scholarly journals Non-Newtonian Effects on the Squeeze Film Characteristics between a Sphere and a Flat Plate: Rabinowitsch Model

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Udaya P. Singh ◽  
Ram S. Gupta
Keyword(s):  
Flat Plate ◽  
Carrying Capacity ◽  
Significant Variation ◽  
Reynolds Equation ◽  
Fluid Model ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Film Pressure ◽  
Load Carrying ◽  
Film Characteristics

The use of additives (polyisobutylene, ethylene-propylene, lithium hydroxy stearate, hydrophobic silica, etc.) changes lubricants’ rheology due to which they show pseudoplastic and dilatant nature, which can be modelled as cubic stress fluid model (Rabinowitsch fluid model). The present theoretical analysis investigates the effects of non-Newtonian pseudoplastic and dilatant lubricants on the squeezing characteristics of a sphere and a flat plate. The modified Reynolds equation has been derived and an asymptotic solution for film pressure is obtained. The results for the film pressure distribution, load carrying capacity, and squeezing time characteristics have been calculated for various values of pseudoplastic parameter and compared with the Newtonian results. These characteristics show a significant variation with the non-Newtonian pseudoplastic and dilatant behavior of the fluids.

Effect of viscosity variation on non-Newtonian lubrication of squeeze film conical bearing having porous wall operating with Rabinowitsch fluid model

2018 ◽  
Vol 233 (7) ◽  
pp. 2538-2551 ◽  
Author(s):  
Pentyala Srinivasa Rao ◽  
Amit Kumar Rahul
Keyword(s):  
Carrying Capacity ◽  
Reynolds Equation ◽  
Porous Wall ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Film Pressure ◽  
Pressure Load ◽  
Load Carrying ◽  
Newtonian Case ◽  
Viscosity Variation

In this study, the effect of viscosity variation of non-Newtonian lubrication on squeeze film characteristics with porous and Rabinowitsch fluid for conical bearings is analyzed. The modified Reynolds equation representing the characteristics of non-Newtonian fluid with viscosity variation on the porous wall followed by the cubic stress law condition is invoked. For lubricant flow in a bearing clearance and in a porous layer Morgan–Cameron approximation is considered. A small perturbation technique is used to compute the pressure generation using modified Reynolds equation of lubrication. Approximate analytical solutions have been obtained for the squeeze film pressure, load-carrying capacity, squeeze film time, and center of pressure. The outcomes are displayed in diagrams and tables, which show that the effect of viscosity variation and porous wall on the squeeze film lubrication of conical bearings decreases film pressure, load-carrying capacity, and response time for the Newtonian case in comparison to the non-Newtonian case.

scholarly journals Effect of Surface Roughness and Viscosity-Pressure Dependency on the Couple Stress Squeeze Film Characteristics of Parallel Circular Plates

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Neminath Bhujappa Naduvinamani ◽  
Siddangouda Apparao ◽  
Ayyappa G. Hiremath
Keyword(s):  
Surface Roughness ◽  
Carrying Capacity ◽  
Couple Stress ◽  
Reynolds Equation ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Circular Plates ◽  
Pressure Dependency ◽  
Load Carrying ◽  
Film Characteristics

Combined effects of surface roughness and viscosity-pressure dependency on the couple stress squeeze film characteristics of parallel circular plates are presented. On the basis of Christensen’s stochastic theory, two types of one-dimensional roughness structures, namely, the radial roughness and azimuthal roughness patterns, are considered and the stochastic modified Reynolds equation for these two types of roughness patterns is derived for Stokes couple stress fluid by taking into account variation of viscosity with pressure. The standard perturbation technique is employed to solve the averaged Reynolds equation and closed form expressions for the mean fluid film pressure, load carrying capacity, and squeeze film time are obtained. It is found that the effects of couple stresses and viscosity-pressure dependency are to increase the load carrying capacity, and squeeze film time for both types of roughness patterns. The effect of azimuthal (radial) roughness pattern is to increase (decrease) these squeeze film characteristics as compared to the corresponding 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.

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.

scholarly journals Thrust Porous Bearing with Rough Surfaces Lubricated by a Rotem-Shinnar Fluid

2016 ◽  
Vol 10 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Anna Walicka ◽  
Edward Walicki
Keyword(s):  
Pressure Distribution ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Hydrodynamic Lubrication ◽  
Equations Of Motion ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Porous Bearing ◽  
Load Carrying ◽  
Plastic Fluid

Abstract In the paper the influence of both bearing surfaces roughness and porosity of one bearing surface on the pressure distribution and load-carrying capacity of a thrust bearing surfaces is discussed. The equations of motion of a pseudo-plastic fluid of Rotem-Shinnar, are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation and Christensen theory of hydrodynamic lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of squeeze film bearing and externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. Thrust radial bearing with squeezed film is considered as a numerical example.

