Experimental Investigation on the Effects of Icing on Multicopter UAS Operation

Ice Accretion on Rotary-Wing Unmanned Aerial Vehicles—A Review Study

“…For the rime-ice case at T ∞ = −12 • C, in 2020, Benmeddour [32] observed that a change in the MVD value from 20 µm to 60 µm with a constant LWC value of 0.5 g/m 3 had only a negligible influence on the rate of change of thrust, torque, and power. Similar observations were made by Kazomara [44] during an icing wind tunnel test of a multicopter UAV under mixed ice conditions (T ∞ = −5 • C). A power increase of 100% was obtained in 80 s for an MVD value of 20 µm, with the same result after 70 s for an MVD value 40 µm.…”

“…The surface roughness characteristics are highly altered by ice accretion and can increase the drag coefficient and power requirements. Kazomara [44] observed that the surface roughness due to ice accretion increases from root to tip and is minimum in the region between the leading edge and the trailing edge. The increase in surface roughness is also observed to increase with MVD.…”

“…Most studies discussed in this review were based on FAR 25 Appendix C icing conditions. When Kazomara [44] performed studies based on Appendix O freezing drizzle conditions by increasing the MVD to 100 µm, the performance curves seemed unaffected when compared to the same conditions at 40 µm. In 2021, Catry [45] performed icing studies on a 9-inch-diameter three-blade propeller with an estimated MVD value of 400 µm at T ∞ = −5 • C. It was observed that the ice accreted with such high MVD values resulted in ragged ice features and complex 'lobster-tail-like' ice structures, as observed by Liu [16] and associated with a considerable increase in ice mass to 17 g within 65 s. At a rate of 25 × 10 −3 N per sec ond, the thrust dropped from 1.65 N to zero in just 65 s. Thicker ice accretions and faster performance degradation were also observed by Villeneuve [42] in 2022 in association with high MVD values (supercooled large droplets).…”

“…Yan [37] commented that the tilt also influences the ice accretion rate, although the existing literature is insufficient to understand the effect, and this relationship remains a knowledge gap. Kazomara [44] performed ice tunnel experiments on a multicopter UAV at an angle of attack of 10 degrees. When comparing to the previous studies at zero-degree angle of attack, the pressure side of the propeller blade was consistently iced.…”