Numerical study of the aerodynamics of sound sources in a bass-reflex port
PublisherEngineering Applications of Computational Fluid Mechanics
Rights accessOpen Access
The aim of this paper is to study the aerodynamics phenomena of a bass-reflex port that causes noise in the audible frequency range. After discarding structural and mechanical vibration issues, the hypothesis considered is that vortex shedding is the source of the noise. Experimental and numerical evidences of the vortex, an analysis of its noise and the similarities between real and simulated performance are presented. The numerically simulated cases with the original geometry are excited at different frequencies and with modifications of the port geometry. Likewise, the internal performance of an enclosure with a closed port was simulated. The simulations have been performed with axisymmetrical geometries using the open-source OpenFOAM® toolbox. Moreover, experimental measurements were carried out. First, acoustic signal experiments were done to analyse the response of the bass-reflex ports. Secondly, a structure vibration measurement was conducted in order to exclude the cabinet structure vibration as a source of the noise in question. A good agreement was found between numerical and experimental results, especially in the frequency band of the detected noise, i.e. the 1000–1500 Hz range. Despite no remarkable improvement being made with the geometry changes explored, the presented CFD approach has proved a useful and cost-effective tool to address this kind of phenomenon.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
CitationGarcía Alcaide, V. M., Pallejà Cabré, S., Castilla, R., Gamez-Montero, P.J., Romeu, J., Pàmies, T., Amate, J., Milán, N. Numerical study of the aerodynamics of sound sources in a bass-reflex port. "Engineering applications of computational fluid mechanics", 20 Gener 2017, vol. 11, núm. 1, p. 210-224.