Validation of ceiling jet flows in a large corridor with vents using the CFD code JASMINE

A field model code, JASMINE, has been adopted to calculate ceiling jet flows caused by plumes from unsteady fire sources in a large corridor. The idealized fast- and medium-fire energy release rates, obeying thet ² law for fire growth, were used. The effects of vents were studied by simulating three different configurations: a centrally located vent—that is, a vent directly above the fire source; an eccentrically located vent; and no vent. The results were compared with recent large-scale experiments conducted at the Swedish National Testing and Research Institute (SP) and with results from the computer program LAVENT. Some calculated sprinkler temperatures with three different RTI values are also presented.The present JASMINE simulations agree reasonably well with measured ceiling temperatures and velocities in large-scale tests. In general, the calculated ceiling jet temperatures are slightly overestimated and the velocities slightly underestimated. Also, the layer thicknesses calculated by JASMINE are somewhat thinner than those measured. The ceiling jet theory and present LAVENT results predict very thin layer thicknesses. However, these theories are only valid when wall effects are eliminated. From the present study it can be concluded that CFD models are generally more accurate when used to predict confined and unconfined flows.