0
research-article

A contribution to the thermal modeling of bump type air foil bearings: Analysis of the thermal resistance of bump foils

[+] Author and Article Information
Andreas Lehn

Technical University Darmstadt, Department of Mechanical Engineering, Institute of Applied Dynamics, Otto-Berndt-Strasse 2, 64287 Darmstadt, Germany
lehn@ad.tu-darmstadt.de

Marcel Mahner

Technical University Darmstadt, Department of Mechanical Engineering, Institute of Applied Dynamics, Otto-Berndt-Strasse 2, 64287 Darmstadt, Germany
mahner@ad.tu-darmstadt.de

Bernhard Schweizer

Technical University Darmstadt, Department of Mechanical Engineering, Institute of Applied Dynamics, Otto-Berndt-Strasse 2, 64287 Darmstadt, Germany
schweizer@ad.tu-darmstadt.de

1Corresponding author.

ASME doi:10.1115/1.4036631 History: Received August 19, 2016; Revised April 11, 2017

Abstract

A detailed analysis of the effective thermal resistance for the bump foil of air foil bearings (AFBs) is performed. The presented model puts emphasis on the thermal contact resistances between the bump foil and the top foil as well as between the bump foil and the base plate. It is demonstrated that most of the dissipated heat in the lubricating air film of an air foil bearing is not conducted by micro-contacts in the contact regions. Instead, the air gaps close to the contact area are found to be thin enough in order to effectively conduct the heat from the top foil into the bump foil. On the basis of these findings, an analytical formula is developed for the effective thermal resistance of a half bump arc. The formula accounts for the geometry of the bump foil as well as for the surface roughness of the top foil, the bump foil and the base plate. The predictions of the presented model are shown to be in good agreement with measurements from the literature. In particular, the model predicts the effective thermal resistance to be almost independent of the applied pressure. This is a major characteristic property that has been found by measurements but could not be reproduced by previously published models. The presented formula contributes to an accurate thermohydrodynamic modeling of AFBs.

Copyright (c) 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In