Piston ring design thesis proposal

Consultant: Tian Tian and Victor W. Wong.

Department: Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Writer: Massachusetts Institute of Technology

Date Issued: 2004

Piston ring friction losses take into account roughly 20% from the total mechanical losses in modern car engines. A decrease in piston ring friction would therefore lead to greater efficiency, lower fuel consumption and reduced emissions. The aim of this research ended up being to develop low-friction piston ring designs to enhance engine efficiency, without adversely affecting oil consumption, blowby, put on, or cost. They are desirable objectives for today’s engine manufacturers because they make an effort to improve exhaust while attempting to meet more and more stringent emissions rules. Utilizing an existing piston ring friction and lube model, the primary contributors to friction in modern car engines were recognized as the very best ring around top dead core compression/expansion strokes and also the oil control ring through the engine cycle. Model predictions established that the very best ring friction might be reduced by applying a skewed barrel profile design or perhaps an upward piston groove tilt design, and oil control ring friction might be reduced by decreasing ring tension. A rise in groove put on was predicted to happen using the upward piston groove tilt design, that could be eliminated by the development of an optimistic static twist on top ring. A rise in oil consumption was predicted to happen using the low-tension oil control ring design, that could be mitigated either by the development of an adverse static twist around the second ring, or through the implementation from the skewed barrel top ring design.

Model predictions established that by mixing the reduced-friction designs, a decrease in piston ring pack friction of 30-35% might be achieved, without a rise in blowby, put on, or oil consumption.(cont.) Experimental results conducted on the full-scale gas power generation engine supported the model predictions for that low-tension oil control ring design. The predicted decrease in piston ring friction would mean b .5-1% rise in brake thermal efficiency, which may create a significant improvement in gas mileage along with a substantial decrease in emissions within the existence from the engine.

Thesis (S.M.)–Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 113-115).

Keywords: Mechanical Engineering.