The major objective of this research was to suggest a water turbine design with higher power efficiency by conducting a parametric study of hydrofoil shapes, modified hydrofoil shapes with circular void, tip speed ratio, pitch angle and solidity. The other objectives of this research included answering the question of whether the efficiency of a chosen Gorlov turbine design can be increased by including circular void in the hydrofoil sections and studying the variation in lift and drag forces on hydrofoil sections with different circular voids in a steady state. The design was intended for a specific case of Gulf Stream ocean currents. Research was carried out using a series of 75 computational fluid dynamic (CFD) 2D simulations which consists of 67 rotating turbine simulations (RTS) and 8 steady state simulations (SSS) using the commercial CFD software, STAR-CCM+. Through this research, the power efficiency of the base case turbine was improved from 31.5% to 49.92% according to the simulation results. Results of this research showed that it is possible to increase the power efficiency of the turbine using the modified hydrofoils with voids.
