Performance of hydrostatic circular thrust pad bearing operating with Rabinowitsch fluid model

Abstract

Polymer-based additives such as poly isobutylene are blended with lubricating oil to enhance the lubricating performance of the base oil. The Rabinowitsch fluid model effectively describes the influence of polymer additives on the lubricating performance of a non-Newtonian (pseudoplastic) lubricant. This article deals with the analysis of a capillary compensated hydrostatic circular thrust pad bearing using Rabinowitsch fluid model. For a circular recess hydrostatic thrust bearing operating with pseudoplastic lubricant, the closed form expressions for load-carrying capacity, lubricant flow rate, fluid film stiffness coefficient and damping coefficient have been obtained using a small perturbation method. The close form solutions for different performance characteristic parameters have been compared with the results obtained from finite element method formulation. The numerically simulated results indicate that pseudoplastic parameter significantly affects the parameters of the bearing performance characteristics such as pocket pressure, lubricant flow rate, fluid film stiffness coefficient and damping coefficient. The value of the fluid film stiffness coefficient gets substantially increased with the pseudoplastic parameter whereas the value of damping coefficient gets reduced. The analytical results presented in this study can be used to obtain an optimum performance of a hydrostatic circular thrust pad bearing.