Performance of hybrid thrust bearing textured surface operating with electro-rheological lubricant

Abstract

This article concerns with the numerical simulations of textured surface hybrid thrust bearings operating with Electro-rheological (ER) lubricant. An ER fluid comprises dielectric particles suspended in an insulating viscous medium. Electrorheological (ER) lubricants are considered smart lubricants. Reynold's equation is used to model the flow of an ER lubricant in textured surface thrust bearings. The texture is provided as hemispherical, cylindrical, elliptical, and square shape micro-depression oriented along the circumferential and radial direction. The Patir and Cheng model is used to describe micro-roughness on a thrust pad. The continuous Bingham model is used to define the viscosity of the ER lubricant in terms of yielding stress, electric field, and shear-strain rate. The Reynolds equation is solved by applying the finite element method to obtain film pressure, load-supporting capacity, frictional power loss, film stiffness, and damping parameters. The texture shapes are optimized for dimple size, depth, and length for getting maximum load-supporting capacity and stiffness coefficient, and minimum frictional power loss. The numerical results predicted an enhancement in the load-supporting capacity (+257.3%) and film stiffness parameters (+323.2%) owing to the synergistic use of ER lubricant and optimized geometric parameters of square/elliptical dimples. The frictional power loss was reported to reduce significantly (−48.8%) by the use of micro-dimples. The application of ER lubricant was also found to slightly enhance (+4.3%) the frictional power loss in textured bearings. The transverse surface roughness vis-à-vis smooth surface is observed to improve the load-supporting capacity, stiffness, and damping parameters of textured surface bearings.