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

The numerical simulation for foundry process is now a hot research point in material processing. The flow field simulation and temperature field simulation and the couple simulation of these two fields have taken an important role in numerical simulation of casting process. The flow field is one of the heaviest workload and of time consuming, and is also the most important part for commercialization of numerical simulation software. So it has great significance for investigating high efficiency method for calculating flow field of casting process in updating the level of whole numerical simulation software.On the base of the original program of flow field which can only calculating the simple anti-gravity flow field, an improved program has been developed for simulating almost all kinds of mold filling process. Then a program was also built up for coupling calculation of flow field and temperature field, and so do a post processor which is able to display computing result in many kinds of pattern.For calculation of flow field, based on the investigation and analysis of each kind of numerical algorithm, an approach named Simple and Conservative Scalar Method was chosen to build up mold filling codes of our software, and this algorithm was used less in the world so far. The Simple Method can precisely calculate the flowing process during mold filling of casting, in the meantime the Conservative Scalar Method can precisely capture the free surface of fluid flow without determining the orient of the grid occupying free surface of fluid, so it is more easy to do 3-dimentional simulation for real casting process. The mold filling process of a test casting—a plate filling in anti-gravity ways, and several real castings—chain wheel, hammer, creeper tread, was calculated by our codes and other commercializing software, and the result showed that the algorithm used in this paper had more precision than Sola Method used in these commercializing softwares.In addition, several new technology are worth to comment, they are: all the static arrays no less than 50 using in our codes had been changed into dynamic arrays successfully; the outlet condition and inlet condition have been rebuilt successfully; and the type and value of convergence had renewed; and all these breakthrough in simulation technique have greatly promoted our program's running velocity, expended the application range of our software to fit to almost mold flow conditions. In the end, by these new techniques, it is possible for commercializing of our software.In the test part of the paper, the simulation result of anti-gravity filling of a big plate was relatively good in accordance with the experimental result. Afterwards, selecting several real castings to compare the accuracy and velocity of the codes with Ft-star and ProCAST software, it has indicated that the program is excellent in precision, however, the velocity still need to be improved. A theoretical analysis was also done in the paper.The reasonability of the coupling calculation program for flow field and temperature field was showed by the simulation result of a test casting. And this study has laid the foundation of the subsequent study for high speed and turbulent flow field simulation and other simulation study such as shrinkage porosity prediction, etc.Finally, using C++Builder and OpenGL, a friendly interface and post program were constructed, which can meet the requirement of calculation and post processor display.