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

TitleNumerical and experimental validation study of flame extent of a pool fire under the ceiling
Publication TypeConference Paper
Year of Publication2015
AuthorsWang Y, Vouros A, Zhang J, Delichatsios M
Conference NameMCS-2015: Ninth Mediterranean Combustion Symposium
Conference LocationRhodes, Greece

The purpose of this work is to establish dimensionless correlations for the flame extent under a ceiling to be used for large scale calculations of radiative heat fluxes for which numerical simulations may be prohibitive and probably, not credible. 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. Fire dynamics simulator (FDS, version 6) was applied. The stoichiometric mixture faction was used to define the continuous flame height which also coincides with the maximum mean temperature on the axis of the fire. The size of the pool fire was 0.1m × 0.1 m having heat release rates (HRRs) from 2 to 100 kW for two heights 30 and 50 cm. The predicted free flame height and horizontal flame extent are plotted as functions of HRR and compared to correlations and experimental data in the literature. Because most of the correlations and measurements are based on the mean (visual) flame height, the predicted continuous flame height is found to be 3/5 of the experimentally mean flame height. It is found that the predicted flame height and horizontal flame extent agree well with existing experimental relations. However, some difference was noted in the horizontal flame extent indicating 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 affecting the entrainment and the turbulence of the ceiling flame jet.