Abstract

Studies demonstrate that the reduced frequency is influenced by the incoming wind speed and the rotor speed . As a dimensionless parameter, characterizes the stability of the flow field, which is a critical factor affecting the performance of vertical-axis wind turbines (VAWTs). This paper investigates the impact of on the performance of straight-blade vertical-axis wind turbines (H-VAWT). The findings indicate that 0.05 is the critical value of .The same results in a similar flow field structure, yet the performance changes vary with different . A decrease in or an increase in leads to an increase in the average value and fluctuation of , which subsequently reduces the rotor rotation torque and decreases the maximum wind energy utilization rate . This reduction in weakens the stability of the flow field. Additionally, the high-speed area of the blade’s trailing edge velocity trajectory at , , and expands with increasing range. Velocity dissipation in the high-speed area of the trailing edge affects the stability of the flow field within the rotor.