Hydro-Dynamic Simulation of a Cylinder Buoy for Wave Energy Conversion

Development of technology to harness the vast amount of renewable energy available in nature has been ever-increasing in popularity. A worldwide desire to limit dependency on fossil fuels as a means to produce power has motivated research in solar, wind, and wave energies, as well as other clean, naturally-abundant energy sources. With a density approximately 1000 times greater than air, the energy potential of ocean water is tremendous, and it is capable of providing power to locations in which other forms of renewable energy are not applicable—namely coastal regions with minimal wind or sunshine, or offshore structures. This research details the hydro-dynamic modeling of an innovative buoy design for a wave energy harvester that converts the heaving motion of waves into electrical power. Power is generated through the use of a bi-directional turbine which is driven by the relative water velocity created by the heaving buoy. In order to predict the changing velocity profile in which the bi-directional turbine will experience, a hydro-dynamic model has been created with a smoother particle hydro-dynamics code, SPHysics. The model can accurately simulate the motion of the buoy as it is excited by various ocean waves for different ocean depths. In order to maximize the flow velocity through the turbine, various geometric parameters will be altered to attempt to have the buoy and ocean wave perfectly out of phase. Additionally, the buoys stability is studied to determine the optimal geometry to promote a vertical motion as any yaw or pitching motion can not be harnessed by the bi-directional turbine.