Design study on enhancing acoustic target strength of underwater spherical embedded corner reflector structure

Objectives To design a compact underwater passive acoustic decoy with high target strength, this study proposes a novel structure in which a specific number of corner reflectors are uniformly embedded on a sphere following a spherical spiral pattern. The acoustic scattering characteristics of this structure are studied.

Methods An acoustic scattering model of the spherical embedded corner reflector structure is established using the finite element numerical calculation method. The acoustic scattering characteristics of the proposed structure are compared with that of a solid sphere. Structural parameters are optimized using a genetic algorithm. The influence of the orientation of the triangular openings and other structural parameters on the acoustic scattering characteristics is revealed.

Results Both numerical calculation and experimental results show that the orientation of the triangular openings has negligible impact on the acoustic scattering characteristics of the model. The number of spherically embedded corner reflectors, their side length, and the area ratio of their circumcircles significantly affect the acoustic scattering of the model. The spherically embedded corner reflector model optimized by the genetic algorithm can enhance the acoustic target strength within a specified angular range.

Conclusions These findings provide a valuable reference for the optimal design of underwater passive acoustic decoys.