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An Analysis of Oil Film Temperature, Oil Film Thickness and Heat Transfer on a Piston Ring of a Diesel Engine: Effect of Local Lubricant Viscosity
Published May 19, 2004 by Society of Automotive Engineers of Japan in Japan
Event: 2004 JSAE Annual Congress
The effect of local lubricant viscosity on the temperature and thickness in oil film on a piston ring in a diesel engine was analyzed by using Reynolds equation, and unsteady and two-dimensional energy equation with heat generated from viscous dissipation. The oil film viscosity for multigrade oil was then estimated by using the local oil film temperature and the local shear rate. Moreover, the heat transfer at ring and liner surfaces was examined. The oil film thickness and heat transfer between ring and liner could be calculated for multigrade oil that has local high shear thinning effects. The oil film thickness obtained this method becomes thinner than that the case where the viscosity based on liner temperature and average shear rate. The heat transfer at ring and liner surfaces exhibits the maximum value at near crank angle of minimum oil film thickness.