The Research And Application Of Numeric Modeling Of Flood Controlling Estimation Based On Unstructured Grid

In our country, the loss caused by flood is quite heavy every year. And along with the development of the economic, the influence of flood disaster on economic is bigger than before. In order to reduce the loss, the government has spent a lot of money in studying the mechanism of flood. The numerical simulation of river way current is a very effective method for researching the disciplinarian of flood movement, and there were many people have studied the problems about it.Based on unstructured grids and by using the method of finite volume, a 2-D numerical model for evaluating the effect of the river flood control is established. Many questions about grid partition are quite embedded talked in this paper, such as the background grid in grid creation, the improvement of the method of front advance, the methods of judging whether the polygon is protruding or concave, the difference of the effect on numerical calculation between wide grid and fine grid, the way of distinguishing the relationship between one point and one close curvilinear, domino effect of scale, the transformation of triangle into polygon, and grid optimizing. By talking above problems, the paper brings forward a new concept that is called the background information of grid creation, and thinks over three points of the improvement of front advance, and puts forward and talks the essential of judging whether the polygon is concave or protruding and six practical methods. Besides, the paper talks amply about some other questions which including the disposal of rough rate, the method of calculation, the format of conservation difference, and high precision FVM. Among these talks, the considering of qualification number is the most important one, which not only talks related theory but also puts forward some new opinions. All of these talks are helpful to improve the numerical model.Aimed at the characteristic of north river that is dry up in low water course and break out flood in rainy season, the paper established 2-D numerical model for evaluating the effect of the river flood control, and apply it to the mining project in the Luanhe river to calculate the flow field of the lower reaches of the Luanhe river. According to the result of the applying of the numerical model that is used for evaluating the effect of the mining project on the flood control, the model is rationality and validity.