UAV icing: Transient icing response of small-scale UAV propeller configurations under a low-LWC icing condition

Atmospheric icing poses a significant operational risk to small-scale Unmanned Aerial Vehicles (UAVs) by inducing rapid aerodynamic degradation and unsteady shedding cycles. This study experimentally compares the transient performance degradation and shedding behaviour of four small-scale UAV propeller configurations under a controlled low-LWC icing condition ( T = − 5 ° C , LWC = 0.2 g/m 3 , MVD = 24 μ m ). These propellers were tested in the VTT Icing Wind Tunnel at a matched advance ratio of J = 0.51 , with performance quantified through synchronized thrust, torque, and vibration measurements. The measured histories varied across the four tested configurations. The 12X6E had the largest mean power-coefficient ( C P ) buildup slope, nearly four times that of the 12X10E; in the most severe runs, thrust approached zero before the first major shedding event. Within each tested diameter pair, the higher-pitch propeller had a lower mean normalized buildup rate and smaller mean changes at shedding. In the 10X6E sensitivity study, shedding timing showed a stronger and more consistent dependence on rotational speed than on freestream velocity, consistent with rotational loading contributing to shedding timing in the tested cases. These measurements compare four tested configurations under one atmospheric condition.