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Development of a Piston-Ring Lubrication Test-Rig and Investigation of Boundary Conditions for Modelling Lubricant Film Properties
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Abstract
A test-rig has been developed to simulate under idealised conditions the lubricating action between the piston-ring and the cylinder-liner in reciprocating engines. Complications arising in production engine piston-assemblies such as lubricant starvation, ring and piston dynamics, thermal and elastic deformations and blowby can thus be avoided so that the lubricant film characteristics are examined in isolation.
The lubricant film thickness and friction at the piston-ring/liner interface were simultaneously measured throughout the stroke as a function of speed and load and compared with the solution of the Reynolds equation for a range of boundary conditions. The examined conditions included the Swift-Stieber (Reynolds), the separation and limiting cases of the Floberg and the Coyne & Elrod boundary conditions using a numerically efficient general purpose program. For a Newtonian base-stock, the film thickness was found to be in close agreement with the numerical predictions for most of the cycle when the Swift-Stieber boundary condition was imposed at the cavitation boundary, except for the period soon after the dead-centres of reciprocation where the measured film thickness was lower than the predicted one. In addition, peaks in the measured hydrodynamic friction data correlated well with the shear rate calculated from the film thickness measurements, reaffirming the existence of thinner than predicted films after the flow reversals. This is in agreement with results reported in the literature where negative pressures have been measured after the reversals in the diverging part of the ring. A delayed cavitation mechanism during the growth of the cavitation region under transient conditions is thought to be responsible for the observed difference between measurements and predictions.
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Arcoumanis, C., Duszynski, M., Flora, H., and Ostovar, P., "Development of a Piston-Ring Lubrication Test-Rig and Investigation of Boundary Conditions for Modelling Lubricant Film Properties," SAE Technical Paper 952468, 1995, https://doi.org/10.4271/952468.Also In
References
- Wakuri Y. Soejima M. Taniguchi T. “On the Oil Film Behaviour of Piston Rings (Correction of Effective Pressure Region of Oil Film)” Bulletin of the JSME 21 152 295 302 1978
- Wakuri Y. Ono S. Soejima M Noguchi N. “Oil-Film Behaviour of Reciprocating Slider with Circular Profile (Observation of Film by Means of Thin Film Interferometry)” Bulletin of the JSME 22 167 755 762 1979
- Wakuri Y. Ono S. Soejima M. Masuda K. “Oil-Film Behaviour of Reciprocating Slider with Circular Profile (Optical Measurement of Oil Film Separation Boundary)” Bulletin of JSME 24 194 1462 1469 1981
- Wada S. et al J. JSME (in Japanese) 16 1 50 1971 Wakuri et al
- Brown S. R. Hamilton G. M. “Negative Pressures Under a Lubricated Piston Ring” Journal Mechanical Engineering Science 20 1 49 57 1978
- Dowson D. Taylor C. M. “Fundamental Aspects of Cavitation in Bearings” “Cavitation and Related Phenomenon in Lubrication” Proc. of the First Leeds -Lyon Symp. on Tribology Dowson D. Godet M. Taylor C. M. London and New York 1974
- Dowson D. Taylor C. M. “Cavitation in Bearings” Ann. Rev. Fluid Mech. 11 35 66 1979
- Floberg L. “On Hydrodynamic Lubrication with Special Reference to Sub-Cavity Pressures and Number of Streamers in Cavitation Regions” 1965
- Floberg L. “Lubrication of Two Rotating Cylinders at Variable Lubricant Supply with Reference to the Tensile Strength of the Lubricant” J. Lub. Tech., Trans. of the ASME 155 165 1973
- Coyne J. C. Elrod H. G. Jr. “Conditions for the Rupture of a Lubricating Film - Part I: Theoretical Model” J. Lub. Tech. Trans. of the ASME 451 456 1970
- Coyne J. C. Elrod H. G. Jr. “Conditions for the Rupture of a Lubricating Film - Part II: New Boundary Conditions for Reynolds Equation” J. Lub. Tech., Trains. of the ASME 156 167 1971
- Hopkins M. R. “Viscous Flow Between Rotating Cylinders and a Sheet Moving Between them” British J. Appl. Phys 8 442 444 1957
- Birkhoff G. Hays D. F. “Free Boundaries in Partial Lubrication” J. Math. Physics 42 2 126 138 1963
- Duffin W. J. “Electricity and Magnetism” Second McGraw Hill 316 317 1973
- Cameron A. “Basic Lubrication Theory” Third Ellis Horwood Ltd. 1981
- Newton, Sir Isaac “Opticks” Book II, Part 1, Observation 11 208 209 1979 1669
- Skinner S. “On the Occurrence of Cavitation in Lubrication” Phil. Mag. 7 329 335 1904
- Savage M. D. “Cavitation in Lubrication. Part 1. On Boundary Conditions and Cavity-Fluid Interfaces” J. Fluid Mech. 80 743 755 1977
- Swift H. W. 1931 “The Stability of Lubricating Films in Journal Bearings” J. Inst. Civ. Engrs 233 267 1931
- Stieber W. “Das Schwimmlager” Berlin 1933
- Dowson D. Taylor C. M. Xu H. “Lubricant Cavitation in Elliptical Contacts with Pure Spin” Proc. Inst. Mech. Engers. Paper C453/028 309 316 1992
- Olsson K. “Cavitation in Dynamically Loaded Bearings” Trans. Chalmers Univ. Tech. Gothenburg, Sweden 308 1965
- Taylor C. M. “Film Rupture for a Lubricated Cylinder Lightly Loaded Against a Plane” J. Mech. Eng. Sci. 16 4 225 231 1974
- Hoult D. P. Wong. V. W. Azzola J. H. “Direct Observation of the Friction Reduction of Multigrade Lubricants” SAE paper 910742 1991
- Jeng Y.-R. “Theoretical Analysis of Piston-Ring Lubrication, Part I - Fully Flooded Lubrication” Tribology Transactions 35 4 696 706 1992
- Taylor R. I. Brown M. A. Thompson D. M. Bell J. C. “The Influence of Lubricant Rheology on Friction in the Piston Ring-Pack” SAE 941981 1994
- Furuhama S. “A Dynamic Theory of Piston Lubrication (1st Report, Calculation)” Bulletin of the JSME 2 7 423 428 1959
- Jeng Y.-R. “Theoretical Analysis of Piston Ring Lubrication, Part II - Starved Lubrication and Its Application to a Complete Ring Pack” Tribology Transactions 35 4 696 706 1992
- Press W. H. Teukolsky S. A. Vetterling W. T. Flannery B. P. “Numerical Recipes in FORTRAN: The Art of Scientific Programming” Second Cambridge University Press 1992
- Chapra S. C. Canale R. P. “Numerical Methods for Engineers” Second McGraw-Hill 1988
- Rastogi A. Gupta R. K. “Effect of Shear Thinning on Cavitation in Lubricant Films” SAE paper 922286 1992
- Hamrock, B. J. “Fundamentals of Fluid Film Lubrication” NASA reference publication 1255, Chapter 3 1991
- Dowson D. Smith E. H. Taylor C. M. “An Experimental Study of Hydrodynamic Film Rupture in a Steadily-Loaded, Non-Conformal Contact” J. Mech. Eng. Sci. 22. 2 71 78 1980