Types of fire whirls
Orateur : Forman A Williams
Distinguished Emeritus Professor of Engineering Physics and Combustion
Department of Mechanical and Aerospace Engineering, University of San Diego
nommé Doctor Honoris Causa AMU sur proposition de la Fédération
Abstract : Fire whirls, also called fire tornadoes, are vortices with burning fuel inside that often accompany wildland fires. They can become the most spectacular attributes of fires as they are intensified by the combustion within, and they often loft firebrands high into the atmosphere, enhancing fire spread by ignition spot fires far ahead of the fire front. Fluid mechanics plays a dominant role in the formation and evolution of fire whirls. Different fluid-dynamic phenomena produce different fire-whirl characteristics. The presentation attempts to classify fire whirls into five categories : whirls generated by fuel distributions in wind, whirls above fuels in pools, tilted whirls, moving whirls, and whirls modified by vortex breakdown. Scaling considerations will be discussed for these five types, and possible prospects for improved understanding and control will be considered. One conclusion will be that a key aspect of the physics that determines the lengths of many fire whirls is not yet understood, hence more research is needed.
Date et Lieu : Jeudi 23 Novembre à 11h, amphithéâtre de l’IRPHE
Voir en ligne : la page personnelle de l’orateur