Numerical Simulation of Soot Formation and Oxidation in Diesel Engines

A linked ignition-soot formation global kinetic model has been developed. The model has been adapted to the extended code CONCHAS-SPRAY.

The so called Shell-model, which was successful in the representation of the ignition global kinetics has been used. Mass balanced reactions for the overall product path, soot formation and soot oxidation have been introduced. The feature to generate soot was prescribed to a stable hydrocarbon intermediate species typical for ignition.

The soot surface growth rate was determined by experimental data of final soot volume fraction given by Wagner et al. for premixed flames. Soot oxidation rate is represented by Lee et al's formula. Turbulent transport properties are calculated with the help of the k-ε model.

The numerical prediction of soot concentration level, generation of soot and resulting oxidation as well as a secondary soot formation at the spray axis have been demonstrated as being in qualitative agreement with known experimental data.