双阿基米德螺旋水轮机阵列特性

Array characteristics of twin Archimedes spiral hydrokinetic turbines

为了探究阿基米德螺旋水轮机双机组的阵列特性,从而实现该型水轮机的高效利用,采用计算流体力学方法对不同排列方式及间距下的双机组阵列进行了三维数值模拟研究.结果表明,在并列排布中,两机组都将获得高于单独机组的性能指标,且二者之间的水动力相互作用的增益效果在达到峰值后随着并列间距的增大而逐渐减弱.反向旋转设置中的两机组的叶尖涡将出现类似于齿轮的啮合效应,而同向旋转设置中的两机组的叶尖涡相互冲突且交织在一起,导致一侧机组的叶尖涡在向下游发展的过程中过早地出现破碎.在串列排布中,当串列间距大于5 D后,上游机组的性能基本不受影响,下游机组的性能随着串列间距的减小而下降明显.反向旋转设置的下游机组的涡流结构较为混乱,出现了一定程度的尾流畸变,而同向旋转设置的下游机组几乎完美地与来自上游的涡流进行了融合,其尾流更像是对上游涡流的一种延伸和继承.研究结果为阿基米德螺旋水轮机的优化布置提供了一定的参考.

Aiming to explore the array characteristics of twin units and realize the efficient utilization of this type of turbine,a three-dimensional numerical simulation study on the different arrangement and spacing of twin unit arrays was carried out using the computational fluid dynamics method.The results show that in a parallel arrangement,both units will achieve higher performance indicators than that of a single unit,and the gain effect of the hydrodynamic interaction between the two units will gradually decrease with the increase of parallel spacing after reaching the peak.Besides,the tip vortices of the two units in the reverse rotation setting will have a gear-like meshing effect,while the tip vortices of the two units in the co-rotation setting collide with each other and are intertwined,leading to a premature breaking of one unit in the process of vortices development.On the other hand,the performance of the upstream units is basically unaffected when the tandem spacing is greater than 5 D,while the perfor-mance of the downstream units decreases significantly with the decrease of tandem spacing in the tandem arrangement.The vortices of the downstream units in reverse rotation setting are relatively disordered,while the downstream units in the co-rotation setting almost perfectly integrate with the upstream vortices,and its wake is more like an extension and inheritance of the upstream vortices.The research results provide certain reference strategies for the optimal arrangements of Archimedes spiral hydrokinetic turbines.