Fire Storm Environmental Model

摘要

To further define the environment within a fire storm, an analytical model was developed which describes the conditions of flow and temperature of the fluid. In the model, the fire is considered to be an area on the ground with a temperature above that of the surroundings. The motion of the fluid produced by the temperature excess was obtained by solution of the equations of energy, motion and continuity by a numerical integration technique. Effects of viscosity and of thermal conduction are included in the analysis without the boundary layer approximations that were used in a previous analyses of the convection column. For this reason, the results obtained in the region near the ground are not subject to the deficiencies of those of the previous analysis. Some of the effects of swirling flow are also included in the model by specification of rotation in the surrounding air. A simplified analysis was also conducted to estimate the time required for the development of swirl flow. In the analysis, the entrainment by a convection column is represented by a line sink. A simple solution is presented for rate of growth of swirl flow for a fluid initially rotating at a speed that corresponds to the rotation of the earth. (Author)