Thermo-fluid dynamic modeling and experimental investigation of a turbocharged Common Rail DI Diesel engine

The paper describes the results of a parallel 1D thermofluid dynamic simulation and experimental investigation of a DI turbocharged diesel engine. The attention has been focused on the overall engine performances (air flow, torque, power, fuel consumption) as well as on the emissions (NO and particulate) along the after-treatment system, which presents a particulate filter. The 1D research code GASDYN for the simulation of the whole engine system has been enhanced by the introduction of a multi-zone, quasi- dimensional combustion model for direct injection diesel engines. The effect of multiple injections is taken into account (pilot and main injection). The prediction of NO and soot has been carried out respectively by means of a super-extended Zeldovich mechanism and by the Hiroyasu kinetic approach. Moreover, a 1D model for the calculation of the filtration process occurring in the particulate trap has been embedded in the numerical model, to predict the fluid dynamic behavior of the DPF. The fluid- dynamic model for the trap is based on the assumption that the pressure drop, due to the Darcian flow, can be described one dimensionally by an equivalent friction process. An experimental investigation has been carried out on a 1.9L JTD Fiat-General Motors Corporation Powertrain diesel engine, to study the behavior of the DPF under different operating conditions, in order to provide a large set of experimental data for the simulation code validation.