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本文采用Fluent软件对半径0.7 m,翼型NACA4415的水平轴风力机的三维非定常尾迹流场进行了大涡模拟(LES)计算,计算结果表明:轴向速度分布相对于尾迹中心不对称,同一风速下,在靠近叶根圆周区域,距离风力机旋转平面2R处风力机轴向速度达到最小,由2R~3R区域逐渐过渡,然后增大最终恢复周围环境速度;而在靠近叶尖的圆周区域,在距风轮旋转平面1R处达到最小值,由1R~2R区域逐渐过渡,最终达到周围环境速度;中心涡对尾流影响的长度要大于叶尖涡对尾流长度的影响。尾流区不仅存在叶尖涡和中心涡,还存在叶片尾缘涡;低风速对尾流长度的影响要小于高风速。
In this paper, the large eddy simulation (LES) is used to calculate the three-dimensional unsteady wake flow field of a horizontal axis wind turbine with a radius of 0.7 m and airfoil NACA4415 using Fluent software. The calculation results show that the axial velocity distribution is asymmetric with respect to the wake center, Under the wind speed, near the root circumference of the blade, the axial velocity of the wind turbine reaches the minimum at 2R from the plane of rotation of the wind turbine and gradually changes from 2R to 3R, and finally increases the velocity of the surrounding environment. In the circumferential area near the blade tip, , Reaching a minimum value at 1R from the plane of rotation of the wind turbine and gradually changing from 1R to 2R to finally reach the ambient velocity. The influence of the central vortex on the wake is greater than that of the tip vortex on the wake length. The wake region has not only the tip vortex and the center vortex, but also the trailing edge eddy of the blade. The effect of low wind speed on wake length is less than that of high wind speed.