消音器における吸音物の効果 : 第2部 内部に装脱容易な吸音物の塊を有する場合の吸音効果

抄録

Generally, the sound absorbing materials are wasted appreciably by high-speed air current and high temperature inside a muffler, and that they become the causes of many troubles when they are used in the muffler. One of the solutions for this is to make the mass of the sound absorbing materials exchangeable. It is described in this paper how effective the small mass of absorbing material is, as the result of the experiments on such mufflers. The attenuation effect by means of a muffler varies with kinds and density of absorbing materials, though a conspicuous effect is always expectable in high frequency region. The absorbing materials inside the muffler may be easily exchanged as it is small. In designing a muffler, it is advisable, to analyze the exhaust noise of the engine, and then to design the overall shape and structure of the muffler in conformity with the theory of acoustic filter together with the method described in this paper.