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Increased Power Density via Variable Compression/Displacement And Turbocharging Using The Alvar-Cycle Engine
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English
Abstract
This paper presents the analysis and design of a variable compression-ratio and displacement engine concept - the Alvar Cycle using a four-stroke engine-performance simulation. The Alvar-Cycle engine uses secondary pistons which reciprocate in auxiliary chambers housed in the cylinder head, at adjustable phase-angle differences from the primary pistons. The phase difference provides both the variable total engine displacement and compression ratio. Results indicate that the Alvar engine can operate at higher power density via a combination of higher intake boost and lower compression ratio to avoid knock at high loads, and capture the better thermal efficiency at higher compression ratios at part loads.
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Citation
Wong, V., Stewart, M., Lundholm, G., and Hoglund, A., "Increased Power Density via Variable Compression/Displacement And Turbocharging Using The Alvar-Cycle Engine," SAE Technical Paper 981027, 1998, https://doi.org/10.4271/981027.Also In
References
- Hatamura, Kouichi et.al. “Development of Miller Cycle Gasoline Engine - Miller Cycle Engine with Late Intake Valve Closing and Lysholm Compressor” SAE Paper 938051
- Adams, W.H. et.al. “Analysis of the Combustion Process of a Spark Ignition Engine with a Variable Compression Ratio” SAE Paper 870610
- Rychter, T.J. et.al. “VR/LE Engine with Variable R/L During A Single Cycle” SAE Paper 850206
- Wirbeleit, F.G. et.al. “Development of Piston with Variable Compression Height for Increasing Efficiency and Specific Power Output of Combustion Engines” SAE Paper 900229
- Ashley, Cedric “Variable Compression Pistons” SAE Paper 901539
- Douaud A.M. Eyzat P. “Four - Octane - Number Method for Predicting the Anti - knock Behavior of Fuels and Engines” SAE Paper 780080
- Rychter, T.J. et.al. “A Theoretical Study of a Variable Compression Ratio Turbocharged Diesel Engine” Journal of Power and Energy 206 A4 227 1992
- Ueda, Naoharu et.al. “A Naturally Aspirated Miller Cycle Gasoline Engine - Its Capability of Emission, Power and Fuel Economy” SAE Paper 960589