Abstract
In low frequencies (ka < 200), the A-wave (Scholte-Stoneley wave) and the S0-wave (first symmetrical Lamb wave) are the subject of a particular attention in the study of the acoustic scattering from empty cylindrical shells immersed in water. If the tube is in water, the A0-wave (flexural Lamb wave) which circumnavigates in the shell in vacuum, does not originate resonances in the backscattered pressure spectrum while the two others are active. Images of the acoustic scattering from cylindrical or spherical targets obtained from the “Schlieren” visualization using a high-speed camera show the typical re-radiation of the A0+-wave in water. Moreover, the backscattered signal recorded with one emitter-receiver transducer shows one echo which cannot attributed to the A- or S0-waves. In this paper, the propagation of the A0+-wave has been especially studied to explain the experimental results. This A0+-wave has a great impact if it crosses over a structure inhomogeneity after a short propagation in the shell, before its complete attenuation.
Poster: Bursting of a Peach-Shaped Wave: High Speed Schlieren Visualization of Detonation Diffraction in Gases
