Modelling sooting jet fires in a large scale offshore compartment

This paper describes the application of a fire field model combined with detailed chemistry to the simulation of sooting propane jet fires in a 135 m3 compartment. The purpose of the research is to investigate the behavior of under-ventilated jet fires, and the formation of toxic products. The kinetic formation of major species (CO, C2H2) and trace species (soot) has been studied using, a detailed reaction mechanism, for propane. The concept of strained laminar diffusion flamelet was adopted to model the main hydrocarbon combustion and the formation of soot. The turbulence-chemistry, interaction followed the conserved scalar and assumed, probability density function (PDF) description of turbulent diffusion flames. The soot formation was modeled by the two-equation approach. Instantaneous temperatures given by the flamelet were modified to account for radiative heat loss. The predictions for velocity, CO, soot, and other main species are given in the paper, and comparison is made between predictions and measurements on a 1,5-MW fire test case that showed the important effect of the entrainment on the formation of toxic species in the enclosure. The predicted result of soot at the vent location is in agreement with the experimental data. The general trend, of temperature distributions have been correctly predicted, but the neglecting of convective heat transfer from the compartment walls and the simplified treatment for radiative heat loss from the jet fire has resulted in some discrepancies on the predictions of temperatures, particularly at the vent location