| || || Goundar, Jai Nendran|
| || || Tidal current assessment and design of a horizontal axis tidal current turbine for Fiji |
Author:Goundar, Jai Nendran
Institution: University of the South Pacific.
Call No.: pac In Process
Copyright:10-20% of this thesis may be copied without the authors written permission
Abstract: Pacific Island Countries (PICs) have a huge renewable energy potential to meet their energy needs. Limited resources are available on land; however, large amount of ocean energy is available and can be exploited for power generation. PICs have more sea-area than land-area. Tidal current energy is very predictable and large amount of tidal current energy can be extracted using tidal current energy converters. It is important to perform tidal current assessment before designing tidal energy converters, and it is necessary to study the hydrodynamics of such converters. A detailed resource assessment was carried out at two locations in Fiji – known as Wilkes passage and Gun-barrel passage - for 3 months. The Gun-barrel passage was found to have a good marine current and current speeds exceeding 2 m/s many times were recorded. Therefore a turbine can be installed at this site. A 10 m diameter, 3-bladed horizontal axis tidal current turbine (HATCT) was designed. Hydrofoils were designed for different blade location; they are named as HF10XX. The hydrodynamic characteristics of the hydrofoils were analyzed. A thick hydrofoil with a maximum thickness of 24% and a maximum camber of 10% was designed for the root region. The maximum thickness of hydrofoils was varied linearly from the root to the tip for easier surface merging. For the tip region, a thinner hydrofoil of maximum thickness 16% and maximum chamber 10% was designed. It was ensured that the designed hydrofoils do not experience cavitation during the expected operating conditions. The characteristics of the hydrofoils HF10XX were compared with other commonly used hydrofoils. The blade chord and twist distributions were optimized using BEM theory. The theoretical power output and the efficiency of the rotor were also obtained. The maximum power at the rated current of 2 m/s is 150 kW and the maximum efficiency is 47.5%. The designed rotor is found to have good efficiency at current speeds of 1-3 m/s.