Noise Reduction on a Low Reynolds Number Propeller

With the mass application of drones in daily work, more attention has been paid to the noise problem. The noise generation mechanism of low Reynolds number propellers is studied in this paper. It is found that there are laminar separation bubbles on the suction surface, causing an increase in broadband noise. Leading edge boundary layer trips are added to remove the bubbles. Finally, experimental measurements indicate that isolated propeller noise reduction is up to 5 dBA. It still has a 1.5 dBA reduction in the full-loaded hovering drone test, which brings many conveniences for daily work.