A model for couple-stress fluid film mechanism with reference to human joints

2007 ◽  
Vol 221 (6) ◽  
pp. 755-759 ◽  
Author(s):  
N Ahmad ◽  
J. P. Singh
Keyword(s):  
Couple Stress ◽  
Fluid Film ◽  
Couple Stress Fluid ◽  
Human Joints

scholarly journals Performance Characteristics of a Long Porous Partial Journal Bearing using Couple Stress Fluid

2019 ◽  
Vol 8 (4) ◽  
pp. 4235-4240
Keyword(s):  
Flow Rate ◽  
Couple Stress ◽  
Journal Bearing ◽  
Fluid Model ◽  
Performance Characteristics ◽  
Fluid Film ◽  
Couple Stress Fluid ◽  
Squeeze Film ◽  
Stress Parameter ◽  
Matlab Programming

After effects of studies led on a long porous partial journal bearing for couple stress fluid are thus displayed. Performance characteristics presently determined incorporate the time-height relationship, Fluid film force, Flow rate, frictional force alongside the coefficient of friction. Plan/Technique/Approach -The paper shows a solution for the squeeze film lubrication of a thick, porous, with couple stress fluid model. It is determined that the changed Reynolds condition inferred the fluid film pressures. The modified state of Reynolds equation is analytically solved and closed form expressions are shown for the time-height, the flow rate and friction force with frictional coefficient numerically with the given starting condition using MATLAB programming, the first non-linear equation in the time-height relationship is resolved. The effects on the squeeze film characteristics of couple stresses and permeability are discussed. Findings – It can be seen that the couple stress parameter enhances the bearing characteristics. The bearing performance can be improved with the increase of couple stress parameter ( l  ), eccentricity ratio (ϵ), permeability parameter (ψ). Additional study may be performed using the couple stress fluid model, including the magnetic effect with heat and mass transfer. This model can be used to compare further with other models such as micropolar fluid, rabinowitsch fluid and for comparative study, which models are the most suitable for improving bearing system performance.

Influence of Couple Stress Lubricant on the Performance of Orifice Compensated Non-Recessed Hole-Entry Hydrostatic/Hybrid Journal Bearing

2012 ◽  
Author(s):  
Satish C. Sharma ◽  
Nathi Ram
Keyword(s):  
Couple Stress ◽  
Journal Bearing ◽  
Fluid Flows ◽  
Fluid Film ◽  
Couple Stress Fluid ◽  
The Finite Element Method ◽  
Fluid Theory ◽  
The Subject ◽  
Fluid Film Thickness ◽  
External Loads

The lubricants are generally additized in order to enhance their lubricating properties. As a consequence of this, they exhibit nonlinear relationship between the shear stress and shear strain. One class of lubricants which has received considerable attention in recent years is the couple stress lubricants. The study of couple stress fluid flows has been the subject of increased interest owing to its widespread industrial and scientific applications such as synthetic fluids, polymer-thickened oils, liquid crystals and animal bloods. The present work is therefore aimed to study analytically the influence of couple stress lubricant on the performance of an orifice compensated non-recessed hole-entry hydrostatic/hybrid journal bearings. The modified Reynolds equation based on Stoke’s couple stress fluid theory has been solved by using the Finite Element Method. The numerically simulated results have been presented for various valves of couple stress parameters and external loads. The numerically simulated results reveal that the influence of couple stress lubricant increases the value of minimum fluid film thickness at constant value of external load for hybrid journal bearing vis-a-vis Newtonian lubricant. Further, it has been observed that the value of direct fluid film damping coefficient (C22) is larger for hydrostatic journal bearing lubricated with couple stress lubricant.

STABILITY OF COUPLE STRESS FLUID FLOW THROUGH A HORIZONTAL POROUS LAYER

2016 ◽  
Vol 19 (5) ◽  
pp. 391-404 ◽  
Author(s):  
B. M. Shankar ◽  
I. S. Shivakumara ◽  
Chiu-On Ng
Keyword(s):  
Fluid Flow ◽  
Porous Layer ◽  
Couple Stress ◽  
Couple Stress Fluid ◽  
Flow Through
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