Effect of cylinder de-activation on the tribological performance of compression ring conjunction

• Published in: Proceedings of the Institution of Mechanical Engineers. Part J, Journal of engineering tribology Journal of engineering tribology, 2017-08, Vol.231 (8), p.997-1006
• Main Authors: Bewsher, SR, Turnbull, R, Mohammadpour, M, Rahmani, R, Rahnejat, H, Offner, G, Knaus, O
• Format: Article
• Language: English
• Subjects: Activation analysis; Automobile engines; Automobile industry; Automotive parts; Catalytic converters; Combustion; Combustion efficiency; Compressing; Converters; Cylinder liners; Deactivation; Exhaust systems; Fluid dynamics; Fluid flow; Gasoline engines; Hydrodynamics; Mechanical engineering; Piston rings; Power loss; Tribology
• ISSN: 1350-6501; 2041-305X
• DOI: 10.1177/1350650116684985

The paper presents transient thermal-mixed-hydrodynamics of piston compression ring–cylinder liner conjunction for a 4-cylinder 4-stroke gasoline engine during a part of the New European Drive Cycle (NEDC). Analyses are carried out with and without cylinder de-activation technology in order to investigate its effect upon the generated tribological conditions. In particular, the effect of cylinder deactivation upon frictional power loss is studied. The predictions show that overall power losses in the piston–ring cylinder system worsen by as much as 10% because of the increased combustion pressures and liner temperatures in the active cylinders of an engine operating under cylinder deactivation. This finding shows the down-side of this progressively employed technology, which otherwise is effective in terms of combustion efficiency with additional benefits for operation of catalytic converters. The expounded approach has not hitherto been reported in literature.