Development and Identification of Phenomenological Models for Combustion and Emissions of Common-Rail Multi-Jet Diesel Engines

The paper deals with the development of a system of phenomenological models for the simulation of combustion and NOx-Soot emissions in Common-Rail Multi-Jet Diesel engines. The system has been built by following a modular modeling approach and is suitable for the implementation in the framework of Hardware In the Loop (HIL) ECU rapid prototyping.

A single-zone model simulates the ignition delay and the combustion during a sequence of pilot, pre and main fuel injections for a production 1,9 liters Diesel engine equipped with High Pressure Injection system, electronically controlled. The heat release model is based on the synthetic description of both premixed and diffusive combustion. The Zeldovich mechanism has been used to simulate the formation of NO emissions while the Soot model is based on the approach proposed by Hiroyasu.

The models have been tested vs. a wide set of experimental data with a good accuracy in predicting pressure cycle and heat release. The results of NOx and Soot simulations have shown a satisfactory prediction of the measured trend vs. engine control and state variables.