Effect of concentration dependence of viscosity on squeeze film lubrication

2020 ◽  
Vol 75 (6) ◽  
pp. 533-542
Author(s):  
Poosan Muthu ◽  
Vanacharla Pujitha
Keyword(s):  
Carrying Capacity ◽  
Iterative Procedure ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Convection Diffusion ◽  
Load Carrying ◽  
Newtonian Viscous Fluid ◽  
Nicolson Scheme ◽  
Human Joint ◽  
Film Lubrication

AbstractThe influence of concentration of solute particles on squeeze film lubrication between two poroelastic surfaces has been analyzed using a mathematical model. Newtonian viscous fluid is considered as a lubricant whose viscosity varies linearly with concentration of suspended solute particles. Convection-diffusion model is proposed to study the concentration of solute particles and is solved using finite difference method of Crank–Nicolson scheme. An iterative procedure is used to get the solution for concentration, pressure and velocity components in film region. It has been observed that load carrying capacity decreases as the concentration of solute particles in the fluid film decreases. Further, the concentration of suspended solute particles decreases as the permeability of the poroelastic plate increases and these results may be useful in understanding the mechanism of human joint.

Numerical investigation of squeeze film lubrication on bioinspired hexagonal patterned surface

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Binbin Su ◽  
Xianghe Zou ◽  
Lirong Huang
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Two Dimensional ◽  
Working Mechanism ◽  
Content Type ◽  
Patterned Surface ◽  
Load Carrying ◽  
Film Lubrication

Purpose This paper aims to investigate the squeeze film lubrication properties of hexagonal patterned surface inspired by the epidermis structure of tree frog’s toe pad and numerically explore the working mechanism of hexagonal micropillar during the acquisition process of high adhesive and friction for wet contacts. Design/methodology/approach A two-dimensional elastohydrodynamic numerical model is employed for the squeezing contacts. The pressure distribution, load carrying capacity and liquid flow rate of the squeeze film are obtained through a simultaneous solution of the two-dimensional Reynolds equation and elasticity deformation equations. Findings Higher pressure is found to be longitudinally distributed across individual hexagonal pillar, with pressure peak emerging at the center of hexagonal pillar. Expanding the area density and shrinking the channel depth or initial film thickness will improve the magnitude of squeezing pressure. Relatively lower pressure is generated inside interconnected channels, which reduces the load carrying capacity of the squeeze film. Meanwhile, the introduction of microchannel is revealed to downscale the total mass flow rate of squeezing contacts. Originality/value This paper provides a good proof for the working mechanism of surface microstructures during the acquisition process of high adhesive and friction for wet contacts.

scholarly journals MULTIGRID METHOD FOR THE SOLUTION OF COMBINED EFFECT OF VISCOSITY VARIATION AND SURFACE ROUGHNESS ON THE SQUEEZE FILM LUBRICATION OF JOURNAL BEARINGS

2017 ◽  
Vol 46 (1) ◽  
pp. 1-8
Author(s):  
Vishwanath B. Awati ◽  
Ashwini Kengangutti ◽  
Mahesh Kumar N.
Keyword(s):  
Surface Roughness ◽  
Carrying Capacity ◽  
Micropolar Fluid ◽  
Reynolds Equation ◽  
Multigrid Method ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Viscosity Variation ◽  
Film Lubrication

The paper presents, the multigrid method for the solution of combined effect of surface roughness and viscosity variation on the squeeze film lubrication of a short journal bearing operating with micropolar fluid. The modified Reynolds equation which incorporates the variation of viscosity in micropolar fluid is analysed using Multigrid method. The governing modified Reynolds equation is solved numerically for the fluid film pressure and bearing characteristics viz. load carrying capacity and squeeze time. The analysis of the results predicts that, the viscosity variation factor decreases the load carrying capacity and squeeze film time, resulting into a longer bearing life. The results are compared with the corresponding analytical solutions.

