对旋风力机功率测量的风洞实验研究

This paper presents the comparison of mechanical power measurement for traditional and contra-rotating wind turbines for identical radius under same free stream velocity in wind tunnel. In order to validate the Wilson design method for single turbine and the coupled aerodynamic design method for contra-rotating wind turbines, the rotating speed, pitch angle, stage distance and free stream velocity are varied to capture the maximum mechanical power. The results indicate that the measured experimental power is slightly smaller than CFD prediction under same working conditions. However, 10% reduction of pitch angles, that is 5°-10° in range and 10% raise of tip speed ratio from theoretical design helps to improve performance of both turbines. The maximum power captured in experiment is bigger than CFD prediction. Except for higher start-up wind speed, contra-rotating wind turbine achieves higher power coefficient than that of single turbine in all wind speed tested. The absolute power coefficient is 0.339-0.412, with rise ratio 5.3%-28.9%. At rated condition, the maximum power coefficient of contra-rotating turbine and single turbines are 0.426 and 0.373, and the riseratio is 16.4%.