Phenomenological Approach for Common Rail Diesel Engine Emission and Performance Prediction

A diesel injection model for common rail application has been built and extended including a quasi-dimensional, multi-zone, diesel combustion-pollutant emission model (NO _x ). In a commercial simulation environment, a lumped parameter electro-mechanical-hydraulic scheme is used to model the injection process. Modeling of spray formation, droplet vaporization, combustion and pollutant emission processes is then implemented in a self developed computation code, accounting for finite thermal conductibility of the liquid phase fuel. The coupling among the models allows for a detailed representation of the involved phenomena at each simulation step; at the same time, it is possible to evaluate the operation of the ensemble injection system-engine on the basis of atomization, combustion and pollutant emission. The results of the numerical prediction are compared to experimental data.