Influence of buoyant dynamics on wildfire spread

Technology has improved our utilization of existing fire models but has contributed little to advancing knowledge of fire spread. The knowledge of physical processes, and their organization in producing fire spread, is essential to reliably modeling wildland fire behaviors beyond current capabilities (crown fire, thresholds etc.). To date, this knowledge has been so incomplete that physical models have been based on assumptions borrowed from other disciplines without considering the unique context of fire and fuels in wildlands. Even now, the roles of radiation and convection have yet to be conclusively determined. This presentation will report results of ongoing experimental research that has revealed how forward convective heating and particle ignition in spreading fires derives from buoyancy - induced instabilities and vorticity.