引黄滴灌斜管式重力沉沙池流场特性数值模拟

针对引黄灌区一种新型重力式沉沙池开展研究,这种沉沙池通过在沉沙池中布置斜管缩短泥沙沉降距离,进而提高沉沙池沉沙效率.基于数值模拟技术,利用Star-ccm+软件中的Realizable k-ε模型模拟了河套灌区斜管式重力沉沙池的水流运动过程.数值模拟计算结果与实测数据吻合良好,表明数值模拟计算的结果可以较好地反映斜管式重力沉沙池流场特性.模拟结果表明沉沙池斜管区域流态比较稳定,有利于泥沙稳定沉降;沉沙池首部与斜管区前部底端与后部顶端存在的旋涡区不利于泥沙的稳定沉降;池尾溢流堰的吸水作用影响了斜管区域的流态稳定,降低了泥沙沉降效率.研究表明,该型沉沙池下一步需要对调流板孔洞布置形式、斜管布置高度、溢流堰位置进行优化.

Numerical simulation of flow field characteristics of inclined tube-gravity sedimentation tank for drip irrigation in Yellow River

The sedimentation tank is the key facility to ensure the safe operation of drip irrigation system in Hetao irrigation areas. It is of great significance to study the flow field characteristics for optimizing the structure of the sedimentation tank and improving the sediment deposition efficiency. A new type of gravity settling basin for Yellow River irrigation areas was studied. It reduced the sediment settling distance by setting the inclined pipe in the sedimentation tank, and further improving the sedimentation efficiency. Based on the numerical simulation technology, the Realizable k-ε model in Star-ccm+software was used to simulate the flow process of the inclined tube-gravity sedimentation tank which was used in Hetao irrigation areas. The numerical simulation results were in good agreement with the measured data, which showed that the numerical simulation results could well reflect the flow field characteristics of the inclined tube-gravity sedimentation tank. The simulation results showed that the flow pattern in the inclined tube area of the settling basin was relatively stable, which was favorable for stable settling of the sediment. The vortex area at the front of the sedimentation tank and the bottom of the front area and the top of the back area of inclined tube area was not conducive to sediment settlement. The water absorption effect of the overflow weir in the back of the sedimentation tank affected the flow stability in the inclined tube area and reduced the sedimentation efficiency. Therefore, it is necessary to further optimize the structural parameters of the sedimentation tank. The research indicates that this type of settling basin needs to optimize the hole arrangement pattern of the adjusting flow board, the assembly height of the inclined tube and the position of the overflow weir.