Wind effects on atria fires

A series of unsteady atria fire calculations are performed using a finite-volume CFD program on two and three dimensional generic buildings immersed in simulated atmospheric boundary layers. The model results reveal that external winds can modify the infiltration and exfiltration of air through external doors and windows, distort thermal and smoke columns rising above test fires in the atria, cause the plumes to impact directly against atria walls, and modify the resultant filling of elevated atria spaces. In some cases aggressive fire “whirls” form, which can enhance fire strength, enclosure mixing, and exposure. Results are compared qualitatively with similar physical model experiments.