Effect of Flapping-wing on the Thrust Generated by Wing Vortex and Wake Based on UVLM

Development of flapping-wing aerial vehicles had been of interest in the aerospace community with ongoing research into unsteady and low Reynolds number aerodynamics based on the unsteady vortex lattice method (UVLM). Although most of the previous research had been about pitching and plunging motion of the flapping-wing aerial vehicles, aerodynamic influences of wing vortex and wake on vehicle thrust should be investigated in order to accurately model the vehicles. In this paper, three dimensions unsteady vortex lattice method was applied on the aerial vehicles models to study instantaneous thrust generated by wing vortex and wake for different flapping frequency. The results show that the average thrust increase with the increasing of flapping frequency and wing vortex generate much more thrust than the wake vortex; the thrust ratio of wing vortex and wake vortex increase with increasing of flapping frequency. This research is helpful to understand the flight mechanism of animals and improve the design of bionic flapping-wing aerial vehicles.