scholarly journals 3D Numerical study on the effect of shaft eccentricity on the tribological performance of lubricated sliding contact

2018 ◽  
Vol 159 ◽  
pp. 02042
Author(s):  
Mohammad Tauviqirrahman ◽  
Bayu Kurniawan ◽  
Jamari
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Study ◽  
Wall Slip ◽  
Sliding Contact ◽  
Eccentricity Ratio ◽  
3D Numerical Modelling ◽  
Hydrodynamic Journal Bearing ◽  
Wedge Effect ◽  
Lubricated Sliding

Recently, a growing interest is given to the wall slip and the artificial texturing for improving the performance of lubricated sliding contact. The use of wall slip, artificial texturing, and the combination of slip and texturing can be the effective approach to enhance the performance of the bearing. The present study examines the effect of shaft eccentricity ratio on the hydrodynamic journal bearing performance. 3D numerical modelling based on modified Reynolds equation is used to analyse the effect of texturing and the wall slip on the characteristics of a hydrodynamically lubricated sliding contact. The analysis results point out that with respect to the load support and the power loss of the bearing, the use of wall slip on smooth surface is the most excellent configuration compared to other patterns (i.e. slip-texturing, pure texturing and conventional patterns). It is also confirmed that the wedge effect due to the shaft eccentricity has a significant role in altering the lubricant behaviour. Thus, a particular care must be taken in choosing the pattern of lubricated sliding contact as well as the shaft eccentricity.

Influence of Surface Texture Configuration and Depth on Tribological Performance of Hydrodynamic Journal Bearing

2012 ◽  
Vol 155-156 ◽  
pp. 318-323 ◽  
Author(s):  
Su Hua Wang ◽  
Jian Hua Zheng ◽  
Xin Yue Wu
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Tribological Performance ◽  
Load Carrying Capacity ◽  
Eccentricity Ratio ◽  
Surface Textures ◽  
Lubrication Performance ◽  
Load Carrying ◽  
Hydrodynamic Journal Bearing ◽  
Inlet Zone

A finite-difference numerical model is used to study the influence of surface textures configuration and depth on lubrication performance of hydrodynamic journal bearing. Reynolds equation is adopted to calculate the bearing dimensionless load carrying capacity, friction force and friction coefficient under different eccentricity ratio, textures configuration and depth. Results show that partial texturing in the inlet zone with shallow dimples and in the cavitation zone with deep dimples could improve bearing performance appreciably. The effect of the textures on bearing tribological performance was influenced by the eccentricity ratio. The advantage of partial textures decreases when the eccentricity ratio increases.

Influence of dimple location and depth on the performance characteristics of the hydrodynamic journal bearing system

2020 ◽  
Vol 234 (9) ◽  
pp. 1500-1513
Author(s):  
Niranjan Singh ◽  
RK Awasthi
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Dynamic Performance ◽  
Performance Characteristics ◽  
Eccentricity Ratio ◽  
Bearing Surface ◽  
Surface Textures ◽  
Hydrodynamic Journal Bearing ◽  
Theoretical Results ◽  
Bearing System

This paper concerns with theoretical investigation to predict the influence of cylindrical textures on the static and dynamic performance characteristics of hydrodynamic journal bearing system and the performance is compared with smooth surface bearing. The Reynolds equation governing the fluid–film between the journal and the bearing surface is solved numerically with the assistance of finite element method and the performance characteristics are evaluated as a function of eccentricity ratio, dimple depth and its location. In this study, four journal bearing configurations viz: smooth (non-textured), full-textured, partially textured-I, and partially textured-II are considered for the evaluation of theoretical results. The simulated results indicate that the influence of surface textures is more significant when the textures were created in upstream zone of 126°–286° and dimple aspect ratio nearly 1.0.

scholarly journals Numerical Investigation of Texturing and Wall Slip in Lubricated Sliding Contact Considering Cavitation

2017 ◽  
Vol 12 (2) ◽  
pp. 67-75 ◽  
Author(s):  
Muchammad ◽  
Mohammad Tauviqirrahman ◽  
Jamari ◽  
Dirk Jan Schipper
Keyword(s):  
Numerical Investigation ◽  
Wall Slip ◽  
Sliding Contact ◽  
Lubricated Sliding

Investigation the combined effects of wear and turbulent on the performance of hydrodynamic journal bearing operating with couple stress fluids

2019 ◽  
Vol 10 (6) ◽  
pp. 825-837
Author(s):  
Mushrek A. Mahdi ◽  
Ahmed Waleed Hussein
Keyword(s):  
Couple Stress ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Performance Characteristics ◽  
Turbulent Regime ◽  
Hydrodynamic Bearings ◽  
Content Type ◽  
Hydrodynamic Journal Bearing ◽  
Local Reynolds Number ◽  
Couple Stress Fluids

Purpose The purpose of this paper is to investigate the combined effect of wear and turbulence on the performance of a hydrodynamic journal bearing operating under Newtonian and couple stress fluids (CSF). Design/methodology/approach The analysis consists of a modified Reynolds equation of incompressible thin viscous films, and the film thickness model taking into account the wear effect. The governing equation was solved numerically using the finite difference approach. Findings The effect of both the wear parameter and the local Reynolds number on the performance characteristics of bearing has been presented and discussed. The obtained results observed that the characteristics of the intact and worn bearing in turbulent and laminar have been enhanced due to the non-Newtonian fluid (CSF) effect. Also, the results display that bearing worn and the turbulent regime cannot be neglected in calculating the performance characteristics of the bearing lubricated with Newtonian and non-Newtonian fluids. The results achieved from this study, specify that the bearing characteristics are significantly affected by these effects. Originality/value The paper investigates the behavior of hydrodynamic bearings considering different aspects simultaneously is interesting, and the application meets the current needs of improvement in modeling hydrodynamic bearings under different conditions.

