Full-Vehicle Experimental Investigation of Propeller Icing on a Hovering Quadcopter

This study investigated the ice accretion process on unmanned aerial vehicle (UAV) propeller blades rotating under various conditions. The experimental tests were carried out in the cold chamber laboratory, and two typical icing scenarios were applied: rime ice and glaze ice. With high-resolution imaging and flight data analysis, the effects of ice formation patterns on UAV performance were studied in detail. The test results revealed different ice accretion characteristics for each condition. In rime ice conditions, the ice layer formed in perfect harmony with the airfoil of the propeller and was less affected by the rotational effects. Glaze ice conditions created complex needle-like ice formations due to the centrifugal force on unfrozen water with the non-dimensional water-loading parameter confirming substantially higher delivered water in glaze (~3:1 ratio relative to rime). The performance loss experienced in the UAV was determined by analysing the motor speed, motor input power and total battery capacity loss data. Averaged over the icing interval, the electrical input power of the affected motors increased by ≈26.4% (front-left) and ≈15.8% (rear-right) in glaze relative to rime. Glaze ice conditions resulted in more severe performance penalties compared to rime ice conditions, leading to greater power loss and the normalised battery state-of-charge fell to 69.85% under glaze and 74.10% under rime conditions. This study examined in detail the icing process occurring on rotating full vehicle UAV propellers and its impact on flight performance and safety.