Rotor blade active flap

An active flap (1) comprising

• a primary body (1P) adapted for mounting to the trailing edge (20TE) of a wind turbine rotor blade (20);
• a flap turning assembly comprising an elastic element (12) comprising an enclosed interior cavity (100) and an inflatable hose (10) disposed in the interior cavity (100), the flap turning assembly adapted to turn the active flap (1) between
• a neutral position (R0), in which the active flap (1) directs airflow (A20S, A20P) towards the suction side (P20S) of the rotor blade (20), and
• a working position (R-Rmax), in which the active flap (1) directs airflow (A20S, A20P) towards the pressure side (P20P) of the rotor blade (20);
• wherein the flap turning assembly is configured to move about a hinge (1H) disposed adjacent to an upstream end of the interior cavity (10) from the neutral position (R0) when the inflatable hose (10) is deflated to the working position (R-Rmax) when the inflatable hose (10) is inflated, whereby a shape of the primary body (1P) is altered when the inflatable hose (10) is inflated so that an upper surface of the primary body (1P) at a downstream portion is deflected downwards and
• a secondary body (1S) mounted to the primary body (1P) and configured to hold the active flap (1) in its neutral position (R0).