Sound Radiation from Two Opposed Semi-Infinite Overlapped Ducts with Partial Lining

The radiation of plane sound waves from two opposed semi-infinite cylindrical duct with overlapping edges is investigated in the case the walls of the ducts lying in overlap region lined with different acoustically absorbent materials. By using the series expansion in overlap region and using Fourier transform technique elsewhere we obtain two uncoupled Wiener-Hopf equations their solutions involve unknown expansion coefficients satisfying a system of linear algebraic equations. Solving the algebraic system numerically by truncating the infinite series, the effect of the absorbent lining on the radiated field are presented graphically.