Study on the integrated calculation method of fluid-structure interaction vibration, acoustic radiation, and propagation from an elastic spherical shell in ocean acoustic environments

A modeling method based on the wave superposition method is studied in this paper. Different underwater acoustic propagation models are used in the near and far field. Taking the acoustic radiation field calculation of an elastic spherical shell as an example, the near and far field can be analyzed as a unified system, using this method. Many studies use FEM/BEM (finite element method/boundary element method) to calculate acoustic radiation fields of elastic structures, but only a few of these methods can be applied when considering finite ocean depth, seafloor reflection loss, and sound velocity profile. In this study, the Green function is calculated differently in the near and far field to significantly simplify calculations. The virtual source method is used to calculate the acoustic radiation field in the near field and source strength, while the normal mode method is used in the far field. The results are compared with those obtained using the COMSOL finite element software, which showed that this method was both computationally efficient and accurate. Based on numerical examples, the influence of sea surface, seafloor, and sound velocity on the acoustic radiation field of elastic structures in an ocean acoustic environment is quantitatively analyzed.