摘要
建立了河口三维非线性斜压潮流盐度数学模型，数学模型中的水平压强梯度分为水位梯度的正压项和密度变化的斜压项，以反映河口盐淡水混合中的斜压现象。采用欧拉—拉格朗日法离散潮流运动方程中的对流项和盐度扩散方程，以提高计算稳定性和数值模拟精度。提出盐度边界条件、初始条件以及盐度场计算稳定标准的设置方法。针对长江河口水域的盐淡水混合情况进行模拟计算，结果反映了部分混合型河口盐度分布特征，表明所建立的河口三维非线性斜压潮流盐度数学模型能够较好地模拟长江河口盐淡水混合的时空分布。
A three dimensional nonlinear baroclinic numerical model in estuaries is developed, in which the gradients of the horizontal pressure contain the normal pressure resulted from the gradient of tidal level and the baroclinic pressure due to the gradient of salinity. The Eulerian-Lagrangian method is employed to discretize the convection terms in the momentum equations of tidal motion, as well as the salt diffusion equation. In order to save the computational time, the ways to install the boundary conditions, the initial conditions and the computational stability standard of the salinity fields are presented. Application of the present model to the Yangtze estuary is carried out for modelling the fresh and salt water mixing. Results show the characteristics of saltwater intrusion in the estuary of partially mixed pattern, indicating that the present model is suitable for simulating the fresh and salt water mixing in the Yangtze estuary.
出处
《海洋通报》
CAS
CSCD
北大核心
2001年第4期1-10,共10页
Marine Science Bulletin
基金
河海大学港航学院科学基金
关键词
长江河口
盐淡水混合
数学模型
斜压
欧拉-拉格朗日法
Yangtze estuary； fresh and salt water mixing； numerical model； baroclinic pressure； Eulerian-Lagrangian method
