Influence of the Thermo-Piezo-Viscous Effect on the THD Lubrication in Porous Self- Lubricating Bearings

2011 ◽  
Vol 312-315 ◽  
pp. 659-664
Author(s):  
S. Boubendir ◽  
Rachid Bennacer ◽  
Salah Larbi
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Study ◽  
Journal Bearings ◽  
Load Carrying Capacity ◽  
Viscous Effect ◽  
Governing Equations ◽  
Viscous Effects ◽  
Load Carrying ◽  
Variation Versus

A numerical study of the behavior for a finite porous journal bearing lubricated with Newtonian fluid is undertaken considering both thermal and piezo-viscous effects. The modified Reynolds equation is obtained by using the thermo-hydrodynamic aspect to account for the viscous variation versus pressure and temperature where Barus law has been used for the visous formulation. To determine the flow in the porous media, the Darcy’s law has considered. The governing equations were solved numerically using a finite difference approach. Obtained results compared with the case of a thermo-viscous aspect, the piezo-viscous parameter increases the load carrying capacity significantly and improves the characteristics of the journal bearings.

Elastohydrodynamic Analysis of an Offset Journal Bearing Lubricated with Couple Stress Fluid

2010 ◽  
Vol 2 ◽  
pp. 53-62
Author(s):  
B. Chetti
Keyword(s):  
Elastic Deformation ◽  
Couple Stress ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Large Molecules ◽  
Couple Stresses ◽  
Load Carrying

This work is an investigation of the performance characteristics of an offset journal bearing lubricated with a fluid with couple stresses taking into consideration the elastic deformation of the liner. The couple stresses might be expected to appear in noticeable magnitudes in liquids containing additives with large molecules. The modified Reynolds equation has been solved using the finite difference method. Load carrying capacity, attitude angle, side leakage and friction coefficients are determined for various values of couple stress parameter of a rigid and deformable bearing. It is found that, the static characteristics of journal bearings lubricated with couple stress fluids are improved compared to journal bearings lubricated with Newtonian fluids. It is concluded that, the elastic deformation of the bearing has significant influence on the bearing characteristics.

Analysis of Misaligned Journal Bearings Operating in Turbulent Regime

1989 ◽  
Vol 111 (2) ◽  
pp. 215-219 ◽  
Author(s):  
Z. S. Safar ◽  
M. M. Elkotb ◽  
D. M. Mokhtar
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Turbulent Regime ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Local Shear ◽  
Bearing Behavior ◽  
Journal Misalignment ◽  
Local Shear Stress

This paper presents an analysis of the performance characteristics for a misaligned full journal bearing operating in turbulent regime. The modified Reynolds equation for turbulent flow is solved taking into consideration that the distribution of the effective viscosity is dependent on local shear stress. It is found that journal misalignment influences bearing behavior especially at lower eccentricity ratios. Also, it is concluded that for the same load carrying capacity misaligned journal bearing consumes more power than an aligned one.

A Contribution to the Analysis of the Thermo-Hydrodynamic Lubrication of Porous Self-Lubricating Journal Bearings

2010 ◽  
Vol 297-301 ◽  
pp. 618-623 ◽  
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
Rachid Bennacer
Keyword(s):  
Thermal Effects ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Porous Matrix ◽  
Journal Bearings ◽  
Governing Equations ◽  
Hydrodynamic Analysis ◽  
Result Show

In this work the influence of thermal effects on the performance of a finite porous journal bearing has been investigated using a thermo-hydrodynamic analysis. The Reynolds equation of thin viscous films is modified taking into account the oil leakage into the porous matrix, by applying Darcy’s law to determine the fluid flow in the porous media. The governing equations were solved numerically using the finite difference approach. Obtained result show a reduction in the performance of journal bearings when the thermal effects are accounted for and, this reduction is greater when the load capacity is significant.

