REVIEW ARTICLE


Aeolian Tones Radiated from Flow Over Bluff Bodies



Mohamed Sukri Mat Ali*, 1, Sheikh Ahmad Zaki Shaikh Salim1, Mohamad Hafz Ismail1, Sallehuddin Muhamad2, Muhammad Iyas Mahzan2
1 Wind Engineering Laboratory, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia
2 Department of Engineering, UTM Razak School of Engineering and Advanced Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia

Article Information


Identifiers and Pagination:

Year: 2013
Volume: 7
First Page: 48
Last Page: 57
Publisher Id: TOMEJ-7-48
DOI: 10.2174/1874155X01307010048

Article History:

Received Date: 16/7/2013
Revision Received Date: 19/7/2013
Acceptance Date: 20/8/2013
Electronic publication date: 18/10/2013
Collection year: 2013

© 2013 Liu et al

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Wind Engineering Laboratory, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia; Tel: +603 – 2203 1286; Fax: +603 – 2203 1266; E-mail: sukri@ic.utm.my


Abstract

Bluff body is a simple but a central shape for many engineering applications. The geometry shape of the bluff body characterises the behaviour of the flow over the bluff body, where a more complex flow structure is found near downstream. Shear layer separation is mainly responsible for the periodic global phenomena, that includes the generation of sound. The magnitude of the aerodynamically generated sound is dominated by the fluctuations of aerodynamics forces, i.e., drag and lift. The study also shows that the sound pressure field is shaped by the aeolian tones that is related strongly to the lift fluctuations of the bluff body. Amplitude and frequency of the fluctuating lift change naturally with the shape of a particular bluff body. Triangular cylinder exhibits the largest sound pressure level (41.9 dB) followed by ellipse and circular shapes. Square cylinder emits the lowest sound pressure level (36.7 dB). This corresponds to the longest downstream vortex formation length at which for a square cylinder the long vortex formation length provides space for more vortex to dissipate.

Keywords: Bluff body, Passive flow and noise control, Aeolian tones, Shear layer, Vortex shedding.