Numerical Prediction of Partially Premixed Flames Based on Extended BML Model Coupled With Mixing Transport and ILDM Chemical Model
To improve the numerical prediction of partially premixed flames occurring in gas turbine combustors the extension of the well-known Bray-Moss-Libby model for premixed combustion is presented. The model modification based on the algebraic closure for a mean chemical source term is coupled to the mixing transport model providing variable equivalence ratio distinguishing partially premixed flames. Finite rate chemistry is incorporated by means of ILDM model solving transport equations for two reaction progress variables conditioned on the flame front. Multivariate presumed PDF model is used for the turbulence chemistry interaction treatment. Turbulence models of two levels of complexity are applied in order to investigate the influence of non-gradient turbulent transport phenomenon. Redistribution terms in second moment transport equations are extended to take into account strongly variable density effects. Model combinations considered are assessed simulating piloted partially premixed flame. The obtained results agree well with experimental data.