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Influence of the Valve-lift Strategy in a CAI™ Engine using Exhaust Gas Re-Breathing - Part 1: Experimental Results and 0D Analysis
Technical Paper
2009-01-0299
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Among the existing concepts that help to improve the efficiency of spark ignition engines at part load, Controlled Auto-Ignition™ (CAI™) is an effective way to lower both fuel consumption and pollutant emissions without major modifications of the engine design. The CAI™ concept is based on the auto-ignition of a fuel mixture highly diluted with burnt gases in order to achieve high indicated efficiency and low pollutant emissions through low temperature combustion.
In a 4-stroke engine, large amounts of burnt gases can be trapped in the cylinder by re-breathing them through the exhaust ports during the intake stroke using a 2-step exhaust valve-lift profile. The interaction between the intake and exhaust flows during the intake stroke was identified as a key parameter to control the subsequent combustion in a CAI™ PFI engine. Consequently, the intake valve-lift profile as well as the exhaust re-opening profile can potentially be used as control parameters for this combustion mode.
In the present study, a fully Variable Valve Actuator was used to investigate the influence of each valve-lift profile (opening/closure timing, opening/closure speed, peak valve-lift and valve-lift duration) on the engine behaviour. Furthermore, the operating points were analysed with a 0D code to investigate the mean in-cylinder conditions (species, pressure, temperature) and to help to understand the consequences of the valve actuation choices. The influence of the valve-lift profile characteristics on the combustion process and the engine efficiency are presented. Finally, the profile characteristics with the best potential to control the engine in real operating conditions are identified.
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Citation
Duffour, F., Vangraefschèpe, F., Knop, V., and de Francqueville, L., "Influence of the Valve-lift Strategy in a CAI™ Engine using Exhaust Gas Re-Breathing - Part 1: Experimental Results and 0D Analysis," SAE Technical Paper 2009-01-0299, 2009, https://doi.org/10.4271/2009-01-0299.Also In
References
- Shen Y. King E. Pfal U. “Fuel Chemistry Impacts on Gasoline HCCI Combustion with Negative Valve Overlap and Direct Injection” SAE Paper 2007-01-4105
- Shen Y. King E. Pfal U “Influences of Intake Charge Preparations on HCCI Combustion in a Single Cylinder Engine with Variable Valve Timing and Gasoline Direct Injection” SAE Paper 2006-01-3274
- Knop V. De Francqueville L. Duffour F. Vangraefschèpe F. “Influence of the Valve-lift Strategy in a CAI engine using Exhaust Gas Re-Breathing - Part 2: Optical Diagnostics and 3D CFD results” SAE Paper 2009-01-0495
- Wiebe I. I. “Semi-empirical expression for combustion rate in engines” Proccedings of Conference on Piston Engines USSR Academy of Sciences Moscow 1956 186 191
- Heywood J. B. “Internal Combustion Engine Fundamentals” McGraw Hill 1988
- Kulzer A. Hathout J.-P. Sauer C. Karrelmeyer R. Fischer W. Christ A. “Multi-Mode Combustion Strategies with CAI for a GDI Engine” SAE paper 2007-01-0214
- Wolters P. Salber S Geiger J. Duesmann M. Dilthey J. “Controlled Auto-ignition Process with an Electromechanical Valve Train” SAE Paper 2003-01-0032
- Cairns A. Blaxill H. “The Effects of Combined Internal and External Exhaust Gas recirculation on Gasoline Controlled Auto-Ignition” SAE Paper 2005-01-0133
- Mori S. Lang O. Salber W. Pischinger S. Bücker C. “Type Analysis of EGR-Strategies for Controlled Auto Ignition (CAI) by Using Numerical Simulations and Optical Measurements” SAE Paper 2006-01-0630
- Lang O. Salber S. Hahn J. Pischinger S. Hortmann K. Bücker C. “Thermodynamical and Mechanical Approach Towards a Variable Valve Train for the Controlled Auto-ignition Combustion Process” SAE Paper 2005-01-0762
- Pischinger S. Stapf K.-G. Seebach D. Bücker C. Adomeit P. Ewald J. “Controlled Auto-Ignition: Combustion Rate Shaping by Mixture Stratification” 29 th International Vienna Motor Symposium 2008
- Fuerhapter A. Unger E. Piock W.F. Fraild G.K. “The new AVL CSI Engine - HCCI Operation on a Multi Cylinder Gasoline Engine” SAE Paper 2004-01-0551
- Kulzer A. Hathout J.P. Sauer C. Christ A. “Controlled Auto Ignition based on GDI-strategies derived from experiment and simulation” IMechE 2007: Internal combustion engines: Performance, Fuel Economy and Emissions
- Knop V. Thirouard B. Cherel J. “Influence of the Local Mixture Characteristics on the Combustion Process in a CAI Engine” SAE Paper 2008-01-1671