Session: 27-03: Bearings Effects in Rotordynamics

Paper Number: 152395

Rigid Air Bearings With 3-Lobe Bore Geometry: Stability and Rotor Dynamics for High-Speed Turbosystems 

This paper considers rigid air bearings with a 3-lobe bore geometry, which usually exhibit very poor stability characteristics, making them unsuitable for practical high-speed rotor systems. However, the stability of these bearings may be significantly improved by providing additional external dissipation, which may be achieved by the introduction of damping or friction. Therefore, the bearing shell or ring is not rigidly fixed in the housing but is either viscoelastically mounted to provide external damping, or it can also be elastically mounted by a foil structure to provide dissipation by dry friction. This type of bearing is called an air ring bearing. By properly selecting the bearing and ring supporting parameters of this bearing type, a very stable and robust bearing design can be obtained.

This paper analyses the non-linear vibration behaviour and stability of high-speed rotor systems with air ring bearings and discusses the influence of various design and system parameters on the dynamics of the system. Run-up simulations are carried out to investigate rotor oscillations. A detailed co-simulation model is used for this purpose. While the movement of the rotor and rings is modelled using a multi-body model, the two air films are modelled using two finite element systems.

Presenting Author: Myra Bianca Mehlhose Technical University of Darmstadt, Institute of Applied Dynamics

Presenting Author Biography: After completing her Master's degree at the Technical University of Darmstadt in 2022, Myra Bianca Mehlhose joined the Institute of Applied Dynamics in Darmstadt as a research assistant. During her PhD studies, her research topic is the dynamic simulation and bifurcation analysis of rotor bearing systems with hydrodynamic air ring bearings.

Authors:

Myra Bianca Mehlhose Technical University of Darmstadt, Institute of Applied Dynamics
Pascal Zeise Technical University of Darmstadt, Institute of Applied Dynamics
Bernhard Schweizer Technical University of Darmstadt, Institute of Applied Dynamics