Student Posters Repository

Large eddy simulations (LES) have proven to be a powerful tool in modeling turbulent premixed flames because they resolve some of the energy carrying eddies unlike RANS. However, the LES sub-filter-scale (SFS) modelling uncertainties are of particular importance in premixed turbulent combustion because the entire reaction occurs within the sub-grid scales. For this reason, the LES SFS model and and combustion model should be extensively validated and verified. A laboratory scale turbulent premixed methane-air Bunsen flame is simulated and compared to experimental results. A LES using a WALE SFS model coupled with the FPI-PCM combustion model is used. The FPI approach is a flamelet type model based on premixed laminar flamelets with chemistry tabulation in terms of a transported progress-of-reaction variable with a presumed PDF to model chemistry-turbulence interactions. Recent experimental measurements have shown a drastic increase in the turbulent intensity in the region near the burner walls. Previous numerical studies did not represent this increased turbulent intensity and it is believed that this resulted in the persistent over prediction of the flame height. To accurately represent the experimentally measured burner inflow turbulence while also controlling computational costs, an equilibrium stress near-wall model will be used to recreate the experimentally observed turbulence. The numerical flame height will be compared to the experimental results to determine if near wall effect can account for previous discrepancies between experimental and numerical predictions.