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Darrieus风轮单个叶片的力矩特性曲线随方位角成波浪形变化,90°和270°方位角的力矩系数为极小值且为负值,严重影响立轴风力机整体气动特性。针对此问题,提出通过导叶来引入干扰气流,对两方位角的流场进行改善,进而提高整体气动特性的性能改善方法。采用SST k-ω湍流模型进行二维数值计算,以270°方位角加导叶的和无导叶的直叶片立轴升力型风轮为对象进行对比分析。研究发现,导叶使270°方位角附近区域的叶片力矩系数明显提升,最大力矩系数由无导叶的-0.03提升到0.07,使270°方位角叶片的吸力面负压系数和压力面正压系数都有较大提高;风轮风能利用系数在运行范围内都有明显提高,在最佳尖速比下提高12%。
The torque curve of a single Darrieus rotor blade varies with the azimuth angle. The torque coefficients at 90 ° and 270 ° azimuths are minimal and negative, which seriously affects the overall aerodynamic characteristics of the vertical axis wind turbine. In view of this problem, it is proposed to introduce disturbing airflow through the guide vanes to improve the flow field at two azimuths, thereby improving the performance improvement of the overall aerodynamic characteristics. The SST k-ω turbulence model was used to conduct two-dimensional numerical calculation. The contrastive analysis was carried out with 270 ° azimuth plus guide vane and vaneless vertical blade vertical shaft lifting wind turbine. The results showed that the vane torque coefficient in the vicinity of azimuth angle of 270 ° was significantly improved and the maximum torque coefficient was increased from -0.03 without guide vane to 0.07, which made the negative pressure coefficient of suction side and pressure surface positive pressure of 270 ° azimuth blade The coefficient has greatly improved; wind turbine wind utilization coefficient in the operating range have significantly improved at the best tip speed ratio increased by 12%.