grids. For an equilibrium chemically reacting air, simplified equations are used to calculate the thermodynamics and transport properties of equilibrium air. The method is applied to hypersonic laminar flows of air over a compression ramp and a circular cylinder. Computational results are compared with those of other numerical methods and experimental data. Excellent agreement is obtained for various flow and heat transfer characteristics. Considerable reduction in computational time has also been achieved compared with the original explicit method.