Title page for ETD etd-02062013-040208
|Type of Document
||Keesee, John Micheal
||Influence of active magnetic bearing sensor location on the calculated critical speeds of turbomachinery
||Master of Science
|Kirk, R. Gordon
|Elrod, David A.
|Leonard, Robert G.
|Date of Defense
The calculation of critical speeds for turbomachinery with active magnetic
bearings (AMBs) is of great interest due to the increasing number of applications
l of this new technology. The potential for increased turbomachine performance
through improved AMB design has created the need for a more accurate method
for predicting the system’s undamped critical speeds. This thesis documents the
development of a method which improves the accuracy of critical speed calculation
by properly accounting for the influence ofAMB sensor location on the undamped
critical speeds. This investigation includes the development of an AMB modified
Jeffcott model. The results from the AMB modified Jeffcott analysis give useful
design guidance for the influence of the sensor location on the first and third
modes of a symmetric rotor system. A more accurate solution using a transfer
matrix method modified to account for AMB sensor locations is presented.
The results from the transfer matrix method for an example compressor are
presented showing the influence of the sensor placement on a standard undamped
critical speed map. The mode shapes with sensor location at a typical design
location are given to illustrate the importance of the sensor location.
|| Approximate Download Time
| 28.8 Modem
|| 56K Modem
|| ISDN (64 Kb)
|| ISDN (128 Kb)
|| Higher-speed Access
next to an author's name indicates that all
files or directories associated with their ETD
are accessible from the Virginia Tech campus network only.
If you have questions or technical
problems, please Contact DLA.