感潮河段盐水入侵的河口水质模型

盐潮入侵将严重影响内河水质。本文考虑强混合型河口潮汐的特点，采用同步不同格式对河口盐潮入侵问题的流场及浓度场进行数值计算。采用欧拉-拉格朗日混合解法将对流-扩散方程中的扩散项和对流项分裂求解，应用高精度时间序列插值的特征差分隐格式求解对流项，扩散项采用传统的有限差分法。在汊口处，将描述河网汊口水质变化的三维对流扩散方程在汊口控制体体积积分，变量间的插值分布采用Panankar提出的幂函数，得到新的汊口离散方程。计算与实测结果比较表明，本文提出的方法有效可行。

Numerical simulation of water quality in tidal river network under the action of unsteady saline water intrusion

The flow field and salinity concentration field of saline water intrusion at estuary under the action of strong mixing type tide are numerically simulated simultaneously by different schemes. The Eulerian Lagrangian method (ELM) is applied to solve the diffusion term and convection term in the diffusion convection equation separately. The implicit method of characteristics using time line interpolation with high accuracy is adopted to solve the convection terms, and the conventional finite difference method is applied to solve the diffusion terms. At the junctions of river network, the three dimensional convection diffusion equation is integraled within the junction control volume, and the power function scheme proposed by Patankar is used to describe the interpolation distribution of the water quality variables to obtain a new discrete equation of finite volume method. The computational results of an example well agree with the observation data.