ON THE ACCURACY AND EFFICIENCY OF CFD METHODS IN REAL-GAS HYPERSONICS

A study of viscous and inviscid hypersonic flows using generalized upw ind methods is presented. A new family of hybrid flux-splitting method s is examined for hypersonic flows. The hybrid method is constructed b y the superposition of the flux-vector-splitting (FVS) method and seco nd-order artificial dissipation in the regions of strong shock waves. The conservative variables on the cell faces are calculated by an upwi nd extrapolation scheme to third-order accuracy. A second-order-accura te scheme is used for the discretization of the viscous terms. The sol ution of the system of equations is achieved by an implicit unfactored method. In order to reduce the computational time, a local adaptive m esh solution (LAMS) method is proposed. The LAMS method combines the m esh-sequencing technique and local solution of the equations. The loca l solution of either the Euler or the Navier Stokes equations is appli ed for the region of the flow field where numerical disturbances die o ut slowly. Validation of the Euler and Navier-Stokes codes is obtained for hypersonic flows around blunt bodies. Real gas effects are introd uced via a generalized equation of state.