In the preceding report, we have dealt with underwater sound radiated from a semi-submerged simple circular shell, and shown the basic role of free water surface. However these results are all about the simple circular cylinder so that they might not be applied to actual ships.
This report deals with this point, namely, to know the influence of the hull section shape on the property of underwater radiated sound, we show the numerical analysis method of the mutual coupled vibration of fluid-hull interaction, in which the vibrations of hull are solved by F. E. M. and the sound into fluid by B. E. M..
At first, we calculate the semi-submerged simple circular shell by this method, compare with the preceding report results, and find a good agreement between them. Next, we show the effect of changing drafts of a circular shell and the effect of hull section shapes. Finally, we calculate the realistic cross section of ships and show the effect of the plate thickness and rigidity on underwater radiated sound.