Experimental and numerical study on underwater noise control of multigrooved metasurface coating with antifouling and drag reduction potential

Acoustic metasurfaces have garnered increasing attention due to their efficacy in low-frequency sound absorption, while achieving broadband sound absorption performance remains challenging. In this study, a novel approach employing a multigrooved metasurface integrated onto a nanocomposite material is undertaken. Before modification, the nanocomposite material exhibits commendable underwater sound absorption capabilities above 4000 Hz, but demonstrates lower performance below this threshold. Integrating the multigrooved metasurface yields a notable enhancement in sound absorption performance below 4000 Hz, with the average absorption coefficient increasing from 0.29 to 0.63. Remarkably, this enhancement almost does not impact the performance above 4000 Hz. Experimental findings additionally reveal improved performance under variable hydrostatic pressures. Notably, the multigrooved surfaces show enhanced antifouling properties, and also exhibit potential for drag reduction compared to smooth surfaces. The proposed multigrooved metasurface in this study introduces a novel strategy towards the development of multifunctional underwater sound absorption coatings.