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 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.

scholarly journals Jenkins model based ferrofluid lubrication of a curved rough annular squeeze film: Effect of slip velocity

2015 ◽  
Vol 42 (1) ◽  
pp. 53-71
Author(s):  
Jimit Patel ◽  
G.M. Deheri
Keyword(s):  
Surface Roughness ◽  
Slip Velocity ◽  
Type Equation ◽  
Stochastic Averaging ◽  
Combined Effect ◽  
Squeeze Film ◽  
Model Based ◽  
Squeeze Film Effect ◽  
Load Carrying ◽  
Transverse Roughness

This paper analyzes the combined effect of slip velocity and transverse roughness on the performance of a Jenkins model based ferrofluid lubrication of a squeeze film in curved rough annular plates. The slip model of Beavers and Joseph has been invoked to evaluate the effect of slip velocity. In order to find the effect of surface roughness the stochastic averaging model of Christensen and Tonder has been used. The pressure distribution is obtained by solving the concerned stochastically averaged Reynolds type equation. The load carrying capacity is calculated. The graphical representations of the results indicate that the effect of transverse surface roughness is adverse in general, however, the situation is relatively better in the case of negatively skewed roughness. Further, Jenkins model based ferrofluid lubrication offers some measures in reducing the adverse effect of roughness when slip parameter is kept at reduced level with a suitable ratio of curvature parameters. Lastly, the positive effect of magnetization gets a boost due to the combined effect of variance (-ve) and negatively skewed roughness suitably choosing the aspect ratio.

scholarly journals Combined Effect of Surface Roughness and Slip Velocity on Jenkins Model Based Magnetic Squeeze Film in Curved Rough Circular Plates

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jimit R. Patel ◽  
Gunamani Deheri
Keyword(s):  
Surface Roughness ◽  
Slip Velocity ◽  
Type Equation ◽  
Squeeze Film ◽  
Circular Plates ◽  
Model Based ◽  
Load Carrying ◽  
Curvature Parameter ◽  
Hyperbolic Form ◽  
Magnetic Strength

This paper aims to discuss the effect of slip velocity and surface roughness on the performance of Jenkins model based magnetic squeeze film in curved rough circular plates. The upper plate’s curvature parameter is governed by an exponential expression while a hyperbolic form describes the curvature of lower plates. The stochastic model of Christensen and Tonder has been adopted to study the effect of transverse surface roughness of the bearing surfaces. Beavers and Joseph’s slip model has been employed here. The associated Reynolds type equation is solved to obtain the pressure distribution culminating in the calculation of load carrying capacity. The computed results show that the Jenkins model modifies the performance of the bearing system as compared to Neuringer-Rosensweig model, but this model provides little support to the negatively skewed roughness for overcoming the adverse effect of standard deviation and slip velocity even if curvature parameters are suitably chosen. This study establishes that for any type of improvement in the performance characteristics the slip parameter is required to be reduced even if variance (−ve) occurs and suitable magnetic strength is in force.

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.

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.

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.

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 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 Influence of Ferrofluid Lubrication on Longitudinally Rough Truncated Conical Plates with Slip Velocity

2019 ◽  
Vol 7 (2) ◽  
pp. 93-101
Author(s):  
M M Munshi ◽  
A R Patel ◽  
G M Deheri
Keyword(s):  
Surface Roughness ◽  
Bearing Capacity ◽  
Slip Velocity ◽  
Performance Enhancement ◽  
Positive Impact ◽  
Squeeze Film ◽  
Bottom Plate ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Load Carrying

The study focuses on analyzing the effect of slip velocity in the case of a Ferrofluid squeeze film when the surface of truncated cone-shaped plates has a longitudinal roughness. Each oblique to the bottom plate was utilized by the external magnetic field. The bearing surface has a roughness that is designed with the help of a random stochastic variable having a nonzero mean, skewness and variance. The load carrying ability of a bearing system’s surface is determined by calculating the dispersal of pressure in the system, which is calculated by using the associated stochastically average Reynolds’ equation. The graphs obtained from the study shows that there is a correlation between the longitudinal surface roughness and the bearing system performance. The magnetic fluid lubrication has a positive impact on a system’s bearing capacity. However, the load bearing capacity declines as a result of the effect of slip. A high negative skewness of the surface roughness also has a positive impact on a bearing’s load carrying capacity. One interesting finding shows that contrasting to the results of transverse roughness, standard deviation positively impacts the load bearing capacity. This investigation suggests despite the im-portance of aspect ratio and semi vertical angle is significant for performance enhancement, it is also essential to maintain the slip at the lowest level.

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