The Finite Magnetohydrodynamic Journal Bearing

1964 ◽  
Vol 86 (3) ◽  
pp. 445-448 ◽  
Author(s):  
D. C. Kuzma
Keyword(s):  
Magnetic Field ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Numerical Data ◽  
Load Carrying Capacity ◽  
Radial Magnetic Field ◽  
Electrically Conducting ◽  
Load Carrying ◽  
The Magnetic Field

An analysis of a finite journal bearing is presented for the case of an electrically conducting fluid in the presence of a radial magnetic field. The magnetohydrodynamic form of the two-dimensional Reynolds equation is derived and solved numerically for the pressure distribution. The load-carrying capacity and torque are determined from the pressure distribution. Numerical data for nonconducting bearing surfaces are compared with the data from the ordinary journal bearing. It is shown that the load-carrying capacity and torque are increased by the application of the magnetic field.

The Magnetohydrodynamic Journal Bearing

1963 ◽  
Vol 85 (3) ◽  
pp. 424-427 ◽  
Author(s):  
Dennis C. Kuzma
Keyword(s):  
Magnetic Field ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Numerical Data ◽  
Conducting Fluid ◽  
Load Carrying Capacity ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Load Carrying

An analysis of an infinite journal bearing is presented for the case of an electrically conducting fluid in the presence of a magnetic field. The magnetohydrodynamic form of Reynolds’ bearing equation is derived and solved for the pressure distribution. The load carrying capacity is determined from the pressure distribution. Numerical data are presented for nonconducting bearing surfaces. These data are compared with the data from the ordinary journal bearing. It is shown that the load carrying capacity is increased by the application of a magnetic field.

The Magnetohydrodynamic Slider Bearing

1962 ◽  
Vol 84 (1) ◽  
pp. 197-202 ◽  
Author(s):  
William T. Snyder
Keyword(s):  
Magnetic Field ◽  
Liquid Metal ◽  
Boundary Conditions ◽  
Carrying Capacity ◽  
Load Capacity ◽  
Numerical Data ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Electrically Conducting ◽  
Load Carrying

An analysis is presented of the slider bearing using an electrically conducting lubricant, such as a liquid metal, in the presence of a magnetic field. The solution permits the calculation of the load-carrying capacity of the bearing. A comparison is made with the classical slider bearing solution. It is shown that the load capacity of the bearing depends on the electromagnetic boundary conditions entering through the conductivity of the bearing surfaces. Numerical data are presented for nonconducting surfaces with the emphasis on a comparison between the classical bearing and the magnetohydrodynamic bearing characteristics. It is shown that a significant increase in load capacity is possible with liquid metal lubricants in the presence of a magnetic field.

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.

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.

Some Characteristics of a Full Journal Bearing Lubricated With Electroconducting Gases

1969 ◽  
Vol 91 (1) ◽  
pp. 199-202
Author(s):  
M. V. Korovchinski
Keyword(s):  
Electric Field ◽  
Pressure Distribution ◽  
Electric Fields ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Load Carrying Capacity ◽  
Ionized Gas ◽  
Lubricating Film ◽  
Neutral Gas ◽  
Load Carrying

The behavior of an infinitely long journal bearing using an ionized gas lubricant in which a magnetic field is applied axially and an electric field is applied transversely to the fluid film is investigated theoretically. It is found that in the absence of an applied electric field the behavior of the bearing with the ionized gas is not much different from that of a bearing using a neutral gas even at large Hartmann numbers. However, by application of the crossed magnetic and electric fields the pressure distribution in the lubricating film can be altered significantly. Various curves showing the effect of the Hartmann, Hughes, and Harrison numbers on the pressure distribution, film load-carrying capacity, and the locus of the journal center in the bearing are presented and discussed.

scholarly journals Numerical Study of Surface Roughness and Magnetic Field between Rough and Porous Rectangular Plates

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ramesh B. Kudenatti ◽  
Shalini M. Patil ◽  
P. A. Dinesh ◽  
C. V. Vinay
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Hartmann Number ◽  
Numerical Study ◽  
Mathematical Formulation ◽  
Load Carrying Capacity ◽  
Parallel Plates ◽  
Load Carrying

This paper theoretically examines the combined effects of surface roughness and magnetic field between two rectangular parallel plates of which the upper plate has roughness structure and the lower plate has porous material in the presence of transverse magnetic field. The lubricating fluid in the film region is assumed to be Newtonian fluid (linearly viscous and incompressible fluid). This model consists of mathematical formulation of the problem with appropriate boundary conditions and solution numerically by finite difference based multigrid method. The generalized average modified Reynolds equation is derived for longitudinal roughness using Christensen’s stochastic theory which assumes that the height of the roughness asperity is of the same order as the mean separation between the plates. We obtain the bearing characteristics such as pressure distribution and load carrying capacity for various values of roughness, Hartmann number, and permeability parameters. It is observed that the pressure distribution and load carrying capacity were found to be more pronounced for increasing values of roughness parameter and Hartmann number; whereas these are found to be decreasing for increasing permeability compared to their corresponding classical cases. The physical reasons for these characters are discussed in detail.

