Study On Visualization Of Numerical Simulation For Unsteady Flow In River Networks

With the rapid development of the computer technology,the computer is adopted more and more when it comes to the study of unsteady flow in river networks. But the conventional programs of hydraulic calculation in river networks are mostly programmed with Fortran,the process of calculating cann't be understood easily,the human interface is lacked,the interactive features is weak,and therefore the application of programs are greatly restricted.Based on the existing methods of numerical simulation for unsteady flow in river networks,the visualization system is developed for river networks by programming with mixed-languages,with which the process of numerical simulation for unsteady flow can be shown dynamically and the calculated results can be shown in graphic way.This paper includes six chapters, and the details are as follows:In chapter 1, the research actuality on mathematical model,main numerical calculation methods and the development of application software for unsteady flow in river networks at home and abroad are generally introduced. In the last the major contents of the paper are stated following above content.In chapter 2, a mathematical model for unsteady flow in river networks is set up.The way to give initial conditions and boundary conditions is analyzed concretely. The process of numerical calculation for unsteady flow in river networks is related in detail.Based on the Saint-Venant equations,the nonlinear algebraic equations derived by the use of Preissmann four-point implicit scheme are solved with the chase method and a relaxation interative arithmetic for simulating unsteady flow in river networks is proposed. In chapter 3, programming with mixed-languages between Fortran 90 and Visual Basic 6.0 is deep discussed. The paper integrates the calculating program of Fortran into the visualization module with the style of DLL(Dynamic Link Library), which communicates with user through the graphical user interface that programmed with Visual Basic 6.0.In chapter 4, the visualization system in unsteady flow numerical simulation is developed for river networks. The general structure of visualization system and the design of each module are related in detail.In chapter 5, the whole visualization system is introduced,included the way to use visualization system and the function that visualization system can be done.The paper cites an instance in illustration of the visualization system.In chapter 6, the whole work in the paper is summed up and further research work is prospected.