基于变流速的活动扩张角导流装置性能研究

针对导流装置型水轮机在高流速条件下叶片承受过大轴向力的问题，提出了一种自适应流速变化的导流装置解决方案。该装置能够在低流速区间保持相对稳定的增速比，而在高流速区间通过调整增速比来减轻叶片负载，提高水轮机在低流速环境下的功率输出。通过数值分析，以增速比作为评估指标，研究了扩张角的调整范围、活动装置的长度和形状，并分析了不同流速条件下的长短轴比例、水轮机所受推力及获能情况。研究结果表明：使用翼型活动装置，保持其长宽比为1.5，扩张角调整范围为0～15°，增速比的调整范围为1.10～1.57；当活动装置的长短轴比例为3.4∶1时，在高速流场中叶片相对受力可降至1.1左右，同时在低流速区域具有较好的能量转换效率。

Performance of flow-adaptive deflectors with variable expansion angles based on variable flow velocity

A self-adaptive solution for the excessive axial force on the blades of a guide vane type turbine under high flow velocity conditions is proposed. This device maintains a relatively stable speed ratio in the low flow velocity range and reduces blade load by adjusting the speed ratio in the high flow velocity range, thereby improving the power output of the turbine in low flow velocity environments. Numerical analysis is conducted to investigate the adjustment range of the expansion angle, the length and shape of the movable device, the aspect ratio of the long and short axes, the thrust on the turbine and the power output under different flow velocity conditions. The research findings indicate that using an airfoil-shaped movable device with an aspect ratio of 1.5 and an expansion angle adjustment range of 0° to 15° can achieve a speed ratio adjustment range of 1.10 to 1.57. When the aspect ratio of the movable device is 3.4∶1, the relative force on the blades can be reduced to approximately 1.1 in the high flow velocity range, while maintaining good energy conversion efficiency in the low flow velocity range.