竖缝式鱼道180°转弯段的水力特性与改进研究

中文摘要: 受布置型式与地形地质条件等因素的限制，大部分鱼道工程需要设计为折返型，而水流方向改变角度为180°的转弯段，是最能充分利用场地条件、节省空间的布置方式。目前，针对180°转弯段水力特性的研究成果鲜见报道，缺乏成熟完整的设计方法可资借鉴。采用数值模拟方法，对180°转弯段的水流流场进行了计算研究。结果表明，主流区水流紧贴边墙流动，并出现尺度过大的回流区。为改善上述不利流态，提出了增设整流导板的改进措施，并对水流流态改善前、后的水力特性进行了对比研究。研究表明:增设整流导板后，主流区基本位于转弯段的中间部分，主流衰减效果显著；弯段上游回流区的尺度大小、流速值与常规水池相当；弯段、弯段下游回流区的尺度减小，流速值明显减小。
Abstract:The flow in 180° turning pools was studied by a numerical simulation method, and the results showed that the mainstream flowed close to sidewalls, and big size recirculation areas appeared on both sides of the mainstream. This poor flow pattern was adjusted by setting rectifier plates, and the hydraulic characteristics of flow structure were studied. The results showed that the mainstream zone was in the middle of the 180° turning pool, and the velocity attenuation was significant after adding rectifier plates. Recirculation zone sizes and velocity values in the upstream of turning part were similar to those of general pools. For reflux zones of the turning part and the downstream, their sizes were reduced, and velocities were weakened.