中文摘要：

针对黄河清淤固堤工程中泥沙输送系统，主要考虑了抽沙平台泵出口侧多通接头的结构优化以改善系统的水力性能。对6种多通接头模型基于三维紊流数值模拟方法进行了流动分析。根据计算结果，总结了各种多通接头的分叉结构对局部流动状态和水力损失的影响，分析了最优模型。研究表明：根据实际的管路连接需求，多通接头的分叉部支管应采用面积均匀变化的圆锥管；减少分叉的数量，能适当减小水力损失；确定多通接头的最佳模型，以获得最优水力性能。

英文摘要：

Against the sand transportation system used in the Yellow River sand-dredging ＆ bank-strengthening project mainly optimizing the structure of multiple-pass junction at the outlet of a sand-dredging pumping platform was analyzed to improve the hydraulic performance of the system. The flow analysis has been conducted based on 3D turbulent numerical simulation for 6 types of multiple-pass junction. Based on the calculation results, the effects of bifurcate structure on local flow and hydraulic loss are summarized, and the optimum model （bifurcate structure） has been discussed. It is noted that： the conical bifurcate with uniform area variation according to the actual connection requirement is suitable for bifurcate pipe ; less bifurcates result in less hydraulic loss; the optimized model of multiple-pass junction is necessary so as to achieve better hydraulic performance.