Analysis of the influence of fluid temperature variation on the behavior of turbocharger lubricated thrust bearings

Abstract

This work aims to analyse the influence of the temperature and the viscosity variation of the lubricant fluid on the behavior of fixed-geometry thrust bearings. For this purpose, a numerical thermohydrodynamic (THD) model, based on the solution of the Generalized Reynolds’ Equation and of the Energy Equation, was developed, enabling the calculation of both pressure and temperature distribution along the fluid film. The influence of heat exchange in the radial direction is analysed by comparing the results of two different THD models: one considering heat exchanges in all directions; another considering heat exchanges only in two directions (circumferential direction and across the film). The results of load capacity of the bearing and its dynamic coefficients are compared to the obtained by a purely hydrodynamic (HD) model. The influence of speed and minimum film thickness on the behavior of the system is also evaluated.