The challenge

Tidal flow regularly oppositely changes its direction of incidence. The same phenomenon occurs in an oscillating water column, when combined with an air chamber, in which the air is pressed out by rising water level and sucked into the chamber again by falling water level. The Wells-Turbine keeps its direction of rotation, even if the incoming flow constantly changes its direction. Symmetrical radial rotor blades however cannot be adapted to different rotational speeds and therefore are ineffective. Is it possible to design a turbine for bidirectional flow avoiding any disadvantageous side effects?

The invention

The RES-Biturbine has a ring-shaped perimetric rotor blade in a symmetric position to its plane of rotation. Elements, that cause resistance within this rotor circle, are deflecting the flow either towards or away from the axis of rotation. At each point of the ring-shaped rotor blade, the incoming flow as the sum of flow speed and rotation speed impacts the rotor blade with a conical angle of incidence, causing rotation.

The advantages

  • Simple and sturdy design for a tidal power plant
  • High effectiveness due to a ring-shaped rotor blade
  • Relief of leeward pressure by upstream thrust as a resulting force

The applications

  • Air turbines for wave power plants
  • Underwater turbines for tidal power plants