scholarly journals Numerical Modelling of Squeeze Film Performance between Rotating Transversely Rough Curved Circular Plates under the Presence of a Magnetic Fluid Lubricant

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Nikhilkumar D. Abhangi ◽  
G. M. Deheri
Keyword(s):  
Magnetic Fluid ◽  
Random Variable ◽  
Squeeze Film ◽  
Circular Plates ◽  
Random Roughness ◽  
Load Carrying ◽  
Nonzero Mean ◽  
Mean Variance ◽  
Positive Effect ◽  
Bearing System

An endeavour has been made to study and analyze the behaviour of a magnetic fluid-based squeeze film between curved transversely rough rotating circular plates when the curved upper plate lying along a surface determined by an exponential function approaches the curved lower plate along the surface governed by a secant function. A magnetic fluid is used as the lubricant in the presence of an external magnetic field oblique to the radial axis. The random roughness of the bearing surfaces is characterised by a stochastic random variable with nonzero mean, variance, and skewness. The associated nondimensional averaged Reynolds equation is solved with suitable boundary conditions in dimensionless form to obtain the pressure distribution, leading to the expression for the load carrying capacity. The results establish that the bearing system registers an enhanced performance as compared to that of the bearing system dealing with a conventional lubricant. This investigation proves that albeit the bearing suffers due to transverse surface roughness, there exist sufficient scopes for obtaining a relatively better performance in the case of negatively skewed roughness by properly choosing curvature parameters and the rotation ratio. It is appealing to note that the negative variance further enhances this positive effect.

scholarly journals Performance of Magnetic-Fluid-Based Squeeze Film between Longitudinally Rough Elliptical Plates

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
P. I. Andharia ◽  
G. M. Deheri
Keyword(s):  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Random Variable ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Axially Symmetric ◽  
Load Carrying ◽  
Mean Variance ◽  
Bearing System ◽  
Oblique Magnetic Field

An attempt has been made to analyze the performance of a magnetic fluid-based-squeeze film between longitudinally rough elliptical plates. A magnetic fluid is used as a lubricant while axially symmetric flow of the magnetic fluid between the elliptical plates is taken into consideration under an oblique magnetic field. Bearing surfaces are assumed to be longitudinally rough. The roughness of the bearing surface is characterized by stochastic random variable with nonzero mean, variance, and skewness. The associated averaged Reynolds’ equation is solved with appropriate boundary conditions in dimensionless form to obtain the pressure distribution leading to the calculation of the load-carrying capacity. The results are presented graphically. It is clearly seen that the magnetic fluid lubricant improves the performance of the bearing system. It is interesting to note that the increased load carrying capacity due to magnetic fluid lubricant gets considerably increased due to the combined effect of standard deviation and negatively skewed roughness. This performance is further enhanced especially when negative variance is involved. This paper makes it clear that the aspect ratio plays a prominent role in improving the performance of the bearing system. Besides, the bearing can support a load even when there is no flow.

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 Magnetic Fluid-Based Squeeze Film Behaviour in Curved Porous-Rotating Rough Annular Plates and Elastic Deformation Effect

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
M. E. Shimpi ◽  
G. M. Deheri
Keyword(s):  
Elastic Deformation ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Random Variable ◽  
Squeeze Film ◽  
Rotational Inertia ◽  
Load Carrying Capacity ◽  
Annular Plates ◽  
Load Carrying ◽  
Transverse Roughness

Efforts have been directed to study and analyze the squeeze film performance between rotating transversely rough curved porous annular plates in the presence of a magnetic fluid lubricant considering the effect of elastic deformation. A stochastic random variable with nonzero mean, variance, and skewness characterizes the random roughness of the bearing surfaces. With the aid of suitable boundary conditions, the associated stochastically averaged Reynolds' equation is solved to obtain the pressure distribution in turn, which results in the calculation of the load-carrying capacity. The graphical representations establish that the transverse roughness, in general, adversely affects the performance characteristics. However, the magnetization registers a relatively improved performance. It is found that the deformation causes reduced load-carrying capacity which gets further decreased by the porosity. This investigation tends to indicate that the adverse effect of porosity, standard deviation and deformation can be compensated to certain extent by the positive effect of the magnetic fluid lubricant in the case of negatively skewed roughness by choosing the rotational inertia and the aspect ratio, especially for suitable ratio of curvature parameters.

Magnetic Fluid Lubrication of a Rough, Porous Composite Slider Bearing

2013 ◽  
Vol 1 (2) ◽  
pp. 46-65 ◽  
Author(s):  
N. D. Patel ◽  
G. M. Deheri ◽  
H. C. Patel
Keyword(s):  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Roughness Parameter ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Porous Composite ◽  
Random Roughness ◽  
Load Carrying ◽  
Negative Effect ◽  
Mean Variance

The purpose of this paper is to analyse the performance of a magnetic fluid based rough, porous composite slider bearing. The bearing surfaces are assumed to be transversely rough. The random roughness of the surfaces is characterized by a stochastical variance with non zero mean, variance and skewness. The associated Reynolds Equation is stochastical averaged with respect to this random roughness parameter solving this Equation in view of suitable boundary conditions. The expression for pressure distribution is obtained leading to the calculation of load carrying capacity. Friction is also computed. It is clearly observed that the load carrying capacity increases due to the magnetization parameter and the bearing surfaces owing to transverse surface roughness in general. However this investigation offers some scope to mitigate the negative effect of roughness by the magnetic fluid lubrication at least in the case of negatively skewed roughness. It is interesting to note that the magnetization fails to alter the friction.

Magnetic fluid‐based squeeze film between porous rotating rough circular plates

2009 ◽  
Vol 61 (3) ◽  
pp. 140-145 ◽  
Author(s):  
Himanshu Patel ◽  
Gunamani M. Deheri ◽  
Rakesh M. Patel
Keyword(s):  
Magnetic Fluid ◽  
Squeeze Film ◽  
Circular Plates

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 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.

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.

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