A numerical study of the aerodynamic performance of damaged dragonfly wings in forward flight.

Dragonfly wings often suffer damage from predators or by wear over their lifespan. The damage is more likely to start from the wing tip and trailing edge, but damage patterns vary, resulting in diverse aerodynamic effects. We generate a series of damaged dragonfly wings according to the probability maps reported by Rajabi et al. [10.1242/bio.027078], and conduct computational fluid dynamics (CFD) simulations to compare the influence of wing area loss on aerodynamic performance in forward flight, as well as the flow field for analyzing the mechanisms of force changes. The simulations are made using our open-source code WABBIT, developed by Engels et al. [10.4208/cicp.OA-2020-0246]. We find that a large area lost on the forewing can lead to a decrease of horizontal force in the ipsilateral hindwing when the wings approach, due to reduced forewing-hindwing interaction. Meanwhile, the forces on the forewing keep the same as intact wing when the ipsilateral hindwing is damaged tremendously.