Numerical Simulation Of Hydrodynamic Characteristics And Sewage Diffusion In Yangtze Estuary

Yangtze Estuary is playing the vital role in the national economy construction by its unique location and copious resources of water and soil. To develop the resources, the characteristic of motion of current and the law of mass transport is needed to know in this region. This provided the essential technique support for the programming research and the engineering design. Thus this region is always be researched. To study the velocity distribution, current pattern of the research domain and the hydrodynamics characteristic in the Yangtze Estuary the two modules (GFGEN,RMA2,RMA4)of SMS(Surface water Modeling System) model will be use in this study. The module GFGEN will be used to create the finite element mesh of the study area, and the module RMA2 will simulate the hydrodynamics condition of the study area. The RMA2 is a two-dimensional depth averaged finite element hydrodynamic model. It also applies finite element method to discrete the hydrodynamics equation in this paper. Additional, it uses Newton-Raphson convergence scheme and the frontal solution scheme for unsymmetrical matrices developed by Hood to obtain a solution. It shows that the calculations are in good agreement with the results of the field observation data .At last, the paper uses 2D quality model RMA4 to predict the transportation and diffusion of the sewage in Yangtze River estuary. The calibration and validation showed that the models are fairly stable and applicable for studying regulation projects and get some qualitative and quantitative conclusions in the Yangtze estuary.