Load-Carrying Capacity Prediction of Magnetic Fluid Hydrodynamic Bearing Under External Magnetic Field

2021 ◽  
Vol 26 (1) ◽  
pp. 25-31
Author(s):  
Yaqi Zhao ◽  
Jianmei Wang ◽  
Dingbang Hou ◽  
Jinsheng Hou
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Hydrodynamic Bearing ◽  
Load Carrying ◽  
Capacity Prediction

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.

Analysis of Magneto Rheological Fluid Journal Bearing

2019 ◽  
Vol 895 ◽  
pp. 152-157 ◽  
Author(s):  
B. Narasimha Rao ◽  
A. Seshadri Sekhar
Keyword(s):  
Magnetic Field ◽  
Newtonian Fluid ◽  
Carrying Capacity ◽  
Smart Materials ◽  
Journal Bearing ◽  
Fluid Film ◽  
Load Carrying Capacity ◽  
Mr Fluid ◽  
Load Carrying ◽  
Magneto Rheological

Magneto Rheological (MR) fluids are a class of smart materials where the shear stress is not directly proportional to rate of shear. The viscosity of fluid changes as magnetic field changes and hence this phenomenon is very useful in bearing-rotor system for attenuating the vibrations. In the present study the application of MR fluid as lubricant instead of Newtonian fluid in the journal bearing is explored through steady state, dynamic characteristics and stability. MR fluid film has been modeled as per Bingham rheological model. FEM with three node triangular elements has been used to solve the Reynolds equation both for the Newtonian fluid film and MR fluid film. The results show the load carrying capacity in the case of MR fluid journal bearing is higher than that of using the Newtonian fluid. The load carrying capacity increases with the increasing magnetic field for all eccentricity ratios. The results also show better stability of the bearing using MR fluid at higher eccentricity ratios. The unbalance response of the rotor mounted on the journal bearing using MR fluid is also estimated to be lower than that of with the Newtonian fluid.

Theoretical and experimental investigation of the effect of oil aeration on the load-carrying capacity of a hydrodynamic journal bearing

2007 ◽  
Vol 221 (7) ◽  
pp. 779-786 ◽  
Author(s):  
M. J. Goodwin ◽  
D Dong ◽  
H Yu ◽  
J. L. Nikolajsen
Keyword(s):  
Carrying Capacity ◽  
Lubricating Oil ◽  
Hydrodynamic Effect ◽  
Air Bubbles ◽  
Load Carrying Capacity ◽  
Hydrodynamic Bearing ◽  
Low Viscosity ◽  
Discernible Effect ◽  
Load Carrying ◽  
Bearing Load

It is widely assumed that the presence of air bubbles in the lubricating oil of a hydrodynamic bearing gives rise to a reduced load-carrying capacity, because of the high compressibility and low viscosity of the air and its tendency, therefore, to upset the hydrodynamic effect. The aim of the work described in the current paper was to investigate the accuracy of this assumption by theoretical and experimental means, and also to provide quantitative data relating to the concentration of air bubbles and their size that are required for any discernible effect. The paper has the following three main contributions: (a) a theoretical model based on Reynolds equation, but modified to allow for the effect of aeration on lubricant viscosity and density, is proposed; (b) a novel method of injecting air bubbles into lubricating oil and for measuring their size and concentration was developed; and (c) an experimental hydrodynamic bearing test rig was implemented and run with both aerated and non-aerated lubricating oil, and in each case measurements of the load-carrying capacity for various operating speeds were made. The results from both theoretical and experiment work show that the presence of air bubbles in the lubricating oil leads to a slight decrease in bearing load-carrying capacity at high operating speeds. For normal operating speeds, however, (i.e. those resulting in eccentricity ratios greater than 0.6) results show that the presence of air bubbles has little effect on bearing load-carrying capacity.

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 Performance of a Ferrofluid Based Rough Parallel Plate Slider Bearing: A Comparison of Three Magnetic Fluid Flow Models

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jimit R. Patel ◽  
G. M. Deheri
Keyword(s):  
Fluid Flow ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Parallel Plate ◽  
Type Equation ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Flow Models ◽  
Load Carrying ◽  
Long Life

Efforts have been made to present a comparison of all the three magnetic fluid flow models (Neuringer-Rosensweig model, Shliomis model, and Jenkins model) so far as the performance of a magnetic fluid based parallel plate rough slider bearing is concerned. The stochastic model of Christensen and Tonder is adopted for the evaluation of effect of transverse surface roughness. The stochastically averaged Reynolds-type equation is solved with suitable boundary conditions to obtain the pressure distribution resulting in the calculation of load carrying capacity. The graphical results establish that for a bearing’s long life period the Shliomis model may be employed for higher loads. However, for lower to moderate loads, the Neuringer-Rosensweig model may be deployed.

APPLICATION OF THE MR LIQUIDS IN SEMI-ACTIVE CONTROL DEVICES

2003 ◽  
Vol 03 (01) ◽  
pp. 55-70 ◽  
Author(s):  
ALESSANDRO BARATTA ◽  
OTTAVIA CORBI
Keyword(s):  
Magnetic Field ◽  
Stress State ◽  
Control Systems ◽  
Carrying Capacity ◽  
Structural Control ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Control Devices ◽  
Semi Solid ◽  
Magneto Rheological

Magneto-rheological liquids are controllable liquids that under the action of a magnetic field can reversibly pass from the linear viscous liquid state with free-flow to the semi-solid one with a controlled stress-state. They are composed of typically non-colloidal magnetic micronized particles and possess a load carrying capacity higher than other, more controllable, fluids, such as electro-rheological liquids; moreover they are less sensitive to impurities and contaminations that may possibly occur in manufacturing. in the paper, the most suitable models for simulation of such devices are investigated with emphasis on evaluation of their efficiency as structural control systems.

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.

The Magnetohydrodynamic Parallel Plate Slider Bearing

1965 ◽  
Vol 87 (3) ◽  
pp. 778-780 ◽  
Author(s):  
D. C. Kuzma
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Carrying Capacity ◽  
Parallel Plate ◽  
Step Function ◽  
Load Carrying Capacity ◽  
Field Profile ◽  
Slider Bearing ◽  
Magnetic Field Profile ◽  
Load Carrying

The effect of a nonuniform applied magnetic field on the operation of a parallel plate slider bearing is investigated analytically. It is found that the optimum magnetic field profile is a step function. This profile increases the load-carrying capacity while decreasing the friction factor. Results indicate that the nonuniform applied magnetic field is definitely superior to the uniform applied magnetic field.

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