Wicket gate for a hydraulic turbine or pump

A wicket gate for a hydraulic turbine or pump, the wicket gate comprising:

• a blade being defined by a pressure side surface, an oppositely facing suction side surface, a leading edge and a spaced apart trailing edge;
• a first trunnion;
• a second trunnion;
• said blade and one of said first and second trunnions having an air passage with an air inlet aperture and air outlet apertures formed therein, wherein said air passage is connected with said air inlet aperture and said air outlet apertures in a way that air can flow from said air inlet aperture through said air passage to each of said air outlet apertures and said air outlet apertures are disposed at said trailing edge of said blade;
• and
• said suction side surface of said blade having a profile along a cross section through a point P1 and a point P2 being concave, whereas the point P1 is disposed on said suction side surface of said trailing edge, directly at said trailing edge where one of said air outlet apertures is disposed, and the point P2 is spaced apart from the point P1 by less than 10% of a wicket gate length L and the point P2 is disposed upstream of the point P1 on a line perpendicular to said trailing edge starting at the point P1, and an angle between a first normal vector on said suction side surface N1 disposed at the point P1 and a second normal vector on said suction side surface N2 disposed at the point P2 being at least 2 degrees.