Wind turbine rotor blade with actuatable airfoil passages
A wind turbine rotor blade includes a pressure side and a suction side. At least one airfoil passage is defined through the blade between the pressure side and suction side. A respective cover is configured over the airfoil passage at each of the pressure and suction sides. The covers are actuatable between a closed position wherein the cover is flush with the respective pressure or suction side and an open position wherein the cover moves to open the airfoil passage.
1. A wind turbine rotor blade, comprising:
a pressure side;
a suction side;
at least one airfoil passage defined between said pressure side and said suction side;
a respective cover configured over said airfoil passage at each of said pressure side and said suction side, said covers actuatable between a closed position wherein said covers are flush with said respective pressure side or suction side and an open position wherein said covers are moved to open said airfoil passage;
a control mechanism configured with said covers to move said covers between the open and closed positions; and
an actuatable lock separate from said control mechanism and operably configured between said first cover and respective said pressure side or suction side to maintain said first cover in the closed position and to release said first cover upon receipt of a control signal at a setpoint load condition whereby said cover moves to the open position by action of the control mechanism.
2. The wind turbine rotor blade as in claim 1 , further comprising a channel member disposed within an interior cavity of said blade between said pressure side and said suction side, said channel member defining said airfoil passage.
3. The wind turbine rotor blade as in claim 2 , wherein said channel member is oriented at an angle from said pressure side to said suction side relative to a horizontal chord plane through said blade and at a chord position on said pressure side so that said channel member extends linearly between said pressure side and said suction side without passing through internal structural members of said blade.
4. The wind turbine rotor blade as in claim 1 , wherein said covers pivot into said airfoil passage in the open position.
5. The wind turbine rotor blade as in claim 1 , wherein said control mechanism associated with at least a first one of said covers is an active control mechanism configured to move said first cover between the open and closed positions in response to the control signal that also releases said lock, said first cover variably positionable between the open and closed positions.
6. The wind turbine rotor blade as in claim 1 , wherein said control mechanism associated with at least a first one of said covers is a passive control mechanism including a biasing element to bias said first cover to the closed position and allow movement of said first cover to the open position at the setpoint load condition experienced by said blade.
7. The wind turbine rotor blade as in claim 6 , wherein said biasing element has sufficient strength to return said first cover to the closed position at loads acting on said rotor blade up to the setpoint load condition.
8. The wind turbine rotor blade as in claim 6 , wherein said biasing element has insufficient strength to maintain or return said first cover to the closed position with a load on said rotor blade, wherein said rotor blade is feathered to an unloaded condition wherein said biasing element moves said first cover to the closed position.
9. The wind turbine rotor blade as in claim 1 , wherein said blade comprises a plurality of said airfoil passages and respective said sets of covers, each said set of covers being independently controlled.