正交曲线网格在导流明渠模拟中的应用

Application of orthogonal curve mesh in flow simulation of open diversion channel

由于在天然河道中修建导流明渠后,过流边界比较复杂,建立数学模型时划分网格难度较大,因此对于明渠水流的数值模拟研究尚不多见。采用非结构三角形网格能较好地划分复杂的计算区域,但对于导流明渠这类人工开挖的规则边界,地形插值后在渠道边坡上形成锯齿状地形,导致边界附近的水流模拟失真。采用局部连续的正交曲线网格划分计算区域,同时保证网格的贴体与良好的正交性,且能较精确地模拟人工开挖边坡,保证计算的稳定性与精度。建立了用于模拟导流明渠流场的平面二维水流数学模型,采用有限差分法求解水深积分方程。数值模拟结果与物理模型测量结果吻合较好,表明建立的数学模型能合理地模拟明渠内的水流。

For the complication of flow boundary condition of open channel built in natural river channel and difficulty of mesh division in mathematical model set-up,the numerical simulation research of open channel flow is few.The complicated computation region can be well divided by non-structure triangular mesh,but for regular boundary of artificial open diversion channel,saw-tooth-shaped topography on canal slope will form after interpolation,resulting boundary flow simulation distortion.If the computation region is divided by consecutive orthogonal curve mesh,and closeness and good orthogonality of mesh are guaranteed,in addition of accuracy simulation of artificial excavation sideslope,the computation stability and accuracy can be guaranteed.The 2 dimensional flow mathematical model for simulation of open diversion channel flow and finite-difference method is used to solute water depth integral equation.The digital simulation and physical model measurement is fitted well,demonstrating the built mathematical model can reasonably simulate the flow in open channel.