Complex Chemistry Modeling of Diesel Spray Combustion

Doctoral thesis, 2001

The thesis illustrates the application of computational fluid dynamics (CFD) to turbulent reactive two-phase flows in piston engines. The focus of the thesis lies on numerical simulations of spray combustion phenomena with an emphasis on the modeling of turbulence/chemistry interaction effects using a detailed chemistry approach. The turbulence/chemistry interaction model accounts for the effects of turbulent micro-mixing on the chemical reaction rates. The models have been implemented in the {\bf KIVA3-V} code and successfully applied to spray combustion analysis in a constant volume and a DI Diesel engine. The limitations and difficulties of representing the spray in a Lagrangian fashion are also adressed. Three different liquid fuels have been used in the simulations: n-heptane, methanol and dimethyl ether (DME). Detailed and reduced chemical mechanisms have been developed and validated for all these fuels and reasonable agreement between experimental data and numerical simulations has been obtained.