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Dynamic Stiffness and Damping Characteristics of a High-Temperature Air Foil Journal BearingUsing a high-temperature optically based displacement measurement system, a foil air bearing's stiffness and damping characteristics were experimentally determined. Results were obtained over a range of modified Sommerfeld Number from 1.5E6 to 1.5E7, and at temperatures from 25 to 538 C. An Experimental procedure was developed comparing the error in two curve fitting functions to reveal different modes of physical behavior throughout the operating domain. The maximum change in dimensionless stiffness was 3.0E-2 to 6.5E-2 over the Sommerfeld Number range tested. Stiffness decreased with temperature by as much as a factor of two from 25 to 538 C. Dimensionless damping was a stronger function of Sommerfeld Number ranging from 20 to 300. The temperature effect on damping being more qualitative, showed the damping mechanism shifted from viscous type damping to frictional type as temperature increased.
Document ID
20010058683
Acquisition Source
Glenn Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Howard, Samuel A.
(NASA Glenn Research Center Cleveland, OH United States)
DellaCorte, Christopher
(NASA Glenn Research Center Cleveland, OH United States)
Valco, Mark J.
(Army Research Lab. Cleveland, OH United States)
Prahl, Joseph M.
(Case Western Reserve Univ. Cleveland, OH United States)
Heshmat, Hooshang
(Mohawk Innovative Technology, Inc. Albany, NY United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2001
Subject Category
Mechanical Engineering
Meeting Information
Meeting: International Joint Tribology Conference
Location: San Francisco, CA
Country: United States
Start Date: October 21, 2001
End Date: October 24, 2001
Funding Number(s)
PROJECT: RTOP 708-1B-13
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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