APPLICATION OF MULTIPLE-SECTION RESONATORS TO AIR-CONDITIONING DUCTS

摘要

We have examined how to compose multiple-section resonators to attenuate air-conditioning duct noise. Regarding characteristics of resonance frequency, the maximum transmission loss was produced when the resonators had a space of one-fourth of the resonance wavelength. Regarding double-section resonators, the equal value of the absorption loss to the transmission loss was obtained by making normalized acoustic resistance of the up-stream resonator"R+1" of the down-stream resonator.