ヘルムホルツ消音器の形状と開口端補正の関係

抄録

This paper describes the relationship between the shape of Helmholtz silencer and open-end correction. A Helmholtz silencer consists of a neck and a cavity, and its natural frequency is determined by the mass of the neck and the spring constant of the cavity. However, the mass of the neck is slightly increased by the open-end correction. The open-end correction of Helmholtz silencers has been studied in the past, and the open-end correction proposed by Rayleigh and Ingard has some problems such as being inaccurate depending on the shape. On the other hand, the method of calculating the additional mass using modal analysis has been proposed by Yamada et al; however, the condition under which the additional mass becomes large has not yet been investigated. Therefore, we investigated the relationship between the open-end correction and the location of the neck, and the relationship between the open-end correction and the height of the cavity of the Helmholtz silencer in this study. The equations of motion of the entire system of Helmholtz silencers were derived using modal analysis. The location of the neck and the height of the cavity that increase the additional mass were investigated through simulations and experiments.