0
Research Papers: Lubricants

A Model for Lubrication by Oil-in-Water Emulsions

[+] Author and Article Information
Sy-Wei Lo

Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Douliou City, Yunlin 64002, Taiwanlosw@yuntech.edu.tw

Tzu-Chun Yang, Yong-An Cian, Kuo-Cheng Huang

Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Douliou City, Yunlin 64002, Taiwan

J. Tribol 132(1), 011801 (Nov 10, 2009) (9 pages) doi:10.1115/1.4000274 History: Received May 06, 2009; Revised September 08, 2009; Published November 10, 2009; Online November 10, 2009

A model for oil-in-water emulsion has been developed in this paper. A group of viscosity coefficients transiting smoothly and incessantly from the thick film region to the thin film region is defined. The contributions from disperse and continuous phases to the total lubricant pressure and pressure gradient are functions of the oil concentration and the film thickness. The parameters used in these functions are determined by a series of computational fluid dynamics simulations. The onset of inversion and the viscosity after inversion are also investigated. It is found that the critical volume fraction of oil in the inception of inversion is dependent on the oil viscosity and a factor regarding the combined effects from the emulsifier, pH value, droplet size, and the shear rate. A series of simulations using the proposed model has been carried out and compared with the experimental results, such as the film thickness and the extension of oil pool for various rolling speeds and supply oil concentrations. The numerical outputs are basically in agreement with the experiments.

FIGURES IN THIS ARTICLE
<>
Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Stresses on volume element in the x-direction

Grahic Jump Location
Figure 2

Equivalent viscosities versus volume fraction of oil before inversion (ϕ∗=0.46)

Grahic Jump Location
Figure 3

Volume fraction of oil at inversion ϕinv versus normalization factor ϕ∗ for various viscosity ratios

Grahic Jump Location
Figure 4

(a) Example of model for CFD simulation of Poiseuille flow (length unit: μm); (b) special arrangement of oil droplets for accelerating mixing effect in the case of small surface gap

Grahic Jump Location
Figure 5

CFD-determined pressure correct factors and fitted curves versus volume fraction of oil for various nondimensional film thicknesses

Grahic Jump Location
Figure 6

Numerical and experimental film thicknesses versus rolling speeds for various emulsions

Grahic Jump Location
Figure 7

Numerical and experimental film thicknesses versus supply oil concentration for various rolling speeds

Grahic Jump Location
Figure 8

Numerical and experimental dimensionless oil phase inlet distances versus rolling speed for various emulsions

Grahic Jump Location
Figure 9

Distributions of the calculated volume fraction of oil for various rolling speeds (supply oil concentration=5%)

Grahic Jump Location
Figure 10

Distributions of the reduced pressure for various rolling speeds (supply oil concentration=5%)

Grahic Jump Location
Figure 11

Numerical and experimental capture coefficients C versus rolling speed for various emulsions

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In