Modeling of the aerodynamics of the integrated four blades (VAWT) having movable vanes

One of the economic problems facing all the public at present is the increasing demand for energy. Because of industrial development, fossil fuel depletion is on the increase, so the use of renewable energies as an alternative to fossil fuels has become apparent. In addition to solving problems caused by fossil fuels on the climate. Wind power is one of the most important renewable energies; the wind turbine is the machine that converts wind energy into mechanical energy. Which is used to pumping water, grind grain and generate electricity. The aim of this work is to study the aerodynamic performance by using Computational Fluid Dynamics (CFD) of a model of a vertical axis wind turbine, which has four integrated blades (each of which consisted of a vertical movable vane with Darius-type airfoil). The objective from combining the airfoil with the vanes comes to solve the low starting torque of the airfoil. The (SST) k-ω turbulence model and finite volume method were used with ANSYS FLUENT 16.1 software. The results concluded from the present numerical simulation give that the drag coefficient Cd is in maximum value at the positive side at 90° angular position, and Cd is decreased to the minimum value in the negative side at 45° angular position. The drop in the static pressure on the positive side is higher than on the negative side. The aerodynamics characteristics results represented by the static and dynamic pressures distributions and velocity distribution show that the air exerted to the turbine blade on the negative side is easily passes without any resistance. Therefore, it can be concluded that the addition of the vertical movable vanes with straight airfoil in one construction of a vertical wind turbine blade helps to solve the Darrieus straight airfoil starting torque and increases the rotation of the turbine rotor.