LES of Premixed Combustion in the Corrugated-Flamelet Regime
Large-eddy simulation (LES) is applied to a fuel-lean turbulent propane-air Bunsen flame in the corrugated-flamelet regime. The subgrid-scale (SGS) modeling includes a previously developed treatment of the total enthalpy along with three different SGS velocity, u'∆, models. In addressing the filtered reaction rate, a presumed probability density function (PDF) approach is employed for the reaction-progress variable, closed by a transport equation for its SGS variance. The statistics obtained using the three u'∆ models are in good agreement with the measurements and do not differ significantly from each other for first order moments suggesting that commonly used SGS modelling may be adequate to get the mean velocities and reaction progress variable. However, all three SGS velocity models fail to reflect a measured bimodality of the PDF of the radial component of the velocity in the central portion of the flame. This emphasizes a need for further development of u'∆ models, required at the reaction rate closure level, for practical LES of combustion in the corrugated-flamelet regime.
This is the final version of te article. It was first available from Taylor & Francis via https://doi.org/10.1080/00102202.2016.1195824