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Extended, and Variable, Stroke Reciprocating Internal Combustion Engines
Technical Paper
2002-01-1941
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Event:
Future Car Congress
Language:
English
Abstract
A description is given, with a supporting thermodynamic analysis, of a four-stroke Diesel engine concept with the expansion and exhaust strokes exceeding the induction and compression strokes due to the use of a novel linkage connecting the piston to the crankshaft. The advantage of such an arrangement, after allowing for engine internal friction losses, is a reduction of about 8% in specific fuel consumption relative to an otherwise similar conventional Diesel engine. There is also a corresponding reduction of emissions. An extension of the concept, incorporating a slightly more complex linkage, is applicable to spark-ignition engines. In this case the arrangement can be operated more flexibly since the expansion ratio can be adjusted with the engine running. This capability also allows a constant compression ratio to be maintained independently of the selected expansion ratio. Reducing, for spark-ignition engines, the induction and compression strokes while extending the expansion and exhaust strokes correspondingly allows the brake specific fuel consumption to be reduced by about 20% at 30 % of full load. This conclusion was also supported by detailed thermodynamic studies with due allowance being made for engine friction losses.
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Citation
KENTFIELD, J., "Extended, and Variable, Stroke Reciprocating Internal Combustion Engines," SAE Technical Paper 2002-01-1941, 2002, https://doi.org/10.4271/2002-01-1941.Also In
References
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