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Optimization of Cold Start Operating Conditions in a Stoichiometric GDI Engine with Wall-guided Piston using CFD Analysis
Technical Paper
2013-01-2650
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The purpose of this paper is to investigate the mixture formation and optimize the operating conditions under cold start in a stoichiometric (λ=1) GDI engine with wall-guided piston using a 3D commercial code, STAR-CD [8]. For GDI engine under cold start, it can be difficult to carry out the optimization of operating conditions by engine test alone without the understanding of mixture formation inside the combustion chamber. In this study, three cold start conditions of the catalyst heating mode with split injection, the cranking under freezing temperature and acceleration before engine warm-up which causes oil dilution were calculated. In particular, injection strategy for each cold start condition were optimized and compared to the engine test data.
The previously validated spray models [6] were applied to the analysis of the spray formation and mixing process inside the combustion chamber. Also, Bai's droplet-wall interaction model and liquid film model considering the film stripping on the surface were used for better prediction of wall film behavior. This approach reasonably predicts the interaction of the injected spray and the in-cylinder flow, the mixture distribution around the spark plug, and liquid film on the wall inside the combustion chamber. The analysis results show that under cold start with relatively low engine speed, injection parameters such as pressure, split injection ratio and timing strongly affect tumble flow, mixture formation and wall wetting. The results for the optimized injection conditions are qualitatively in good agreements with experimental data in terms of combustion stability (RPM variation), HC emission, and oil dilution.
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Kim, S., Hyun, S., and Park, J., "Optimization of Cold Start Operating Conditions in a Stoichiometric GDI Engine with Wall-guided Piston using CFD Analysis," SAE Technical Paper 2013-01-2650, 2013, https://doi.org/10.4271/2013-01-2650.Also In
References
- Landenfeld , T. , Kufferath , A. , and Gerhardt , J. Gasoline Direct Injection - SULEV Emission Concept SAE Technical Paper 2004-01-0041 2004 10.4271/2004-01-0041
- Morita , K. , Sonoda , Y. , Kawase , T. , and Suzuki , H. Emission Reduction of a Stoichiometric Gasoline Direct Injection Engine SAE Technical Paper 2005-01-3687 2005 10.4271/2005-01-3687
- Davis , R. , Mandrusiak , G. , and Landenfeld , T. Development of the Combustion System for General Motors' 3.6L DOHC 4V V6 Engine with Direct Injection SAE Int. J. Engines 1 1 85 100 2008 10.4271/2008-01-0132
- Xu , Z. , Yi , J. , Wooldridge , S. , Reiche , D. et al. Modeling the Cold Start of the Ford 3.5L V6 EcoBoost Engine SAE Int. J. Engines 2 1 1367 1387 2009 10.4271/2009-01-1493
- Malaguti , S. , Fontanesi , S. , and Severi , E. Numerical Analysis of GDI Engine Cold-Start at Low Ambient Temperatures SAE Technical Paper 2010-01-2123 2010 10.4271/2010-01-2123
- Kim , S. , Kim , Y. , and Lee , J. Analysis of the In-Cylinder Flow, Mixture Formation and Combustion Processes in a Spray-Guided GDI Engine SAE Technical Paper 2008-01-0142 2008 10.4271/2008-01-0142
- Kim Sung-jun et. al Analysis of the In-cylinder Flow, Mixture Formation and Combustion Processes in a Stoichiometric GDI Engine KSAE08-S0002
- STAR-CD User Manual ver. 4.12
- es-ice User Manual ver. 2.16