Three-dimensional flame propagation above liquid fuel pools

Ignition and ame spread above liquid fuels initially below the ashpoint temperature are studied. Opposed air ow to the ame spread due to forced and/or natural convection is considered. Unsteady computations are performed in order to study the ignition event and to describe both uniform and pulsating ame spread. Pools of nite width and length are studied in air channels of prescribed height and width, thereby requiring a three-dimensional space resolution in order to capture the eects at the edge of the pool and at the side walls of the air channel. The eects of variations in surface tension due to surface temperature variations and of buoyancy in both the liquid and gas phases are considered. One-step chemical kinetics, Fickian diusion, Fourier heat conduction, and laminar ow with variable properties are considered. Boundary layers at the walls and at the liquid/gas interface are resolved. A moving mesh scheme is employed to follow the ame motion. Regions of pulsation are found at both 1-g and 0-g. Average ame speed and pulsation frequency increase with initial fuel temperature. Surface tension can have a major eect, e.g., cause a recirculation. Buoyancy can modify ame speed and ame shape. The ame extends over the edge of the pool producing some clearly three-dimensional eects such as lateral air motion. The computations are intended to guide and to explain experiments that are being performed at NASA Glenn by H. Ross and F. Miller.