ダクト壁に設けた細いスリットによる高次モード波を含む円形ダクト内音波の消音

概要

論文の詳細を見る
Sound attenuation in a circular duct through a slit on the duct wall was studied for the plane wave and the higher-order mode waves. The slit is the duct expanision with very short axial length. The transmission property through the slit was calculated numerically using a computer. The transmission coefficient through the slit was measured using the apparatus with the sound source that can generate the plane wave, the (1, 1) mode wave and the (2, 1) mode wave. Both the calculated and the measured sound attenuation by the slit ocurred at a specific frequency. This frequency strongly depends on the slit depth. The prediction of this frequency by the calculation is approximately accurate. Because the slit width is very narrow, the slit is not likely to disturb fluid in a duct. Hence the slit is expected to be an effective sound attenuator for the noise in a duct with flow.
一般社団法人日本機械学会の論文
1993-12-25