Design of flat pad aerostatic bearings with the aid of finite element analysis

A need has been recognised for an aerostatic, flat pad bearing design procedure that has the simplicity of use of design charts, whilst retaining the accuracy offered by finite difference or finite element models. To meet this requirement a finite element code has been combined with the automatic mesh generation procedure described here. The results provided by this code for a range of bearing designs are also presented. It is shown that the identification of an optimum pressure ratio is more complex than with journal bearings, due to the lack of a natural, concentric position and the variation in pressure ratio over a number of orifices. It is concluded that the multi-criteria nature of the bearing design problem should be taken into account at an early stage. A code capable of determining a Pareto optimal but criteria constrained set of bearing designs is proposed.