Vertical temperature profile of fire-induced facade thermal plume ejected from a fire compartment window with two adjacent side walls

This work investigates the vertical temperature profiles of fire-induced facade thermal plumes ejected from a compartment window with two adjacent side walls. A small-scale cubic compartment (1:8) with its window attached by a vertical facade wall is employed. Two side walls are positioned symmetrically at the two sides of the window of the compartment. The compartment ventilation and side wall constraint conditions are varied by changing the window dimensions and the side wall separation distances during the experiments. K-type thermocouples are installed along the facade wall to measure the vertical temperature profile. Results show that the temperature at a given height increases with the decrease in side wall separation distance for a “(half) axisymmetric plume”, as the air entrainment into the plume is reduced with the presence of side walls. A global model is further developed, based on the change of the air entrainment (in relation to the separation distance of side walls, the characteristic length scales of the window and dimensionless excess heat release rate), to account for the side wall constraint effect on vertical temperature profile upon the facade wall. Experimental data for various window dimensions and side wall separation distances are well correlated by the proposed model.