An Analysis of the Squeeze Film Between Porous Rectangular Plates

1972 ◽  
Vol 94 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Hai Wu
Keyword(s):  
Film Thickness ◽  
Pressure Distribution ◽  
Laplace Equation ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Rectangular Plates ◽  
Load Carrying ◽  
In Series

The squeeze film between two rectangular plates when one has a porous facing is studied theoretically. The problem is described by the modified Reynolds equation in the film region and the Laplace equation in the porous region. Results are presented for pressure distribution, load-carrying capacity, and film thickness as functions of time in series form. The effect of the porous facing on the squeeze film behavior is discussed and found to be important.

scholarly journals The Performance of Squeeze Film between Parallel Triangular Plates with a Ferro-Fluid Couple Stress Lubricant

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Akbar Toloian ◽  
Maghsood Daliri ◽  
Nader Javani
Keyword(s):  
Magnetic Field ◽  
Carrying Capacity ◽  
Couple Stress ◽  
Volume Concentration ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Uniform External Magnetic Field ◽  
Film Characteristics ◽  
The Magnetic Field

The present study aims at investigating a couple stress ferrofluid lubricant effects on the performance of the squeezed film when a uniform external magnetic field is applied. For this purpose, Shliomis ferrohydrodynamic and couple stress fluid models are employed. The considered geometry is parallel triangular plates. The effects of couple stress, volume concentration, and Langevin parameters on squeeze film characteristics including time vs. height relationship and load-carrying capacity are investigated. According to the results, employing couple stress ferrofluid lubricant in the presence of the magnetic field leads to an increased performance of the squeeze film.

scholarly journals Thrust Bearing with Rough Surfaces Lubricated by an Ellis Fluid

2014 ◽  
Vol 19 (4) ◽  
pp. 809-822
Author(s):  
A. Walicka ◽  
E. Walicki ◽  
P. Jurczak ◽  
J. Falicki
Keyword(s):  
Pressure Distribution ◽  
Analytical Solutions ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Thrust Bearing ◽  
Equations Of Motion ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Plastic Fluid

Abstract In the paper the influence of bearing surfaces roughness on the pressure distribution and load-carrying capacity of a thrust bearing is discussed. The equations of motion of an Ellis pseudo-plastic fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and using the Christensen theory of hydrodynamic rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of a squeeze film bearing and an externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.

scholarly journals Mechanical Parameters of the Curvilinear Squeeze Film Bearing Lubricated by a Gecim-Winer Fluid

2017 ◽  
Vol 22 (2) ◽  
pp. 465-473
Author(s):  
A. Walicka ◽  
E. Walicki
Keyword(s):  
Fluid Flow ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Flow Model ◽  
Equations Of Motion ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Mechanical Parameters ◽  
Numerical Examples ◽  
Load Carrying

AbstractBased upon a Gecim-Winer fluid flow model, a curvilinear squeeze film bearing is considered. The equations of motion are given in a specific coordinates system. After general considerations on the Gecim-Winer fluid flow these equations are used to derive the Reynolds equation. The solution of this equation is obtained by a method of successive approximation. As a result one obtains formulae expressing the pressure distribution and load-carrying capacity. The numerical examples of the Gecim-Winer fluid flow in gaps of two simple bearings: radial and spherical are presented.

Effect of surface roughness on magneto-hydrodynamic squeeze-film characteristics between a sphere and a porous plane surface

2014 ◽  
Vol 66 (3) ◽  
pp. 365-372 ◽  
Author(s):  
Neminath Bhujappa Naduvinamani ◽  
Mareppa Rajashekar
Keyword(s):  
Surface Roughness ◽  
Response Time ◽  
Carrying Capacity ◽  
Hydrodynamic Lubrication ◽  
Plane Surface ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Content Type ◽  
Load Carrying ◽  
Film Characteristics

Purpose – The purpose of this article is to analyse the effects of surface roughness on the magneto-hydrodynamic (MHD) squeeze-film characteristics between a sphere and a porous plane surface, which have not been studied so far. Design/methodology/approach – The analytical model takes into account the effect of porosity by assuming that the flow in the porous matrix obeys modified Darcy's law. The stochastic MHD Reynold's type equation is derived by using the Christensen's stochastic method developed for hydrodynamic lubrication of rough surfaces. Two types of one-dimensional surface roughness (radial and azimuthal) patterns are considered. Findings – The expressions for the mean MHD squeeze-film pressure and mean load-carrying capacity are obtained numerically. The results are shown graphically for selected representative parametric values. It is found that the response time increases significantly for the MHD case as compared to the corresponding non-conducting lubricants. The effect of roughness parameter is to increase/decrease the load-carrying capacity and the response time for azimuthal/radial roughness patterns as compared to the smooth case. Also, the effect of porous parameter is to decrease the load-carrying capacity and response time as compared to the solid case. Originality/value – In this paper, an attempt has been made to analyse the combined effects of surface roughness and permeability on the MHD squeeze-film characteristics between a sphere and a plane surface.

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