Characteristics of Externally Venting Flames and Their Effect on the Façade: A Detailed Experimental Study

In a compartment fire, externally venting flames (EVF) may significantlyincrease the risk of fire spreading to adjacent floors or buildings; EVF-induced risksare constantly growing due to the ever-increasing trend of using combustible materialsin building facades. The main aim of this work is to investigate the fundamentalphysical phenomena associated with EVF and the factors influencing their dynamicdevelopment. In this context, a series of fire tests is conducted in a medium-scalecompartment-fac¸ade configuration; an n-hexane liquid pool fire is employed, aimingto realistically simulate an ‘‘expendable’’ fire source. A parametric study is performedby varying the fire load density (127.75, 255.5 and 511 MJ/m2) and ventilation factor(0.071 and 0.033 m3/2). Emphasis is given to characterization of the thermal fielddeveloping adjacent to the fac¸ade wall. Experimental results suggest that the threecharacteristic EVF phases, namely ‘‘internal flaming’’, ‘‘intermittent flame ejection’’and ‘‘consistent external flaming’’, are mainly affected by the opening dimensions,whereas the fuel load has a notable impact on the fuel consumption rate and heatflux to the fac¸ade. Fuel consumption rates were found to increase with increasing fireload and opening area, whereas the global equivalence ratio increases with decreasingopening factor. The obtained extensive set of experimental data can be used to validateCFD fire models as well as to evaluate the accuracy of available fire design correlations.