Onsetting internal fire whirls in a room with ceiling vents

Onset of internal fire whirls in a room with ceiling vents was studied numerically with Computational Fluid Dynamics (CFD). Two different ventilation arrangements were set up by varying the door height. Two fires of 0.12 MW and 0.24 MW were considered. Swirling air flow, changes in eddy size, and whirling speed near to the fire source were simulated. CFD predictions indicate that air swirled up from the lower to the upper part of the room. Onset of an internal fire whirl depends on the interaction between the indoor hot air and the outdoor cool air flows. Swirling motion results when there is ventilation provision at the sidewall.