International Journal of Automotive Technology

The Korean Society of Automotive Engineers (한국자동차공학회)
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STUDY ON THE EFFECT OF AERATED LUBRICANT ON THE JOURNAL TRACES IN THE ENGINE BEARING CLEARANCE

  • JANG S. (School of Mechanical and Automotive Engineering, Kookmin University) ;
  • PARK Y. (Graduate School of Automotive Engineering, Kookmin University)
  • Published : 2005.06.01
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Abstract

This work analyzes the behaviors of aerated lubricant in the gap between con-rod bearing and journal. It is assumed that the film formation with aerated lubricant is influenced by the two major factors. One is the density characteristics of the lubricant due to the volume change of lubricant for the formation of bubbles and the other is the viscosity characteristics of the lubricant due to the surface tension of the bubble in the lubricant. These two major factors surprisingly increase the load capacity in some ranges of bubble sizes and densities. Modified Reynolds' equation is developed for the computation of fluid film pressure with the effects of aeration ratio in the lubricant. From the calculated load capacity by solving modified Reynolds' equation, journal locus is computed with Mobility method after comparing it with the applied load at each time step. The differences of journal orbits between aerated and pure lubricants are shown in the computed results.

Keywords

References

  1. Booker, J.F. (1965). Dynamically loaded joumal bearing: Mobility method of solution. ASME J. Basic Engineering 87, 3, 537-546 https://doi.org/10.1115/1.3650602
  2. Chamniprasart, K., AI-Sharif, A., Rajagopal, K.R. and Szeri, A.Z. (1993). Lubrication with binary mixtures: bubbly oil. J. Tribology, 115, 253-260 https://doi.org/10.1115/1.2920999
  3. Hamrock, B.J. (1994). Fundamentals of Fluid Film Lubrication. McGraw-Hill. New York
  4. Nikolajsen, J.L. (1999a). The effect of aerated oil on the load capacity of a plain journal bearings. STLE, Tribology Transactions 42, 1, 58-62 https://doi.org/10.1080/10402009908982190
  5. Nikolajsen, J.L. (1999b). Viscosity and density models for aerated oil in fluid-film bearings. Tribology Trans., 42, 186-191 https://doi.org/10.1080/10402009908982207
  6. Streeter, V.L. (1958). Fluid Mechanics. McGraw-Hill. New York