潮流能水轮机导流罩的水动力性能研究

借鉴传统水平轴潮流能水轮机结构的构造原理，本文提出一种可根据海流方向做自适应调整的轴流、悬浮式潮流能水轮机结构。为了提高这种新型潮流水轮机的发电效率，在水轮机外围设置了曲线线型的悬浮式导流罩结构。首先基于样机物理模型实验，验证了拟采用的CFD数值仿真方法的有效性。进而分别计算拟定的不同形状的10种导流罩模型结构的水动力性能，仿真结果表明收缩段和扩张段均为双三次曲线xm=0．3的对称线型导流罩具有最优的水动力性能。最后对这种新型潮流水轮机整体结构的水动力性能展开研究，结果表明相对于无导流罩工况，水轮机叶轮加装收缩段和扩张段均为双三次曲线xm=0．3的对称线型导流罩之后，其输出功率有较大提升。

Analysis of Hydrodynamic Characteristics about Fairwater of A Current Turbine

Referring to the structure of traditional axial-flow tidal current turbine and fairwater, a suspend- ing type axial-flow tidal current turbine system has been developed by the authors of this paper. In order to im- prove its power generating efficiency, a buoyancy-providing fairwater has been installed around the turbine, like diffusers used in the field of wind turbines. At first, based on the prototype experiment, the effectiveness of the proposed CFD numerical simulation has been verified. Then, by means of this CFD software, the hydrodynamic characteristics of fairwater schemes with ten different shapes have been analyzed. Through systematically compar- ison, the results show that the fairwater with symmetrical surface of Xm=0.3 bicubic smoothed-spline has excellent hydrodynamic characteristics. The hydrodynamic characteristics about the system of turbine and fairwater have also been studied. It has been found that the output power of the system with turbine surrounded by fairwater （symmetrical bicubic smoothed-spline surface of xm=0.3） is larger than the one in the case of open water.