scholarly journals Influence of viscosity variation on ferrofluid based long bearing

2022 ◽  
Vol 3 (1) ◽  
pp. 37-45
Author(s):  
Jimit Patel ◽  
◽  
G. M. Deheri ◽  
Keyword(s):  
Fluid Flow ◽  
Theoretical Analysis ◽  
Pressure Distribution ◽  
Magnetic Fluid ◽  
Carrying Capacity ◽  
Type Equation ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Viscosity Variation

This paper deals with a theoretical analysis on the effect of viscosity variation on a ferrofluid based long bearing. The model of Tipei considering viscosity variation is deployed here. The magnetic fluid flow is governed by Neuringer-Rosensweig model. The pressure distribution is obtained after solving the associated Reynolds type equation, which gives the load carrying capacity. The computed results indicate that the increased load carrying capacity owing to magnetization gets negligible help from the effect of viscosity variation.

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.

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.

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 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.

The Effects of Geometric Irregularities of Journals on the Performance of Porous Bearings

1994 ◽  
Vol 208 (2) ◽  
pp. 141-145 ◽  
Author(s):  
T S Chennabasavan ◽  
R Raman
Keyword(s):  
Theoretical Analysis ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Eccentricity Ratio ◽  
Attitude Angle ◽  
Load Carrying ◽  
Permeability Variation ◽  
Very High

In the theoretical analysis of porous bearings the journal has so far been assumed to be ideal, that is perfectly cylindrical. In the present analysis the geometric irregularities of the journal, such as circumferential undulations and barrel/bellmouth shapes, are taken into account. The permeability variation along the length of the bearing as found in commercial bearings has also been taken into account. The present analysis reveals that, at the critical Sommerfeld number, the friction is very low compared to the very high value for an ideal journal. The present analysis also reveals that the friction and the attitude angle are lower for any Sommerfeld number and that the load-carrying capacity is lower for any eccentricity ratio than that for an ideal journal.

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.

STABILITY PROBLEMS OF STEEL‐CONCRETE MEMBERS COMPOSED OF HIGH‐STRENGTH MATERIALS

2010 ◽  
Vol 16 (3) ◽  
pp. 352-362 ◽  
Author(s):  
Zdeněk Kala ◽  
Libor Puklický ◽  
Abayomi Omishore ◽  
Marcela Karmazínová ◽  
Jindřich Melcher
Keyword(s):  
Theoretical Analysis ◽  
Experimental Research ◽  
Carrying Capacity ◽  
High Strength ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Load Carrying ◽  
Geometrical Imperfections

The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utilization of the plastic reserve in the determination of the load carrying capacity of the analysed strut is shown. The influence of the initial geometric imperfections of initial strut curvature on the load carrying capacity is also presented. Santrauka Straipsnyje pateikta plienbetonio pastatu elementu didžiausiu ribiniu būkliu stochastine analize, analizuojama plienbetonio kolonu, sudarytu iš plieniniu profiliuočiu, padengtu didelio stiprio betonu, laikomoji galia gniuždant. Pirmoje straipsnio dalyje išvardytos kolonos teorines laikomosios galios nustatymo prielaidos. Tamprumo ir plastiškumo principai taikyti itempiams betono ir plieno skerspjūviuose nustatyti. Nustatytos medžiagu ir geometriniu defektu statistines charakteristikos, teorines analizes rezultatai palyginti su eksperimentiniu tyrimu rezultatais. Teorines analizes metu gautu rezultatu statistines charakteristikos patikrintos taikant iš eksperimentiniu tyrimu gautus statistinius rodiklius. Pritaikytas skaitinis modeliavimas LHS ir Monte Karlo metodais, kurie ivertina pradiniu defektu kintamumo itaka. Parodyta plastiškumo atsargos naudojimo itaka, nustatant analizuojamojo statramsčio laikomaja galia, pateikta pradinio statramsčio išlinkio pirminiu geometriniu defektu itaka laikomajai galiai.

An Approximate Solution for the Infinitely Long, Gas Lubricated Slider Bearing

1965 ◽  
Vol 87 (4) ◽  
pp. 1085-1086
Author(s):  
H. J. Sneck
Keyword(s):  
Exact Solution ◽  
Approximate Solution ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Load Carrying ◽  
Numerical Design ◽  
The One ◽  
Design Calculations

The only exact solution for the infinitely long, gas-lubricated slider bearing is the one obtained by Harrison [1] for the plane wedge isothermal film. The resultant formulas for the pressure distribution and load-carrying capacity are complicated and therefore quite cumbersome in numerical design calculations. In the analysis to follow, a simplified, approximate solution is developed which can be applied to any infinitely long slider geometry.

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.

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