An Improved Soot Formation Model for 3-D Diesel Engine Simulations

In this study, a phenomenological three-equation soot model was developed for modelling soot formation in diesel engine combustion based on considerations of acceptable computational demand and a qualitative description of the main features of the physics of soot formation. The model was developed based on that of Tesner et al. The model was implemented into the commercial STAR-CD CFD package and was demonstrated in the modelling of soot formation in a single-cylinder research version of Caterpillar 3400 series diesel engine with exhaust gas recirculation. Numerical results show that the new soot formulation overcomes most of the drawbacks in the existing soot models and demonstrates a robust and consistent behaviour with experimental observation. Compared to the existing soot models for engine combustion modelling, some distinct features of the new soot model include: no soot is formed at low temperature, minimal model parameter adjustment for application to different fuels, and there is no need to prescribe the soot particle size.