REDIM-PFDF modelling of turbulent partially-premixed flame with inhomogeneous inlets using top-hat function for multi-stream mixing problem

Abstract

Present study focuses on numerical investigation of two important partially-premixed inhomogeneous types of flames using REDIM-PFDF sub-grid scale combustion model. REDIM-PFDF model is based on the reaction-diffusion manifold (REDIM) technique and presumed filtered density function (PFDF) method. The detailed chemical kinetics is reduced into a two-dimensional chemistry table which is using the mass fractions of CO2 (YCO2) and N2 (YN2) as the reduced coordinates. The shapes of the Filtered Density Function (FDF) for YCO2 and YN2 are presumed to be clipped Gaussian and top-hat, respectively. We find that the top-hat function, in context of LES, is a suitable option to deal with multi-stream mixing problem. The comparison between LES and experimental data shows that the mixture fraction and mass fractions of several species are in a good agreement with the experimental data. The characteristics of two flames are also analyzed by comparing their OH mass fractions and CO2 production rates.