This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Assessing the Limits of Downsizing in Diesel Engines
Technical Paper
2014-32-0128
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Direct injection compression ignited (CI) engines are today's most efficient engine technology, granting efficiencies exceeding 40% for their optimal operation point. In addition, a strong technological development has allowed the CI engine to overcome its traditional weak points: both its pollutant emissions and the gap in specific power regarding its competitor, i.e. the spark ignited (SI) engine, have been noticeably reduced. Particularly, the increase in specific power has led to the downsizing as an effective method to improve vehicle efficiency. Despite the reduction in total displacement, the cylinder displacement of current CI engines is still around 0.5 liters. For some applications (urban light duty vehicles, Range Extenders…) it may be interesting to reduce the engine displacement to address power targets around 20kW with high efficiencies. This paper assesses the thermo- and fluid-dynamic limitations which make challenging extending the application of automotive CI engines to the low power region: Firstly, space limitations for injection and combustion processes. In second place the increase of surface-to-volume ratio which gives rise to higher heat losses. Finally, limits related to the air management, most notably with turbocharging, due to the reduction in turbocharger efficiency with decreasing size.
The combination of scaling laws with parametric studies carried out with CFD tools allows quantifying the impact of the previous issues on the engine efficiency. The paper also addresses which would be the minimum size of a CI engine for automotive applications (specific power around 40KW/liter and 40% efficiency) with state of the art technology, which according to the authors, is bounded at 150cm3 for cylinder displacement and 450-500cm3 for total displacement due to injection and turbocharging limitations, respectively. Finally, the authors propose a design of such a minimum size engine, which is currently under construction.
Recommended Content
Authors
Topic
Citation
Payri, F., Lopez, J., Pla, B., and Graciano Bustamante, D., "Assessing the Limits of Downsizing in Diesel Engines," SAE Technical Paper 2014-32-0128, 2014, https://doi.org/10.4271/2014-32-0128.Also In
References
- Panorama of Transport Eurostat Statistical Books 2009 1831-3280
- Abthoff , J. , Duvinage , F. , Pischinger , S. , and Weber , S. , The Potential of Small DI-Diesel Engines with 250 cm3/Cylinder for Passenger Car Drive Trains SAE Technical Paper 970838 1997 10.4271/970838
- Wang R. and Lukic S. M. Review of driving conditions prediction and driving style recognition based control algorithms for hybrid electric vehicles Vehicle Power and Propulsion Conference (VPPC) 2011
- Pelkmans L. and Debal P. Comparison of on-road emissions with emissions measured on chassis dynamometer test cycles Transportation Research Part D: Transport and Environment 11 4 233 241 2006
- Aichlmayr H. T. , Kittelson D. B. and Zachariah M. R. Miniature free-piston homogeneous charge compression ignition engine-compressor concept Chemical Engineering Science 57 4161 4186 2002
- Payri F. , Desantes J.M. Motores de Combustión Interna Alternativos Reverté 978-84-291-4802-2 2011
- Torregrosa A. , Olmeda P. , Degraeuwe B. and Reyes M. A concise wall temperature model for DI Diesel engines Applied Thermal Engineering 26 11-12 1320 1327 2006
- Stager , L. and Reitz , R. , Assessment of Diesel Engine Size-Scaling Relationships SAE Technical Paper 2007-01-0127 2007 10.4271/2007-01-0127
- Heywood J. B. Internal Combustion Engine Fundamentals McGraw-Hill series in mechanical engineering 0-07-028637-X
- Galindo J. , Serrano J.R. , Arnau F. and Piqueras P. Description and analysis of a one-dimensional gas-dynamic model with independent time discretization Journal of Engineering for Gas Turbine and Power 2008 187 197 2008
- Chen H. and Connor W. Turbocharger compressor developments for passenger car gasoline engine applications 7th International conference on turbochargers and turbocharging, IMechE, C602/016/2002 14-15 May 2002
- Watson N , Janota S Turbocharging the internal combustion engine London McMillan Publishers Ltd. 1982 0-333-24290-4
- Matsumoto , S. , Yamada , K. , and Date , K. , Concepts and Evolution of Injector for Common Rail System SAE Technical Paper 2012-01-1753 2012 10.4271/2012-01-1753
- Hiroyasu , H. and Arai , M. , Structures of Fuel Sprays in Diesel Engines SAE Technical Paper 900475 1990 10.4271/900475.p