结合高雷诺数κ-ε模型,建立了辐流式沉淀池三维两相流紊流模型,在动量方程中考虑了曳力、虚拟质量力、升力的作用,以及悬浮物浓度的影响。在考虑池形结构变化条件下,对辐流式二沉池三维流态及悬浮物分布进行了模拟研究。结果表明:环向流速受池底、边壁、进口挡板及出口溢流堰影响较大,与假设切向速度为零的理想沉淀池存在很大差异,三维模型能更好的反映水流和悬浮物变化;采用外堰出水效果很差;当距离池壁2m时,采用内侧堰出水和双堰出水,其去除效果较外堰出水明显改善;与Deininger等的实测资料进行了对比,模拟值与实测值吻合较好。
A 3D two-phase flow model for a radial secondary sedimentation tank was developed by employing the high Reynolds number -equation. The momentum transfer term includes the drag, virtual mass and lift forces. The volume fraction and density effects of suspended solids were taken into account. The simulation results with the tank configuration variant show that the tangent velocity is nonuniform and is influenced by the tank bottom, sidewall, baffle and weir. It significantly differs with the assumption velocity of an ideal sediment basin. The 3D model is a better one to simulate the distribution of flow field and SS. The peripheral weir gets unsatisfied results. About the 2m away from the margin, both the inboard weir and twin weir make the property of the outflow markedly improved. By comparison with the experimental data of Deininger et al, the flow field predicted by the model indicates a good agreement with a real one.