Structure-Acoustic Coupling Analysis of Underwater Acoustic Radiation Characteristics of a Multiple Intersecting Spherical Shell Under Acoustic Excitation

The underwater acoustic radiation of deepwater submersibles has become a growing concern in both academic and industrial communities. This study investigates the structure-acoustic coupling characteristics of a novel deepwater pressure hull, idealized as a triple spherical shell. A numerical model is established using a combined finite element and boundary element method to analyze the vibro-acoustic response of the target structure. The effects of three excitation types—unit sound excitation, unit force excitation, and their combined application—on the acoustic radiation of the intersecting spherical shells are systematically compared. Furthermore, the external sound power radiated by distributed acoustic excitations applied at different positions on each spherical shell is examined. Numerical examples are presented and discussed in detail, providing a useful technical reference for the quantitative acoustic design of underwater deepwater vehicles. The results show that the vibro-acoustic response of the triple spherical shell depends strongly on the excitation type and source position. For the selected unit inputs, the internal acoustic excitation produces a larger response than the local force excitation. After normalization to equal input power, the acoustic excitation produces a higher external radiated sound power than the force excitation in almost the entire frequency range. The radiated sound power is influenced by both the source–shell distance and the symmetry of the source position in the simulated cases.