The Effect of Turbulence on Slider-Bearing Lubrication

1959 ◽  
Vol 26 (1) ◽  
pp. 122-126
Author(s):  
Ye Tsang Chou ◽  
Edward Saibel
Keyword(s):  
Laminar Flow ◽  
Analytical Solution ◽  
Turbulent Flow ◽  
Carrying Capacity ◽  
Power Loss ◽  
Load Carrying Capacity ◽  
Mixing Length ◽  
Slider Bearing ◽  
Load Carrying ◽  
The One

Abstract Based on Prandtl’s mixing-length mechanism, the pressure equation for turbulent flow in slider-bearing lubrication is derived. An analytical solution is given and compared with the one for laminar flow. It is found that the turbulent effect increases the pressure and, consequently, the load-carrying capacity. However, the power loss also increases.

An Approximate Solution for the Infinitely Long, Gas Lubricated Slider Bearing

1965 ◽  
Vol 87 (4) ◽  
pp. 1085-1086
Author(s):  
H. J. Sneck
Keyword(s):  
Exact Solution ◽  
Approximate Solution ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Load Carrying ◽  
Numerical Design ◽  
The One ◽  
Design Calculations

The only exact solution for the infinitely long, gas-lubricated slider bearing is the one obtained by Harrison [1] for the plane wedge isothermal film. The resultant formulas for the pressure distribution and load-carrying capacity are complicated and therefore quite cumbersome in numerical design calculations. In the analysis to follow, a simplified, approximate solution is developed which can be applied to any infinitely long slider geometry.

A Comparison of Porous Structures on the Performance of a Slider Bearing with Surface Roughness in Couple Stress Fluid Film Lubrication

2015 ◽  
Vol 813-814 ◽  
pp. 921-937
Author(s):  
P.S. Rao ◽  
Santosh Agarwal
Keyword(s):  
Surface Roughness ◽  
Carrying Capacity ◽  
Couple Stress ◽  
Type Equation ◽  
Random Variable ◽  
Couple Stress Fluid ◽  
Load Carrying Capacity ◽  
Porous Structures ◽  
Slider Bearing ◽  
Load Carrying

This paper presents the theoretical study and analyzes the comparison of porous structures on the performance of a couple stress fluid based on rough slider bearing. The globular sphere model of Kozeny-Carman and Irmay’s capillary fissures model have been subjected to investigations. A more general form of surface roughness is mathematically modeled by a stochastic random variable with non-zero mean, variance and skewness. The stochastically averaged Reynolds type equation has been solved under suitable boundary conditions to obtain the pressure distribution in turn which gives the expression for the load carrying capacity, frictional force and coefficient of friction. The results are illustrated by graphical representations which show that the introduction of combined porous structure with couple stress fluid results in an enhanced load carrying capacity more in the case of Kozeny-Carman model as compared to Irmay’s model.

scholarly journals Experimental Research on AFRP Reinforced Recycled Steel Tube Columns Subjected to Axial Compression

2017 ◽  
Vol 26 (6) ◽  
pp. 096369351702600
Author(s):  
Min Hou ◽  
Jiangfeng Dong ◽  
Lang Li ◽  
Shucheng Yuan ◽  
Qingyuan Wang
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Basalt Fiber ◽  
Steel Tube ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
The One ◽  
Effective Use

In order to make an effective use of the recycled aggregate concrete (RAC), a total of six steel tube RAC columns and six basalt fiber (BF) reinforced RAC columns, including six columns that were externally strengthened with aramid fiber reinforced polymer (AFRP) sheets, were fabricated and tested. This were to provide a strengthening solution to upgrade the load carrying capacity, ductility and rigidity of the RAC filled steel tube columns. Besides, the recycled coarse aggregate (RCA) replacement ratios for production of RAC was analyzed. The results show that the load carrying capacity and ultimate displacements of the RAC filled ST columns could be improved greatly by adding of basalt fiber, especially for the specimens with 50% and 100% RCA replacement ratio. The similar result was also found for the specimens strengthened with AFRP reinforcement, along with the stiffness of the columns were enhanced obviously. Moreover, the highest improving on the load carrying capacity, stiffness and ultimate displacement was found in the specimens both reinforced by adding of BF and strengthening of AFRP. However, the failure modes of the specimens with BF reinforced RAC gave a higher deformability than the one with AFRP strengthening arrangement.

scholarly journals A STUDY OF FERROFLUID LUBRICATION BASED ROUGH SINE FILM SLIDER BEARING WITH ASSORTED POROUS STRUCTURE

2019 ◽  
Vol 59 (2) ◽  
pp. 144-152
Author(s):  
Mohmmadraiyan M. Munshi ◽  
Ashok R. Patel ◽  
Gunamani B. Deheri
Keyword(s):  
Porous Structure ◽  
Carrying Capacity ◽  
Graphical Representation ◽  
Negative Impact ◽  
Positive Impact ◽  
Numerical Approach ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Load Carrying ◽  
The Impact

