Integrated Numerical Simulations of Gas Foil Bearing Static Performance
Keywords:gas foil bearing, fluid-structure interaction, computer simulations, bearing performance, eccentricity ratio, comparative study
Oil-free gas foil bearings have always been attractive in the high-speed lightly-loaded applications because of its simple and effective design. Compliance of bump foil with the interaction of top foil causes the rotor to levitate at high rotational speeds separated by air pressure. Many researches established frameworks to simplify the relationship of foil structure reaction under an unequal pressure generation along the bearing circumference. However, there is a lack of evidence to evaluate the proper model with appropriate parametric case studies. In this study, the connections between the hydrodynamic pressure in the bearing clearance and the foil assemblies are made by a coupled fluid-structure interaction (FSI) model to predict the static performance of the journal bearing. Input parameters such as eccentricity ratio and an attitude angle are applied to the initial journal position in order to capture the pressure distribution, foil deflection and load carrying capacities which were vital parameters in the performance of the rotor-bearing system. Case studies are carried out for different journal speeds and loading states to picture the bearing performance. The predicted values coincide with the published experimental data and indicate reasonable outcome.