Numerical Model for the Hydraulic Performance of Perforated Pipe Underdrains Surrounded by Loose Aggregate
Numerical Model for the Hydraulic Performance of Perforated Pipe Underdrains Surrounded by Loose Aggregate
复制标题
DOI：
10.1061/(asce)hy.1943-7900.0001134
复制
发表时间：
2016-08-01
影响因子：
2.4
通讯作者：
Testik, F. Y.
中科院分区：
文献类型：
--
作者：
Afrin, T.;Khan, A. A.;Testik, F. Y.
本文介绍了一个计算流体动力学（CFD）模型研究的结果，地下水流和多孔管暗渠的水力学。该研究使用ANSYS Fluent中构建的三维CFD模型进行。该模型进行了验证，通过复制以前的实验结果的饱和地下水流（水面以上的聚合物）为10.2厘米多孔管笼罩在松散的骨料。对于给定水头和骨料深度，计算流体动力学模型始终高估流速，平均高估11%。在考虑了集料对管道穿孔堵塞的影响后，平均超预测降低到仅6%。使用计算流体力学模型计算的多孔管的流量系数为0.54，与实验中的0.49相比。还发现，在管道的上游端，排放量相当小，大部分水在出口附近进入管道。最后，计算结果表明，在饱和水流条件下，流动主要是在垂直方向内的聚集体，而它主要是水平的水面水平低于顶部的聚集体水平（非饱和条件）。探讨了与两种流动情景相关的损失。所得结果对多孔暗管的设计和分析具有实际应用价值。
This paper presents the results of a computational fluid dynamics (CFD) model study of the hydraulics of groundwater flow and porous pipe underdrains. The study was conducted using a three-dimensional CFD model built in ANSYS Fluent. The model was validated by replicating previous experimental results of saturated subsurface flow (water surface level above the aggregate) for a 10.2-cm perforated pipe shrouded in loose laid aggregate. The CFD model consistently overpredicted the flow rate for a given head and aggregate depth by an average of 11%. After considering the effect of pipe perforation blockage due to aggregate, the average overprediction decreased to only 6%. The discharge coefficient for the perforated pipe computed using the CFD model was 0.54 compared with 0.49 from experiments. It was also found that the discharge was quite small at the upstream end of the pipe, with the bulk of the water entering the pipe in the vicinity of the outlet. Finally, the computational results showed that, for saturated flow conditions, the flow was predominantly in the vertical direction within the aggregate whereas it was mainly horizontal when the water surface level was below the top of the aggregate level (unsaturated condition). The losses associated with the two flow scenarios were explored. The results obtained have practical applications in the design and analysis of porous pipe underdrains.