Study On Numerical Simulation Of 2d River Flow And Water Quarlity With Complicted Boundary

Enviromental pollution and protection is one of the big problems in the world. With the development of industry, A large amount of industry waste and life polluted water harmfull to people and other living things is discharged into river, lake, reservoir and ocean and make the natural water much more polluted. To protect environment, people must learn and study the transportation of the polluted matter in water, to obtain the distribution of the polluted matter concentration. Here, a mathematical model for numerical simulation of two-dimensional flow and polluted matter transportation with complex boundary under orthogonal curvilinear coordinate system. A comparison between computed results and measured data for practical engineering shows a satisfactory agreement. The research details of this paper are as follows:l.Some problems concerning the adjusting factors in the commonly-used Thompson method in the generation of curvilinear grid are pointed out. A new expression of adjusting factors is proposed, and some curvilinear grid generation examples show that by using the proposed adjusting factors ideal grids can be generated for simple-connected regions and connected- regions with complex boundary. The curvilinear grid is orthogonal and the interior grids can be adaptive to the variation of physical parameters of fluid.2. The governing equations are transformed from physical plane (x, y coordinate system) to computational plane ( , n orthogonal curvilinear coordinate system), and the governing equations under orthogonal curvilinear coordinates are decretized and solved. The computed examples show that orthogonal curvilinear grid generation proposed here can be used to overcome the difficulties resulting from numerical simulation of 2D flow with complex boundary.3. ADI method is used to solve the transformed equations under orthogonal curvilinear coordinates, and the polluted matter diffusion term is considered. And the mathematical model is used to numerical simulation of a 2D pollution problem and two 2D flows. The results show that the model is a effective, correct, good model.