Combined effect of surface roughness and pressure-dependent viscosity over couple-stress squeeze film lubrication between circular stepped plates

2018 ◽  
Vol 232 (5) ◽  
pp. 525-534 ◽  
Author(s):  
BN Hanumagowda ◽  
BT Raju ◽  
J Santhosh Kumar ◽  
KR Vasanth
Keyword(s):  
Surface Roughness ◽  
Carrying Capacity ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
One Dimensional ◽  
Pressure Dependent Viscosity ◽  
Load Carrying ◽  
Dependent Viscosity ◽  
Film Lubrication ◽  
Effect Of Surface

In this paper, the effect of surface roughness and pressure-dependent viscosity over couple-stresses squeeze film lubrication between circular stepped plates is studied. The modified average Reynolds equation is derived for the one-dimensional roughness structures, namely the radial roughness pattern and azimuthal roughness pattern. Modified equations for the nondimensional pressure, load-carrying capacity, and nondimensional squeeze film time are obtained. Also, the obtained results of our study for some special cases are compared with the previously published smooth surface case, and the results are found to be in very good agreement. It is observed that, one-dimensional azimuthal (radial) roughness pattern on the rough circular stepped plate increases (decreases) the load-carrying capacity and the squeeze film time as compared to the smooth case.

Stochastic Reynolds equation for the combined effects of piezo-viscous dependency and squeeze-film lubrication of micropolar fluids on rough porous circular stepped plates

2021 ◽  
pp. 135065012110224
Author(s):  
Hanumagowda Bannihalli Naganagowda ◽  
Sreekala Cherkkarathandayan Karappan
Keyword(s):  
Carrying Capacity ◽  
Stochastic Approach ◽  
Squeeze Film ◽  
Closed Form Expression ◽  
Load Carrying Capacity ◽  
Micropolar Fluids ◽  
Pressure Dependent Viscosity ◽  
Load Carrying ◽  
Dependent Viscosity ◽  
Film Characteristics

The aim of this paper is to presents a theoretical analysis on squeeze-film characteristics of a rough porous circular stepped plate in the vicinity of pressure-dependent viscosity and lubrication by micropolar fluids. A closed-form expression for non-dimensional pressure, load, and squeezing time is derived based on Eringen’s theory, Darcy’s equation, and Christensen’s stochastic approach. Results indicate that the effects of pressure-dependent viscosity, surface roughness, and micropolar fluids play an important role in increasing the load-carrying capacity and squeezing time, whereas the presence of porous media decreases the load-carrying capacity and squeezing time of the rough porous circular stepped plates.

Effect of Velocity Slip on Porous-Walled Squeeze Films

1972 ◽  
Vol 94 (3) ◽  
pp. 260-264 ◽  
Author(s):  
E. M. Sparrow ◽  
G. S. Beavers ◽  
I. T. Hwang
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Carrying Capacity ◽  
Response Times ◽  
Velocity Slip ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Flow Processes ◽  
Time Relation

The fluid flow processes in a squeeze film having one porous bounding wall are analyzed. The analysis takes account of velocity slip at the surface of the porous medium as well as of the coupled flows in the squeeze film and the porous material. Results are presented for the load-carrying capacity of the squeeze film and its thickness–time relation. The results show that porous media are effective in diminishing the response times of squeeze films. In particular, substantially faster response can be attained by the use of porous materials which accentuate velocity slip.

An Attempt to Provide a Unified Treatment of Tribology Through Load Carrying Capacity, Transport, and Continuum Mechanics

1980 ◽  
Vol 102 (2) ◽  
pp. 153-164 ◽  
Author(s):  
M. Godet ◽  
D. Play ◽  
D. Berthe
Keyword(s):  
High Temperature ◽  
Continuum Mechanics ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Third Body ◽  
Continuum Approach ◽  
Load Carrying ◽  
Solid Liquid ◽  
Film Lubrication ◽  
The Continuum

This paper attempts to give a unified treatment of experiments obtained with solid, liquid and boundary lubricants, different plastics, high temperature steels and elastomers. The argument is centered around third body role, load-carrying capacity, transport and continuum mechanics. This study suggests that an extension to general tribology of the continuum approach used in full film lubrication could be profitable.

