Planear 2-D Numerical Model And Study Of Damming Caused By Bridge Pier

Open channel flow exists widely and its numerical simulation is of reality. The damming caused by a bridge pier is one of the aspects considered intentionly while building a bridge on a river which flood control standard is low and flood control cost is high so the study of damming is of important value.In this thesis a numerical model to solve the planear 2-D Depth-Integrated Flow(DIF) has been established with irregular body-fitted mesh Finite Volume Method and explicit MacCormack predictor-corrector method and applied to the study of damming caused by a bridge pier under 14 working conditions varied with the combination of different pier shape . flow rate and contraction ratio. The experimental results in a physical model are adopted to verify the simulated damming heights.Irregular body-fitted mesh Finite Volume Method can really simulate complicated boundaries and improve the predicting precision so it is more ideal to process the complicated boundaries met often in open channels. In this point of view this approach is better than Finete Element Method in which only few elements can be used and Finite Diffence Method in which the rectangular grid is always used.That the predicted values of damming height agree well with the exprimental results proves the validity of the numerical model.In the addition, the locally refining mesh method has been studied preliminarily and applied to the study of the local flow around a bridge pier. It is found that the use of the locally refining mesh method can improve the results in the refined area greatly, and can improve the results outside the refined area to a certain extent too. This method has the potential application in studying many problems with the great characteristic size ratio .