勾头长度对非淹没丁坝周围水流特性的影响

Effects of bend head length on flow characteristics around non-submerged spur dike

采用RNG k-ε紊流模型,数值模拟了丁坝周围水流的三维流动过程,分析不同长度勾头对丁坝周围水流结构和流速场的影响。计算结果表明,在勾头的影响下,勾头段出现横轴漩涡,远离坝头区域纵向流速减小,大流速向坝头集中,坝轴后方横流减弱,上下游最大水位差减小,影响效果随勾头长度的增加而增大。为深入探讨利用勾头改善丁坝周围通航水流条件奠定了基础。

The RNG k-ε turbulence model was used for numerical simulation of the three-dimensional flow process of water flows around the spur dike, so as to analyze the influence that different lengths of bend head have on the structure and velocity field of water flows around the spur dike. The computed results show that transverse vortex appears at the bend head section under the influence of the bend head; The longitudinal flow velocity decreases in the area away from the dike head; High flow velocity concentrates towards the dike head; Transverse flows weaken behind the dike axis; The maximum difference between upstream and downstream water levels reduces; And the effect of influence enhances as the length of bend head increases. These findings lay a foundation for investigation on improving the navigation flow condition around the spur dike by the bend head.