Large-eddy simulation of a fuel-lean premixed turbulent swirl-burner

摘要

Large-eddy simulation (LES) of a fuel-lean premixed turbulent swirling flame is performed, in the configuration of a burner experimentally studied by Meier et al. ICombust. Flame 150 (1-2) (2007) 2-26]. Measurements of velocity field, temperature, and major species concentrations are compared against LES results. The unresolved sub-grid scale turbulent species and temperature fluctuations are accounted for using a presumed probability density function and flamelet tabulated detailed chemistry. Before the turbulent burner is simulated, various strategies to introduce tabulated detailed chemistry into a fully compressible Navier-Stokes solver are discussed and tested for laminar flames. The objective is to ensure a proper coupling between chemical tables and unsteady solutions of the Navier-Stokes equations in their fully compressible form, accounting for the inherent constraints of high-performance computing. Comparisons of LES results with experiments are discussed in terms of filtered quantities, leading to the introduction of an extra term to account for the difference in filter sizes used in experiment and LES. Velocity, temperature, and major species LES fields are then compared against measurements. Most of the turbulent flame features are reproduced, and observed discrepancies are analyzed to seek out possible improvements of the subgrid-scale modeling.