PREDICTION OF MIXTURE FORMATION AND HEAT-RELEASE IN A TURBOCHARGED DIRECT-INJECTION DIESEL-ENGINE

A multi-zone combustion model has been developed to predict the rate o f heat-release in a turbocharged direct-injection diesel engine. The m odel considers the complete air-fuel jet mixing process and temperatur e-dependent reaction rates in each zone; this allows the distribution of the burning rate, local temperature and equivalence ratio to be det ermined both spatially and temporally. The predicted combustion pressu res in the closed engine cycle are validated satisfactorily by experim ental results obtained from a computer-controlled engine test-bed. The extension of the model to prediction of exhaust emissions during tran sient engine operation is also discussed.