Session: 23-07 Gas Foil Thrust Bearings

Paper Number: 151936

Passively Enhancing Gas Thrust Bearing Performance Through an Inexpensive and Straightforward Design Optimization of the Rotor Disk 

This article presents a passive approach for reducing the thermal bending deformations of rotor disks in gas thrust bearings, featuring an optimized design for the rotor disk. Small geometry changes are incorporated and inertia effects are utilized in order to compensate the thermal bending deformations, which increases bearing performance markedly.

A fully coupled, multiphysical nonlinear finite element model is used to model the foil thrust bearing performance. This model calculates the deformations and temperature of the bearing foils, the pressure and temperature distribution within the lubricating air gap as well as temperature and thermo-elastic deformations of the rotor disk. Additionally, heat fluxes through the rotor are represented, accounting for an assembly including journal foil bearings, the machine housing, and an electric motor.

The performance results of the foil thrust bearing with the newly optimized rotor disk design are compared against a standard symmetric thrust disk design. Results indicate that the thrust load capacity of the foil bearing can be increased markedly by implementing the proposed small changes to the rotor disk design. The use of this detailed model for the presented rotor-bearing system provides a reasonable estimation of the impact of the optimized rotor disk design in real turbomachinery applications.

Presenting Author: Johannis Triebwasser Technical University of Darmstadt, Institute of Applied Dynamics

Presenting Author Biography: After completing his Master’s studies in Mechanics at the Technical University of Darmstadt in 2020, Johannis Triebwasser joined the Institute of Applied Dynamics in Darmstadt as a research assistant. During his PhD studies, his subjects of research are the optimization of hydrodynamic air foil thrust and journal bearings and the simulation of the dynamic behavior of rotor bearing systems.

Authors:

Johannis Triebwasser Technical University of Darmstadt, Institute of Applied Dynamics
Markus Eickhoff Technical University of Darmstadt, Institute of Applied Dynamics
Bernhard Schweizer Technical University of Darmstadt, Institute of Applied Dynamics