为了优化潮流能垂直轴水轮机排布方案，采用计算流体动力学（CFD）方法得到双水轮机在不同轴间距H、不同相对位置角(RPA)β及前后排水轮机不同尖速比λ下平均功率系数CP变化规律，分析流场的速度和涡量云图，解释变化机理。同时，对比单、双水轮机尾流速度分布情况，探究双水轮机尾流特性。结果表明：后排水轮机处于前排水轮机尾流区内时平均功率系数随轴间距增大线性增大，处于尾流区外时双水轮机间距较小、平均功率系数较大；受前排水轮机尾流的影响，后排水轮机最佳尖速比会随着距离和角度的不同发生变化；双水轮机交错排布的平均功率系数高于单水轮机，但尾流速度需要较长的距离恢复。

In order to investigate the optimized layout of the tidal current energy vertical axis hydraulic turbine,computational fluid dynamics(CFD) method was used to obtain the variation laws of average power coefficient CP under different axial spacings H,relative position angle (RPA) β and different tip speed ratios λ of upstream and downstream hydraulic turbines, the velocity and vorticity contours of the flow field were analyzed to explain the changing mechanism. At the same time, the wake velocity distributions of single hydraulic turbine and double hydraulic turbines were compared to explore the wake characteristics of double hydraulic turbines.The results show that the average power coefficient increases linearly with the increase of the spacing when the downstream hydraulic turbine is located inside the wake zone of the upstream hydraulic turbine, while outside the wake zone,the spacing between the double hydraulic turbines is smaller and the average power coefficient is larger.Due to the influence of the wake flow of the upstream hydraulic turbine,the optimal tip speed ratio of the downstream hydraulic turbine changes with the variations of distance and angle.The staggered arrangement of double hydraulic turbines can make the average power coefficient higher than that of single hydraulic turbine,but the recovery of wake velocity needs a long distance.

TK730