IMPACT OF ROTOR SOLIDITY ON THE DESIGN OPTIMIZATION OF FLOATING VERTICAL AXIS WIND TURBINES

Increasing the solidity of a vertical axis wind turbine (VAWT) leads to increases in annual energy production and aerodynamic loads. To explore the effects of solidity on design and optimization of floating VAWTs, the rotor solidity is varied by changing the blade chord size of a 5MW floating VAWT while other geometry parameters of the rotor are kept same. A series of 5MW Darrieus-type rotors with different solidities are designed and optimized according to the rotor design loop including satisfying strength, deflection, fatigue, buckling, dynamics and flutter requirements. A cost analysis is performed by evaluating trade-off in the rotor material cost versus the AEP (Annual Energy production) to decide the optimal solidity for the structural design. The tension leg platforms (TLPs) are designed and optimized to support the optimal rotors. Dynamic responses of the optimized platforms subject to various environmental conditions are evaluated using a semi-coupled aero-servo-hydro numerical model.