Numerical and experimental validation study of flame extent of a pool fire under the ceiling

The purpose of this work is to establish dimensionless correlations for the flame extent under a ceiling that can be used for large-scale calculations of radiative heat fluxes for which numerical simulations may be prohibitive. Towards this objective, this paper presents a numerical study of the flame height in an open pool fire and the subsequent flame extent under the ceiling. The stoichiometric mixture fraction is used to define the continuous flame height which also coincides with the maximum mean temperature along the centerline of the fire. The size of the pool fire is 0.1 m × 0.1 m having heat release rates (HRRs) from 2 to 100 kW for two ceiling heights of 30 and 50 cm. The predicted free flame height and horizontal flame extent are compared to existing correlations and experimental data in the literature. It is found that the predicted continuous flame height is about three fifths that of the experimental mean flame height reported in the literature. The predicted horizontal flame extent also agrees well with existing experimental correlations, although some difference may indicate that the relation between the mean and continuous flame heights derived for an open free pool fire may no longer apply due to the presence of the ceiling which affects air entrainment and the turbulence of the ceiling flame jet.