https://doi.org/10.1140/epjp/s13360-025-07282-0
Regular Article
Trailing-edge noise reduction effect of bio-inspired finlets installed at different positions along the chord of airfoil
College of Mathematics and Physics, Shanghai University of Electric Power, 201306, Shanghai, China
a
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Received:
11
August
2025
Accepted:
30
December
2025
Published online:
23
January
2026
Abstract
Turbulent boundary layer trailing-edge noise can be effectively suppressed by mounting an array of finlets on wind turbine blades inspired by the unique comb-like structures on owl wings. This work numerically investigates the noise reduction effects of finlets with fixed spanwise spacing arranged at different positions along the chordwise direction on the suction side of the NACA0018 airfoil without finlets (Baseline). Large Eddy Simulation (LES) and Ffowcs-Williams and Hawkings (FW-H) acoustic analogy integral formula are employed to calculate the flow field and far-field noise under a Reynolds number of 
and an angle of attack of 0
. The results show that all nine finlet-equipped UP-x% airfoils (finlets installed at x%c position from the trailing edge of NACA0018, in 5% increments) can markedly reduce noise without causing a noticeable change in aerodynamic performance significantly. Flow field analysis reveals detailed physical mechanisms of noise reduction: (1) Finlets lift-up the most energetic turbulent eddies away from the boundary layer thereby significantly weakening the edge scattering phenomena. (2) Flow velocity decreases after passing the finlets. (3) Large-scale turbulent vortices are effectively broken down into smaller structures. Especially, among nine finlet-equipped airfoils, UP-20% achieves the optimal noise reduction performance with a far-field overall sound pressure level (OASPL) attenuation of 15.4 dB relative to the baseline within 20-20,000Hz. This is attributed to the highest turbulent kinetic energy (TKE) region near 20%c, wherein the finlets effectively disrupt turbulence partly reflected in 35% reduction of TKE near the trailing edge, thereby conducive to noise suppression.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2026
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
