A Front Tracking Method for the Motion of Premixed Flames

A front tracking method to study multi-fluid flows in which a sharp interface separates incompressible fluids of different densities and viscosities is adopted to simulate the unsteady motion of an infinitely thin premixed flame characterized by significant chemical heat release and hence thermal expansion. The flow field is discretized by a conservative finite difference approximation on a stationary grid, and the flame surface is explicitly represented by connected marker points that move with the local flame speed, relative to the flow field. The performance of the method is tested by applying it to a steady planar flame and the Darrieus-Landau instability. The numerical results are in good agreement with analytical results. The method is also applied to the interaction between a flame and a vortex array. The results show that the flame can destroy the vorticity originally in the unburnt gas and generate vorticity of opposite sign in the burnt gas.