Magnetic Fluid-Based Squeeze Film Performance in Rotating Curved Porous Circular Plates: The Effect of Deformation and Surface Roughness

This investigation aims at analyzing the behaviour of a magnetic fluid based squeeze film between two rotating transversely rough porous circular plates taking bearing deformation into consideration. The results presented in graphical form inform that the transverse surface roughness introduces an adverse effect on the performance characteristics while the magnetic fluid lubricant turn in an improved performance. It is found that the combined effect of rotation and deformation causes significantly reduced load carrying capacity. However, this investigation establishes that the adverse effect of porosity, deformation and standard deviation can be compensated up to some extent by the positive effect of magnetic fluid lubricant in the case of negatively skewed roughness by choosing curvature parameters. To compensate, the rotational inertia needs to have smaller values

Hydromagnetic Short Bearing

This article deals with the performance of a hydromagnetic short porous bearing. An electrically conducting lubricant in the presence of a transverse magnetic field has been taken into consideration while the plates are electrically conducting. The related Reynolds’ equation governing the fluid film pressure is solved under suitable boundary conditions to get the pressure distribution leading to the computation of load carrying capacity. The results presented in graphical form establish that the bearing system registers an improved performance due to hydromagnetization. Besides, the load carrying capacity increases considerably with respect to the conductivity. It is revealed that the negative effect of porosity and the ratio of breadth to height can be neutralized up to a considerable extent by the positive effect of hydromagnetization suitably choosing the plate conductivity and the aspect ratio. It is found that the hydromagnetization presents the friction at both the plates to be equal

Jenkins Model Based Ferrofluid Lubrication of a Curved Rough Annular Squeeze Film with Slip Velocity

This paper deals with the combined effect of roughness and slip velocity on the performance of a Jenkins model based ferrofluid squeeze film in curved annular plates. Beavers and Joseph’s slip model has been adopted to incorporate the effect of slip velocity. The stochastic model of Christensen and Tonder has been deployed to evaluate the effect of surface roughness. The associated stochastically averaged Reynolds type equation is solved to derive the pressure distribution, leading to the calculation of load carrying capacity. The graphical representation makes it clear that although, the effect of transverse surface roughness is adverse in general, Jenkins model based ferrofluid lubrication provides some measures in mitigating the adverse effect and this becomes more manifest when the slip parameter is reduced and negatively skewed roughness occurs. Of course, a judicious choice of curvature parameters and variance (-ve) add to this positive effect

Shliomis model based ferrofluid lubrification of a rough, porous parallel slider bearing with slip velocity

International journal of engineering and industrial management. - ISSN 1645-8915. - N. 4 (2012). - p. 105-127.This study aims to analyze the performance of a transversely rough porous parallel slider bearing under the presence of a magnetic fluid lubricant flowing as par Shliomis model, taking velocity slip in to account. The associated stochastically averaged Reynolds equation is solved to get the pressure distribution thereby leading to the calculation of load carrying capacity. Further, the friction is computed. THe results show that magnetization not only increases the load carrying capacity but also increases the friction. But the slip parameter decreases the load carrying capacity as well as the friction. Besides, it is noticed that the standarddeviation and the positively skewed roughness decrease the friction. It becomes clear from this investigation that the magnetization can minimize the adverse effect of roughness up to some extent when relatively small values of the slip parameter are involved. A comparison of this investigation with the Neuringer-Rosensweig model indicates that the reduction of the adverse effect of roughness is comparatively more here. This article makes it clear that the bearing can support a load even where there is no flow

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

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

Squeeze film between porous rough elliptical plates

This paper concerns the study of the effect of surface roughness on the performance of the squeeze film formed when the upper plate with a porous facing approached an impermeable and flat lower plate. The bearing surfaces are assumed to be transversely rough. The roughness of the bearing surface is described by a stochastic random variable with non zero mean, variance and skew ness. The associated Reynolds’ equation is solved with appropriate boundary conditions. Results for bearing performance characteristics such as load carrying capacity and response time for different values of mean, standard deviation and measure of symmetry are numerically computed and the same are presented graphically as well as in tabular form. It is observed that more or less the bearing suffers because of transverse surface roughness. However, negatively skewed roughness may enhance the performance of the bearing system for suitable choices of variance. Further, the performance of the bearing system registers a steady improvement with the increasing values of the aspect ratio. Even the negative variance may lead to a better performance. In addition, the response time adopts the trends of the load carrying capacity. This article reveals that the aspect ratio has a strong effect on the performance of the bearing system. The investigation conducted in this article suggests that the roughness must be accounted for while designing the bearing system even though there is the occurrence of a suitable aspect ratio.Key words: Reynolds equation, random roughness, squeeze film, pressure, load carrying capacit

Shliomis Model Based Ferrofluid Lubrication of a Rough Porous Convex Pad Slider Bearing

An attempt has been made to analyze the performance characteristics of a Shliomis model based ferrofluid lubrication of a rough porous convex pad slider bearing. Regarding roughness, the stochastic method adopted by Christensen and Tonder finds the application here in statistical averaging of the associated Reynolds equation. The graphical representation suggests that the adverse effect of surface roughness can be reduced to certain extent by the positive effect of Shliomis model based ferrofluid lubrication. Further, for this type of bearing system, this model remains more effective as compared to Neuringer-Rosensweig model