Empirical Treatment of Hydrodynamic Journal Bearing Performance in the Superlaminar Regime

1970 ◽  
Vol 12 (2) ◽  
pp. 116-122 ◽  
Author(s):  
H. F. Black
Keyword(s):  
Reynolds Number ◽  
Field Equation ◽  
Experimental Work ◽  
Reynolds Equation ◽  
Pressure Field ◽  
Journal Bearing ◽  
Load Capacity ◽  
Journal Bearings ◽  
Theoretical Treatment ◽  
Hydrodynamic Journal Bearing

The application of a perturbation in terms of simple correlations for friction in turbulent Couette and ‘screw’ flows, together with a further empirical assumption consonant with the experimental work of Smith and Fuller (1), leads to a pressure field equation identical in form with the Reynolds equation. The load capacity of journal bearings throughout most of the superlaminar range may be represented by a single curve, and existing laminar solutions may be applied with the parameters modified by Reynolds number. The theory is compared with published experimental results, and with the most successful theoretical treatment (4). The correlations obtained confirm the adequacy of the theory to predict performance in the superlaminar régime.

Determination of Dynamic Coefficients in a Hydrodynamic Journal Bearing Based on the 3-D Navier-Stokes Equations and Considering Cavitation Effects

2012 ◽  
Author(s):  
Changhu Xing ◽  
Minel J. Braun
Keyword(s):  
Pressure Distribution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Maximum Magnitude ◽  
Navier Stokes Equations ◽  
Dynamic Coefficients ◽  
Finite Perturbation ◽  
Hydrodynamic Journal Bearing

Dynamic coefficients are very important for the stability of a hydrodynamic journal bearing and therefore for its design. In order to determine the stiffness, damping and added mass coefficients of the hydrodynamic bearing, the finite perturbation method around its stabilization position was employed. Based on the Reynolds equation with Gumbel cavitation algorithm, the maximum magnitude of the perturbation was judged by comparing results from finite perturbation (numerical way) to those from infinitesimal perturbation (additional analytical equations need to be derived based on order analysis), as well as theoretical analysis. Using the determined perturbation amplitude, the full three-dimensional Navier-Stokes equations in CFD-ACE+ were used to evaluate coefficients from an actual lubricant and compare to those obtained with Reynolds equation. Finally, a homogeneous gaseous cavitation algorithm is coupled with the Navier-Stokes equation to establish the pressure distribution in the bearing. When gas concentration was varied, the pressure distribution as well as the dynamic coefficients changed significantly.

Performance Analysis of Grooved Hydrodynamic Journal Bearing with Multi-Depth Textured Surface

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
K.M Faez ◽  
S Hamdavi ◽  
T.V.V.L.N. Rao ◽  
H.H Ya ◽  
Norani M. Mohamed
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Textured Surface ◽  
Plain Bearing ◽  
Bearing Surface ◽  
Grooved Surface ◽  
Hydrodynamic Journal Bearing ◽  
Efficiency And Reliability ◽  
Capacity Performance

In recent research, theoretical studies and investigations for the textured surface of a hydrodynamic journal bearing has been widely used. This is due to the journal bearing’s performance in terms of load capacity which affects the system performance, efficiency and reliability. It has been proven that a textured surface and grooved surface have managed to improve the performance of journal bearings to some extent. In this work, the performance of a grooved hydrodynamic journal bearing has been analysed with a multi-depth textured surface. The study has been conducted using the modified Reynolds equation to numerically solve the load capacity and pressure distribution, respectively. From the results obtained, it was found that the surface complexity features on the journal bearing lowered the load capacity performance when compared to the plain bearing. The pressure, meanwhile, was distributed throughout the textured sections on the bearing surface, even though it was lower as compared to the plain bearing.

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 Reliability of a Hydrodynamic Journal Bearing

2015 ◽  
Vol 789-790 ◽  
pp. 342-352
Author(s):  
Khadim Diop ◽  
Abdérafi Charki ◽  
Stéphane Champmartin ◽  
Abdelhak Ambari
Keyword(s):  
Failure Probability ◽  
Structural Reliability ◽  
Reynolds Equation ◽  
New Technologies ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Design Quality ◽  
Technical Requirements ◽  
Reliability Method ◽  
Hydrodynamic Journal Bearing

Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of fluid journal bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gümbel and Reynolds, and a short journal bearing with the hypothesis of Gümbel).

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