Numerical study of the effects of fire on the flow and wake structures of an idealized building.

Fire hazard is a crucial issue in urban arears. Fire plumes have large buoyancy forces and can significantly change the flow pattern around buildings. However, the interaction of these plumes with buildings under atmospheric boundary flow conditions has rarely been studied, and the effect on the wake characteristics of the buildings remains unclear. To investigate the interaction of fire with the wake flow around a building, the large-eddy simulation framework is used to simulate the flow and wake structures of an idealized cubic building. Fire is found to produce significant changes in the wake structures. In particular, fire leads to strong fire-swirl vortices near the trailing edges of the building and intense fire-plume vortices in the midair region downstream of the building. In the time-averaged results, a pair of tip vortices appears behind the top corners of the building and counter-rotating vortex pairs are observed downstream. [ABSTRACT FROM AUTHOR]