Fluid Flow and Thermal Features of Gas Foil Thrust Bearings at Moderate Operating Temperatures

摘要

This study aims to analyze the flow characteristics and the thermal features of foil thrust bearing. The flow in the gas film is modeled with 2D compressible Reynolds equation including effects of centrifugal forces in the gas film. The Couette Approximation is adopted for the analysis of temperature distribution in the gas film, and the small perturbations method is used to calculate its dynamic force coefficients. The results show that the Couette Approximation can be used to calculate the temperature distribution in foil thrust bearing with reasonable accuracy and the analysis of the fluid flow reveals that most of the side-leakage occurs in the low-temperature converging region removing less than 5 % of the heat generated in the gas film. Furthermore, with the proper control of cooling flow rate through the bump foils, more than 70 % of the heat generated in the gas film can be removed.