Large Eddy Simulation of piloted pulverized coal combustion using the velocity-scalar joint filtered density function model

A piloted pulverized coal jet flame was simulated by Large Eddy Simulation (LES). For the sub-grid scale (SGS) effects of the turbulence velocity and the scalar fluctuation of the gas flow on the coal particles, the velocity-scalar joint filtered density function (VSJFDF) model was used. Other models such as the governing equations for particles and coal combustion sub-models were also presented. Simulation results with the VSJFDF model, non-VSJFDF model and those by Franchetti et al. [7] were compared with the experimental data, including the mean and RMS (root mean square) velocity, temperature and species concentrations. The results showed that VSJFDF can distinctly improve the predictions, both in quantity and quality. The location where coal particles start burning could be roughly predicted along the centerline of the flame by VSJFDF model.