Aeroengine Division, National Aerospace Laboratory(NAL)
Aeroengine Division, National Aerospace Laboratory(NAL)
Aeroengine Division, National Aerospace Laboratory(NAL)
出版者
航空宇宙技術研究所
出版者(英)
National Aerospace Laboratory(NAL)
雑誌名
航空宇宙技術研究所報告
雑誌名(英)
Technical Report of National Aerospace Laboratory TR-488
巻
488
ページ
15
発行年
1977-02
抄録(英)
The previous report(ref.2), confirmed that the unbalance vibration of single spool turbo-jet engines and vibration damping effect of the squeeze film damper bearing could be estimated with sufficient accuracy for design purposes, by theoretical analysis. Following these results, calculations on unbalance vibration in 2 typical models of 2 spool fan-jet engine were made, with consideration given to the different rotor speeds. The results of the analysis showed that- (1)Medium to large size 2 spool fan-jet engines have many resonance frequencies in the speed ranges, and at some speeds and positions, the vibration amplitudes exceed the critical value, without a damper bearings. (2)In most cases, however, the vibration amplitude at the critical speed can be suppressed to within a safe value, using one or two damper bearing(s) at some adequate position(s).