A new internal combustion engine configuration: opposed pistons with crank offset

Malpress, Ray and Buttsworth, David R. (2007) A new internal combustion engine configuration: opposed pistons with crank offset. In: 16th Australasian Fluid Mechanics Conference (AFMC 2007), 3-7 Dec 2007, Gold Coast, Australia.


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[Abstract]: Theoretical and experimental performance results for a new
internal combustion engine configuration are presented in this paper. The engine is a piston ported, spark ignition petrol engine which consists of two opposed pistons in a single cylinder controlled by two synchronously timed crankshafts at opposite ends of the cylinder. It makes use of crank offset to create the required piston motion aimed at engine efficiency improvements through thermodynamic performance gains. In particular, the engine employs full expansion in which the power stroke displaces a larger volume than the compression stroke, thereby allowing the expanding gas to reach near atmospheric pressure before the exhaust port opens. This allows more work to be done
by each thermodynamic cycle. It also features a greater rate of volume change after combustion than a convention 4-stroke engine for the same crank speed. This reduces the time that the temperature difference between the gas and the cylinder is high relative to a conventional engine which in turn, should reduce the heat lost from the combustion products. Thermodynamic and friction modelling of the engine indicated that efficiencies around 38% might be achieved. However, experiments with a prototype engine demonstrated that friction losses in the engine exceeded
that predicted in the original modelling.

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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Additional Information: No evidence of copyright restrictions.
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Mechanical and Mechatronic Engineering
Date Deposited: 04 Dec 2007 06:18
Last Modified: 02 Jul 2013 22:55
Uncontrolled Keywords: internal combustion engine design
Fields of Research : 09 Engineering > 0904 Chemical Engineering > 090405 Non-automotive Combustion and Fuel Engineering (incl. Alternative/Renewable Fuels)
09 Engineering > 0913 Mechanical Engineering > 091399 Mechanical Engineering not elsewhere classified
09 Engineering > 0902 Automotive Engineering > 090201 Automotive Combustion and Fuel Engineering (incl. Alternative/Renewable Fuels)
URI: http://eprints.usq.edu.au/id/eprint/3611

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