Yes / The presence of lubricant droplets in the gas that flows through the piston assembly and crankcase of an internal combustion engine (generically termed oil misting) has important implications for performance, particularly lubricant supply to the upper piston assembly, oil consumption and lubricant degradation. A significant source of these droplets is thought to be oil shearing and blow-through by blow-by gas flows in the piston assembly. An
experimental rig was developed to simulate the high velocity gas and lubricant film interactions at a top piston
ring gap where the flow conditions are most severe. Flows of lubricant droplets were produced and characterised
in terms of the proportion of the oil flow that formed droplets in the gas flow and the size distribution of the droplets produced. Considering various aspects of a commercial automotive crankcase formulation, the effect of lubricant viscosity was found to be particularly important. Of the lubricant additives evaluated, viscosity modifiers were found to have the greatest effect on the tendency to form droplets: Detailed study on a range of viscosity
modifiers identified that the influence of their molecular architectures on viscoelasticity was the key mechanism.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/18928 |
| Date | 08 April 2022 |
| Creators | Dyson, C.J., Priest, Martin, Lee, P.M. |
| Publisher | Springer |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Published version |
| Rights | © 2022 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/, CC-BY |
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