A flow control device (12) on a structure (2) such that strain in the structure is at least partially transferred to the flow control device (12). The flow control device (12) has at least two states, or shapes, separated by an elastic instability region. The flow control device (12) is arranged to rapidly transition, or snap through, from the first state to the second state when strain in the structure exceeds an activation threshold of the flow control device. In an example, a spoiler (12) on an aerofoil (2) has a rest position where it is substantially flush with the low pressure surface and an activated position where it protrudes from the low pressure surface and modifies the airflow over that surface. The spoiler bends to move from the rest position to the activated position when the strain in the aerofoil crosses a threshold. The deployed spoiler reduces the lift on the aerofoil, acting to reduce the lift induced strain of the aerofoil to which the spoiler is attached.
Flow control device
2020-12-09
Patent
Electronic Resource
English