回流区水流运动二维数值模拟

建立了基于无结构网格有限体积法的平面二维水流数学模型.数值方法上,采用有限体积法离散方程,并采用基于黎曼解的Osher格式计算有限体积界面通量:采用三角形单元对计算区域进行剖分;提出了一种确定紊动黏滞系数的方法.用此模型对平面上突扩引起的回流区竖轴环流进行了模拟,流速断面分布的计算结果与实测结果接近,再现了因主、副流剪切层不稳定引起的涡脱落、涡向下游输移以及被竖轴环流吞并的过程,预报了回流区的水面共振现象.

2D Numerical Modeling for Circulation in a Flume with Dead Zone

A numerical flow model based on FVM using unstructured grid has been developed for the circulation in the flume with a dead zone.In the numerical method,the Osher's scheme that is based on Reiman solution is used to calculate the horizontal flux through the interface of two adjacent cells.Triangular grid system is adopted for the discretization of the computational domain.By using this model,the large scale circulation with vertical axis in the dead zone is modeled and comparison between the calculated velocity profiles and the measured one is carried out,which shows good agreement.The vortex caused by instability of shear layer is well simulated in terms of its formation,transportation and abstraction into the circulation,the seiche phenomena of water surface elevation in the dead zone is also predicted.