Research And Development Of Visual Software System In FDM Calculation For Underground Water

FDM(Finite Difference Method) is one of the important numeric calculation methods used in Groundwater Gynamics.The application of FDM has advanced rapidly Groundwater Gynamics. Visualization in Scientific Computing is a important studying direction in the fields of calculation in Groundwater Gynamics. The calculation of FDM need the support of Visualization in Scientific Computing, which makes for the development of Groundwater Gynamics.Actual hydrological and geological conditions are often more complex, using theanalytic method is very difficult,.numerical method to study these issues has opened up new ways. It based on groundwater percolation theory and water balance or quality conservation builds mathematical model which can reflect the whole regional groundwater movement. Being the earliest numerical simulation methods, derivatives of control equation are replaced with differece quatient of grid node function ,correspondingly, boundary and initial conditions dealed in similar, by which FDM set up equation set ,value of grid nodes unknown.With intuitive mathematical concepts, simple expression fdm is one of mature numerical methods.The paper system uses object-oriented thinking, based on the finite difference method, Visual Basic6.0 platform for the development, research and development on the basis of groundwater flow visualization system.From the functions of the system is divided into pre-processing, finite difference, post-processing module. The pre-processing stages can finish rectangular grid and the irregular triangular grid. TIN generated by the insertion point by point. In calculation stage,the system according to hydrological and geological conditions, selecting the appropriate mathematical model, based on the finite difference method, can finish one-dimensional, two-dimensional pressure steady flow and non-steady flow of the analysis, design and implementation.In post-processing phase, the system ,using ActiveX Automation technology, embedded Surfer in VB programming quickly ,efficiently plot coutour map. The system using OpenGL draw a non-steady flow curve.The system selects confined aquifer two-dimensional non-steady flow as engineering examples to test main functions,which is feasible for calculating the distribution of water head.