The Static and Dynamic Characteristic of Elliptical Journal Bearing Lubricated with Couple-Stress Fluid

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.

Download Full-text

Lubrication of a narrow porous journal bearing with a couple stress fluid

Lubrication Science ◽

10.1002/ls.3010140403 ◽

2002 ◽

Vol 14 (4) ◽

pp. 393-413 ◽

Cited By ~ 3

Author(s):

N. B. Naduvinamani ◽

P. S. Hiremath ◽

Syeda Tasneem Fathima

Keyword(s):

Couple Stress ◽

Journal Bearing ◽

Couple Stress Fluid

Download Full-text

Preload effects on the static characteristics of three-lobe journal bearings lubricated with a couple stress fluid

Industrial Lubrication and Tribology ◽

10.1108/ilt-12-2018-0435 ◽

2019 ◽

Vol 71 (10) ◽

pp. 1136-1143 ◽

Cited By ~ 1

Author(s):

Boualem Chetti ◽

Wael Ahmed Crosby

Keyword(s):

Friction Coefficient ◽

Carrying Capacity ◽

Couple Stress ◽

Journal Bearing ◽

Significant Rise ◽

Couple Stress Fluid ◽

Load Carrying Capacity ◽

Static Characteristics ◽

Content Type ◽

Load Carrying

Purpose The purpose of this paper is to present the effect of the preload on the static characteristics of three-lobe bearings lubricated with a fluid blended with high polymer additives modeled as a couple stress fluid. Design/methodology/approach Based on the micro-continuum theory, the modified Reynolds equation for couple stress fluids is solved using a finite difference method to obtain the distribution of the pressure, the load-carrying capacity, the attitude angle, the friction coefficient and the side leakage for various values of the couple stress parameter and the preload factor. Findings The results show that the presence of a couple stress in the lubricants improves the static characteristics of this type of bearing compared to those lubricated with Newtonian fluids for any value of the preload factor. Thus, it is found that the preload significantly affects the performance of the three-lobe journal bearing lubricated with a couple stress fluid or a Newtonian fluid. Moreover, the investigation showed that increasing the preload factor exhibits an increase in the load carrying capacity and the attitude angle, but it decreases the friction coefficient and the side leakage especially at a lower preload factor. Furthermore, using a couple stress fluid and a higher preload factor led to a significant rise in the load carrying capacity and a significant reduction in the friction coefficient. Practical implications This study helped improve the performance characteristics of the three-lobe journal bearing. Originality/value The presence of couple stress in the lubricants improves the static characteristics of this type of bearing compared to those lubricated with Newtonian fluids for any value of the preload factor. The usage of the couple stress fluid and the higher preload factor led to a significant rise in the load carrying capacity and a significant reduction in the friction coefficient.

Download Full-text

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

ASME/STLE 2012 International Joint Tribology Conference ◽

10.1115/ijtc2012-61013 ◽

2012 ◽

Cited By ~ 2

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.

Download Full-text