APPLYING LARGE EDDY SIMULATION IN THE STUDY OF FIRE AND SMOKE SPREAD AT UNDERGROUND CAR PARK

In this study, the large eddy simulation technique has been applied to predict the spread of smoke and fire in a public underground car park. The simulation platform has been the fire dynamics simulator, which was developed by the US National Institute of Standards and Technology (NIST). The results show that in such a confined space the smoke from a severe fire can spread quickly and dangerously. With the use of the conventional balanced ventilation system as the means of smoke extraction, a higher ventilation rate tends to accelerate the spread of fire, smoke, carbon dioxide and carbon monoxide. At the same time, this leads to a higher temperature environment which can endanger the human life. The probability of flashover was also found to increase with higher ventilation rates. The findings suggest that the current fire safety design recommendations are insufficient. Several suggestions on improving the public car park safety are raised, such as to avoid the use of excessive ventilation rate, to increase the number of emergency exits, and to shorten the vehicle exit routes.