Research On Three-Dimensional Numerical Simulation Technology For Mold Filling Process Of Casting

Our country has a big foundry industry, but there are many defects in the castings due to the low technological level, so it can not be regarded as a powerful country. With the development in the technology of computational fluid dynamics, the numerical simulation of casting has grown much mature, and become a reliable way of scientific analysis. The research should be actively carried out in China, because it has important scientific and practical value for the foundry industry to catch up with the international advanced level.On the base of summarizing a variety of methods which simulate the flow field, the paper established a mathematical model for mold filling process according to governing equation of Momentum and continuity, then using finite difference method to discrete the model in space and time domain, while applicating "stragger grid method" to solve the problems of unreasonable iteration results, such as "waveform" or "board-shaped" velocity and pressure field, cased by ordinary discrete method. In the process of numerical simulation, established the flow chart to solve the flow field according to SOLA algorithm, and derived a simple and effective method to treat the free surface based on VOF method, which can calculate the changes of flow and get a new solution basin. Repeated the process above to complete the entire river basin flow field solution. In order to ensure the calculation process carried out successfully, the boundary conditions of velocity and pressure also has been reasonable set.In program designing, the paper uses object-oriented programming method, independently developed a module which possesses flow field computing functions and integrated itself into the main program through a unified connector which integrated the functions of 3D displaying, mesh generation, numerical simulation and dynamic simulation. The software has simple, friendly interface and well-structed, and the program has good scalability, maintainability and reliability as well.Finally, by comparing the pictures of BenchMark testing block experiment with the computer simulating results, it found that the simulation are basically consistent with the experiment, the results reflect the objective law of fluid flow and show that the mathematical model, flow field calculation methods and boundary conditions approach are fundamentally right. The software can be applied to the simulation of some simple casting, however, there are some inaccuracy in detail which needs deeper study in the future.