Within examples, systems for enhanced performance blades for rotor craft are provided and methods for operation. An example system for a rotary device is provided comprising a rotor blade coupled to a rotor hub. The system also comprises an air channel disposed within the rotor blade, where the air channel is sealed proximate to a distal end of the rotor blade. The system also comprises an inlet positioned at a proximal end of the rotor blade, where the inlet is in fluid communication with the air channel. The system also comprises a plurality of outlets positioned along the rotor blade, where each of the plurality of outlets are in fluid communication with the air channel.

A method for operating a wind turbine to avoid stall during derating thereof includes providing an initial pitch setting for one or more rotor blades of the wind turbine. Further, the method includes operating the wind turbine based on a rated power curve with the one or more rotor blades fixed at the initial pitch setting. Further, the method includes identifying at least one condition of the wind turbine that is indicative of stall. The method also includes derating the wind turbine. Further, the method includes modifying the initial pitch setting to an updated pitch setting when the at least one condition is identified.

A method of adjusting a pitch angle of a rotor blade of a rotor of a wind turbine is provided. The method comprises varying the pitch angle of the rotor blade during wind operation of the wind turbine from a starting angle to reach a limit angle (1, 2) at which the rotor blade and/or an operational value (P) of the wind turbine reaches a predefined threshold limit (P1/2; 1, 2), deriving a safe angle (3, 4) dependent on the limit angle (1, 2), operating the rotor blade at the safe angle (3, 4) or an angle from the safe angle (3, 4) away from the limit angle (1, 2). A pitch angle adjustment system is also provided for the same purpose.

A rotor blade system includes a hub for rotational movement in a defined direction of rotation. A first airfoil having a quarter-chord defined along a span thereof is coupled to the hub, but is uncoupled from the rotational movement of the hub. A second airfoil having a quarter-chord defined along a span thereof is coupled to the hub for rotation in direct correspondence with the rotational movement of the hub. The quarter-chord of the first airfoil leads the quarter-chord of the second airfoil when the hub experiences its rotational movement in the defined direction of rotation. A connector couples the tip of the first airfoil to the tip of the second airfoil.

A method of retrofitting vortex generators on a wind turbine blade is disclosed, the wind turbine blade being mounted on a wind turbine hub and extending in a longitudinal direction and having a tip end and a root end, the wind turbine blade further comprising a profiled contour including a pressure side and a suction side, as well as a leading edge and a trailing edge with a chord having a chord length extending there between, the profiled contour, when being impacted by an incident airflow, generating a lift. The method comprises identifying a separation line on the suction side of the wind turbine blade, and mounting one or more vortex panels including a first vortex panel comprising at least one vortex generator on the suction side of the wind turbine blade between the separation line and the leading edge of the wind turbine blade.

A rotor blade system includes a hub for rotational movement in a defined direction of rotation. A first airfoil having a quarter-chord defined along a span thereof is coupled to the hub, but is uncoupled from the rotational movement of the hub. A second airfoil having a quarter-chord defined along a span thereof is coupled to the hub for rotation in direct correspondence with the rotational movement of the hub. The quarter-chord of the first airfoil leads the quarter-chord of the second airfoil when the hub experiences its rotational movement in the defined direction of rotation. A connector couples the tip of the first airfoil to the tip of the second airfoil.

A method of retrofitting vortex generators on a wind turbine blade is disclosed, the wind turbine blade being mounted on a wind turbine hub and extending in a longitudinal direction and having a tip end and a root end, the wind turbine blade further comprising a profiled contour including a pressure side and a suction side, as well as a leading edge and a trailing edge with a chord having a chord length extending there between, the profiled contour, when being impacted by an incident airflow, generating a lift. The method comprises identifying a separation line on the suction side of the wind turbine blade, and mounting one or more vortex panels including a first vortex panel comprising at least one vortex generator on the suction side of the wind turbine blade between the separation line and the leading edge of the wind turbine blade.

An airflow generation device of an embodiment has a main body and a voltage application unit. The main body has a base formed of an insulating material and provided with a first electrode and a second electrode. The voltage application unit generates an airflow by applying voltage between the first electrode and the second electrode. Here, the main body is formed to include a portion which gradually decreases in thickness from a center portion to an end portion.

The rotor blades of a wind turbine each have a plurality of fiber-optic pressure variation sensors which can detect the onset of a stall condition. The output of the stall condition sensors is input to a stall count circuit which increases a stall count signal each time a stall indication is received. The stall count signal is decayed exponentially over time and the current signal is summed with the decayed signal from a previous sampling period to form a value from which a stall margin is determined. An : curve of tip speed to wind speed ratio against pitch angle reference is then determined from the stall margin.

Within examples, systems for enhanced performance blades for rotor craft are provided and methods for operation. An example system for a rotary device is provided comprising a rotor blade coupled to a rotor hub. The system also comprises an air channel disposed within the rotor blade, where the air channel is sealed proximate to a distal end of the rotor blade. The system also comprises an inlet positioned at a proximal end of the rotor blade, where the inlet is in fluid communication with the air channel. The system also comprises a plurality of outlets positioned along the rotor blade, where each of the plurality of outlets are in fluid communication with the air channel.