Fluid Inertia Effects in a Non-Newtonian Squeeze Film Between Two Plane Annuli

1999 ◽  
Vol 122 (4) ◽  
pp. 872-875 ◽  
Author(s):  
R. Usha and ◽  
P. Vimala
Keyword(s):  
Carrying Capacity ◽  
Integral Method ◽  
Squeeze Flow ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Fluid Inertia ◽  
Inertia Effects ◽  
Load Carrying ◽  
Analytical Expressions ◽  
Plastic Fluids

An analysis is presented for the laminar squeeze flow of an incompressible powerlaw fluid between parallel plane annuli using the modified lubrication theory and energy integral method. The local and the convective inertia of the flow are considered in the investigation. Analytical expressions for the load carrying capacity of the squeeze film are obtained using both the methods and are compared with those based on the assumption of inertialess flow. It is observed that the inertia correction in the load carrying capacity is more significant for pseudo-plastic fluids, n<1.[S0742-4787(00)00504-X]

SEARCH FOR THE MOST USEFUL GEOMETRY OF AN ACOUSTIC JOURNAL BEARING

Tribologia ◽  
2018 ◽  
Vol 273 (3) ◽  
pp. 15-66 ◽  
Author(s):  
Rafał GAWARKIEWICZ
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Simulations ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Squeeze Film ◽  
Acoustic Levitation ◽  
Load Carrying Capacity ◽  
The Finite Element Method ◽  
Load Carrying

Computer simulations of a number of journal bearing’s geometries utilising acoustic levitation were carried out. The choice of the best geometry depended on the ability of a deformed shape, created by piezo-electric elements, to facilitate squeeze film ultrasonic levitation, and also to create three evenly distributed diverging aerodynamic gaps. Deformations of analysed variants of the bearing’s shape were generated by numerical simulations utilising the finite element method. For the chosen shapes of geometry, prototype bearings were made and their usefulness verified experimentally. As a result, the bearing with the highest load carrying capacity was identified.

Effect of surface roughness and elastic deformation on the performance of a magnetic fluid-based squeeze film in rotating porous annular plates

2014 ◽  
Vol 66 (3) ◽  
pp. 490-497
Author(s):  
Mukesh E. Shimpi ◽  
Gunamani Deheri
Keyword(s):  
Elastic Deformation ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Type Equation ◽  
Squeeze Film ◽  
Rotational Inertia ◽  
Load Carrying Capacity ◽  
Content Type ◽  
Annular Plates ◽  
Load Carrying

Purpose – The purpose of this paper is to study and analyse the behaviour of a magnetic fluid-based squeeze film between rotating transversely rough porous annular plates, taking the elastic deformation into consideration. Design/methodology/approach – The stochastic film thickness characterizing the roughness is considered to be asymmetric with non-zero mean and variance and skewness while a magnetic fluid is taken as the lubricant. The associated stochastically averaged Reynolds-type equation is solved with appropriate boundary conditions to obtain the pressure distribution, which in turn is used to derive the expression for the load-carrying capacity. Findings – It is observed that the roughness of the bearing surfaces affects the performance adversely, although the bearing registers an improved performance owing to the magnetic fluid lubricant. Also, it is seen that the deformation causes reduced load-carrying capacity. The bearing can support a load even in the absence of flow, unlike the case of conventional lubricants. Originality/value – The originality of the paper lies in the fact that the negative effect of porosity, deformation and standard deviation can be minimized to some extent by the positive effect of the magnetic fluid lubricant in the case of negatively skewed roughness by suitably choosing the rotational inertia and aspect ratio. This effect becomes sharper when negative variance occurs.

Sign in / Sign up

Export Citation Format

Share Document