A fluid-structure-thermal model for bump-type foil thrust bearings

This paper presents a multi-physics multi-timescale computational framework for the three-dimensional and two-way coupled fluid-structure-thermal simulation of foil thrust bearings. Individual solvers for the transient fluid flow, structural deformation, heat conduction and the coupling strategy are discussed. Next, heat transfer models of the solid structures within foil thrust bearings are also described in detail. The result is a multi-physics computational framework that can predict the steady state and dynamic performance of foil thrust bearings. Numerical simulations of foil thrust bearings with air and CO2 are then performed. It is found that the centrifugal pumping that naturally occurs in CO2 bearings due to the high fluid density provides a new and effective cooling mechanism for the CO2 bearing.