Three-Dimensional Numerical Simulation Of Filling Process Of Casting

The numerical simulation for foundry process is now a hot research point in material processing. The flow field simulation have taken an important role in nu-merical simulation of casting proces.However,The calculation of flow field is one of the heaviest workload and of time consuming, seriously impactingr the commercial-ization 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.A computational model on the flow simulation in casting process is partial differential equations which include the continuous equation, the momentum equa-tions and the volume of fluid function equation. In this paper,we use VOF method to deal with the volume of fluid function equation. we give three methods to solvethe velocity field and the pressure field:SOLA method,the pressure equation difference method and charecteristics fractional step method.Now SOLA method has a broader application. It only use an iterative process to solve the velocity field and the pres-sure field. In the paper, we transmute the discrete momentum equations to get the items with pressure and the items without pressure. with the discrete continuous equation, we get the pressure poisson equation. we get the pressure field by solving this pressure equation,and then get the velocity field. The compution of charecter-istics fractional step method is divided into two steps. In the first step, we use the characteristics finite difference method to calculate the intermediate value; In the second step, we gain the possion equation of the revised pressure with help of the continuous equation, and then get the new pressure field and the new velocity field.In three dimensions, the status of a free surface mesh according to the empty adjacent grid can be summarized in 9 categories.In the paper,we give nine different conditions of free surface with the continuous equation and the symmetry princi-ple. In addition, we give the condition of corner point grid with the actual casting situation.For the free surface pressure boundary condition, this paper presents a simplified method.Based on the main frame,we develop a numerical calculation program using the pressure equation difference algorithm and VOF method,we calculate the pressure field and the velocity field using the pressure equation difference algorithm and the volume of fluid function using VOF method, and the results will be passed to the main frame. The simulation results can be displayed in multi-angle. We can see the flow of fluid intuitively by three-dimensional view, and the filling condition of any cross-section by two-dimensional.In the end, we compare the result that got using our software and the result that got using JSCAST. By analyzing the result, we are glad to see that the result is fit quite well.