In order to reduce the aerodynamic load fluctuations on wind turbine blades by innovative control solutions, strategies of active circulation control acting at the blade airfoil trailing edge are studied. This paper focuses on a comparison of results obtained by performing plasma and continuous squared jet actuation experimentally and slotted jet actuation numerically on a blade airfoil designed with a rounded trailing edge. Plasma actuators and slotted jets act uniformly in the spanwise direction (two-dimensional action), whereas squared jets blow through small squared holes distributed along the span, and therefore, provide a three-dimensional action on the flow. Results are presented for a chord Reynolds number of 2x10 5. Time averaged aerodynamic values, flow fields were analysed to assess the effectiveness of these actuators located at the rounded trailing edge and to highlight flow mechanisms involved in this type of flow control strategy.