论文部分内容阅读
为准确掌握180°弯曲水槽内床面冲淤特征及其演化过程,采用基于非结构化三角形网格的三维流动和地形冲淤数值模型对180°弯曲水槽内床面的冲淤演化过程进行复演。运用标准k-ε紊流模型和显式2步投影方法求解RANS方程,推移质输沙率选取Van Rijn输沙公式计算,对于二次流强度较强、横向坡度对输沙方向影响较大的强弯曲水槽,采用方便实用的Engelund方法计算横向底坡所引起的输沙方向的偏移,同时对河床变形所引起的河床临界起动切应力变化进行修正及对流动和地形冲淤相同时间步模拟非恒定的河床冲淤演化过程。与试验测量结果对比显示:数值模型对强弯曲水槽冲淤特征有较好的模拟效果;Engelund方法对计算输沙方向偏移角度具有明显的改进;模型同样也具备复演内床面非恒定冲淤演化过程的能力。
In order to accurately grasp the bed scouring and silting characteristics and its evolution in a 180 ° bent flume, the numerical simulation of three-dimensional flow and terrain scouring and silting based on an unstructured triangular grid is used to simulate the scouring and silting evolution in a 180 ° curved flume play. The standard k-ε turbulence model and the explicit 2-step projection method are used to solve the RANS equation. The sediment transport rate is calculated by Van Rijn sediment transport formula. For the second-order flow, the horizontal gradient has a significant influence on the sediment transport Strong curved tank, the Engelund method is used to calculate the deviation of sediment transport direction caused by the horizontal bottom slope, and the correction of the critical shear stress of river bed caused by the deformation of the riverbed and the same time step simulation of flow and topography erosion and sedimentation Unsteady riverbed ebb and flow evolution. Compared with the test results, the numerical simulation results show that the numerical model has a good simulation effect on the erosion and silting characteristics of strong curved flume. The Engelund method has a significant improvement on the calculation of the drift angle of the sediment transport. The model also has the advantages of non- The ability of siltation evolution.