Large eddy simulation of partially premixed flames with inhomogeneous inlets based on the DTF combustion model

Abstract

Study of partially premixed flames involves a practical importance. In the present work, large eddy simulations (LES) are performed using dynamic thickened flame (DTF) model to study the challenging turbulent partially premixed flames with inhomogeneous and near-homogeneous inlets. In order to apply the DTF model for partially premixed flames, laminar flame thickness and laminar flame speed parameters are introduced as fitting functions of mixture fraction values. Therefore, thickening factor and efficiency function used in the DTF model can be adjusted according to mixture fraction values at the flame locations. The detailed comparisons of calculated mixture fraction and temperature radial statistics with experimental results show the good agreement between simulation and experimental results. Investigations of important combustion characteristics like local extinctions and blow-off limits further validate current sub-grid scale combustion modeling approach. Additionally, quantitative assessment of simulation results is performed by Wasserstein metric. The Wasserstein metric calculations exhibit modeling error close to one in terms of standard deviation for all the considered flame cases, showing the good performance of current simulations.