平陆运河老村河支流入汇段通航水流条件优化

Optimization of navigational flow conditions in tributary confluence section of Laocun River of Pinglu Canal

支流入汇会导致主流局部出现横向流速及明显的水位波动,进而对运河安全通航产生不利影响。天然条件下,老村河汇入口的局部区域横向流速超过相关通航标准的要求,严重影响航道航行安全,因此需要对超标河段进行优化整治。针对汛期泄洪支流对运河通航水流条件的影响,采用重整化群(RNG)k-ε紊流模型开展三维精细数值模拟,对不同洪水流量组合下汇流区的通航条件进行研究。结果表明,原设计方案扩宽流速超标河段后,虽然能有效改善汇流区水流条件,但部分区域横向流速仍然超标。优化方案同时采用下移衔接段、设置导水挡墙和扩宽河道等措施,采用优化方案后,汇流区整体通航条件效果良好,水流、水位条件均能满足船舶安全通航要求。

Tributary inflow will result in localized lateral flow in the main steam as well as significant water level fluctuations.Changes in flow conditions can adversely affect the safe navigation of the canal.Under natural conditions,lateral flow velocities at tributary confluences in localized areas exceed the minimum requirements of the navigational criteria,which seriously affect the safe navigation of the waterway.The optimization of the exceeded section of the river is required.In view of impact of flood discharge tributaries on navigable flow conditions in canals during flood season,the renormalization group(RNG)k-εturbulence model is adopted to carry out the three-dimensional fine numerical simulations,and navigational conditions in the confluence area under different combinations of flood flows are studied.The results show that although the widening of the channel can effectively improve the flow conditions in the confluence area,the lateral flow velocities in some areas still exceed the standard under the original design scheme.The measures are adopted for the optimized scheme,such as moving down the connecting section,setting up water diversion retaining walls,and widening the river way and etc.When the optimized scheme is applied,the overall navigational conditions in the confluence area are satisfactory,and the flow and water level conditions can meet the requirements for safe navigation of ships.