典型弯道水流中的水沙二相流三维数值模拟研究水力学及河流动力学专业论文.docxVIP

I I 典型弯道水流中的水沙二相流三维数值模拟研究 摘 要 弯道式渠首是利用水沙在弯道中的分离特性来处理泥沙，并提高引水质量的一种简单有效的工 程措施。弯道中的水沙淤积形态直接体现弯道设置是否合理，本文主要从物理模型试验和数值模拟 两方面对典型弯道水沙二相流进行研究，主要内容和结论如下： （1）通过物理模型试验，得到了在所有工况下典型弯道水流的物理试验数据，主要有不同流量 下，弯道段清水流场的水面线、流速分布及动床泥沙冲淤平衡时典型断面的泥沙冲淤等高线图。 （2）综合比较紊流模型的优缺点及适用性，选用 Fluent 软件提供的 RNG紊流模型对弯道 水沙二相流进行三维数值模拟，将数值模拟结果与物理试验结果进行对比，结果表明二者吻合较好， 说明 RNG紊流模型对弯道水沙二相流进行三维数值模拟是可行的。 （3）数值模拟结果表明，紊流模型可以较好地模拟实际工程中的弯道水流，可以为弯道式渠首 的设计提供理论指导，从而弥补物理模型试验的不足，减少物理模型试验所耗费的时间以及人力物 力。 关键词：弯道水流；水沙二相流；数值模拟；VOF 模型 Study on 3D numerical simulation for water-sediment two-phase flow in typical curve bend Abstract Head sluice connected with the curve bend where the sediment can be separated from the flow by itself is well known as a qualified system for decreasing sediment concentration in the water. And the evaluation standard for curve bend’s design is the form of sedimentation in the bend. In this paper, both the experimental study on physical model and numerical simulation on numerical models have been carried out for the send-water two-phrase flow in typical curve bend. The conclusions of the study are as follows: (1) After experiments on the physical model with different rate of flow, the water surface profile and velocity distribution in the flow field for pure water have been tested. And the sedimentation form at several typical sections in the curve trend where sedimentation get equilibrium between scouring and deposition on the shifting bed have been measured for flow analyzation. (2)A 3D turbulence model for sand-water two-phrase flow in the typical curve trend has been built based on RNG k-ε turbulence model in FLUENT after compared with several other models comprehensively. The results of the numerical simulation agree well with the experimental results. (3)The numerical results show that the 3D turbulence model can simulate sand-water two-phrase flow in the typical curve trend very well, and the numerical model can also provide instructions for the physical experiment optimization in the typica