A COMPREHENSIVE SIMULATION-MODEL FOR MIXING AND COMBUSTION CHARACTERISTICS OF SMALL DIRECT-INJECTION DIESEL-ENGINES

An analytical model has been developed to predict the fuel-air mixing and burning characteristics of small direct injection (DI) diesel engi nes. Four mass and momentum conservation equations are written along t he tangential and normal directions to the spray for both free and wal l regions based on the continuum integral approach. The spray structur e is multi-zonal and the simulation of atomization, droplet-size distr ibution, evaporation, turbulent mixing and combustion processes is inc luded. The model predictions show good correlation with the experiment al data and respond well to the variations in input parameters. The le vel of predictions from the model is satisfactory and the model is qui te suitable to optimize the injection characteristics, bowl geometry a nd air motion in small DI diesel engines.