Pressure generation in rough conical bearing using non-Newtonian Rabinowitsch fluid with variable viscosity

2019 ◽  
Vol 71 (3) ◽  
pp. 357-365 ◽  
Author(s):  
Pentyala Srinivasa Rao ◽  
Amit Kumar Rahul
Keyword(s):  
Surface Roughness ◽  
Response Time ◽  
Fluid Model ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Content Type ◽  
Pressure Load ◽  
Load Carrying ◽  
Conical Bearing ◽  
Viscosity Variation

Purpose This paper aims to investigate the effect of surface roughness (radial and azimuthal) and viscosity variation on a squeeze film of a conical bearing with a non-Newtonian lubricant by using Rabinowitsch fluid model. Design/methodology/approach The main objective is to determine the stochastic nonlinear modified Reynolds equation for rough conical bearing. Later, first-order closed-form solutions are obtained using a small perturbation method and are numerically solved using the Gauss quadrature method. Findings The findings of this paper, numerical calculations, are analyzed for pressure, load carrying capacity and response time. The simulated results indicate that the influence of surface roughness increases the pressure, load carrying capacity and response time, whereas the viscosity variation factor decreases the pressure, load and response time. Originality/value According to both types of surface roughness with viscosity variation, the performance of a squeeze film rough conical bearing was improved by using Rabinowitsch fluid model. As it is inevitable to consider viscosity variation for bearing designer, it leads to a long life period of conical bearing.

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.

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 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.

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.

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.

scholarly journals Combined Effect of Slip Velocity and Surface Roughness on a Magnetic Squeeze Film for a Sphere in a Spherical Seat

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
G. M. Deheri ◽  
Sejal J. Patel
Keyword(s):  
Surface Roughness ◽  
Slip Velocity ◽  
Type Equation ◽  
Velocity Slip ◽  
Performance Characteristics ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Slip Model ◽  
Load Carrying ◽  
Effect Of Surface

This investigation analyzes the performance of a magnetic fluid based squeeze film for a sphere in a rough spherical seat with slip velocity. The slip model of Beavers and Joseph has been deployed to study the effect of velocity slip while the stochastic model of Christensen and Tonder has been used to calculate the effect of surface roughness. The concerned statistically averaged Reynolds’ type equation is solved to derive the pressure distribution which results in the calculation of load carrying capacity. The results presented in graphical forms confirm that the adverse effect of slip velocity can be overcome to a large extent at least in the case of negatively skewed roughness. However, lower values of slip may be preferred for enhancing the performance characteristics of the bearing system. Besides, variance (−ve) provides a little support to improve the performance characteristics.

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.

Effects of piezo-viscous–coupled stress lubricant on the squeeze film performance of parallel triangular plates

2019 ◽  
Vol 234 (9) ◽  
pp. 1514-1521 ◽  
Author(s):  
H Aminkhani ◽  
M Daliri
Keyword(s):  
Pressure Distribution ◽  
Carrying Capacity ◽  
Couple Stress ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Film Performance ◽  
Pressure Dependency ◽  
Load Carrying ◽  
Viscosity Variation ◽  
Coupled Stress

The paper shows the combined effects of couple stress fluids and lubricant viscosity variation with pressure in squeeze film performance of parallel triangular plates. By solving Reynolds equation and using perturbation method, the pressure distribution is obtained with consideration of viscosity variation with pressure. Also, with integrating pressure in the film region, load-carrying capacity is derived. A fourth-order Rang–Kutta is used to solve the nonlinear differential equation between lubricant film thickness and time. Various cases of couple stress, iso-viscous and piezo-viscous contributions are analyzed. According to the results, it is found that using couple stress fluid as a lubricant and considering viscosity–pressure dependency will increase characteristics of the squeeze film such as load-carrying capacity, pressure distribution, and triangular plates moving time, significantly as compared to the classical Newtonian iso-viscous lubricant.

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.

scholarly journals EFFECT OF SURFACE ROUGHNESS ON CHARACTERISTICS OF MAGNETIC FLUID BASED SQUEEZE FILM BETWEEN POROUS CIRCULAR PLATES

2020 ◽  
Vol 14 (1) ◽  
pp. 90-98
Author(s):  
P. L. Thakkar ◽  
H. C. Patel
Keyword(s):  
Surface Roughness ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Type Equation ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Circular Plates ◽  
Load Carrying ◽  
Better Than ◽  
Effect Of Surface

The effect of surface roughness on characteristics of magnetic fluid based squeeze film between porous circular plates is hypothetically analysed. The pressure distribution is obtained by solving concern Reynolds type equation with suitable boundary conditions and the result is utilized to obtain load carrying capacity. It is concluded that the load carrying capacity increases with increasing magnetization, while load carrying capacity decreases due to the standard deviation. It is observed that the negatively skewed roughness and negative mean increase the load carrying capacity. It is also observed that the magnetic fluid lubricant improves the performance of a bearing system, thereby, suggesting that the performance of the bearing with magnetic fluid lubricant is better than the conventional lubricant.

Sign in / Sign up

Export Citation Format

Share Document