中文摘要：

为了提高潮流水轮机的效率,参照风力机扩散器原理设计了一种适用于竖轴直叶片水轮机的导流罩.主要考虑潮流工作流场对称性的特点,提出了二大类型6种导流罩设计模型方案;应用F luent软件进行水动力性能计算,确定流速大,阻力小的S3为最优型线;在导流罩出口位置增加对称的扩张门,可以进一步提高导流罩内流场的流速和稳定性;模型实验验证了S3型导流罩设计模型的有效性,加导流罩后轮机功率系数曲线整体上升,峰值可提高39%.该设计研究为导流增强型潮流水轮机的研究和实践提供了理论基础.

英文摘要：

In order to improve the efficiency of a tidal-stream hydro turbine, a dome for a straight-blade turbine was devised based on diffusers used with wind turbines. After conside power station, six 2-D dome models of 2 types were suggested. Calc g ul the symmetry of flow fields in a tidal stream ations of their hydrodynamic properties were done with Fluent software. From the calculated results, S3 was determined to be the optimal profile, as it exhibits greatest velocity and smallest resistance. A pair of symmetrical diffusers were installed at the outlet of the dome, improving the velocity and stability of flow fields in the dome. The effectiveness of S3 was proved by experiments with models. After the dome was added, the power coefficient curve of the hydro turbine rose over the full range, and the peak value increased by 39%. This design and research work offers an academic basis for further research on tidal-stream hydro turbines with installed domes