This paper attempts to study a ferrofluid lubrication based rough sine film slider bearing with assorted porous structure using a numerical approach. The fluid flow of the system is regulated by the Neuringer-Rosensweig model. The impact of the transverse surface roughness of the system has been derived using the Christensen and Tonder model. The corresponding Reynolds’ equation has been used to calculate the pressure distribution which, in turn, has been the key to formulate the load carrying capacity equation. A graphical representation is made to demonstrate the calculated value of the load carrying capacity which is a dimensionless unit. The numbers thus derived have been used to prove that ferrofluid lubrication aids the load carrying capacity. The study suggests that the positive impact created by magnetization in the case of negatively skewed roughness helps to partially nullify the negative impact of the transverse roughness. Further investigation implies that when the Kozeny-Carman’s model is used, the overall performance is enhanced. The Kozeny-Carman’s model is a form of an empirical equation used to calculate permeability that is dependent on various parameters like pore shape, turtuosity, specific surface area and porosity. The success of the model can be accredited to its simplicity and efficiency to describe measured permeability values. The obtained equation was used to predict the permeability of fibre mat systems and of vesicular rocks.

Hydrodynamic Lubrication of Finite Slider Bearings: Effect of One Dimensional Film Shape, and Their Computer Aided Optimum Designs

1983 ◽  
Vol 105 (1) ◽  
pp. 48-63 ◽  
Author(s):  
C. Bagci ◽  
A. P. Singh
Keyword(s):  
Numerical Solution ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Hydrodynamic Lubrication ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Design Data ◽  
Slider Bearings ◽  
Load Carrying ◽  
Computer Aided

The effect of the film shape on the load carrying capacity of a hydrodynamically lubricated bearing has not been considered an important factor in the past. Flat-faced tapered bearing and the Raileigh’s step bearing of constant film thickness have been the primary forms of film shapes for slider bearing studies and design data developments. This article, by the computer aided numerical solution of the Reynolds equation for two dimensional incompressible lubricant flow, investigates hydrodynamically lubricated slider bearings having different film shapes and studies the effect of the film shape on the performance characteristics of finite bearings; and it shows that optimized bearing with film shapes having descending slope toward the trailing edge of the bearing has considerably higher load carrying capacity than the optimized flat-faced tapered bearing of the same properties. For example the truncated cycloidal film shape yields 26.3 percent higher load carrying capacity for Lz/Lx = 1 size ratio, and 44 percent higher for Lz/Lx = 1/2. The article then presents charts for the optimum designs of finite slider bearings having tapered, exponential, catenoidal, polynomial, and truncated-cycloidal film shapes, and illustrates their use in numerical bearing design examples. These charts also furnish information on flow rate, side leakage, temperature rise, coefficient of friction, and friction power loss in optimum bearings. Appended to the article are analytical solutions for infinitely wide bearings with optimum bearing characteristics. The computer aided numerical solution of the Reynolds equation in most general form is presented by which finite or infinitely wide hydrodynamically or hydrostatically lubricated bearings, externally pressurized or not, can be studied. A digital computer program is made available.

Equivalent slenderness ratio for built-up members

1993 ◽  
Vol 20 (4) ◽  
pp. 708-711 ◽  
Author(s):  
Murray C. Temple ◽  
Ghada Elmahdy
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
Load Carrying Capacity ◽  
Lateral Deformation ◽  
Numerical Example ◽  
Ratio Equation ◽  
Load Carrying ◽  
The One ◽  
Equivalent Slenderness Ratio

Built-up struts that buckle about an axis perpendicular to the plane of the connectors should be treated as a "built-up" member as opposed to a "simple" member. This mode of buckling causes shear and moments in the connectors which deform the connectors. These deformations increase the lateral deformation of the member and hence affect the load-carrying capacity. To account for this effect the easiest method is to use an equivalent slenderness ratio such as the one included in the Canadian Standard. This note outlines the derivation of the equivalent slenderness ratio equation, discusses when it should and should not be used, and includes a numerical example. A rewording of the applicable clause in the Canadian Standard is suggested. Key words: battens, built-up members, connectors, slenderness ratio.

