Multi-objective optimization of three-dimensional riblet surfaces for hydrodynamic and acoustic performance.

Area of Science:

• Bioinspired engineering
• Fluid dynamics
• Acoustics

Background:

• Shark skin denticles inspire riblets for drag reduction.
• Previous research focused on 2D riblets, leaving 3D topographies underexplored.
• Complex 3D denticle-inspired surfaces challenge parameterization, simulation, and fabrication.

Purpose of the Study:

• Introduce a 3D, riblet-reinforced surface topography.
• Reduce drag and suppress flow-induced noise.
• Provide a scalable solution for towed array sonar applications.

Main Methods:

• Utilized Bayesian optimization and computational fluid dynamics (CFD).
• Developed and analyzed a novel 3D riblet-reinforced surface topography.
• Performed flow field analysis to understand near-wall vorticity dynamics.

Main Results:

• Optimal design reduced sound pressure level by 6.87 dB and drag by 0.34%.
• Maximum noise reduction achieved was 8.81 dB, with a slight drag increase.
• Maximum drag reduction was 5.18%, with significant noise suppression.

Conclusions:

• CFD simulations and Bayesian optimization efficiently refine 3D riblet surfaces.
• The developed topography balances noise mitigation and hydrodynamic performance.
• This bioinspired design improves acoustic stealth and efficiency in underwater applications.