Novel design of an ocean wave power device utilizing a bi-directional turbine

This paper details an innovative design for a wave energy harvester that converts the heaving motion of waves into electrical power. The conceptual design utilizes a unique bi-directional turbine system that develops a torque in a given direction, independent of whether the fluid is moving upward or downward. The result is power production both as the buoy is heaved upward by a wave as well as while the buoy falls after the wave passes. Although a Wells turbine is a bi-directional turbine currently in use, the proposed bi-directional design, unlike the Wells turbine, is intended to use the ocean water as the working fluid. In addition, in the proposed design, stator blades redirect the fluid to flow nearly parallel to the blade angle, as opposed to the nearly perpendicular flow that acts on the Wells blade. A simple computational fluid dynamics (CFD) program demonstrated the feasibility of the proposed bi-directional design, indicating a 22.3% torque increase over a NACA 0012 Wells turbine blade of equal size.