Guide vane with a winglet for an energy converting machine and machine for converting energy comprising the guide vane

A machine for converting energy, comprising:

• a casing;
• a guide vane being fixed at the casing;
• a rotor shaft rotatably supported within the casing for rotating the rotor around an axial direction orthogonal to a radial direction;
• wherein the guide vane extends inwards from the casing towards the rotor shaft;
• the guide vane comprising:
• a guide vane body for guiding a streaming fluid, the guide vane body having a pressure surface and a suction surface;
• and
• a winglet for reducing leakage of the streaming fluid from the pressure surface to the suction surface,
• a trailing edge;
• and
• a leading edge;
• wherein the winglet extents from the trailing edge to the leading edge,
• wherein the winglet is arranged at a longitudinal end of the guide vane body, and
• wherein the winglet is arranged at the pressure surface,
• wherein the winglet is free of protrusions beyond the leading edge and beyond the trailing edge,
• wherein the longitudinal end of the guide vane body corresponds to a radially inner end of the guide vane,
• wherein the winglet protrudes transversely from the pressure surface of the guide vane body with a protrusion dimension,
• wherein the protrusion dimension measured at a position along the direction from the leading edge towards the trailing edge depends on a thickness of the guide vane body at the position, the thickness being a distance between the pressure surface and the suction surface of the guide vane body,
• wherein the distance between the pressure surface and the suction surface varies along a path from the trailing edge to the leading edge,
• wherein the greater the thickness the greater the protrusion dimension,
• wherein the protrusion dimension increases in a first region extending from the trailing edge of the guide vane body to an intermediate position of the guide vane body along a direction from the trailing edge of the guide vane body towards the intermediate position of the guide vane body,
• wherein the protrusion dimension decreases in a second region extending from the intermediate position to the leading edge of the guide vane body along a direction from the intermediate position towards the leading edge of the guide vane body, and
• wherein the protrusion dimension at any given position along a direction from the leading edge towards the trailing edge amounts to between 0.5 and 1.5 times the thickness of the guide vane body at the given position along the direction from the leading edge towards the trailing edge, and
• wherein the winglet has a thickness along a direction parallel to the leading edge, wherein the thickness is less than 70% of the protrusion dimension.