This work explores the interaction of streamwise vortices generated by a leader wing on rigid and flexible follower wings in a close homogeneous V-formation. Computations are performed using high-fidelity implicit LES simulations coupled with a geometrically nonlinear Reissner-Mindlin finite element plate model. Several areas are explored in order to provide a better understanding of the unsteady flow structure, aerodynamic loading, and aeroelastic response that might be encountered by light-weight high aspect ratio wings in close-formation. First, exploration of positioning between rigid wings shows interaction between the incident streamwise vortex and follower wing tip vortex. These effects include vortex-dipoles, instability of the vortex cores, and bifurcation which can all significantly reorient wake features with a small change in lateral or vertical positioning. Each case demonstrates an enhanced lift-to-drag ratio while unsteady loading remains comparable to that of a single wing. This suggests fluctuations in the incident vortex due to atmospheric disturbances or unintended/uncontrollable aircraft motion might be a more dominant source of buffeting behavior in the case of flexible wings. Such an effect would be magnified in the presence of a stronger incoming vortex as shown in the case of increasing the leader-wing angle of attack. Second, computations of flexible wings in close-formation primarily results in static-aeroelastic spanwise deflection of the wing and repositioning of the vortex-encounter. Consequently, large changes in flow structure and loading result from small static spanwise bending deformations. A small dynamic response is observed in the twisting-mode of the moderately flexible case which amplifies pitching-moment fluctuations and would have implications on the fatigue life of the wing structure. Interestingly, this source of unsteadiness was diminished on the vortex-encounter side of the wing.
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