Performance Improvement of a Wind Turbine Blade by Variable Thickness Membrane Airfoil Considering Two-Way Fluid-Solid Interaction

A membrane wind turbine airfoil is analyzed through two-way Fluid-Solid Interaction (FSI) using finite element method. The problem is considered as a quasi 2D with full membrane flexibility. The results of the fluid-solid interaction in every time step are transferred to the subsequent step, and the effects of the fluid section and solid deformations on each other are also examined. The standard S809 airfoil is investigated in four different angles of attack and a Reynolds number of 2×106. Initially, the membrane airfoil with uniform membrane thickness is investigated, and the superiority of its aerodynamic factors over rigid airfoil is confirmed. Next, variable-thickness membranes are considered to enhance the efficiency and improve aerodynamic performance compared to the uniform thickness state. Results show that membranes with variable thickness can increase the airfoil efficiency compared to the uniform-thickness condition. The power required to rotate the blade is also reduced in this case.