Comparative Study of Algebraic and Transported FSD Models for LES of Premixed Flames in Flamelet and Thin Reaction Zones Regimes

摘要

A comparative study is performed of two variants of flame surface density (FSD) subfilter-scale (SFS) model, a flamelet-based model for large-eddy simulation (LES) of turbulent premixed combustion. Both algebraic-and transport-equation variants of the FSD flamelet approach were studied so as to investigate the importance of non-equilibrium transport of the flame surface by the turbulence. Six different cases are considered with various turbulence intensities in both lean and stoichiometric turbulent premixed Bunsen flames corresponding to conditions ranging from the upper limit of the flamelet regime to well within the thin reaction zones regime. The predicted LES solutions are compared to the experimental data from a laboratory-scale axisymmetric Bunsen-type premixed turbulent flame. The results of the comparisons highlight weaknesses and strengths of the SFS modelling approaches.