明渠交汇口水流浅水二维数学模型研究

Shallow water two-dimensional numerical simulation of open channel influx

针对明渠交汇口缓流流动特性,建立基于高性能有限体积数值方法、具有二阶精度的非恒定浅水二维水流数学模型。基本控制方程采用浅水二维水流方程;采用能够有效捕捉激波的高性能有限体积方法离散控制方程;采用了隐式方法处理阻力项,从而保证了模型的稳定性。采用非结构三角形网格系离散计算区域。最后,应用实测资料对两种模型进行了验证比较,结果表明该模型可模拟明渠交汇口基本流动特性,显示了对天然河流广阔的应用前景。

This paper presents a high-resolution two-dimensional finite-volume numerical model with twoorder accuracy for flow characteristics at open channel junction. The governing equations of the model comprise the shallow water equations with bed slope and resistance source. A high-resolution numerical method governing equations, which may accurately capture shocks, is adopted. To alleviate the problems associated with numerical instabilities due to small water depths near a wet/dry boundary, the friction source terms are treated in a fully implicit way. Finally, the measured data for open channel junction is used in the present model. Results indicate that present model may well simulate the flow characteristics at open channel junction.