A Comprehensive Review on Advancements in Noise Reduction for Unmanned Aerial Vehicles (UAVs)

Unmanned Aerial Vehicles (UAVs), or drones, have transformed numerous industries, yet their noise emissions pose challenges in urban and natural environments. The current review paper focus on advancements in reduction of noise and emphasizing the critical need to mitigate noise pollution from UAV's. As research progresses, collaborative innovation and technology transfer hold potential to address noise pollution challenges across diverse industries, underscoring the importance of interdisciplinary approaches in advancing noise reduction solutions for UAVs and beyond. To elaborate the discussion on controlling the noise, the author focused on passive and active methods. Passive methods, such as increasing propeller blades, utilizing sound reflectors, and biomimicry-inspired aerofoil shapes, offer innovative approaches to noise reduction while presenting design complexities and weight considerations. Active methods, including synchro-phaser technology, Active Noise Control (ANC) systems, and magnetically excited propeller blades, demonstrate cutting-edge solutions by dynamically mitigating noise emissions. Noctua's RotoSub (R) technology, originally developed for computer cooling fans, showcases electromagnetic interactions to emit anti-noise signals, promising quieter and more sustainable UAV operations.