Numerical studies on the transient behaviour of a fire plume and ceiling jet

Transient behaviour of a thermally induced fire plume and ceiling jet is predicted using the field modelling technique. In the field model, the k-ε model is used to simulate the turbulent air flow. The traditional wall-function approach is applied to describe the solid-wall boundary effect. The building concerned is composed of a floor and a ceiling, but is without walls. The height is varied from 3 m to 9 m. Transient behaviour of air temperature, velocities, smoke concentration, etc., are predicted. The air entrainment rates to the fire plume and the entrainment constants are also calculated and compared with empirical expressions.