Fluid motion within the cylinder of internal combustion engines - The 1986 Freeman Scholar Lecture
The flow field within the cylinder of internal combustion engines is the most important factor controlling the combustion process. Thus it has a major impact on engine operation. This paper reviews those aspects of gas motion into, within, and out of the engine cylinder that govern the combustion characteristics and breathing capabilities of spark-ignition engines and compression-ignition or diesel engines. Necessary background information and reciprocating engine operating cycles, the primary effect of piston motion and the spark-ignition and diesel engine combustion processes is first summarized. Then the characteristics of flow through inlet and exhaust valves in four-stroke cycle engines, and through ports in the cylinder liner in two-stroke cycle engines are reviewed. The essential features of common in-cylinder flows - the large scale rotating flows set up by the conical intake jet, the creation and development of swirl about the cylinder axis, the flows produced during compression due to combustion chamber shape called squish, flow during the combustion process, and two-stroke scavenging flows - are then described. The turbulence characteristics of these flows are then defined and discussed. Finally, flow phenomena which occur near the walls, which are important to heat transfer and hydrocarbon emissions phenomena, are reviewed.
- Research Organization:
- Sloan Automotive Lab., Massachusetts Institute of Technology, Cambridge, MA 02139
- OSTI ID:
- 5532940
- Journal Information:
- J. Fluids Eng.; (United States), Journal Name: J. Fluids Eng.; (United States) Vol. 109; ISSN JFEGA
- Country of Publication:
- United States
- Language:
- English
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