Generation and propagation of "buzz-saw" noise in transonic fan with blade vibrations

  • Xiaolong Tang*
  • , Xiaodong Li
  • *Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

When compared with the ideal rotor, "buzz-saw" noise radiated by real transonic fan is different because of blade variations. Apart from the initial blade irregularities, additional unsteady blade variations are introduced by blade vibration. The influence of blade vibration on the generation and propagation of "buzz-saw" noise is still not clear. NASA rotor 67 is selected to investigate the effect of blade vibration on the generation and propagation of "buzz-saw" noise. The blade eigenfrequency and the maximum displacement are obtained from flow/structure interaction data. By applying the fast reconstruction method proposed by the authors, these data are used to generate the unsteady rotor-alone pressure fields of vibrating rotors. Then, the pressure fields are transformed to saw-tooth waves and marched upstream by analytical method. Comparisons are performed among the non-vibrating and vibrating versions of the ideal rotor and the rotor with initial stagger variations. Blade vibration increases the sound pressure level of the sub-harmonics, which forms a narrow-band peak near half the blade passing frequency. These sub-harmonics behave differently with the blade passing frequency and its harmonics during the propagation.

Original languageEnglish
Title of host publication"Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021
EditorsEleonora Carletti, Malcolm Crocker, Marek Pawelczyk, Jiri Tuma
PublisherSilesian University Press
ISBN (Electronic)9788378807995
StatePublished - 2021
Event27th International Congress on Sound and Vibration, ICSV 2021 - Virtual, Online
Duration: 11 Jul 202116 Jul 2021

Publication series

Name"Advances in Acoustics, Noise and Vibration - 2021" Proceedings of the 27th International Congress on Sound and Vibration, ICSV 2021
ISSN (Print)2329-3675

Conference

Conference27th International Congress on Sound and Vibration, ICSV 2021
CityVirtual, Online
Period11/07/2116/07/21

Keywords

  • Analytical method
  • Blade vibration
  • Buzz-saw noise
  • Source fast reconstruction

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