Vol. 9, No. 1 (December, 2009)

Three-dimensional analysis of wave propagation in rectangular ventilation unit
Nishimura Yuya, Nishimura Sohei, Nishimura Tsuyoshi and Yano Takashi

A model for manufacturing windows which are capable of ventilating, reducing traffic noise and so on for the developing tropical countries is presented. These windows combine two basic components which are ventilation unit and lighting unit. The former also serves as an import function in reducing noise. 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. In this work, a method to predict the insertion-loss of rectangular ventilation unit with input and output openings at various positions is proposed by solving the wave equation, considering the resonance frequencies of higher-order mode. The results of the analysis have been confirmed by experiments.

Key words: higher order mode, insertion loss, windows, wave equation

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