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A Stability Analysis for a Hydrodynamic Three-Wave Journal BearingThe influence of the wave amplitude and oil supply pressure on the dynamic behavior of a hydrodynamic three-wave journal bearing is presented. Both, a transient and a small perturbation technique, were used to predict the threshold to fractional frequency whirl (FFW). In addition, the behavior of the rotor after FFW appeared was determined from the transient analysis. The turbulent effects were also included in the computations. Bearings having a diameter of 30 mm, a length of 27.5 mm, and a clearance of 35 microns were analyzed. Numerical results were compared to experimental results obtained at the NASA GRC. Numerical and experimental results showed that the above-mentioned wave bearing with a wave amplitude ratio of 0.305 operates stably at rotational speeds up to 60,000 rpm, regardless of the oil supply pressure. For smaller wave amplitude ratios, a threshold of stability was found. It was observed that the threshold of stability for lower wave amplitude strongly depends on the oil supply pressure and on the wave amplitude. When the FFW occurs, the journal center maintains its trajectory inside the bearing clearance and therefore the rotor can be run safely without damaging the bearing surfaces.
Document ID
20080023023
Acquisition Source
Glenn Research Center
Document Type
Reprint (Version printed in journal)
Authors
Ene, Nicoleta M.
(Toledo Univ. Toledo, OH, United States)
Dimofte, Florin
(Toledo Univ. OH, United States)
Keith, Theo G., Jr.
(Toledo Univ. Toledo, OH, United States)
Date Acquired
August 24, 2013
Publication Date
October 3, 2007
Publication Information
Publication: Tribology International
Publisher: Elsevier
Volume: 41
Subject Category
Mechanical Engineering
Funding Number(s)
CONTRACT_GRANT: NNC06AA06A
Distribution Limits
Public
Copyright
Other

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