An Experimental Investigation on Dynamic Water Runback Process Over the Blade Surface of a Rotating Drone Propeller

Flights during heavy rainfall highlighted a substantial increase in power consumption, highlighting the operational challenges faced by UAVs in adverse weather. This study examines the impact of heavy rainfall on the performance of multirotor UAVs, with a focus on the transient water runback behavior over the rotating propeller. A novel Digital Image Projection (DIP) method was utilized to enable quantitative measurements, for the first time, of the spatial-temporal thickness distributions of surface water films over the UAV propeller across varying rotational speeds. To enable the DIP method on a rotating propeller, an advanced phase lock technique is utilized to enable a high-speed camera to capture the propeller at a fixed phase during each revolution. The quantitative DIP measurements reveal the impact of water accumulation on aerodynamic performance. This research represents a significant step forward in understanding the complex interaction between water and high-speed rotating surfaces. By enabling precise quantification of transient water film behavior on the propeller, this work lays the foundation for developing more resilient and efficient UAV systems capable of operating reliably in challenging weather conditions.