Development and identification of phenomenological models for combustion and emissions of common-rail, multi-jet diesel engines

摘要

The paper deals with the development of a system of phenomenological models for the simulation of combustion and NO{sub}x-Soot emissions in Common-Rail, Multi-Jet diesel engines. The system has been built by following a modular modelling 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 versus a wide set of experimental data with a good accuracy in predicting pressure cycle and heat release. The results of NO{sub}x and Soot simulations have shown a satisfactory prediction of the measured trend versus engine control and state variables.