Theoretical Analysis of Externally Pressurized Air Journal Bearing

1970 ◽  
Vol 12 (2) ◽  
pp. 123-129 ◽  
Author(s):  
B. C. Majumdar
Keyword(s):  
Experimental Data ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Design Parameters ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Dimensional Parameters ◽  
Bearing Design

A theoretical investigation is made to predict the performance of an externally pressurized air journal bearing having several pressure sources. The pressure distribution, which leads to the determination of load-carrying capacity and flow requirement, is obtained by solving Reynolds equation numerically. The load and flow, expressed in non-dimensional parameters, are presented for different bearing design parameters (dimensionless). The results predicted by this method are compared with others' experimental data.

Elastic Deformation Effects on the Thermo-Hydrodynamic Aspect of Porous Journal Bearings

2014 ◽  
Vol 353 ◽  
pp. 275-279
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
R. Bennacer
Keyword(s):  
Elastic Deformation ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Maximum Pressure ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Governing Equations ◽  
Load Carrying ◽  
Variation Parameter ◽  
Viscosity Variation

In this paper, the effects of porous bush elastic deformation on the static characteristics of finite porous journal bearing are investigated using Darcy’s law. The modified Reynolds equation applied to thermo-hydrodynamic problems is modified by considering the viscosity variation along the film thickness. The film pressure distribution and other characteristics such as the load carrying capacity and attitude angle are obtained by solving the governing equations numerically. Obtained results showed that deformation is considerable in the maximum pressure zone, and the elastic deformation will decrease the load carrying capacity. The viscosity variation parameter tends also to decrease the load carrying capacity.

scholarly journals Numerical Analysis of a Hydrodynamic Herringbone Grooved Journal Bearing

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
D. Souchet ◽  
A. Senouci ◽  
H. Zaidi ◽  
M. Amirat
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Study ◽  
Hydrodynamic Lubrication ◽  
Dynamical Behavior ◽  
Axial Flow ◽  
Journal Bearings ◽  
Film Rupture ◽  
High Rotational Speed ◽  
Fluid Leakage

In hydrodynamic lubrication, at very high rotational speed, the phenomenon of axial fluid leakage is often present. This can involve an increase of shear stress in the contact and consequently a considerable increase of the temperature. For that and in order to solve this problem, we took interest in the herringbone grooved journal bearings. The researches made before on these types of groove bearing have shown that they present a good dynamical behavior with a low eccentricity and a low axial flow. In this paper, a numerical study of a herringbone journal bearing operating behavior, under laminar and isothermal regime, is presented. The theoretical model, based on the classical Reynolds equation, is used. In order to include the film rupture and reformation, the Reynolds equation is modified using a mass conservative algorithm. To understand the behavior of these herringbone grooved journal bearings well, numerical modeling, using finite element method, has been developed. Various geometrical shapes of the herringbone grooved journal bearings have been analyzed, allowing us to limit the fluid leakage problem, by working particularly on the contact form.

scholarly journals CFD Analysis of Journal Bearing with a Heterogeneous Rough/Smooth Surface

Lubricants ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 88
Author(s):  
Mohammad Tauviqirrahman ◽  
J. Jamari ◽  
Arjuno Aryo Wicaksono ◽  
M. Muchammad ◽  
S. Susilowati ◽  
...  
Keyword(s):  
Journal Bearing ◽  
Noise Source ◽  
Journal Bearings ◽  
Broadband Noise ◽  
Load Carrying Capacity ◽  
Computational Investigation ◽  
Roughness Model ◽  
Load Carrying ◽  
Cfd Method ◽  
Lower Noise

In the present study, a computational investigation into acoustic and tribological performances in journal bearings is presented. A heterogeneous pattern, in which a rough surface is engineered in certain regions and is absent in others, is employed to the bearing surface. The roughness is assumed to follow the sand-grain roughness model, while the bearing noise is solved based on broadband noise source theory. Three types of heterogeneous rough/smooth journal bearings exhibiting different placement and number of the rough zone are evaluated at different combinations of eccentricity ratio using the CFD method. Numerical results show that the heterogeneous rough/smooth bearings can supply lower noise and larger load-carrying capacity in comparison with conventional bearings. Moreover, the effect on the friction force is also discussed.

