Effect of Foil Materials On Performance of Gas Foil Journal Bearings

Abstract

Applying gas foil bearings in the high-speed rotor is under extensive investigation in turbomachinery design and development fields. Gas-lubricated foil bearings are self-acting bearings consisting of a thin smooth top foil, one or more corrugated foil and a bearing base to hold both the foil. The thin corrugated foils in the bearings are compliant in nature. They are introduced to enhance load-carrying capacity and to tailor the stiffness and damping of the conventional rigid gas bearings. The performance of the gas foil bearings is significantly affected by the material, shape and geometry of the foils. The thickness of the foils is usually in the range of 100 to 150 m. Several researchers have tried to investigate the performance of bearings with various foil materials for different applications. In the current research, a detailed investigation is done through numerical analysis to predict the performance of gas foil bearings for various foil bearings. The foil material used in the study includes Inconel X-750, Inconel 909, Inconel 713C, Beryllium Copper, Phosphorous Bronze, and EN42J Spring Steel. The bearing's performance investigated includes hydrodynamic pressure distribution, radial film thickness and load-carrying capacity. The pro and cons of each material for a definite shape and geometry is analyzed and documented. The author believes the reported conclusions from the detailed investigation will be helpful for the researchers in selecting suitable foil material while designing gas foil bearings.