عنوان مقاله [English]
The purpose of this research is to investigate the performance of hybrid Darrieus- Savonius wind turbines to achieve a model with high starting moment and suitable performance conditions. Straight-bladed Darrieus wind turbines have high-amplitude fluctuations in moment and, at some angles, this moment is not enough to start the turbine motion. The hybrid turbine is compared with two equivalent models of straight-bladed Darrieus wind turbines. The first model has equal available power and the second model has equal height with the hybrid turbine. Three-dimensional simulation is performed using computational fluid dynamics and solving unsteady Reynolds averaged Navier-Stokes equations with finite volume method, using turbulence model and rotating mesh for rotation of the turbine. According to the results, at the self-starting, the hybrid turbine possesses 22.24% and 17.5% less standard deviation and 69.8% and 56.9% more average moment, respectively, compared to the first and second equivalent turbines. In operational mode, the hybrid turbine at the rotational speed of 30 RPM possesses 16.1% and 27.3% less standard deviation and 19.1% and 1.03% more average moment, respectively. Therefore, the hybrid turbine at the self-starting, as well as at low rotational speeds, possesses more average moment and less fluctuations compared to equivalent Darrieus turbines.