On the Performance Degradation of UAV Propellers Under Rainfall and Icing Weather Conditions

Unmanned-Aerial-Vehicles (UAVs) pose a high risk of accidents due to rainfalls and inflight icing in cold weather. In this study, a series of fly test campaigns are conducted to fly an instrumented UAV under thunderstorms with heavy rainfalls and icing weather conditions to characterize the aerodynamic performance degradation of UAV propellers induced by rainfall and inflight icing, in comparison to those under normal weather conditions. By leveraging the unique Raining/Icing Research Tunnel available at Iowa State University, a comprehensive lab experiment campaign was also conducted to elucidate the underlying physics pertinent to the rain-induced and icing-induced performance degradation of the UAV propellers. The research findings are very helpful in bridging the knowledge gap between the idealized operation conditions commonly used in UAV propeller design and the realistic weather conditions experienced by UAVs to ensure more reliable and predictable UAV operations under all weather conditions.