Abstract: A boundary layer wind turbine having one or more flaps coupled to the underneath of a turbine disk is provided. The turbine uses an assembly of closely stacked disks that are rotated by the wind blowing across the face of the disks to rotate a turbine shaft that is attached to an electrical generator to generate electricity. The wind moves the turbines as it flows across the surface of the closely spaced disks. The disks include one or more flaps attached to the bottom side of the disks. The wind blows against the flap, which in turn exerts a force on the disk, causing the turbine to rotate. The flaps may be located near the outer circumference of the disks. The one or more flaps on the disks retract automatically as the rotational velocity of the turbine increases.