US Patent 9789956 Vortex generators responsive to ambient conditions

A deployable vortex generator attached to a lifting surface includes a vane moveable relative to the lifting surface. The vane moves from a deployed position to a retracted position in response to a change in ambient conditions. In the deployed position, the vane acts on the air flow to create vortices. In the retracted position, the vane is closely aligned with the free stream velocity.