Modeling of soot formation in kerosene turbulent jet flames

A coupled radiation/flamelet combustion model was applied to the numerical simulation of turbulent jet flames fed with pre-vaporized aviation kerosene at several pressures. The temperature and major species fields were calculated using the Steady Laminar Flamelet (SLF) model in a non-adiabatic formulation. The formation of soot particles was predicted using the Method of Moments (MOM), coupled with semi-empirical models of soot nucleation, growth, oxidation and aggregation available in the literature. Attention was devoted to the effects of turbulent fluctuations on soot chemistry. In particular, the closure of soot source terms in the moment equations was described by a probability density approach based on the laminar flamelet formulation. The final objective was to investigate the feasibility of the applied methodology for estimating soot formation in complex combustion devices. Numerical results were found in satisfactory agreement with the experimental measurements, in terms of temperature and soot fields. It was confirmed that the coupling between soot production and radiative heat transfer cannot be neglected, especially when soot volume fraction is large. Moreover, simulations showed that turbulent fluctuations must be carefully taken into account to obtain a reliable and accurate prediction of soot formation. Unfortunately the results were found to be strongly dependent on the model applied to predict growth of soot particles.