A MODEL OF CONCURRENT FLOW FLAME SPREAD OVER A THIN SOLID FUEL

A numerical model is developed to examine laminar flame spread and extinction over a thin solid fuel in low-speed concurrent flows. The model provides a more precise fluid-mechanical description of the flame by incorporating an elliptic treatment of the upstream flame stabilization zone near the fuel burnout point. Parabolic equations are used to treat the downstream flame, which has a higher flow Reynolds number. The parabolic and elliptic regions are coupled smoothly by an appropriate matching of boundary conditions. The solid phase consists of an energy equation with surface radiative loss and a surface pyrolysis relation. Steady spread with constant flame and pyrolysis lengths is found possible for thin fuels and this facili-tates the adoption of a moving coordinate system attache