Propagation of sound in a duct with mean flow

We have considered the problem of radiation of sound from a semi-infinite soft duct. This duct is symmetrically located inside a hard but infinite duct. The problem is solved when the whole fluid region inside these ducts is in motion with a constant fluid velocity. We obtained a closed form solution by using the integral transform and Wiener–Hopf technique. The graphical results are also presented which show that how effectively the unwanted noise can be reduced by proper selection of different parameters.