Combustion and soot modelling of a high-pressure and high-temperature Dodecane spray

Abstract

Diesel engines are known to be one of the main sources of soot particle emission in the atmosphere. The norms to restrain these emissions have created a need of accurate soot models for piston engine emissions prediction in the automotive industry. This article addresses this question by coupling a sectional soot model with a tabulated combustion model for Reynolds-averaged Navier–Stokes simulations of the engine combustion network Spray A, a high-pressure Dodecane spray with conditions very similar to diesel engine sprays. The sectional soot model, which has already been used in diesel engines Reynolds-averaged Navier–Stokes simulations with a simpler combustion model, is implemented in the IFP-C3D Reynolds-averaged Navier–Stokes computational fluid dynamics code. At each time and location, transport equations are solved for several soot sections, including source terms for collisional and chemical processes. The soot model is here coupled to the approximated diffusion flame – presumed conditional moment model, which is a tabulated combustion model. It allows to represent the minor species required by the soot model with a much lower computational cost than a kinetic solver and includes complex turbulence–chemistry interactions. The predictions of these models agree with the experimental measurements for most of the Spray A cases for flame structure and soot production. These results show that detailed soot models can be coupled to tabulated combustion models with good results in turbulent flames.