The diffractive effect of rounding the corners of scattering structures

A numerical study of the scattering of an acoustic plane wave by an infinite cylindrical structure with corners is reported. An integral equation formulation is employed for which rapidly convergent quadrature schemes are developed. Three different boundary conditions are examined - Dirichlet, Neumann and an impedance condition. The effect on the scattered field of rounding the corners is measured as a function of the radius of curvature.