The influence of the end effects in the wake development of a vertical axis wind turbine is studied using a Large-Eddy Simulation methodology, coupled with an Immersed-Boundary technique, for a value of solidity σ ​= ​Nc/D ​= ​0.5 (N: number of blades; c: chord length of the blades; D: diameter of the turbine), a tip speed ratio TSR ​= ​RΩ/U_∞ ​= ​2.206 (R: radius of the turbine; Ω: angular speed; U_∞: free-stream velocity) and a Reynolds number Re ​= ​DU_∞/ν ​= ​180, 000 (ν: kinematic viscosity). The end effects at the tip of the blades originate significant secondary flows, especially on the windward side. They promote additional lateral displacement of the momentum deficit from the leeward side towards the windward side, increase the levels of turbulence and reinforce the asymmetry of the wake system. Turbulence is also intensified by the shear produced at the top and bottom boundaries of the wake between the free-stream and the decelerated flow downstream of the turbine. Significant vertical flows are produced, whose intensity and orientation were found dependent on the horizontal coordinate between leeward and windward sides. Their overall effect consists in contributing to momentum recovery downstream of the turbine, which is indeed faster at the locations closer to its spanwise boundaries, especially on the leeward side.

在垂直轴风力涡轮机的尾流发展末端效应的影响是使用大涡模拟方法，加上浸入-边界技术的研究，为了牢固的值σ  = Nc个/ d  = 0.5 （ñ：叶片的数量; ç：叶片的弦长; d：在涡轮机的直径），尖端速度比TSR  = RΩ / Ù _∞  = 2.206（- [R ：所述涡轮机的半径; Ω：角速度; û _∞：自由流速度）和雷诺数Re = DU _∞ /ν  = 180，000（ν：运动粘度）。叶片尖端的末端效应会产生大量的二次流，尤其是在迎风侧。它们促进了动量赤字从背风侧向迎风侧的附加横向位移，增加了湍流水平并增强了尾流系统的不对称性。在自由流和涡轮下游的减速流之间，在尾流的顶部和底部边界处产生的剪切力也加剧了湍流。产生了大量的垂直流，其强度和方向取决于背风侧和迎风侧之间的水平坐标。它们的整体效果在于促进了涡轮机下游的动量恢复，而在靠近翼展方向边界的位置，这的确更快。