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Dynamic Performance Characteristics of a Curved Slider Bearing Operating with Ferrofluids

DOI: 10.1155/2012/278723

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Abstract:

In the present theoretical investigation, the effect of ferrofluid on the dynamic characteristics of curved slider bearings is presented using Shliomis model which accounts for the rotation of magnetic particles, their magnetic moments, and the volume concentration in the fluid. The modified Reynolds equation for the dynamic state of the bearing is obtained. The results of dynamic stiffness and damping characteristics are presented. It is observed that the effect of rotation of magnetic particles improves the stiffness and damping capacities of the bearings. 1. Introduction In the field of engineering and technology, slider bearings are often designed to bear the transverse loads. The study of performance characteristics of slider bearings with different shape and different lubricants has been done from time to time by the researchers. Gupta and Kavita [1] analysed the effect of frame rotation for porous slider bearing, Singh and Gupta [2] investigated the performance of a pivoted curved slider bearings for pseudoplastic and dilatant lubricants, Pascovici et al. [3] presented an experimental evidence of cavitation effects in a Rayleigh step slider, Venkateswarlu and Rodkiewicz [4] discussed the thrust bearing characteristics considering the terminal speed of the slider, Williams and Symmons [5] analysed the performance of hydrodynamic slider bearings for non-Newtonian lubricants, and Sharma and Pandey [6] presented an experimental comparison of the slider bearing performance for different shapes. In last few decades, the researches shown that the performances of the bearings can be improved, and enhanced pressure and load carrying capacity can be obtained by use of the magnetic lubricants and magnetic fields [7–10]. The applications of magnetic lubricant are widely found in dampers, seals, sensors, loudspeakers, gauges, steppers, and coating systems [11]. Investigators have used the Jenkins model [12] for the lubricant flow. On the other hand, Shliomis [13, 14] proposed a ferrofluid flow model, in which the effects of rotation of magnetic particles, their magnetic moments, and the volume concentration are included. Ram and Verma [15] used the Shliomis model to investigate the performance of a porous inclined slider bearing and reported an increased pressure and load capacity. Shah and Bhat [16] used this model to study the ferrofluid-based squeeze film characteristics of curved annular plates and obtained similar results. Yamaguchi [17] presented a detailed analysis and simplification of the Shliomis model for different lubricating conditions. Recently,

References

[1]  R. S. Gupta and P. Kavita, “Analysis of rotation in the lubrication of a porous slider bearing: small rotation,” Wear, vol. 111, no. 3, pp. 245–258, 1986.
[2]  U. P. Singh and R. S. Gupta, “On the performance of pivoted curved slider bearings: rabinowitsch fluid model,” in Proceedings of the National Tribology Conference (NTC '11), p. 24, IIT Roorkee, 2011.
[3]  M. D. Pascovici, A. Predescu, T. Cicone, and C. S. Popescu, “Experimental evidence of cavitational effects in a Rayleigh step slider,” Proceedings of the Institution of Mechanical Engineers, Part J, vol. 225, no. 6, pp. 527–537, 2011.
[4]  K. Venkateswarlu and C. M. Rodkiewicz, “Thrust bearing characteristics when the slider is approaching terminal speed,” Wear, vol. 67, no. 3, pp. 341–350, 1981.
[5]  P. D. Williams and G. R. Symmons, “Analysis of hydrodynamic slider thrust bearings lubricated with non-newtonian fluids,” Wear, vol. 117, no. 1, pp. 91–102, 1987.
[6]  R. K. Sharma and R. K. Pandey, “Experimental studies of pressure distributions in finite slider bearing with single continuous surface profiles on the pads,” Tribology International, vol. 42, no. 7, pp. 1040–1045, 2009.
[7]  V. K. Kapur, “Magneto-hydrodynamic pivoted slider bearing with a convex pad surface,” Japanese Journal of Applied Physics, vol. 8, no. 7, pp. 827–835, 1969.
[8]  M. E. Shimpi and G. M. Deheri, “A study on the performance of a magnetic fluid based squeeze film in curved porous rotating rough annular plates and deformation effect,” Tribology International, vol. 47, pp. 90–99, 2012.
[9]  N. C. Das, “A study of optimum load-bearing capacity for slider bearings lubricated with couple stress fluids in magnetic field,” Tribology International, vol. 31, no. 7, pp. 393–400, 1998.
[10]  R. B. Kudenatti, D. P. Basti, and N. M. Bujurke, “Numerical solution of the MHD reynolds equation for squeeze film lubrication between two parallel surfaces,” Applied Mathematics and Computation, vol. 218, pp. 9372–9382, 2012.
[11]  K. Raj, B. Moskowitz, and R. Casciari, “Advances in ferrofluid technology,” Journal of Magnetism and Magnetic Materials, vol. 149, no. 1-2, pp. 174–180, 1995.
[12]  J. T. Jenkins, “A theory of magnetic fluids,” Archive for Rational Mechanics and Analysis, vol. 46, no. 1, pp. 42–60, 1972.
[13]  M. I. Shliomis, “Effective viscosity of magnetic suspensions,” Soviet Physics, vol. 34, pp. 1291–1294, 1972.
[14]  M. I. Shliomis, “Magnetic fluids,” Soviet Physics, vol. 17, pp. 153–169, 1974.
[15]  P. Ram and P. D. S. Verma, “Ferrofluid lubrication in porous inclined slider bearing,” Indian Journal of Pure and Applied Mathematics, vol. 30, no. 12, pp. 1273–1281, 1999.
[16]  R. C. Shah and M. V. Bhat, “Ferrofluid squeeze film between curved annular plates including rotation of magnetic particles,” Journal of Engineering Mathematics, vol. 51, no. 4, pp. 317–324, 2005.
[17]  H. Yamaguchi, Engineering Fluid Mechanics, Springer, Amsterdam, The Netherlands, 2008.
[18]  J. R. Lin, “Derivation of ferrofluid lubrication equation of cylindrical squeeze films with convective fluid inertia forces and application to circular disks,” Tribology International, vol. 49, pp. 110–115, 2012.
[19]  S. Abramovitz, “Theory for a slider bearing with a convex pad surface; side flow neglected,” Journal of the Franklin Institute, vol. 259, no. 3, pp. 221–233, 1955.
[20]  C. M. Taylor and D. Dowson, “Turbulent lubrication theory—application to design,” Journal of Lubrication Technology, vol. 96, no. 1, pp. 36–47, 1974.

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