Analysis of an Aerodynamic Compliant Foil Thrust Bearing: Method for a Rapid Design

Abstract

A very simple design method for an aerodynamic compliant foil thrust bearing is presented in this paper. It is based on 3D modeling (called: complete direct calculation) of the elastoaerodynamic problem. In this approach, the structural analysis has been simplified. This enables the calculation to be carried out faster. However this model, based on the resolution of the Reynolds equation, only gives the performance of a thrust bearing for a given geometric profile. An efficient method for solving the inverse problem for predicting the desired bearing performance parameters is presented. The complete direct calculation is only used to improve the profile geometry thus found. Finally, the proposed method has been applied for the design of a 80 mm outer diameter 40 mm inner diameter thrust bearing operating between 20,000 and 50,000 rpm. It is shown that the thrust bearing designed by this approach has a high load capacity (300 kPa) at a speed of 50,000 rpm. It is also shown that the predicted performance of the bearing agrees well with the complete direct calculation.