水深变化影响下潮流能水轮机尾流场特性实验研究

Experimental Study on the Influence of Different Water Depth on Tidal Turbine Hydrodynamic Characteristics

以水平轴潮流能水轮机模型为研究对象,利用精确的声学多普勒测速仪,在循环水池中研究不同水深工况下水轮机尾流场特性。实验结果表明,和平均速度、湍流强度等特性一样,尾流旋转与湍动能在尾流场中也出现近尾流区域衰减迅速,并随下游距离增加恢复速度逐渐减缓。速度亏损与湍流强度在水平面上呈现对称分布。固定桩的阻塞作用会破坏近尾流的旋转效应,其下游的脱落涡会与水轮机尾流产生相互作用,增加尾流湍流强度的同时,使下游尾流产生向上的偏移,垂直面上的流场特性均非对称分布。水深的变化会改变水轮机扫略区域外流体流速,影响近尾流区域内速度亏损形状和远尾流恢复速度。

Taking the horizontal axis tidal current turbine model as the research object, the characteristic of the turbine’s wake under different water depth were studied in the circulating flume by using the detailed Acoustic Doppler Velocimeter. The experimental results show that, similar to the average velocity and turbulence intensity, the wake rotation effect and turbulent kinetic energy decline rapidly in the near wake and gradually slows subsequently. The velocity deficit and turbulence intensity are symmetrically distributed on the horizontal plane. The blockage effect of the pile interrupts the rotation effect of the near wake, and the shedding vortex modifies the wake of turbine, increasing the turbulence intensity of the wake. The wake downstream the pile shift upwards, and the wake structure are asymmetrically distributed on the vertical plane. The change of water depth influences the fluid velocity outside the sweep area of the turbine, affecting the shape of velocity deficit in the near wake area and the recovery rate of the far wake.