Computational fluid dynamics modelling of fire

Kevin McGrattana*, Randall McDermotta, Jason Floydb, Simo Hostikkac, Glenn Forneya & Howard Bauma a National Institute of Standards and Technology , Gaithersburg , Maryland , USA b Hughes Associates, Inc , Baltimore , Maryland , USA c VTT Technical Research Centre , Espoo , Finland * E-mail: kevin.mcgrattan@nist.gov An overview of a methodology for simulating fires and other thermally-driven, low-speed flows is presented. The model employs a number of simplifications of the governing equations that allow for relatively fast simulations of practical fire scenarios. The hydrodynamic model consists of the low Mach number large-eddy simulation subgrid closure with either a constant or dynamic coefficient eddy diffusivity. Combustion is typically treated as a mixing-controlled, single-step reaction of fuel and oxygen. The radiation transport equation is written in terms of a spectrally-averaged grey gas. Applications of the model include the design of fire protection systems in buildings and the reconstruction of actual fires.