Optimization of turbine design for deep sea (ocean current) power energy technology.

Abstract

The main objective of this thesis is to study renewable energy based on ocean current energy conversion. Different technologies based on ocean energy conversion are described and this research focuses on the design of a horizontal axis turbine running in free stream water under a range of different velocity values. We explain the concept of the design, the source of the power, thrust formulae and use computational tools to analyze the efficiency of the project. For this design, we have considered data collected at different sites where a full scale project could be implemented. The test site was chosen on the basis of statistical analysis of the best velocity profile available. From studies on wind turbine airfoils we chose a profile that seemed to be efficient for the range of Reynold number equivalents required according to the conditions of the chosen site. This profile was adapted to suit an ocean current turbine. Combining the chosen profile data and formulae for optimum pitch angle, we designed different prototypes using Autodesk Inventor Professional. These designs are based on concepts after Betz, Schmitz, Blade Element Momentum and also using a design tool named Turbem which has been developed for design of water turbine blades. We used Autodesk CFD to run simulations and analysis of the turbines. The results provide an average of the change in water pressure on the surface of the blades and average power based on a series of calculations. Results are presented in tables showing the power output of the system in relation with the velocity of water and the radius of the turbine. Studies on material, implantation on site and cost still need to be conducted but we can recommend ocean current energy conversion as an alternative source of electrical energy.