Influence of interaction with tangential lean blade and box type casing on blade passing frequency noise level in small axial-flow fans

Taku Iwase, Tetsuya Hioki, Yoshihiko Kato, Taro Tanno, Osamu Sekiguchi, Masato Furukawa

Research output: Contribution to journalArticlepeer-review

Abstract

Influence of interaction with a tangential lean blade and a box type casing on blade passing frequency (BPF) noise level in small axial-flow fans was investigated by measurement and computational fluid dynamics (CFD). Noise level of five fans having different tangential lean angles was measured. By increasing tangential lean angle, BPF noise level and broadband noise level reduced. An unsteady CFD simulation of tangential lean angle 31-degrees and 63-degrees was conducted to analyze the cause of BPF noise reduction. By increasing tangential lean angle, the inward blade force of the 63-degrees blade was increased compared to the 31-degrees blade. The increase of the inward blade force decreased centrifugal flow in radial direction at the exit of casing, because the inward blade force gave a momentum to the flow in radial inward direction. The decrease of the centrifugal flow suppressed interaction of the flow with the casing wall. The suppression of the interaction reduced static pressure fluctuation for BPF of the casing wall. The reduction of static pressure fluctuation for BPF was found to have a great influence on the BPF noise reduction. It is therefore clarified that increasing tangential lean angle was effective in reduction of the BPF noise.

Original languageEnglish
Pages (from-to)1620-1629
Number of pages10
JournalNihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Volume77
Issue number780
DOIs
Publication statusPublished - 2011
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Influence of interaction with tangential lean blade and box type casing on blade passing frequency noise level in small axial-flow fans'. Together they form a unique fingerprint.

Cite this