GUIDED WAVES IN A WATER LOADED HOLLOW CYLINDER

Abstract A study on the leakage of guided waves in hollow cylinders is presented to find suitable modes that are basically independent of water loading. In this study, a boundary value problem of leaky cylindrical guided wave propagation is derived and solved in complex domain by using a complex wave number to obtain velocity and attenuation dispersion curves. Cross–sectional displacement and power flow distributions are also calculated at some sampling points on the dispersion curves in order to extract physically based answers on their attenuative natures. It turns out that the cross-sectional particle displacement distribution of a leaky mode, named wave structure in this paper, is remarkably sensitive with respect to outside water loading, resulting in a significant profile change at an interface between water and a tube. However that of a non-leaky mode is nearly independent. Ratios of the radial and tangential power flows are calculated for estimations of portions of leaky ultrasonic energy. An experiment is carried out to confirm the theoretical study with an inconel tube