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Incorporation of Lubricant Shear-Thinning in a Two-Dimensional Lubrication Analysis for Automotive Piston-Ring Packs
ISSN: 0148-7191, e-ISSN: 2688-3627
Published June 19, 2000 by SAE International in United States
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Piston-ring packs are major components of automotive engines. These engines are commonly lubricated with multigrade oils, which usually exhibit a non-Newtonian (shear-thinning) behaviour. That is, their viscosity decreases with an increase in shear rate. Consequently, this will effect the tribological performance of piston-ring packs. In this work, a two-space-dimensional lubrication model of piston-ring packs developed initially for Newtonian lubricants has been extended to include the effect of lubricant shear-thinning. A modified power-law model was used to characterise the lubricant shear-thinning behaviour, and it was incorporated in an existing flow-continuity algorithm, which forms the base of the current ring pack lubrication model. The extended lubrication model has been verified with published experimental results. Good agreement between theory and experiment has been achieved in terms of friction mean effective pressure (fmep). The effect of lubricant shear-thinning on the performance of a modern automotive piston-ring pack was examined. Both circular and non-circular cylinder bores were used to conduct the examination. Results show a significant lubricant shear-thinning effect.
CitationMa, M., "Incorporation of Lubricant Shear-Thinning in a Two-Dimensional Lubrication Analysis for Automotive Piston-Ring Packs," SAE Technical Paper 2000-01-1786, 2000, https://doi.org/10.4271/2000-01-1786.
- Sorab, J., Holdeman, H.A. and Chui, G.K., Viscosity prediction for multigrade oils. SAE Paper 932833, 1993.
- Duda, J.L., Klaus, E.E., Lin, S.C. and Lee, F.L., High-shear viscosity studies of polymer-containing lubricants. Proceedings of the 13th Leeds-Lyon Symposium on Tribology, ELSEVIER Science, 1987, pp. 325-332.
- Lee, F.L., Klaus, E.E. and Duda, J.L., Measurement and analysis of high-shear viscosities of polymer-containing lubricants. SAE Paper 881663, 1988.
- Wright, B., van Os, N.M. and Lyons, J.A., European activity concerning engine oil viscosity classification. Part IV: the effects of shear rate and temperature on the viscosity of multigrade oils. SAE Paper 830027, 1983.
- Dien, I.K. and Elrod, H.G., A generalized steady-state Reynolds equation for non-Newtonian fluids, with application to journal bearings. ASME J. Lubri. Technology, 1983, pp. 385-390.
- Ju, S.-M. and Weng C.-I, Thermohydrodynamic analysis of finite-width journal bearings with non-Newtonian lubricants. Wear, Vol. 171, 1994, 41-49.
- Rajalingam, C., Rao, B.V.A. and Prabhu, B.S., The effect of a non-Newtonian lubricant on piston-ring lubrication. Wear, Vol. 50, 1978, pp. 47-57.
- Johnson, M.W. Jr. and Manghoesoebroto, S.P., Thin film theory for the power law fluid with application to piston ring lubrication. SAE Paper 922285, 1992.
- Taylor, R.I., Kitahara, T., Saito, T. and Coy, R.C., Piston assembly friction and wear: the influence of lubricant viscometry. Proceedings of the International Tribology Conference, Yokohama, Japan, 1995, pp. 1423-1428 (published 1996, Japanese Society of Tribologists).
- Tian, T., Wong, V.W. and Heywood, J.B., A piston ring-pack film thickness and friction model for multigrade oils and rough surfaces. SAE Paper 962032, 1996.
- Ma, M.-T., Sherrington, I. and Smith, E.H., Analysis of lubrication and friction for a complete piston-ring pack with an improved oil availability model. Part 1: circumferentially uniform film. Proc. Instn. Mech. Engrs., Part J, Vol. 211 (J1), London, 1997, pp. 1-15.
- Ma, M.-T., Smith, E.H. and Sherrington, I., Analysis of lubrication and friction for a complete piston-ring pack with an improved oil availability model. Part 2: circumferentially variable film. Proc. Instn. Mech. Engrs., Part J, Vol. 211 (J1), London, 1997, pp. 17-27.
- Ma, M.-T., Sherrington, I. and Smith, E.H., Implementation of an algorithm to model the starved lubrication of a piston-ring in distorted bores; prediction of oil flow and onset of gas blow-by. Proc. Instn. Mech. Engrs., Part J, Vol. 210 (J1), London, 1996, pp. 29-44.
- Elrod, H. G., A cavitation algorithm. Trans. ASME, J. Lubric. Technol., 1981, Vol. 103, pp. 350 - 355.
- Wakuri, Y., Kitahara, T., Hamatake, T. and Soejima, M., Friction characteristics of piston rings in a diesel engine. Proceedings of the International Tribology Conference, Yokohama, 1995. (published 1996, Japanese Society of Tribologists).
- Ma, M.-T., Evaluation of shear-thinning effects in piston-ring pack lubrication with two non-Newtonian fluid models. Proceedings of the 5th International Tribology Conference in Australia, Brisbane, 1998, pp. 371-376.