基于多相流模型的深隧系统的入流竖井气-水-沙三相流动研究

Numerical simulation of air-water-sand three-phase flow in inflow shaft based on multi-phase model

该文以国内某深隧系统工程的入流竖井为研究对象,采用Eulerian模型与Realizable k-ε湍流模型对竖井段含沙水流动态入流过程开展数值模拟,通过物理模型试验验证所用计算模型的可靠性。通过分析不同工况下,竖井段气-水-沙三相流动特性,得到泥沙输移规律及淤积分布情况。结果表明:竖井段内泥沙淤积区域整体呈现对称性分布特征;含沙率越高,含沙水流运动受泥沙运动影响流速降低越明显,最终所形成的淤积区域与沉积量也更大。设计入流速度工况下(4.2m/s),沉沙池右侧淤积泥沙呈“先扩散,再聚拢”的运动趋势,淤积泥沙高度远低于溢流堰,证明该结构可有效避免已沉积泥沙被来流冲入竖井;较小入流速度工况下(3 m/s),沉沙池右侧的泥沙淤积区域中心最大流速相对于水流流动速度低50%,沉积泥沙的流动扩散性降低。

Based on Eulerian model,the Realizable k-εturbulence model is used to simulate the air-water-sand three-phase flow of the inflow shaft under different inflow conditions,and the reliability of the calculation model is verified by physical model test.By analyzing the characteristics of air-water-sand three-phase flow in the shaft section under different conditions,the law of the distribution and movement of the sediment are obtained.The s ilt deposition area shows a symmetrical distribution as a whole.The higher the sediment content,the more obvious the velocit y reduction of the sand-bearing water flow movement affected by the sediment movement,and the larger the siltation area and t he amount of the final sedimentation.Under the design inflow conditions,the deposited sediment on the right side of the sed imentation basin shows a movement trend of"spread firstly,then gather".When the inflow velocity is small,such as the inflow condition of 3m/s,the maximum flow velocity in the center of the sedimentation area is 50%lower than the flow velocity of the water,and the flow diffusibility of the deposited sediment is reduced.