This seminar is part of the 2021-2022 Missoula Fire Lab Seminar Series.

Presented by Michael Gollner, Associate Prof. & Deb Faculty Fellow, Dept. Mechanical Engineering, University of California, Berkeley

Large wildfires of increasing frequency and severity threaten local populations and natural resources while contributing carbon emissions into the earth-climate system. Although wildfires have been researched and modeled for decades, no verifiable physical theory of spread is available to form the basis for the precise predictions needed to manage fires more effectively and reduce their environmental, economic, ecological, and climate impacts. This presentation will begin by summarizing recent research conducted at the Fire Lab aimed at unraveling how buoyant flame dynamics seen in wildfires contribute to their spread. Scale modeling experiments conducted at the University of Maryland and UC Berkeley further exploring this behavior will be detailed, including new flow measurement techniques. In the most extreme urban and wildland fires, fire whirls can form, presenting significant hazards. After a brief review of our state of knowledge concerning fire whirls, two new approaches using the intensification of combustion seen in fire whirls to reduce their emissions will be covered. First, exciting recent studies on the blue whirl will be presented, describing how this small, completely blue, soot-free flame that evolves from traditional fire whirls forms. Finally, new results on the use of fire whirls to clean up oil spills over water will be presented.