Aeroacoustics in owl flight: biomechanisms and biomimetics.

Owls have evolved remarkable adaptations for near-silent flight, offering a compelling model for understanding aerodynamic noise reduction. Their morphological specialisations-such as leading-edge serrations, trailing-edge fringes, and velvety wing surfaces-provide crucial insights into bioinspired solutions for various engineering applications. However, the exact aeroacoustic mechanisms underlying these adaptations remain only partially understood. This review provides a comprehensive synthesis of the key biomechanisms associated with silent flight, including both historical perspectives and the latest experimental and computational findings. We also systematically classify and analyse current biomimetic applications in various engineering contexts-including aircraft noise reduction, wind turbine blade optimisation, and other industrial implementations-thereby establishing a clear mechanistic link between fundamental aeroacoustic principles and real-world engineering solutions. Finally, we discuss the key challenges and future directions in owl-inspired aeroacoustics, emphasising the integration of morphological adaptations, wing flexibility, and flight kinematics. By bridging biological insights with engineering innovation, this work underscores the potential of owl-inspired designs to drive the development of quieter, more eco-friendly technologies.