Elasto-gasdynamic modeling of air foil thrust bearings with a two-dimensional shell model for top and bump foil

Abstract

Performance of air foil thrust bearings is strongly influenced by the stiffness characteristics of the foil structure. In this paper, a fully coupled elasto-gasdynamic model for air foil thrust bearings is presented. Top and bump foil are modeled as two-dimensional thick shells including shear, membrane, and bending effects. A penalty type contact model and Coulomb friction are used for the contact between the foils. Stiffening effects due to interacting forces and bending moments are discussed. Fundamental differences between straight and curved bump strips are found. The influence of different foil models on the pressure distribution is analyzed. Applicability of reduced foil models is evaluated on the basis of the presented detailed shell model.