Experimental and Numerical Approach to Injection and Ignition Optimization of Lean GDI-Combustion Behavior 1999-01-0173
The first part of the paper gives an overview of the current development status of the GDI system layout for the middle displacement engine, typically 2 liter, using the stoichiometric or weak lean concept. Hereafter are discussed the particular requirements for the transition to a small displacement/small bore engine working in stratified lean conditions.
The paper continues with a description of the application of the different steps of the optimization methodology for a 1.2 liter, small bore 4 cylinder engine from its original base line MPI version towards the lean stratified operation mode. The latest changes in the combustion model, used in the numerical simulation software applied to the combustion chamber design, are discussed and comparison made with the previous model. The redesign of the combustion chamber geometry, the proper choice of injector atomizer type and location and the use of two-stage injection and multi-spark strategies are discussed in detail.
The paper concludes with a discussion of the impact on the component industrialization layout of the specification requirements necessary to fulfill an optimized lean combustion behavior for the small displacement/small bore engine.
Citation: Pontoppidan, M., Gaviani, G., Bella, G., de Maio, A. et al., "Experimental and Numerical Approach to Injection and Ignition Optimization of Lean GDI-Combustion Behavior," SAE Technical Paper 1999-01-0173, 1999, https://doi.org/10.4271/1999-01-0173. Download Citation
M. Pontoppidan, G. Gaviani, G. Bella, A. de Maio, V. Rocco
Magneti Marelli - Engine Control Div., Tor Vergata Univ., Department of Mechanical Engineering
International Congress & Exposition
Direct Injection SI Engine Technology 1999-SP-1416