Facade flame heights from enclosure fires with side walls at the opening

摘要

This paper presents an investigation of facade flame heights from an under-ventilated enclosure fire having an opening with side walls. A reduced-scale model, consisting of a cubic enclosure of 0.4 m with a vertical facade wall and two side walls was constructed for the experiments. The temperature profile inside the enclosure was measured by thermocouples whereas a CCD camera was employed to obtain the mean flame height of the ejected flames. It is found that the presence or the separation distance of the side walls have no impact on the critical heat release rate of the enclosure (1500 AH~(1/2) in kW). The effects of the side walls on the mean flame height are pronounced for a relative larger flame than a small one having the same separation distance of the side walls. In addition as the side wall distance decreases, the effects become larger leading to flame heights much higher than those without sidewalls. A global dimensionless parameter K is proposed to account for the side wall effects, based characteristic length scales of the opening, and the distance between the side walls D. The experimental data for different opening dimensions and side wall distances are well correlated by this global parameter.