An Experimental Investigation on the Impact of Burner Height and Location on the Characteristics of Externally Venting Flames

Fire sources in actual compartment fires exhibit a predominantly uneven spatial distribution. In this context, the impact of the height and location of the fire source, as well as the heat release rate (HRR) of the fire, on the thermal characteristics of Externally Venting Flames (EVF) is experimentally investigated. A systematic parametric analysis is performed, involving 33 separate fire tests, using a 1/4 scale compartment‐façade experimental test rig to evaluate the impact of three fire power levels, three horizontal burner positions and four burner elevations. A comprehensive array of measurement sensors is utilized to accurately characterize the thermal and geometric properties of the developing EVF. In general, experimental results indicate that increasing the burner height results in decreasing temperatures outside the compartment, while increasing the distance between the burner and the opening leads to increased flame projection. Flame intermittency contours are generated using a custom image processing tool to determine the mean EVF height and horizontal projection. The external dimensions of the EVF envelope, as well as its vertical temperature distribution, are compared to the respective values predicted by relevant fire engineering design correlations proposed in the Eurocode design guidelines (EN 1991‐1‐2). In most cases, large discrepancies are observed between the experimental data and the Eurocode predictions, ranging from 22% for the EVF height up to 41% for the EVF projection, while the EVF temperature average deviation is 16%; however, the Eurocode correlations are found to produce, in general, conservative results, with the exception of the EVF temperatures close to the opening's lintel. The obtained results can provide an experimental foundation to assist in further improving and extending currently available fire safety design engineering correlations.