A diffuse interface method for simulating the dynamics of premixed flames

A diffuse interface method for simulating dynamics of premixed flames is proposed. The flame is treated as a diffuse moving front with its propagation automatically captured by the convection-diffusion equation of the progress variable. The diffusion and reaction terms are constructed using the flame speed and flame thickness, and the flame speed is taken as a function of the local stretch rate to incorporate the stretch effect. This equation is coupled with the continuity equation and the momentum equation to describe flame dynamics in complex flows, and the lattice Boltzmann method is employed in the present study as the computational platform, since its feature of explicit computation is highly consistent with the advantage of flame auto-capturing of the present method. To test the performance of the method, simulations including 1-D flame propagation, 2-D Darrieus-Landau instability, 2-D cylindrical flame propagation with stretch effect, and 2D flame-vortex interaction are conducted, and the consequent results are in good agreement with analytical solutions.