Patent ID: 11493232

Abstract:
An object is to provide a silencing system that can achieve both high ventilation performance and high soundproof performance, can silence a plurality of pieces of resonant sound, and has high general-purpose properties since the silencing system does not need to be designed according to a tubular member. In a silencing system where silencers are disposed on a tubular member, the silencers silence sound having a frequency of first resonance of the tubular member, each silencer includes a cavity portion and an opening portion, the opening portions are connected to a sound field space of the first resonance of the tubular member, a conversion mechanism for converting sound energy into thermal energy is disposed in each cavity portion or at a position where the conversion mechanism covers the opening portion, a ratio S1/Sd of the area S1 to the area Sd satisfies “0<S1/Sd<40%” in a case where the area of the opening portion of the silencer is denoted by S1 and the surface area of an inner wall of the cavity portion is denoted by Sd, and the depth Ld of the cavity portion in the traveling direction of an acoustic wave in the silencer satisfies “0.011×λ<Ld<0.25×λ,” in a case where the wavelength of an acoustic wave at the resonant frequency of the first resonance is denoted by λ.