新型组合式导管水轮机水动力性能研究

为了解决导管水轮机尾流分离的问题同时减小系统轴向的阻力,采用计算流体力学(CFD)与拖拽水池试验相结合的手段对一种新型带流道的组合式导管水平轴水轮机进行了水动力性能研究。分析了导管流道数量、流道宽度及流道形状对系统水动力的影响。研究结果表明:相比原导管水轮机,组合式导管水轮机在保证输出功率基本不变的前提下,在低叶尖速比运行状态下能显著减少导管的轴向阻力并改善尾流流动情况,提高系统的运行稳定性。同时在一定范围内,随着流道数及流道宽度的增大,尾流改善效果将变得更明显。对于流道形状而言,直流道为最佳流道。研究成果为解决该型水轮机流动分离问题提供了参考依据,对水轮机及支撑装置的优化设计具有参考作用。

Hydrodynamic performance of new type of combined ducted turbine

To reduce the flow separation with the ducted turbine and reduce its axial force, this paper presents a new type of combined ducted horizontal axis turbine with ducted flow paths and an analysis on its hydrodynamic performance using computational fluid dynamics (CFD) and towing tank experiments. The influence of the number, width and shape of the ducted flow paths is examined. Results show that compared with the original ducted turbine, the combined ducted turbine can significantly reduce the axial force on the duct and improve the wake flow condition and stability of a turbine system at low tip speed ratios while keeping a nearly fixed power output. And within a certain range, such an effect will become more obvious with the increase in the number or width of flow paths. Of the flow paths in different shapes, a straight passage produces the best effect. The study provides a new ducted turbine design helping reduce flow separation and optimize the turbine and its supporting devices.