论文部分内容阅读
为了解决实际河道中丁坝附近的冲刷和淤积问题,必须探明其水力特性的分布规律.采用气液两相流混合模型结合大涡模型(Large Eddy Simulation)对不同平行导流墙长度下L头丁坝绕流三维水力特性进行数值模拟研究.采用有限体积法离散计算区域,速度与压力耦合方程组求解时使用半隐式SIMPLE(Semi-Implicit Method for Pressure-Linked Equations)算法,模拟自由水面采用了VOF(Volume of Fluid)法.对不同平行导流墙长度下丁坝附近回流区域和涡量分布“云图”进行分析比较,得出当平行导流墙长度与丁坝坝轴线长度相等时对丁坝后漩涡的限制效果最好;平行导流墙长度对水槽中水流流速的影响很小,可以忽略.在河道中合理布设L头丁坝可以减小漩涡回流区范围,但对主流区流速的影响很小.
In order to solve the problem of erosion and deposition near the dams in actual river channels, the distribution of hydraulic characteristics must be proved.Using the mixed model of gas-liquid two-phase flow and Large Eddy Simulation, The numerical simulation of the three-dimensional hydraulic characteristics of the flow around the Dingba dam was carried out. The finite volume method was used to solve the coupled equations of velocity and pressure in the discrete calculation region. Semi-implicit SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) VOF (Volume of Fluid) method was used to analyze and compare the backflow area and vorticity distribution near the dams under different parallel diversion wall lengths. The results show that when the length of parallel diversion wall is equal to the axial length of the dams, The effect of vortex is the best, and the effect of parallel diversion wall length on water flow velocity in the water tank is negligible.The rational distribution of L headspill in the river can reduce the range of swirl reflux zone, but the influence on the flow rate in the mainstream is very small small.