The challenge

A spoked wheel with a rim stabilized and pressurized by prestressed spokes is a highly effective lightweight structure that can be built in almost any size with diameters from e.g. 1-200 m. How would the rim of a spoked wheel look like when used as a ring-shaped rotor blade?

The invention

The RES-Sinusodial Ring Turbine is characterized by the following features:

  • The rim is subdivided in an equal number of segments
  • The segment consists of airfoils exposed with their nose to the incoming flow
  • Each segment is divided in a convex and a concave half
  • Within one segment the suction side and the drag side of an airfoil change from the outside to the inside of the rim
  • Prestressed spokes connect the sinusodial ring to a nozzle that houses the generator
  • The turbine is driven directly by uplift resulting from each half of a segment creating torque at the horizontal axis of rotation

The advantages

  • Elegant and effective rotor drive
  • Uncompromised lightweight structure
  • The sinusodial ring-shaped rotor blade works with an optimal distance to the axis of rotation

The applications

  • Small wind turbine for local power generation
  • Medium size wind turbine for a wider distance to buildings
  • Large turbines for offshore generation of electric power