Wave Energy Harvesting Turbine: Performance Enhancement

The performance of an oscillating water column (OWC) wave energy system depends upon several factors including its turbine performance. OWC turbines have inherently low efficiency and low operating range. Through this work, the shape of a Wells turbine was tried to modify to enhance the efficiency and enlarge the operating range. A numerical investigation with steady state flow condition has been reported to change blade thickness from hub to tip. A new concept to combine NACA0015 and NACA0024 at the hub, the midspan and the tip section were developed and the blade was produced through smooth polynomial so that the blade will have different thickness along the span. A commercial code ANSYS-CFX (R) v14.5 was used for the simulations. The turbulence k-omega SST model was adopted and the reference turbine performances were compared with existing results reported in the literatures. It was found that a blade thinner at midspan gives lesser flow separation, which helps increasing the turbine performance. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).