2005 Volume 47 Issue 140 Pages 129-136
In this study, we have numerically investigated flame spread over solid fuel in partially premixed atmospheres, which may occur under poorly ventilated conditions, forming the combustible mixtures of oxygen and fuel vapors. For simplicity, only gas phase is considered to simulate the flame spread, by moving the area of fuel injection at the solid surface. To confirm the validity of our numerical model, we have experimentally examined a non-premixed flame in the laminar boundary layer over a porous flat plate, from the surface of which fuel gas is injected uniformly. The plate of fuel injection is placed parallel to the ambient air flow. Methane is added in this ambient air to form the partially premixed mixture. Temperature measurement has been conducted. Results show that, the flame structure over the porous flat plate is well simulated, although the flame temperature is much overpredicted. In partially premixed atmospheres, the flame spread rate is increased, with the expanded high temperature region. This is because the fuel already exits in the upstream region to support the flame propagation. These results are very similar to our previous experiments using filter paper sheet as solid fuel.