This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A New Analysis Method for Accurate Accounting of IC Engine Pumping Work and Indicated Work
Technical Paper
2004-01-1262
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
In order to improve fuel economy, engine manufacturers are investigating various technologies that reduce pumping work in spark ignition engines. Current cylinder pressure analysis methods do not allow valid comparison of pumping work reduction strategies. Existing methods neglect valve timing effects which occur during the expansion and compression strokes, but are actually part of the gas exchange process. These additional pumping work contributions become more significant when evaluating non-standard valve timing concepts.
This paper outlines a new analysis method for calculating the pumping work and indicated work of a 4-stroke internal combustion engine. Corrections to PMEP and IMEP are introduced which allow the valid comparison of pumping work and indicated efficiency between engines with different pumping work reduction strategies. Several example data sets are presented which illustrate the method and the necessity for the corrections when analyzing engines with non-standard valve timings.
The upper limit potential improvement in BSFC available from PMEP reduction is presented and compared to the actual benefit obtained with three pumping work reduction strategies: 1) variable valve timing, 2) intake charge dilution (stratified lean operation) and 3) cylinder deactivation.
Recommended Content
Authors
Citation
Shelby, M., Stein, R., and Warren, C., "A New Analysis Method for Accurate Accounting of IC Engine Pumping Work and Indicated Work," SAE Technical Paper 2004-01-1262, 2004, https://doi.org/10.4271/2004-01-1262.Also In
References
- Kerley, R. V. Thurston, K. W. “The Indicated Performance of Otto-Cycle Engines” SAE paper 620508 1962
- Stein, R. A. Galietti, K. M. Leone, T. G. “Dual Equal VCT - A Variable Camshaft Timing Strategy for Improved Fuel Economy and Emissions” SAE paper 950975 1995
- Asmus, T. W. “Valve Events and Engine Operation” SAE paper 820749 1982
- Leone, T. G. Christenson, E. J. Stein, R. A. “Comparison of Variable Camshaft Timing Strategies at Part Load” SAE paper 960584 1996
- Stein, R. A. Chou, T. Lyjak, J. C. “The Combustion System of the Ford 5.4L 3-Valve Engine” Global Powertrain Congress 2003
- Flierl, R. Kluting, M. “The Third Generation of Valvetrains for Throttle-Free Load Control” SAE paper 2000-01-1227 2000
- Urata, Y. Umiyama, H. Shimizu, K. Fujiyoshi, Y. Sono, H. Fukuo, K. “A Study of Vehicle Equipped with Non-Throttling S.I. Engine with Early Intake Valve Closing Mechanism” SAE paper 930820 1993
- Tuttle J. H. “Controlling Engine Load by Means of Late Intake-Valve Closing” SAE paper 800794 1980
- Tuttle J. H. “Controlling Engine Load by Means of Early Intake- Valve Closing” SAE paper 820408 1982
- Hara S. Nakajima Y. Nagumo S. “Effects of Intake-Valve Closing Timing on Spark-Ignition Engine Combustion” SAE paper 850074 1985
- Nagumo S. Hara S. “Study of fuel economy improvement through control of intake valve closing timing: cause of combustion deterioration and improvement” JSAE Review 16 1995 13 19 1995
- Leone, T. Pozar, M. “Fuel Economy Benefit of Cylinder Deactivation - Sensitivity to Vehicle Application and Operating Constraints” SAE paper 2001-01-3591 2001