Title :
Damping of Sub-Synchronous Whirl in Rotors With High-Temperature Superconducting Bearings
Author :
Hull, John R. ; Strasik, Michael ; Mittleider, John ; McIver, Carl ; McCrary, Kevin ; Gonder, John ; Johnson, Phil
Author_Institution :
Boeing Res. & Technol., Seattle, WA, USA
fDate :
6/1/2011 12:00:00 AM
Abstract :
For large flywheel rotors supported by high-temperature superconducting (HTS) bearings, the amplitude of sub-synchronous whirl can become so large that it limits the maximum speed to a value less than that dictated by its mechanical strength. Internal damping, in the form of hysteretic loss in the rotor material, creates a force that adds energy to the forward whirl. We examine the effect of internal damping as the cause of the sub-synchronous whirl and show that theoretical predictions of the onset criteria agree with experimental data. We next show how it is possible to damp the whirl from a theoretical context and discuss a practical approach to accomplish this that has had success in our laboratory experiments.
Keywords :
flywheels; high-temperature superconductors; machine bearings; rotors; superconducting machines; synchronous motors; flywheel rotors; high-temperature superconducting bearings; hysteretic loss; internal damping; sub-synchronous whirl; Assembly; Damping; Force; High temperature superconductors; Rotors; Shock absorbers; Springs; Flywheels; high-temperature superconductors; rotating machines; superconducting rotating machines;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Conference_Location :
5/5/2011 12:00:00 AM
DOI :
10.1109/TASC.2010.2090118