Thin Film Theory for the Power Law Fluid with Application to Piston Ring Lubrication

A lubrication theory for the power law fluid is developed and analyzed. Only the infinite width gap is considered. Considered is flow between rigid walls of arbitrary shape under combined Couette and squeezing motion with a pressure gradient. Equations appropriate to a thin film are derived by asymptotic integration of the three-dimensional equations of fluid mechanics. Further integration of these equations yields an algebraic equation for the pressure gradient. Working out the details of the structure of this equation enables us to develop a numerical algorithm for its solution. To illustrate the theory, it is used to calculate the pressure distribution for a parabolic slider bearing and the pressure gradient and velocity distribution when the mass flux is prescribed. The latter results are compared with results obtained earlier by Dien and Elrod (1983).

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POWER LAW FLUID MODEL INCORPORATED INTO THIN FILM ELASTOHYDRODYNAMIC LUBRICATION OF CIRCULAR CONTACTS

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2015-0042 ◽

2015 ◽

Vol 39 (3) ◽

pp. 547-556 ◽

Cited By ~ 1

Author(s):

Li-Ming Chu ◽

Hsiang-Chen Hsu ◽

Chia-Hsiang Su

Keyword(s):

Thin Film ◽

Power Law ◽

Fluid Model ◽

Elastohydrodynamic Lubrication ◽

Middle Layer ◽

Flow Index ◽

Power Law Fluid ◽

Lubricating Film ◽

Lubrication Characteristics ◽

Adsorption Layers

The modified Reynolds equation for power-law fluid is derived from the viscous adsorption theory for thin film elastohydrodynamic lubrication (TFEHL) of circular contacts. The lubricating film between solid surfaces is modeled as three fixed layers, which are two adsorption layers on each surface and a middle layer. The differences between classical EHL and TFEHL with power-law lubricants are discussed. Results show that the TFEHL power law model can reasonably calculate the pressure distribution, the film thickness, and the velocity distribution. The thickness and viscosity of the adsorption layer and the flow index significantly influence the lubrication characteristics of the contact conjunction.

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Non-Newtonian Squeeze Film Between Two Plane Annuli

Journal of Lubrication Technology ◽

10.1115/1.3253192 ◽

1982 ◽

Vol 104 (2) ◽

pp. 275-278 ◽

Cited By ~ 9

Author(s):

A. F. Elkouh ◽

N. J. Nigro ◽

Y. S. Liou

Keyword(s):

Thin Film ◽

Power Law ◽

Load Capacity ◽

Parallel Plane ◽

Squeeze Film ◽

Squeezing Flow ◽

Fluid Inertia ◽

Power Law Fluid ◽

Analytic Expressions ◽

Time Relation

An analysis is presented for the laminar squeezing flow of an incompressible power-law fluid between parallel plane annuli. The results obtained are based on the thin-film approximation, and negligible fluid-inertia. Analytic expressions for the load capacity of the squeeze film and its thickness-time relation are presented.

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Thin-Film Flow of a Power-Law Fluid Down an Inclined Plane

Journal of Fluids Engineering ◽

10.1115/1.4006406 ◽

2012 ◽

Vol 134 (4) ◽

Cited By ~ 3

Author(s):

A. Ganguly ◽

M. Reza ◽

A. S. Gupta

Keyword(s):

Thin Film ◽

Power Law ◽

Film Flow ◽

Equations Of Motion ◽

Dimensionless Time ◽

Two Dimensional ◽

Thin Film Flow ◽

Power Law Fluid ◽

Inclined Plane ◽

Two Dimensional Flow

An analysis is presented for two-dimensional flow of a thin layer of power-law fluid down an inclined plane. Integration of the equations of motion using lubrication approximations shows that for both pseudoplastic and dilatant fluids, the rate of advance of a blob of fluid of given volume decreases with increasing time. The analysis further reveals that for dimensionless time less than about 0.50, a blob of the fluid (of fixed volume) with given exponent n moves faster than a fluid of same volume with larger n. However, thereafter, a blob of the latter fluid moves faster than the former fluid.

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