Magnetic fluid based squeeze film between porous rough conical plates

Abstract

We make an endeavor to study and analyze the effect of surface roughness on the performance of a magnetic fluid based squeeze film between conical plates. The lubricant used here is a magnetic fluid and the external magnetic field is oblique to the lower plate. The bearing surfaces are assumed to be transversely rough. The roughness of the bearing surface is modeled by a stochastic random variable with non-zero mean variance and skew-ness. The associated Reynolds' equation is solved with appropriate boundary conditions to get the pressure distribution, which is, then used to obtain the expression for load carrying capacity leading to the computation of the response time. The results are presented graphically as well as in tabular form. It is noticed that although the bearing suffers owing to transverse surface roughness, the load carrying capacity registers an increase in the case of negatively skewed roughness. Even the negative variance causes an increase in the load carrying capacity. It is observed that the reduction in the load carrying capacity induced by the porosity and the standard deviation can be neutralized up to certain extent by the positive effect of the magnetization parameter μ^* with suitable values of the semi-vertical angle ω in the case of negatively skewed roughness. A close scrutiny of some of the results presented graphically makes it clear that the positive effect of variance dominates the effect of the skew-ness whose impact is slightly better than that of the magnetization parameter. It is needless to say that the performance of the rough bearing with the magnetic fluid lubricant is definitely better than the one with conventional lubricant. This article reveals that there is a scope for enhancing the performance of the bearing system considerably by choosing a suitable combination of the magnetization parameter and semi-vertical angle of the cone in the case of negatively skewed roughness especially when negative variance is involved.