Numerical simulation of supersonic turbulent combustion flows based on flamelet model

A solver based on the combination of Reynolds-Averaged Navier-Stokes (RANS) equations and laminar flamelet model is designed to simulate supersonic turbulent combustion within the finite volume framework on a hybrid unstructured polyhedral-cell mesh system. The implicit Lower-Upper Symmetric Gauss-Seidel (LU-SGS) algorithm is used as the time evolution method, while the convective fluxes are computed with the Harten-Lax-van Leer-Contact (HLLC) scheme. Menter's shear stress transport (SST) k-ω turbulence model is implemented to model the turbulence. The laminar flamelet model is used as the combustion model and the flamelet table is constructed by the FlameMaster 3.9 code. The interaction between turbulence and chemistry is accounted for by using the assumed β-a nd δ-PDF models. The solver is used to simulate the supersonic combustion flows in the DLR (German Aerospace Center) hydrogen fueled scramjet combustor and the ethylene (C₂H₄) fueled aeroramp injector/gas-portfire (ARI/G-P) Scramjet combustor at Beihang University (BUAA). The numerical results agree well with those of the experiments. It is concluded that combustion takes place in the wake of the fuel jets downstream the strut for a typically center equipped parallel injection strut Scramjet combustor, with the flame core settled in the vicinity region of the stoichiometric Z_st.