SMOKE MOVEMENT IN ATRIUM BUILDINGS

A computational fluid dynamics (CFD) model based on PHOENICS has been used to evaluate the distribution of fire-induced air flow, temperature and smoke concentration in an atrium. Two numerical experiments carried out in two atria with similar size, fan locations and fire type, but of different height have been examined. A physical model in an atrium with different size and fan locations, but of the same fire type has also been studied. In the first numerical experiment where the fire source was located at the base of a 30 m high atrium, it was found that smoke was extracted effectively by the extraction system. In the second numerical experiment where the fire source was located at the base of a 60 m high atrium, smoke was not extracted effectively by the extraction system. Stratification was observed at 240 s. In the physical model with the fire source located at the base of a 50 m high atrium, smoke was trapped at the ceiling of the atrium and moved into the shops of the same level. The extraction fans located at the smoke reservoir were not able to extract the smoke in the area effectively. The results of the simulations highlight the effect of atrium height and locations of exhaust fans on the smoke movement in atrium buildings.