Savonius式水轮机水动力学性能

为了研究S式水轮机水动力学性能，利用流体动力学软件建立S式水轮机的网格模型，分析流场特性，对S式水轮机在不同叶尖速比与重叠比的水动力学及能量提取性能进行研究.结果表明：S式水轮机在运动过程中存在负力矩情况，这是造成功率系数较低的主要原因.S式水轮机适合在低叶尖速比下工作，且力矩系数随着叶尖速比的增大而减小，存在一个最优叶尖速比使水轮机的功率系数达到最大，重叠比能减少甚至消除负力矩情况，改善水轮机的水动力学性能.在研究参数范围内，重叠比在0.15附近时，S式水轮机综合性能最优，功率系数可以达到最大值0.256.

Hydrodynamic performance of Savonius water turbine

The mesh model was established and a numerical study was presented on the characteristics of the flow field of the Savonius water turbine by the ANSYS based on computational fluid dynamics in order to analyze the hydrodynamic performance of the Savonius water turbine. The influence of the tip speed ratio and the overlap ratio on the hydrodynamics and energy extraction performance of the Savonius water turbine was analyzed. Results show that the Savonius water turbine exists the negative moment in the process of the work, which is the main reason of its lower power coefficient. It is appropriate to work at the low tip speed ratio, and the torque coefficient decrease with the increase of the tip speed ratio. There is an optimal tip speed ratio that makes the power coefficient be the maximum. The Savonius water turbine with the overlap ratio can reduce or even eliminate the negative moment, thus the performance of the Savonius water turbine can be improved. When the overlap ratio is near 0.15, the Savonius water turbine under research range of parameters has the best performance, and the highest power coefficient can reach 0.256.