浑水水力分离装置中水沙两相湍流的数值模拟  

Numerical simulation of turbulent water-sediment two-phase flow in hydraulic separators for turbid water

作　　者：李琳[1] 邱秀云[1] 

机构地区：[1]新疆农业大学水利与土木工程学院,新疆乌鲁木齐830052

出　　处：《水利学报》2007年第11期1279-1284,共6页Journal of Hydraulic Engineering

基　　金：国家自然科学基金重点项目(50469003);新疆维吾尔自治区高校科研计划科学研究重点项目(XJEDU2004121)

摘　　要：文章采用RNG(重整化群)k-ε双方程紊流模型和简化的多相流Mixture(混合)模型,对浑水水力分离装置内水沙两相湍流场进行了数值模拟,得到浑水水力分离装置的柱体区、悬板区以及锥体区内含沙水流的平面速度矢量分布、含沙水流的紊动强度分布以及泥沙体积浓度分布。通过装置内清、浑水流场的计算结果,分析了泥沙的存在对装置内水流平均流速和紊动强度的影响,以及不同区域内影响水沙分离的主要作用力。研究结果表明泥沙的存在不会削弱水流的平均运动,但泥沙可有效地抑制水流的紊动扩散作用,有利于悬浮泥沙的沉降,装置内不同部位影响水沙分离的主要作用力不同,在锥体区和悬板区水沙分离主要依靠离心力,而在柱体主要依靠重力沉降。The improved RNG κ-ε two-equation model for turbulent flow and simplified mixture model for two-phase flow were used to simulate the water-sediment two-phase flow in hydraulic separators for turbid water. The distributions of flow velocity vector, turbulence intensity and sediment concentration at various planes in different locations of the devices were calculated. The comparison of the calculation results with those of clear water show that the existence of sediment will not reduce the average velocity in the device, but it will effectively restrain the turbulent diffusion effect and is in favor of the settling of suspended sediment. The dominant forces influencing the separation of water and sediment in different locations of the devices are not the same. In the conical part of the tank and in the regions among the suspended plates, the separation effect is due to the centrifugal force, whereas, in the cylindrical part of the tank the separation is dependent on the settling. The simulation results are helpful for improving the efficiency of hydraulic separators.

关 键 词：水沙分离 RNG κ-ε模型 Mixture模型 紊动强度分布 泥沙体积浓度分布 

分 类 号：TV142[水利工程—水力学及河流动力学]