Abstract： Coupled cylindrical-conical Shells, submarine, sound radiation, effect factors. Based on the simple coupled cylindrical-conical shell, a new modal stiffened by ribs and bulkhead was used to simulate the typical submarine afterbody. Adopting FEM and FM-BEM, the effects of bulkhead configuration, excitation direction, fluid effects, the conical shell stiffness and hull damp factors on the shell acoustic radiation were researched. First the dry modes of the initial shell were verified, and then the sound power of the new modal under each case was calculated. Results show that: (1) under distributed axial excitation, the spherical bulkhead stiffened shell radiates minimum sound power and radiation efficiency; (2) as the radial force can easily excites circumferential modes of the shell, so it excited stronger sound than axial force, but the effect of axial force cannot be neglected; (3) under radial excitation, smaller axial displacement and stronger radial displacement of the shell in water were discovered than that of in air; (4) the conical shell stiffness has minor effect on the sound suppression, while the damp can well suppress the sound radiation. The obtained conclusion can afford some suggestions to the optimum acoustic design of the sub-marine afterbody.
2012, Vol. 31 
