Effect of rotor blade position on Vertical Axis Wind Turbine performance

In this paper a numerical study is presented with the aim of evaluating the performance output of three Vertical Axis Wind Turbine (VAWT) configurations. Here using Computational Fluid Dynamics (CFD) a two-dimensional Multi Reference Frame (MRF) approach has been used to perform steady state simulations. For this purpose an inlet velocity of 4m/s has been used along with rotor blade Tip Speed Ratios (λ) in the range of 0 to 0.6. The effects of varying rotor blade position on the global and local flow fields have been quantified. Furthermore, the influence of rotor blade position on the performance output has been computed. It has been found that within a typical rotor blade passage, maximum torque is obtained at a unique rotor angle. It can be seen that the torque output of the turbine decreases with an increase in rotor tip speed ratio (λ) for all rotor blade positions. From the data obtained it can be concluded that the VAWT power curve characteristics vary with relative rotor blade position.