Magnetohydrodynamic Journal Bearing (Report 1)

1969 ◽  
Vol 91 (3) ◽  
pp. 380-386 ◽  
Author(s):  
S. Kamiyama
Keyword(s):  
Journal Bearing ◽  
Load Capacity ◽  
External Loading ◽  
Load Carrying Capacity ◽  
Radial Magnetic Field ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Load Carrying ◽  
Pressure Region ◽  
Driving Torque

A theoretical analysis of an infinite full journal bearing is presented for the case of an electrically conducting fluid in the presence of a radial magnetic field. The analysis is based on general external loading conditions. The pressure distribution is obtained under the Reynolds’ boundary conditions in which the cavitation occurrence in the low-pressure region is taken into account. The characteristics of the magnetohydrodynamic journal bearing, namely, load-carrying capacity, altitude angle, and journal driving torque are determined. Furthermore the influence of the wall properties on the load capacity is clearly shown.

scholarly journals Load and stiffness of a planar ferrofluid pocket bearing

2017 ◽  
Vol 232 (1) ◽  
pp. 14-25 ◽  
Author(s):  
SGE Lampaert ◽  
JW Spronck ◽  
RAJ van Ostayen
Keyword(s):  
Magnetic Field ◽  
High Precision ◽  
Carrying Capacity ◽  
Viscous Friction ◽  
Load Carrying Capacity ◽  
Stick Slip ◽  
Hydrostatic Bearing ◽  
Load Carrying ◽  
Stiffness Characteristics ◽  
The Magnetic Field

A ferrofluid pocket bearings is a type of hydrostatic bearing that uses a ferrofluid seal to encapsulate a pocket of air to carry a load. Their properties, combining a high stiffness with low (viscous) friction and absence of stick-slip, make them interesting for applications that require fast and high precision positioning. Knowledge on the exact performance of these types of bearings is up to now not available. This article presents a method to model the load carrying capacity and normal stiffness characteristics of this type of bearings. Required for this is the geometry of the bearing, the shape of the magnetic field and the magnetization strength of the fluid. This method is experimentally validated and is shown to be correct for describing the load and stiffness characteristics of any fixed shape of ferrofluid pocket bearing.

The Granular Lubricated Journal Bearing: Evidence of Lift Formation

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Venkata K. Jasti ◽  
Martin C. Marinack ◽  
Deepak Patil ◽  
C. Fred Higgs
Keyword(s):  
Carrying Capacity ◽  
Granular Flow ◽  
High Speed ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Flow Behavior ◽  
Extreme Environments ◽  
Granular Flows ◽  
Load Carrying Capacity ◽  
Load Carrying

This work demonstrates that granular flows (i.e., macroscale, noncohesive spheres) entrained into an eccentrically converging gap can indeed actually exhibit lubrication behavior as prior models postulated. The physics of hydrodynamic lubrication is quite well understood and liquid lubricants perform well for conventional applications. Unfortunately, in certain cases such as high-speed and high-temperature environments, liquid lubricants break down making it impossible to establish a stable liquid film. Therefore, it has been previously proposed that granular media in sliding convergent interfaces can generate load carrying capacity, and thus, granular flow lubrication. It is a possible alternative lubrication mechanism that researchers have been exploring for extreme environments, or wheel-regolith traction, or for elucidating the spreadability of additive manufacturing materials. While the load carrying capacity of granular flows has been previously demonstrated, this work attempts to more directly uncover the hydrodynamic-like granular flow behavior in an experimental journal bearing configuration. An enlarged granular lubricated journal bearing (GLJB) setup has been developed and demonstrated. The setup was made transparent in order to visualize and video capture the granular collision activity at high resolution. In addition, a computational image processing program has been developed to process the resulting images and to noninvasively track the “lift” generated by granular flow during the journal bearing operation. The results of the lift caused by granular flow as a function of journal rotation rate are presented as well.

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