MULTIPLE DIFFRACTION OF PLANE-WAVES BY AN ACOUSTICALLY PENETRABLE STRIP LOCATED BETWEEN 2 SOFT HARD HALF-PLANES

A uniform asymptotic high-frequency solution is developed for the diff raction of plane waves ? by an acoustically transmissive strip located between two half-planes which are soft at the top and ?hard at the bo ttom. After simulating the partially transmissive strip by a set of ap proximate boundary ?conditions used recently by Rawlins et al., the th ree-part boundary value problem is formulated into ?a ''modified matri x Wiener-Hopf equation''. By performing the factorization of the kerne l matrix ?through the Daniele-Khrapkov method, the modified matrix Wie ner-Hopf equation is first reduced ?to a pair of coupled Fredholm inte gral equations of the second kind and then solved by iterations. An ?i nteresting feature of the present solution is that the classical Wiene r-Hopf arguments yield unknown ?constants that can be determined by me ans of the edge conditions.