Abstract
This study investigates the influence mechanism of biomimetic microstructures on propeller pressure fluctuations and radiated noise using numerical simulations. Based on the SST k-ω turbulence model and Lighthill’s acoustic analogy, the flow field and acoustic performance of propellers with and without microstructures are comparatively analyzed under different advance coefficients. Results show that microstructures arranged at the trailing edge optimize surface pressure distribution and promote a more uniform flow field. More importantly, they facilitate orderly vortex generation and shedding, reducing blade surface vortex intensity and suppressing flow-induced pressure fluctuations at the source. Acoustic analysis confirms that microstructures effectively reduce discrete noise at characteristic frequencies, with far-field maximum sound pressure level reductions of 5.94 dB at J = 0.5 and 3.11 dB at J = 1, while the noise directivity pattern is transformed from a “figure-of-eight” to a “heart-shaped” distribution. This study reveals the hydrodynamic mechanism of passive flow control for noise reduction via biomimetic microstructures, providing novel insights and theoretical foundations for low-noise propeller design and acoustic stealth technology development.