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Transversely rough slider bearings with squeeze film formed by a magnetic fluid

Deheri G.M., Andharia P.I., Patel R.M.

International Journal of Applied Mechanics and Engineering

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2005

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Vol. 10, no 1

53-76

EN

In this article it has been sought to study the effect of transverse roughness on the behaviour of slider bearings with squeeze film formed by a magnetic fluid. The roughness of the bearing surface is modelled by a stochastic random variable with non zero mean, variance and skewness. The associated Reynolds' equation is stochastically averaged with respect to the random roughness parameter. Results for bearing performance characteristics such as load carrying capacity, center of pressure, frictional force and coefficient of friction for different values of mean, standard deviation and measure of symmetry are numerically computed. In order to decipher the quantitative effect of roughness on the performance characteristics four different shapes namely; plane slider, exponential slider, hyperbolic slider and secant slider for the lubricant film are considered. The results are presented graphically. It is noticed that the bearing suffers on account of transverse surface roughness. The results show that the use of a magnetic fluid as lubricant increases the load carrying capacity, decreases the coefficient of friction and affects the center of pressure marginally. It is further observed that the effect of magnetization on the plane and secant shaped bearings is nominal while the effect on exponential and hyperbolic slider bearing is significant. In addition it is easily seen that by increasing the strength of the magnetic field the adverse impact on the bearing due to roughness can be minimized.

2

Effect of longitudinal surface roughness on the behaviour of squeeze film in a spherical bearing

Andharia P. I., Deheri G. M., Gupta J. L.

International Journal of Applied Mechanics and Engineering

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2001

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Vol. 6, no 4

885-897

EN

Efforts have been made to study the effect of longitudinal surface roughness on the performance of a hydrodynamic squeeze-film between a non-rotating spherical surface and a hemispherical bearing under a steady load using the general stochastic analysis without using a specific probability distribution for describing random roughness, It is assumed that the bearing surface as well as the surface of the approaching sphere have random roughness, which is distributed throughout the surfaces. The stochastic film thickness characterizing the roughness is considered to be symmetric with non-zero mean ('alpha') and variance ('sigma'2). In order to get the expression for pressure the modified Reynolds equation is solved. Then by making use of this expression we obtain the expressions for load carrying capacity, which in turn is used to find the expression for response time. These expressions are numerically computed and the results are presented graphically as well as in tabular form. It is observed that the composite roughness of the surfaces affects the performance of the bearing significantly.

3

Effect of transverse surface roughness on the behaviour of squeeze film in a spherical bearing

Andharia P. I., Gupta J. L., Deheri G. M.

Applied Mechanics and Engineering

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1999

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Vol. 4, no spec.

19-24

EN

Effect of transverse roughness on the behaviour of a hydrodynamic squeeze film between a non-rotating spherical surface and a hemispherical bearing under a steady load is discussed. It is assumed that the bearing surface as well as the surface of the approaching sphere have random roughness which is distributed throughout the surfaces. The stochastic film thickness characterizing the roughness is assumed to be symmetric with non-zero mean (a) and variance (s2). The modified Reynolds equation is solved and then the expressions for pressure, load carrying capacity and the response time are obtained and numerically computed. The results are presented both in graphical as well as tabular form. It is observed that the composite roughness of the surfaces affects the performance of the bearing adversely.