SIMULATION OF LAMINAR METHANE-AIR FLAMES USING AUTOMATICALLY SIMPLIFIED CHEMICAL-KINETICS

The method of intrinsic low-dimensional manifolds to simplify chemical kinetics is applied to laminar methane-air flames. The procedure is b ased on a mathematical analysis of the reaction system. Neither steady state assumptions for some species, nor partial equilibrium for react ions have to be specified explicitly. The only requirements to the sch eme are a derailed reaction mechanism and the number of degrees of fre edom desired for the simplified scheme. All necessary information on t he thermochemical state (species concentrations, temperature, density, etc.) is then given as function of a small number of reaction progres s variables, associated with the degrees of freedom. Therefore, less e quations (for two or three reaction progress variables instead of for 34 species in case of CH4) have to be solved, thus drastically reducin g the computational effort compared to calculations using detailed che mistry. Subsequent use of a tabulation procedure, where all informatio n is stored, guarantees an efficient use in various CFD applications.