Influence of sliding surface roughness and oil temperature on piston ring pack operation of an automotive IC engine
نویسنده
چکیده
In the paper a comprehensive model of a piston ring pack motion on an oil film has been presented. The local oil film thickness can be compared to height of the combined roughness of sliding surfaces of piston rings and cylinder liner. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been combined and used in this paper. The developed model takes the following phenomena into account: hydrodynamic and contact forces, spring and gas forces acting on piston rings. The rings motion concerning low and high temperature of cylinder surface has been compared. These results concern cases of hydrodynamic and mixed lubrication. Changes of oil wetted area and contact zone of piston rings have been shown. In addition the oil film thickness distribution along cylinder liner and all the forces acting on piston rings have been analysed and discussed. The results have been presented in form of relevant diagrams. The developed model and software can be utilized for optimization of piston rings design.
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