2016 Fiscal Year Final Research Report
Physical explanation of fan noise using numerical calculation, investigation of design for fan noise reduction, and active control experiments for fan noise
| Project/Area Number |
26420813
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Aerospace engineering
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| Research Institution | Kyushu University |
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Principal Investigator |
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| Research Collaborator |
ABO Makoto
HANO Hiroki
TOMITA Shuhei
NAGAYAMA Yoshimi
TOKUNAGA Syo
KAI Takahiro
MATAMURA Narumi
KAKOI Ryota
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | ファン騒音 / 動静翼干渉 / トーンノイズ / 分離解法 / アクティブノイズコントロール / URANS / 乱流モデル / 広帯域乱流騒音 |
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| Outline of Final Research Achievements |
Non-linear compressible viscous flows are solved with the unsteady RANS solver and linear sound propagation is solved analytically or solved with the linear unsteady solver. By using such a hybrid approach, physical mechanisms of generation and propagation of fan tone and broadband noise are investigated and clarified. The effectiveness for noise reduction of tone noise are discussed, also using the hybrid numerical approach, against the design parameters such as the distance between the rotor and stator, the lean angle of the stator, and the swept angle of the stator.
On the other hand experiments have been conducted to demonstrate the ANC, active noise control. By implementing a Filtered-X LMS algorithm in frequency domain to use with 32 loud-speakers and 32 microphones, the tone noise at 2500 rpm fan speed (about 840 Hz) can be reduced about 20 dB at maximum.
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| Free Research Field |
unsteady aerodynamics
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