Computer simulation on the performance of a combined-type vertical axis wind turbine

The starting performance is one of the problems which greatly affects the development of the straight-bladed vertical axis wind turbine (SB-VAWT). A combined type straight-bladed vertical axis wind turbine (CT-SBVAWT) was designed in this study by setting a Savonius rotor having good starting performance into the SB-VAWT to solve this problem. Computer simulations based on the 2 dimensions incompressible steady flow were carried out both on the model of CT-SBVAWT and SB-VAWT for comparison. The simulation included the static torque coefficients at different azimuth angles and the dynamic torque coefficients at different tip speed ratios. The flow fields around the two type wind turbines were also obtained at some tip speed ratio. Based on the computation results, the effects of the existence of Savonius rotor on the starting and dynamic performance of the CT-SBVAWT were discussed.