WIND TURBINE BLADE

Boundary layer control means for maintaining the flow of a flowing medium attached to the exterior of a flow control member having a flow control surface, where the flow has a flow direction. The means to maintain flow includes a channel submerged in the flow control surface. The channel has a first end facing the flow of the flowing medium, a second end positioned downstream in the flow of the flowing medium from the first end, and a bottom surface extending from the first end to the second end. Furthermore, the channel comprises a first sidewall extending between the flow control surface and the bottom surface and extending between the first end and the second end, the first sidewall forming a first sidewall edge between the first side wall and the flow control surface, as well as a second sidewall extending between the flow control surface and the bottom surface and extending between the first end and the second end, the second sidewall forming a second sidewall edge between the second side wall and the flow control surface. The channel at the first end comprises a first flow accelerating channel zone, where the flow is accelerated, and at the second end comprises a second channel zone, where the first sidewall and the second sidewall are diverging in the flow direction.