SOLUTION OF THE EULER FIELD-EQUATIONS FOR PLANE-WAVE SCATTERING BY ANEND-CAPPED CYLINDER VIA THE UNIFORM GEOMETRICAL-THEORY OF DIFFRACTION

An approximate solution to the problem of plane-wave scattering by a f inite, hemispherically terminated (end-capped) cylinder of circular cr oss section is found via the uniform geometrical theory of diffraction (UTD). Both Dirichlet and Neumann boundary conditions are considered. A scattering model is applied in which a reduced set of geodesic path s or rays is used to obtain the acoustic pressure field at any point i n space where the UTD is valid. A standard method for obtaining transf er functions describing the pressure field changes along the geodesic paths is briefly outlined. This method uses asymptotic expansion of th e exact solutions to two related problems (plane wave scattering by a sphere and an infinite cylinder) whose ray sets together comprise the total ray set for the end-capped cylinder problem. An approximation to the total pressure field is then found for the case when an impinging plane wave is scattered by an end-capped cylinder. The predicted scat tered fields demonstrate the expected similarities to and differences from the field patterns produced by the infinite cylinder and sphere t argets. The origin and significance of a discontinuity in the pressure field predictions is discussed.