Improving aircraft aerodynamic performance with bionic wing obtained by ice shape modulation

For Unmanned Aerial Vehicles (UAVs) with limited electrical power to achieve effec-tively anti-/de-icing at the leading edge of the wing, a strategy of ice shape modulation was pro-posed. Isolated simulated ice shape pieces printed by 3D printing technology are mounted on a NACA0012 finite wing model, and its lift/drag coefficients and suction-side velocity fields are mea-sured by the six-component force balance and the Particle Imaging Velocimetry (PIV), respectively. The ratio of the spanwise length of a single ice shape piece to chord length and the spanwise length of the non-icing area between the two adjacent single ice shape pieces are defined as dimensionless ice shape length (w/c) and dimensionless modulation ratio (w/)), respectively. The results indicate that for a fixed w/), the wing lift coefficient first increases and then drops with increasing w/c, and a peak value exists when w/c is between 0.1 and 0.2. The lower the w/) is, the higher the wing lift coefficient will be. The periodical variation of the flow separation area along the spanwise direc-tion is attributed on the one hand to the acceleration effect of the flow field in the non-icing area which reduces the separation area, and on the other hand to the cross-flow caused by the streamwise vortices from the non-icing area to the icing area which promotes the mixing of the flow field (sim-ilar to vortex generators). The obtained modulation law is verified through flight tests and provides guidance for the use of ice shape modulation scheme for UAVs that cannot be completely anti-/de-icing under severe weather conditions.(c) 2022 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/ ).

Automated summary

A strategy of ice shape modulation is proposed for UAVs with limited electrical power to effectively anti-/de-icing at the leading edge of the wing. Experimental measurements of a 3D printed ice shape on a NACA0012 finite wing model reveal that the wing lift coefficient varies with the dimensionless ice shape length (w/c) and the dimensionless modulation ratio (w/)). The flow separation area along the spanwise direction is influenced by the acceleration effect and the cross-flow caused by streamwise vortices. Flight tests verify the effectiveness of the modulation scheme for UAVs in severe weather conditions.