This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Numerical Investigation of Mixture Preparation in a GDI Engine
Technical Paper
2006-01-3375
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The purpose of the present paper is to develop an engine simulation tool in a commercial CFD code to study the spray and mixing process that can be used to access the performance of a Gasoline Direct Injection (GDI) engine. The ignition, combustion and pollutant formation are strongly dependent on the quality of the fuel-air mixture. The fuel is injected directly into the combustion chamber by high-pressure fuel injector. The fuel atomization and evaporation process takes place due to the interaction of the small fuel particles generated by the injector and the in-cylinder air motion. Experimental study on the spray and mixing process is difficult and expensive, which has been recognized as a major obstacle towards the optimization of the combustion chamber geometry, engine components and the injection strategies. This study is part of an effort to develop a means to determine injection spray characteristics in a unique combustion chamber to help define injector specifications through analysis instead of costly repetitive dyno tests. The program will be used as a selection tool to determine injector requirements for a specific customer combustion chamber.
In the current study, the engine intake flow and fuel spray are simulated using a commercial CFD code. The fuel jet is tracked by a discrete phase model in the Lagrangian scheme, in which the liquid fuel jet is modeled by groups of droplets. The interaction of the jet and the gas flow is simulated to predict the breakup and evaporation of the liquid phase. The spray model constants are calibrated against a spray bench provided by Delphi. The spray model is applied to the fuel injection and mixing simulation of the GDI engine. The equivalence ratio distribution is calculated in the combustion chamber, and the spark plug location is picked to monitor the local air-fuel ratio as a parameter for evaluating the ignition and combustion performance. The injection pressure and injection timing are studied to understand the effects of different engine operating conditions on the quality of the combustion process.
Recommended Content
Authors
Topic
Citation
Yi, Y. and DeMinco, C., "Numerical Investigation of Mixture Preparation in a GDI Engine," SAE Technical Paper 2006-01-3375, 2006, https://doi.org/10.4271/2006-01-3375.Also In
References
- Zhao F.Q. Lai M.-C. Harrington D.L. “A Review of Mixture Preparation and Combustion Control Strategy for Spark-Ignited Direct-Injection Gasoline Engines” SAE paper 970627
- Noma K. Iwamoto Y. Murakami N. Lida K. Nakayama O. “Optimized Gasoline Direct-Injection Engine for the European Market” SAE paper 980150
- Harada J. Tomita T. Mizuno H. Mashiki Z. Ito Y. “Development of Direct-Injection Gasoline Engine” SAE paper 970540
- Shih T.-H. Liou W.W. Shabbir A. Yang Z. Zhu J. “A New Eddy-Viscosity Model for High Reynolds Number Turbulent Flows - Model Development and Validation” Computers Fluids 24 3 227 238 1995
- Fluent User Manual 2005
- Reitz R. D. “Mechanisms of Atomization Processes in High-Pressure Vaporizing Sprays” Atomization and Spray Technology 3 309 337 1987
- Reitz R. D. Bracco F. V. “Mechanisms of Breakup of Round Liquid Jets” The Encyclopedia of Fluid Mechanics ed. Cheremisnoff N. 3 223 249 1986
- O'Rourke P. J. “ Collective Drop Effects on Vaporizing Liquid Sprays ” Princeton University Princeton, New Jersey 1981
- Ranz W. E. Marshall, W. R. Jr. “Evaporation from Drops, Part I & II” Chem. Eng. Prog. 48 3 141 146 March 1952
- Ranz W. E. Marshall, W. R. Jr. “Evaporation from Drops, Part I & II” Chem. Eng. Prog. 48 4 173 180 April 1952
- Kuo K. K. Y. “ Principles of Combustion ” John Wiley and Sons New York 1986
- Naber J. D. Reitz R. D. “Modeling Engine Spray/Wall Impingement” Society of Automotive Engineers, General Motors Research Laboratories Warren, MI 1988
- Waidmann Winfried Boemer Andreas Braun Markus “Adjustment and Verification of Model Parameters for Diesel Injection CFD Simulation” SAE 2006-01-0241