Yu Tingchao, Qiu Hongying, Yang Jeffrey, Shao Yu, Tao Liang
Department of Civil Engineering, Zhejiang University and Key Laboratory of Drinking Water Safety and Distribution Technology of Zhejiang Province, Hangzhou 310058, China.
U.S. EPA, Office of Research and Development, National Risk Management Research Laboratory, Cincinnati, Ohio 45268, USA.
Water Sci Technol Water Supply. 2016 May 21;16(6):1595-1602.
Pipe flow mixing with various solute concentrations and flow rates at pipe junctions is investigated. The degree of mixing affects contaminant spread in a water distribution system, and many studies have focused on mixing at the cross junctions; however, only a few have focused on double-Tee junctions of unequal pipe diameters. To investigate the solute mixing at such junctions, a series of experiments was conducted in a turbulent regime (Re = 12,500-50,000) with different Reynolds number ratios and connecting pipe lengths. Dimensionless outlet concentrations were found to depend on mixing mechanism at the impinging interface of junctions, where junctions with a larger pipe diameter ratio were associated with more complete mixing. Further, the inlet Reynolds number ratio affected mixing more strongly than the outlet Reynolds number ratio. Finally, the dimensionless connecting pipe length in a double-Tee played an important and complicated role in the flow mixing. The results were used to develop two-dimensional isopleth maps for the calculation of normalized north outlet concentrations.
研究了管道交汇处不同溶质浓度和流速下的管道流动混合情况。混合程度会影响配水系统中污染物的扩散，许多研究都聚焦于交叉交汇处的混合；然而，只有少数研究关注不等管径的双三通交汇处。为了研究此类交汇处的溶质混合情况，在湍流状态（雷诺数Re = 12500 - 50000）下，针对不同的雷诺数比和连接管长度进行了一系列实验。发现无量纲出口浓度取决于交汇处撞击界面的混合机制，其中管径比更大的交汇处混合更完全。此外，入口雷诺数比对混合的影响比出口雷诺数更强。最后，双三通中无量纲连接管长度在流动混合中起着重要且复杂的作用。这些结果被用于绘制二维等值线图，以计算归一化的北向出口浓度。