Pressure Buildup Mechanism in a Textured Inlet of a Hydrodynamic Contact

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Samuel Cupillard ◽  
Michel J. Cervantes ◽  
Sergei Glavatskih
Keyword(s):  
Velocity Profile ◽  
Carrying Capacity ◽  
Flow Analysis ◽  
Maximum Efficiency ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Pressure Buildup ◽  
Flow Recirculation ◽  
Recirculating Flow ◽  
Load Carrying

A flow analysis is carried out for an inclined slider bearing with the aim of showing the governing mechanism at conditions where an optimum in load carrying capacity is achieved. The effects of surface texture on pressure buildup and load carrying capacity are explained for a textured slider bearing geometry. Numerical simulations are performed for laminar, steady, and isothermal flows. The energy transferred to the fluid from the moving wall is converted into pressure in the initial part of the converging contact and into losses in the second part. The convergence ratio can be increased, in order to get the greatest pressure gradient, until the limiting value where flow recirculation begins to occur. The texture appears to achieve its maximum efficiency when its depth is such that the velocity profile is stretched at its maximum extent without incurring incoming recirculating flow. The wall profile shape controlling the velocity profile can be optimized for many hydrodynamic contacts.

The limiting load-carrying capacity of foil thrust bearings

2017 ◽  
Vol 232 (8) ◽  
pp. 1046-1052
Author(s):  
P Samanta ◽  
MM Khonsari
Keyword(s):  
Analytical Solution ◽  
Carrying Capacity ◽  
Simple Procedure ◽  
Load Carrying Capacity ◽  
Thrust Bearings ◽  
Limiting Load ◽  
Load Carrying ◽  
Closed Form Analytical Solution ◽  
Foil Thrust Bearing ◽  
Thrust Load

A simple procedure is proposed for predicting the limiting pressure and corresponding limiting of the load-carrying capacity of a foil thrust bearing. A closed-form analytical solution for the limiting load is derived, and the predictions are verified by the numerical solution. An approximate solution for limiting thrust load is also obtained and compared to the value obtained through the analytical solution. A parametric analysis is performed to examine the dependency of the limiting load on different geometric parameters for the bearing.

scholarly journals EFFECT OF SLIP VELOCITY ON THE PERFORMANCE OF A SHORT BEARING LUBRICATED WITH A MAGNETIC FLUID

2013 ◽  
Vol 53 (6) ◽  
pp. 890-894 ◽  
Author(s):  
Rachana U. Patel ◽  
G. M. Deheri
Keyword(s):  
Aspect Ratio ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Velocity Slip ◽  
Load Carrying Capacity ◽  
Slip Parameter ◽  
Slider Bearing ◽  
Load Carrying ◽  
Improved Performance ◽  
Bearing System

This paper aims at analyzing the effect of velocity slip on the behavior of a magnetic fluid based infinitely short hydrodynamic slider bearing. Solving the Reynolds’ equation, the expression for pressure distribution is obtained. In turn, this leads to the calculation of the load carrying capacity. Further, the friction is also computed. It is observed that the magnetization paves the way for an overall improved performance of the bearing system. However the magnetic fluid lubricant fails to alter the friction. It is established that the slip parameter needs to be kept at minimum to achieve better performance of the bearing system, although the effect of the slip parameter on the load carrying capacity is in most situations, negligible. It is found that for large values of the aspect ratio, the effect of slip is increasingly significant. Of course, the aspect ratio plays a crucial role in this improved performance. Lastly, it is established that the bearing can support a load even in the absence of flow, which does not happen in the case of a conventional lubricant.

On the study of Rayleigh step slider bearings lubricated with non-Newtonian Rabinowitsch fluid

2017 ◽  
Vol 69 (5) ◽  
pp. 666-672
Author(s):  
N.B. Naduvinamani ◽  
Siddharam Patil ◽  
S.S. Siddapur
Keyword(s):  
Carrying Capacity ◽  
Reynolds Equation ◽  
Maximum Load ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Content Type ◽  
Slider Bearings ◽  
Load Carrying ◽  
Modified Reynolds Equation ◽  
Frictional Coefficients

Purpose Nowadays, the use of Newtonian fluid as a lubricant is diminishing day by day, and the use of non-Newtonian fluids has gained importance. This paper presents an analysis of the static characteristics of Rayleigh step slider bearing lubricated with non-Newtonian Rabinowitsch fluid, which has not been studied so far. The purpose of this paper is to derive the modified Reynolds equation for Rabinowitsch fluids for two regions and to obtain the optimum bearing parameters for the Rayleigh step slider bearings. Design/methodology/approach The governing equations relevant to the problem under consideration are derived. The modified Reynolds equation is derived, and it is found to be highly non-linear and hence small perturbation method is adopted to find solution. Findings From this study it is found that there is an increase in the load-carrying capacity, pressure and frictional coefficients for dilatant fluids as compared to the corresponding Newtonian case. Further, for dilatant lubricants the maximum load-carrying capacity is attained for the slightly larger values of entry region length of Rayleigh step bearing as compared to Newtonian and pseudoplastic lubricants. Originality/value Rabinowitsch fluid is used for the study of lubrication characteristics of Rayleigh step bearings. The author believes that the paper presents these results for the first time.

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