A Devoloped Model for Emissions Prediction of a DI Diesel Engine

In this paper, on the basis of multi -zone combustion modeling concept, a developed quasi-dimensional multi-zone model for emissions prediction of DI diesel engine is put forward. In the model, the fuel spray is divided into many zones. Each zone goes through such processes as fuel spray broken, droplet evaporation, air involvement, mixed air - fuel combustion, etc. The influence of spray touching the wall and the swirl are considered. The heat transfer formula from each zone to combustion chamber wall has been improved and the space distribution ununiformity of the diameter of fuel droplets has been considered. Based on the chemical equilibrium calculation, Zeldowich disequilibrium theory is used to predict the emission of NOx. For C, CO and HC, the kinetics reactions are adopted. In addition, an simplified model for rough prediction of particulate emission is provided.