Performance Improvement of Lift Type Wind Turbine with Straight Blades Based on Interference Airflow Technology

Abstract

Abstract：The method of interference airflow is put forward to solve the problem of H-type wind turbine, lower performance, caused by the small angle of attack. The double-multiple stream-tube model is used for analyzing the influence of the interference airflow to the angle of attack in the speed radios of 5 and 6 respectively. Calculation shows that: Disturbance airflow increases the blade angle of attack, and the growth increases with the increase of the azimuth angle within the two scopes of the interference that is 0º≤θ≤15º and 345º<θ≤360º, but the growth decreases in the scope of azimuth angle between 175º and 185º. In the same scope of interference, as tip speed ratio higher, the growth of blade element angle of attack lower instead; The range of interference to the improved performance in 0º azimuth angle is higher than that is in 180º azimuth angle, in azimuth angle between 0º and 15º, the growth of the blade element torque is higher than that in scopes of 345º<θ≤360º, and that is the lowest in the azimuth angle scope 175º≤θ≤185º. At the same time, the effect rules of interference angle impact on wind turbine performance is analyzed, studies have shown that, increasing the interference angle in 0º and 180º appropriately can improve wind turbine performance and the torque growth of the up-disk is higher than down-disk when the interference angle growth is equal.