Performance Predictions of a Circulation Controlled-Vertical Axis Wind Turbine With Solidity Control Available to Purchase

Conventional straight bladed vertical axis wind turbines are typically designed to produce maximum power at tip speed ratio, but power production can suffer when operating outside of the design range. These turbines, unless designed specifically for low speed operation, may require rotational startup assistance. Circulation control methods, such as using blowing slots on the trailing edge could be applied to a Vertical Axis Wind Turbine (VAWT) blade. Improvements to the amount of power developed at lower speeds and elimination or reduction of startup assistance could be possible with this lift augmentation. Selection of a beneficial rotor solidity and control over when to utilize the blowing slots for the CC-VAWT (Circulation Controlled-Vertical Axis Wind Turbine) appears to have a profound impact on overall performance. Preliminary performance predictions indicate that at a greater range of rotor solidities, the CC-VAWT can have overall performance levels that exceed a conventional VAWT. This paper describes the performance predictions and solidity selection of a circulation controlled vertical axis wind turbine that can operate at higher overall capture efficiencies than a conventional VAWT.