Horizontal Two-Dimensional Numerical Simulation Of Unsteady Open Channel Flow

The research and application of two-dimensional open channel flow mathematical model has been a long history, and many researches have been applied to such projects as water conservancy, environment, port and channel, flood defense, which plays an important guiding role in the design and construction for a project and sustainable development of waters. With the development of national economy, more hydraulic power resources have been further exploited and utilized, which makes a higher demand for open channel flow mathematical model. Meanwhile, it also provides a good chance and prerequisite for the development of fundamental research of water current and gives a better service to the production practice. This thesis is going to establish a horizontal two-dimensional mathematical model of unsteady open channel flow under curvilinear coordinate system on the basis of the proposed boundary-fitted coordinate technology and try to obtain the flow fields with complex boundaries. The research details of the thesis are as follows.1. An orthogonal curvilinear gird has been established by employing the boundary-fitted coordinate technology, which aims to overcome difficulties of numerical simulation resulting from complex boundary. Besides, an economical and effective sliding boundary processing method of improving the orthogonality of the boundary has been proposed.2. By means of tensor analysis, shallow water wave equations of two dimensional unsteady channel flow in orthogonal curvilinear coordinates have been deducted.3. In the computational domain, shallow water wave equations of two dimensional unsteady channel flow have been dispersed by finite difference method and solved by the alternating direction implicit technique. The established mathematical model mentioned above is applied to test and verify Nantong section of Yangtze River, the result of which proves to be satisfactory. And if it is testified by the eddy viscosity coefficient, the result turns out to be much better.4. Iteration method and upwind scheme have been respectively added to the mathematical mode mentioned above to modify the model, and the result of which proves to be reasonable and helpful to improve the computational accuracy of the model.