study of the self-starting performance of a vertical-axis wind turbine

The self-starting performance of vertical-axis wind turbines (vawts) is crucial for their widespread utilization. conventional evaluation methods using the static torque coefficient (cts) or self-starting time have limitations. &the minimum 1st derivative of angular acceleration in the lift acceleration state& is proposed to serve as a suitable indicator for the completion of self-starting. understanding the behavior of the self-starting process in vawts is crucial for optimizing power output. a comprehensive methodology is used that integrates experiments and computational fluid dynamics (cfd). wind tunnel experiments are conducted to evaluate the self-starting and power output performance of the turbines. cfd is employed utilizing the fluent 6dof module to investigate the torque and flow field characteristics during the self-starting process. additionally, the objectives of our study are to investigate the effect of static evaluation methods on the dynamic start-up process and to explore the effects of airfoil type, pitch angle, and inlet wind speed on the self-starting behavior of turbines. the results indicate that a high cts ensures initial rotation, but the subsequent self-starting time remains independent of this factor. increasing the pitch angle enhances the self-starting performance. at an inlet speed of 5 m/s, for the naca2418 airfoil turbine, the self-starting times for pitch angles of 10 ° and 5 ° are reduced by 20% and 12%, respectively, compared to that for 0 °. the naca0018 airfoil turbines with pitch angles of 0 ° and 5 ° fail to complete self-starting. the airfoil type also plays a crucial role, with the naca2418 airfoil demonstrating superior self-starting performance and power performance. furthermore, the minimum self-starting wind speed of the naca0018 airfoil turbine was explored and determined be between 5.5 m/s and 6 m/s. the utilization of this novel self-starting evaluation method addresses the limitations of traditional approaches, providing a more universally applicable interpretation of the characteristics of turbine self-starting behavior.