Nonlinear rotordynamic-thermal analysis of micro gas turbines

A compliant tilting pad air bearing concept has been proposed as a solution for low power micro gas turbines. In this paper, the nonlinear dynamic models for this bearing concept are extended with a thermal model. With simulations and experiments it is demonstrated that the thermal expansion of the bearing journals may negatively affect the power loss, and the nonlinear rotordynamic response of the rotor and these bearings. Therefore, designing these bearings for a micro gas turbine requires both a nonlinear rotordynamic model and a thermal model of the micro turbine