NUMERICAL CALCULATION OF SOUND PROPAGATION IN THREE-DIMENSIONAL CIRCULAR DUCTS

The numerical calculation of sound propagation in 3-D lined circular ducts has been completed. In this paper, the numerical method and the finite difference schemes are offered, and the effect of various circumferential distributions of the absorbing material on sound attenuation is also discussed. It is shown by the numerical solutions that the face-to-face circumferential distribution has optimum sound attenuation.