Enhanced Mixture Preparation Approach for Lean Stratified SI-Combustion by a Combined Use of GDI and Electronically Controlled Valve-Timing 2000-01-0532
The first part of the paper gives an overview of the current status in fuel consumption gain of the GDI-vehicles previously launched on the European market.
In order to increase the potential for a further gain in specific fuel consumption the behaviour of 3 different combustion chamber layouts are studied.
The chamber layouts are aimed to adapt as well as possible to the particular requirements for application to a small displacement/small bore engine working in stratified lean conditions.
The paper continues with a description of the application that shows the different steps of a structured optimisation methodology for a 1.2 litre, small bore 4-cylinder engine.
The applications of an air-motion-guided and a wall-guided layout with a mechanically actuated valve train to the same combustion chamber are discussed. The potential of the air-motion-guided concept is enhanced through the introduction of an electromagnetic fully variable valve train.
The layouts are analysed through numerical simulation and tested either on a single cylinder or on a 4 cylinder engine test rig.
The paper concludes with a discussion of the impact of the improvement, which can be obtained through a combination of GDI with fully variable control systems for air-motion and low energy consuming auxiliary components.
Citation: Pontoppidan, M., Gaviani, G., Bella, G., Schilardi, M. et al., "Enhanced Mixture Preparation Approach for Lean Stratified SI-Combustion by a Combined Use of GDI and Electronically Controlled Valve-Timing," SAE Technical Paper 2000-01-0532, 2000, https://doi.org/10.4271/2000-01-0532. Download Citation
M. Pontoppidan, G. Gaviani, G. Bella, M. Schilardi, V. Rocco
Magneti Marelli, Università Tor Vergata
SAE 2000 World Congress
Direct Injection Sl Engine Technology 2000-SP-1499