Rotordynamic characteristics of an APU gas turbine rotor-bearing system having a tie shaft

Authors
Citation
As. Lee et Ys. Lee, Rotordynamic characteristics of an APU gas turbine rotor-bearing system having a tie shaft, KSME INT J, 15(2), 2001, pp. 152-159
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanical Engineering
Journal title
KSME INTERNATIONAL JOURNAL
ISSN journal
1226-4865 → ACNP
Volume
15
Issue
2
Year of publication
2001
Pages
152 - 159
Database
ISI
SICI code
1226-4865(200102)15:2<152:RCOAAG>2.0.ZU;2-3
Abstract
In this paper it is intended to set-up a sound model of the 60,000 rpm 100 kW prototype APU gas turbine rotor-bearing system, and particularly to inve stigate the influences of the tie shaft on the rotordynamic characteristics of the entire APU gas turbine rotor-bearing system, employing the dual sha ft model. Firstly, a mock-up APU rotor has been constructed to test and ver ify the model. Analytical natural frequency results have agreed with the co rresponding modal test ones to within 5% difference. Then, the rotordynamic characteristics of the prototype APU rotor-bearing system have been invest igated. Natural vibration and unbalance response analyses results have show n that the inner tie shaft resonance can cause high enough vibration of the outer main rotor shaft. This could be a concern as the rotor journals oper ate on very thin air film at high speed. It is concluded as a conservative design practice that the inner tie shaft should be explicitly modeled in th e rotordynamic analysis of the APU rotor-bearing system.