Optimization Design and Simulation of Acoustic Adaptation Structure for Underwater Gliders

To address the technical bottleneck in balancing hydrodynamic efficiency and acoustic detection performance during the design of acoustic adaptation structures for long-endurance underwater gliders(UGs), this study proposed a dual-objective collaborative design method integrating computational fluid dynamics-finite element method(CFD-FEM) co-simulation. By coupling simulation of turbulent flow in arbitrary regions-computational continuum mechanics+(STAR-CCM+) for viscous flow analysis and COMSOL Multiphysics for acoustic-structure interaction, a parametric geometric model was proposed based on the Myring equation, utilizing the sharpness factor and aspect ratio as key variables. Multi-objective collaborative optimization was carried out by adopting intelligent optimization algorithms. The results indicate that the optimized acoustic adaptation structure achieves a total drag reduction of 10.4%–15.6% across a speed range of 0.5–3 m/s. Specifically, the configuration with an aspect ratio of 1.875 and a sharpness factor n = 2 exhibits a resistance reduction to 8.178 N at 1 m/s. Regarding acoustic performance, under 2 000 Hz plane wave incidence, the scattered sound pressure level increases by 1.5 dB; sidelobe suppression capability is enhanced by 2–3 dB, and acoustic reception directivity is improved significantly. Validation through angle of attack tests demonstrates that the optimized solution maintains drag reductions of 6%-17% within a ±10° angle of attack, effectively resolving the conflicting requirements between hydrodynamic resistance and acoustic performance inherent in traditional designs. The constructed “fluid-structure-acoustics” multiphysics collaborative optimization paradigm provides theoretical support for the engineering design of next-generation long-endurance, high-detection, and composite UGs and expands the UG multidisciplinary optimization methodology system.