Fire Safety Science Digital Archive

A novel analytical formulation, hereafter referred to as the curved plume formulation, has been developed for assessing air entrainment into a thermal plume that spills over a balcony edge into an atrium void. The curved plume formulation is based on an analytical treatment for a two-dimensional spill plume, which incorporates layer momentum, does not resort to the Boussinesq approximation and is consistent with the physical engineering theory of plumes. It provides calculations for virtual source. An asymptotic analysis has been performed to determine the plume behaviour in the turning region and in the far field. The results of the curved plume formulation have been compared with CFD predictions from the JASMINE model and the data from reduced-scale experiments. It has been shown that the formulation has reproduced reasonably satisfactorily air entrainment into the spill plume. It has also shown that the virtual source is located approximately three times the layer depth of the approach flow below the balcony in a reasonably good agreement with the reduced-scale experimental data.