The Study And Application Of River Flood Mathematical Model

In the paper, Some study works are shown and applied on two projects, numerical simulation research of"suspended river"in Lower Yellow River and numerical simulation research of flood evaluation for Qingshuipu dock in Yongjiang River, by studying numerical simulation theory and calculation method on river flood simulation. Firstly, three study works have been done on river flood numerical simulation,which are expressed as follow:1. By analyzing in hydraulic method, the correctness of four kinds of hydraulic boundary is related to flow pattern . If there is no additional condiction, the steady flow simulation results would be effected by the initial condiction when the discharge condictions are set in the both boundaries.2. Combined with finite difference method and finite volume method, a new discret format has been found for one dimension flow simulation. In the new discret format, the timer partial derivative is soluted by finite difference with weighting coefficient, but the space partial derivative is soluted by finite volume method and convention item is soluted by upwind format.3. A new 1D-2D couple flow model, which needn't superpose grids and can make the mass, energy and momentum be conserved , has been found. solutions for some problems in couple model have been given out.Secondly, two study works have been done on numericl simulation program design and pre-post dealt way ,which are expressed as follow:1.Combined AutoCAD and Matlab, a software has been done for dealing the pre-work and post-work in river flood numerical simulation. The solution for transmitting data between Matlab and Visual C++ has been given out. The software has been found that it could perfectly improve efficiency of pre-work, easily look up and edit simulation results, and visualize simulation results.2.The program design method of object-oriented programming has been applied in the river flood numerical simulation, and is a better solution for developing more and more complex numerical simulation program by team work. Thirdly, some ideas have been gained in the river flood numerical simulation practice of two projects.By applying 2D flow and sand mathematic model to research"suspended river"in Lower Yellow River, a critical condiction of suspending height vertically from the bottomland near by riverbank to channel alignment top has been found. Based on the simulation results, the compound method of enlarging bankful discharge and doing train to bottomland would get a better result for training suspended river.By applying 1D-2D couple model to do flood evaluation for Qingshuipu dock in Yongjiang River, precision flow fields have been gained when the dock built before and after. A solution for elaborate field simulation in a long reach in tide river has been given out.