泵站出口与河道主流交汇区流动特性数值模拟

Numerical Simulation of Flow Characteristics at the Confluence of Pumping Station Outlet and Main Channel

侧向出流的泵闸枢纽存在出水池流量不均问题,增加了汇流口流态的复杂性,给通航安全带来未知风险。为此,以溧阳某泵闸枢纽为例,建立基于浅水方程和κ-ε紊流模型的二维模型以研究泵站出口与河道主流交汇区的流动特性。结果表明,河道主流在交汇区支渠河堤的作用下整体右偏,偏转程度随汇流比降低而减弱,并在支流顶托下形成涡旋与分离区;泵站流量的不均衡性使出水池内主流集中,导流墩能够改善该现象,逆时针旋转10°可有效改善墩前流态;横向流速在上下游流线偏转区域较大,在涡动两侧较小且具有周期性,改善河道通航状况应从平顺干渠形状入手。研究成果为改善交汇流水域通航条件与泵站出水池流态提供参考。

The imbalance of flow in the side-direction outlet pool of combmea slutce-pumpmg srauon increases tile complexity of confluence flow and brings unknown risks to navigation safety. A two-dimensional model based shallow wa- ter equations and e-e turbulence model was developed to study the flow characteristics at the confluence of Liyang Sluice pumping Station. The results show that the right deflection of streamline in the main channel was resulted from the shape of confluence and decreased with the reducing of discharge ratio, as well as the formation of vortex and separation zone was resulted from the backwater effect of branch channel; Water concentration in outlet pool was due to imbalanced flow of pumping station and would get improved when setting up guide walls; Guide walls with a deflection angle of 10~ would make the flow state in front of them better; The shape of main canal should be ad}usted firstly when improving navigation condition because the transverse velocity was mainly in the deflection areas, as the transverse velocity of vortex was slow and periodic. These outcomes can he applied to the research of improving navigation condition at confluence and flow state of outlet pool.