Réponse basse fréquence d'une coque sphérique mince immergée
Résumé
Some results about thin spherical shells are presented here. They are devoted to low frequencies : (ka <25) (k is the wave number and a represents the external radius of the shell). Numerical expressions have been derived in order to search out the different target resonances. When applied to numerical data, they are in good agreement with experimental results. The target is a shell, made of Fortal (Aluminium). Fort every thin shells, one puts forward theoretically a new mode called l = 0. It was not verified due to the fact that it exists only ay very low frequencies. This work enhances the importance of resonance in acoustic diffraction. This method could eventually successfully be applied in acoustic spectroscopy to identify target characteristics.