A study of modified vertical axis tidal turbine to improve lift performance

A design of Darrieus vertical axis tidal turbine using modified airfoil was studied numerically in this work. The turbine design was evaluated in 2D CFD model using k-? turbulence model, upwind interpolation scheme and simulated using OpenFOAM. The turbine had three blades which were arranged symmetrically. The blades were of NACA 0012 airfoil which had been modified in the trailing edge region to increase its lift performance. The modification was made by truncating the trailing edge at the 15% of chord length from the trailing edge. Single normal and blunt airfoil were modelled and investigated prior to the turbine design evaluation. For generating the mesh, C-structured grid was employed to the single airfoil model and hybrid mesh to the vertical axis tidal turbine model. From the single airfoil simulations, it was found that blunt NACA0012 had 12% higher lift coefficient than normal airfoil and the pressure coefficient magnitude of blunt vertical axis tidal turbine significantly rise two times from vertical axis tidal turbine using normal NACA0012 airfoil.