Analysis of Static and Dynamic Performance Parameters of Two-Lobe Journal Bearing Operating With Non-Newtonian Lubricant

2019 ◽  
Author(s):  
Ashutosh Kumar ◽  
Sashindra Kumar Kakoty
Keyword(s):  
Couple Stress ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Variable Viscosity ◽  
Dynamic Performance ◽  
Load Carrying Capacity ◽  
Performance Parameters ◽  
Noticeable Increase ◽  
Load Carrying ◽  
Nano Lubricant

Abstract Static and dynamic performance parameters of two-lobe journal bearing, working with non-Newtonian lubricant has been obtained. Krieger-Dougherty model is used to obtain the effective viscosity of nano-lubricant for a given concentration of solid-particle in base lubricant. Modified Reynolds equation is solved to obtain bearing performance parameters for couple stress model and variable viscosity model. Dynamic coefficients are also determined for various couple stress parameter. Results reveal a noticeable increase in flow co-efficient and load carrying capacity while there is a decrease in friction variable. It also reveals a significant betterment in dynamic co-efficient of bearing.

scholarly journals Theoretical investigation of porous hydrostatic journal bearing under micropolar fluid lubrication

2020 ◽  
Vol 234 (1-2) ◽  
pp. 11-18
Author(s):  
Biplab Bhattacharjee ◽  
Prasun Chakraborti ◽  
Kishan Choudhuri
Keyword(s):  
Carrying Capacity ◽  
Micropolar Fluid ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Low Flow ◽  
Load Carrying Capacity ◽  
Static Stiffness ◽  
Design Charts ◽  
Hydrostatic Bearings ◽  
Load Carrying

The features of micropolar fluid (a non-Newtonian fluid)–lubricated short single-layered porous hydrostatic journal bearing are analyzed theoretically by an iterative method. To investigate hydrostatic journal bearing characteristics, a modified Reynolds equation in the case of micropolar fluid is derived and solved numerically. The obtained results in this work are validated by comparing the same with previously published results with Newtonian and non-Newtonian lubricants in the form of design charts. The static stiffness and load-carrying capacity of the investigated bearing are 80% and 75% higher than conventional hydrostatic bearings. The porous hydrostatic journal bearing exhibits more economical performance as it requires 40% low flow rate and low pump power, and it generates 50% less heat in contrast with other hydrostatic bearings.

Geometrical analysis of elliptical journal bearings and its effects on friction and load capacity

2019 ◽  
Vol 234 (5) ◽  
pp. 743-750
Author(s):  
Ali Ebrahimi ◽  
Saleh Akbarzadeh ◽  
Hassan Moosavi
Keyword(s):  
Friction Force ◽  
Reynolds Equation ◽  
Load Capacity ◽  
Major Axis ◽  
Journal Bearings ◽  
Maximum Pressure ◽  
Geometrical Parameters ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Lower Temperature

Elliptical bearings are one type of non-circular journal bearings which has two main advantages over the conventional circular bearings: lower temperature rise and lower vibrations. In this study, the energy equation and Reynolds equation are simultaneously solved under adiabatic boundary conditions. The predicted pressure and temperature are compared to the results of published literature for verification purposes. A parametric study is then conducted on the effect of geometrical parameters of the elliptical journal bearing on the load capacity, friction force, pressure, and oil temperature. Effect of geometric parameters of the bearing on the performance is studied. The results show that non-circularity parameter is the most influential parameter in the bearing, and an increase in the non-circularity results in the decrease in maximum pressure and temperature as well as the friction force. Increasing the eccentricity ratio, on the other hand, will cause an increase in the pressure, temperature, and the friction force. Changes in the angle between the major axis of the bearing and load direction decrease the load-carrying capacity and the non-dimensional pressure and results in an increase in the friction coefficient.

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