供水管网十字节点混合模型的数值模拟

Numerical Study of Mixing at Cross Junction in Water Distribution Systems

当供水管网存在污染物入侵时,如何快速地明确污染物的分布情况,提出相应的应对措施是水务公司迫切需要解决的问题。目前国内外公认的EPANET水质软件假定节点完全和瞬时混合,而Romero-Gomez[1]（2006）提出节点完全和瞬时混合的假设存在较大误差。因此,研究节点混合模型,建立精确的供水管网水质模型至关重要。目前节点混合模型的研究主要是基于物理性实验分析和数值模拟。由于数值模拟具有耗时短,成本低等优点,被越来越多的学者所使用。本文结合目前的研究成果,利用FLUENT软件中的组分输运模型对供水管网中的等管径十字节点进行分析,研究了雷诺数大于10000的节点混合,发现入口雷诺数比和出口雷诺数比对节点混合的影响,结果显示入口雷诺数比和出口雷诺数比对节点混合有较大影响。

When there are contaminations in the water distribution systems,water supplying company must determine the distribution of contaminations and give the corresponding counter-measures. The most popular software EPANET assumes that the mixing of solutes is instantaneous and complete. However,Romero-Gomez et al[1]（ 2006） indicates that such assumption can lead to an erroneous prediction of water quality. So,it is important to study the mixing at junctions and establish precise water quality model. The study methods of solute mixing are experiment and numerical simulation. Because the latter is superior to the former in time and cost,more and more researchers choose numerical simulation to study the solute mixing. In this paper,we used FLUENT software to simulate the solute mixing of cross junction and found that when Re > 10000,the ratio of Reynolds number of inlets ReW/Sand outlets ReN/Ehave a great influence on mixing.