Combustion System Optimization of a New 2 Liter Diesel Engine For EURO IV

• Published in: SAE transactions Vol. 114; pp. 670 - 679
• Main Authors: Fasolo, Bertrand, Doisy, Anne-Marie, Dupont, Alain, Lavoisier, Frédéric
• Format: Journal Article
• Language: English
• Published: Society of Automotive Engineers, Inc 01-01-2005
• ISSN: 0096-736X; 2577-1531

While the development of Diesel engine market leads to significant CO₂ emission reduction, customers are now demanding for more driving pleasure and comfort. Renault and Nissan have therefore decided to develop a new 2 liter 4 cylinder Diesel engine family in order to comply with future customer requirements and to prepare more stringent emission regulation like Euro 4. This paper presents the main characteristics of the combustion system (injector, cylinder head and piston) and explains the technical choices made in accordance with design and cost constraints. The distinctive characteristics of this new engine are : ▪ Low compression ratio (16) and high maximum cylinder pressure level ; ▪ Third generation common-rail FIE (piezoelectric with a maximum rail pressure of 1600 bar) ; ▪ Multiple injection strategies ; ▪ Refined design of the combustion chamber : bowl shape of the piston, valve pockets depth, cylinder head swirl level and injector number of holes. The optimum matching of combustion chamber design and injection system characteristics leads to a very good trade-off between performance at full load and pollutant emission at part load : a maximum specific power of 65 kW per liter has been reached in compliance with Euro 4 exhaust gas emissions regulation. This paper outlines the optimization of the combustion system and describes its relevant characteristics.