Steven L. Means
Appl. Res. Lab., P.O. Box 30, Penn State Univ., State College, PA 16804
On fluid-loaded cylindrical shells there is a wave type that propagates in the axial direction at low frequencies and is characterized by a phase velocity slightly lower than the sound speed of the surrounding fluid. When such a wave is incident on a shell discontinuity, energy is scattered back along the cylinder's axis and into the surrounding fluid. This phenomenon may be modeled by considering a wave propagating along a semi-infinite cylindrical boundary having a given surface impedance attached to a semi-infinite rigid cylinder. This model allows one to use the Wiener--Hopf technique to obtain analytic expressions, in integral form, for the scattered pressure in the surrounding fluid. These expressions are then used to obtain visualizations of the scattered field. Comparisons are made with analogous surface waves scattered by a discontinuity of an elastic plate on an elastic foundation.