OFFSHORE VERTICAL AXIS WIND TURBINE SIMULATION

The world is undergoing a paradigm shift as more people are becoming aware of energy consumption patterns, reinforcing the need for developing cleaner and more sustainable ways to generate electrical energy. Globally, the development of onshore wind farms is sometimes impeded by factors such as aesthetic impact, acceptance by the public, the threats to surrounding biodiversity, noise from the power plant and possible land use conflicts. Vertical Axis Wind Turbines (VAWTs) are now being developed and tested for offshore and far offshore power generation. The following paper aims to test a helical turbine design for sites identified off the coast of South Africa. The paper investigates multiple blade profiles under the equivalent blade Reynolds number for the identified sites. Each of the blades' characteristic profiles were analysed to understand the lift and drag characteristics under various Reynolds conditions. The Selig series S1046 blade profile showed good results in comparison to the other blade profiles. The results showed that the lift and drag coefficients are not significantly affected by the level of ambient disturbance. The performance curves under low solidity ratios showed that the S1046 profile was preferable in comparison to the NACA23018 and NACA0015 blade profiles. With respect to torque distribution on the turbine rotor, the S1046 profile depicted stable output over a larger range of tip speed ratio. The turbine results also show that an aspect ratio of 1.5 proved to have a larger operating range than that of the higher aspect ratio of 2.5.