Vol. 11, No. 1 (December, 2011)

Sound Propagation through the Elliptical SVU
Sohei Nishimura, HuyQuang Nguyen, Yuya Nishimura, Noriko Horibe, Tsuyoshi Nishimura, Takashi Yano

A conceptual model for window manufacturing which is capable of ventilation, regulating sunlight, and reducing a traffic and environment noise has been presented in previous studies. This window combines two basic components: a soundproofing ventilation unit (SVU) and a lighting unit. Due to the fact that the ventilation unit must have a large volume to attenuate low-frequency noise, many resonance of higher-order mode wave will be generated inside the unit. To minimize the higher-order mode in order to have a great soundproofing effect, an elliptical cavity is take into consideration in this paper. At first, by using the Mathieu function, the general expression of the output pressure to the given input uniform velocity is obtained for a whole ventilation unit. Next, based on the calculation results, the cause and mechanism of resonance frequencies inside an element are discussed in detail.

Keywords: soundproofing ventilation unit, higher-order mode wave, sound propagation

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