斜向管涵进流城市雨水泵站箱涵流态分析及整流措施研究

为了研究斜向管涵进流对城市雨水泵站水力流态特性的影响,探寻改善不良流态的有效整流措施,基于计算流体动力学(CFD)方法,开展斜向管涵进流城市雨水泵站箱涵流态分析及整流措施研究。针对不良进水流态,通过在闸门井内设计布置了3种不同的整流措施,分析比较各整流措施对箱涵进水流态及其配水均匀性的改善效果,优选出最佳方案并进行物理模型试验验证。研究表明:斜向管涵进流容易造成箱涵各孔流量分配不均且存在偏流、回流、旋涡等不良流态,从而恶化前池进水流态和影响泵站安全运行;采用"分流墩、组合梁以及相背布置短导流墩"的组合式整流措施可以显著改善闸门井、箱涵以及前池进口处的不良流态,有效提高箱涵各孔的流量分配的均匀程度,其中箱涵各孔流量分配不平衡度降至±0.03之间、箱涵总流量分配均匀度提高为0.905。本文的研究成果可为同类型城市雨水泵站设计提供有益的参考。

Study on the flow patterns and rectification measures of box culvert of urban storm water pumping station with oblique pipe culvert

In order to study the influence of the oblique inflow on the hydraulic characteristics of the ur-ban storm water pumping station and explore the effective rectification measures to improve the adverse flow pattern, the flow patterns and rectification measures of box culvert of urban storm water pumping sta-tion with oblique pipe culvert were studied based on computational fluid dynamics method. Three different rectification measures were designed and set in the gate shaft to improve the adverse flow pattern and wa-ter distribution uniformity, and the best scheme was verified by the physical model test. The research re-sults showed that the flow maldistribution and some adverse flow patterns in each of box culvert channel,e. g. transverse flow, backflow, vortex flow, were caused by the inflow from oblique pipe culvert. The ad-verse flow patterns would deteriorate the inflow condition in the pumping station forebay and affect the secu-rity performance of the pumping station. The rectification measures, including splitting-flow pier, composite beam and back-to-back guide pier, could significantly and efficiently improve the flow patterns and flow distribution uniformity. Not only the box culvert flux distribution unbalance factor drop to between positive and negative 0.03, but the total flow distribution uniformity was increased to 0.905. The research achieve-ment of this paper could offer some valuable references to the similar type of urban storm water pumping station.