Predicting range-dependent underwater sound propagation from structural sources in shallow water using coupled finite element/equivalent source computations

Predictions of underwater sound propagation (USP) from structural sources in complex shallow-water environ-ments are crucial for underwater navigation, communication, and localization. Modeling range-dependent USP in shallow water remains challenging because structural acoustic radiation is coupled with complex waveguide physics. This paper presents a coupled finite element (FE)/equivalent source (ES) computation scheme for predicting the range-dependent USP from a structural source. The scheme involves coupled vibroacoustic FE/ES analyses and waveguide-field ES computations. The former computes the structural vibration response and reproduces the structural-acoustic radiation at arbitrary spatial positions. The coupled vibroacoustic FE/ES analysis provides the input for the waveguide-field ES computations, which couple the structural-acoustic radiation with the shallow-water environment. A multilayer acoustic-elastic ES method (ESM) is developed to accommodate sound speed inhomogeneities and a range-dependent elastic seabed. Numerical simulations demonstrate the interactions of structural-acoustic radiation with two-dimensional topographies and internal solitary waves. The proposed scheme is extended to three dimensions by combining the coupled vibroacoustic FE/ES analysis with a pre-corrected fast Fourier transform-accelerated ESM. The results validate the proposed scheme and demonstrate its benchmark-quality solutions and high numerical efficiency, suggesting great application potential for optimizing the sonar performance at the preliminary design stage.

Automated summary

This paper presents a coupled finite element (FE)/equivalent source (ES) computation scheme for predicting the range-dependent underwater sound propagation (USP) from a structural source in complex shallow-water environments. The proposed scheme involves coupled vibroacoustic FE/ES analyses and waveguide-field ES computations, which accommodate sound speed inhomogeneities and a range-dependent elastic seabed. Numerical simulations validate the proposed scheme and demonstrate its benchmark-quality solutions and high numerical efficiency, suggesting great application potential for optimizing sonar performance.