ABSTRACT
A reduced semi-analytical model for gas foil bearings is presented, which allows time-efficient run-up simulations, while maintaining the main physical properties of the gas foil bearing. Hence, it may be used to optimise the rotor/bearing system over the complete speed range. The nonlinear force/displacement relationship of the bearing is approximated with hysteresis curves, generated in a pre-processing step by means of numerical simulations or measurements. Instability effects caused by the gas film cannot be predicted with the presented model, however, the nonlinear response of the rotor-bearing system may be predicted accurately, if the rotor speed is below the threshold speed of instability.
