Numerical Study of Two Air Intake Strategies for a New Fire Laboratory

Abstract

Computational fluid dynamic (CFD) simulations are carried out to select a better air intake system for a new fire laboratory, designed for experiments with a maximum fire heat release rate of 7 MW. Two different air intake systems are considered: a louver system around the lower perimeter of the building or a chimney system that employs vertical ducts to bring fresh air down from the roof to the lower part of the building. The two systems are investigated with different fire sizes and wind speeds. The results show that the chimney system gives a more stable smoke and temperature stratification inside the building and a higher hot smoke layer above the floor. The louver system, on the other hand, gives rise to unsymmetrical air movements inside the building when the wind speed outside is high. The louver system also yields a lower hot smoke layer that can spill smoke through the louvers to the outside of the building, especially for small fires with low exhaust flow rates. The results, therefore, suggest that an evenly distributed chimney system would provide a more stable ventilation environment for conducting fire experiments and would prevent smoke leakage to the outside of the building.