Two particular problems concerning the ignitability of a pool of liquid fuel are considered. First is the problem of d&rung the domain of ignitability of a pool of fuel at a superflash temperature subjected to a cross wind. it is postulated that this domain is bounded by the lean mixture limit or by the blowofT limit of the local fuel-air mixture, whichever is encountered first above the surface. This domain is calculated for a laminar boundary layer over a fiat pool of fuel. The agreement between this predicted boundary and the boundary found here experimentally is generally quite good.
Second is the problem of determining what factors control the ignitability of a liquid pool of fuel at a subflash temperature.
The heating of such a pool to the point of ignition, by an energy source in the space above it. is retarded considerably by motion induced in the pool. Suppression of the motion enhances the ignitability markedly. The induced motion produces a vortex cell whose size depends on various fuel and igniter parameters. The driving force causing this ! fluid motion is postulated to be a combination of the farces resulting from buoyancy in the pool and surface tension gradient on tire surface.