Modelling and computation of the casting process by particle method

Particle-based computational methods, such as the Smoothed Particle Hydrodynamics (SPH) method, do not require a numerical mesh. Because of the mesh-less characteristics, they are suitable for the numerical simulation of the casting process. In order to optimize the production condition, the simulation of the semi solid casting by the particle method is expected to be applicable. In the semi solid casting process, we push the mold in order to fill solidifying molten metal into the narrow space. As the previous study of the casting simulation by particle method, Cleary’s numerical results are known [1]. In their results, the shrinkage cavity and the residual pressure distributions in final castings are shown. These results imply possibility of the casting simulation by the particle method. However, the important elements in the calculation of semi solid casting, which are mentioned as follows, were not considered in their method. (1) The influence of the surface tension should not be ignored, when molten metal flows into the narrow space. (2) Unnatural vibration of the density may become the problem when we calculate the pressurized fluid by the particle method. (3) In order to resolve the narrow space, large number of the particles is necessary for the simulation i.e. vast computational cost is needed Therefore we enabled the numerical method controlling density vibration, and the numerical method of the surface tension in addition to the original method of Cleary [2] [3]. Furthermore, using the parallel computer, we enabled the flow calculation of the narrow space. Then, in this study, we developed the numerical method based on that of Cleary for the semi-solid casting by the particle method. We will show the numerical results of the castings by our method.