潮流能水轮机仿真及尾流场分析

为了研究潮流能水轮机尾流场的变化规律,本文在水平轴水轮机现有理论基础上,采用计算流体力学技术建立了数值模型,计算了水轮机的功率特性,进行了网格独立性验证,比较了模型中旋转区域不同对结果的影响。仿真结果与试验结果进行了对比分析,验证了数值模型的有效性。研究了全工况下尾流场速度衰减随尖速比和距离变化的规律,结果显示在小尖速比下尾流场速度恢复情况相对大尖速比下较好;靠近水轮机轮毂中心线位置处,衰减相对较大。研究建议水轮机在同等功率表现下尽量选择在小尖速比下工作,水轮机组在实际排列时避免采用成列布置,水轮机设计阶段应综合考虑功率特性和尾流场衰减。本文研究内容可以为潮流能水轮机的研究以及阵列式应用提供参考。

Simulation of marine current turbine and wake research

In order to study the velocity reduction rule of marine current turbine wake, a numerical model is established using CFD based on the existing horizontal axis turbine in this paper. The power-out performance of turbine is calculated, the independence of grid is verified, and the result of different rotating areas is compared. The simulation result is compared with the experiment result, and the validation of the simulation model is identified. Velocity reduction of the wake along with the tip speed ratio and the distance is studied, and the result shows that the wake velocity recovery is better under small tip speed ratio than big tip speed ratio, and that the velocity reduction is bigger near the center line of turbine hub. The authors point out that the turbine should work under small tip speed ratio when the power performance is the same; the array arrangement of the turbine should avoid column layout in practical application; and the power-out performance characteristics and the wake velocity reduction should be considered in the period of turbine design. The research can provide a reference for the marine current turbine research and the array arrangement.