Laboratory Investigations of Wildfire Spread Processes in Live and Dead Fuel

Background Experimental work undertaken by the Forest Service and cooperators has revealed for the first time that buoyant instabilities of the flame zone are responsible for non-steady convective heating of fuel particles leading up to ignition. The university of Kentucky has been a key player in the investigation of fuel particle heating response using customized IR camera of laboratory burns. The collaborative study reveals new findings about how wildfires actually spread and could have significant impacts on firefighter safety and fuel hazards mitigation. Published in the prestigious Proceedings of the National Academy of Sciences journal, the study, "Role of buoyant flame dynamics in wildfire spread," specifically reveals how flame dynamics that produce and transport convective heat effectively governs the spread of wildfire. It was previously unclear how radiation and convection heat transfer processes, which both occur in wildfires, are organized to produce wildfire spread. Statement of Work This continuing work will be jointly conducted by the Forest Service Missoula Fire Science Laboratory and the University of Kentucky. It will concentrate on 1) completing the scale modeling analysis of laboratory and field data that exist and become available during the year, 2) design refinements to laboratory sampling of fuel particle response, and 3) participating in the field collections from prescribed fires to test the scaling from laboratory to field proportions. Expected Results The Joint efforts are anticipated to produce scale modeling analysis on instabilities and fluid dynamics of the flame zone to help develop a theory of fire spread and derived practical models for wildland fire behavior.