Abstract
Mitigation of sound radiation from subsonic axial fan in the fan-ducted system at low frequencies remains a technical challenge. Traditional dissipative approach such as absorption material often requires sufficiently long attenuation path for desirable noise reduction performance. More advanced passive control technology such as membrane housing which relies on vibro-acoustic coupling mechanism works effectively on the attenuation of the first and second blade passage frequency in case of steady flow. However, the performance of such device which is composed of thin membrane may be affected by unsteady flow field. This study examined the interaction between vortex unsteady motion, a tensioned membrane housing of finite length and axial fan with dipole nature using the matched asymptotic expansion technique and potential theory. A two-dimensional numerical model is established to explore the sound radiation of each components and the performance of the membrane housing for controlling sound radiation from axial fan in the present of vortex inside uniform mean flow. The results show that there is higher chance of sound amplification when a vortex stream is closer to the light membrane under weak mean flow speed. Under the condition of weak mean flow speed, the sound radiation from the membrane is also amplified when the cavity height is shallower. The result is beneficial for the design of the device of membrane housing.
Original language | English |
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Title of host publication | INTERNOISE 2014 - 43rd International Congress on Noise Control Engineering |
Subtitle of host publication | Improving the World Through Noise Control |
Publisher | Australian Acoustical Society |
ISBN (Electronic) | 9780909882037 |
Publication status | Published - 1 Jan 2014 |
Event | 43rd International Congress on Noise Control Engineering: Improving the World Through Noise Control, INTERNOISE 2014 - Melbourne, Australia Duration: 16 Nov 2014 → 19 Nov 2014 |
Conference
Conference | 43rd International Congress on Noise Control Engineering: Improving the World Through Noise Control, INTERNOISE 2014 |
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Country/Territory | Australia |
City | Melbourne |
Period | 16/11/14 → 19/11/14 |
Keywords
- Axial fans
- Flow-induced noise generation in ducts and pipes
ASJC Scopus subject areas
- Acoustics and Ultrasonics