Mold Filling Simulation Method Using Non-Orthogonal Element by the Direct Finite Difference Method

Abstract

  A new technique of two dimensional mold filling simulation based on the Direct Finite Difference Method has been developed. Non-orthogonal elements can be employed in this technique so that the original complicated and thin shape of a casting, including the gating system, can be retained in its simulation model. Pressure points are located at each centroid of the rectangular element while fluid velocity vectors are at vertexes which are the representative points of nodal regions formed around the vertexes. The momentum equation is discretized in each nodal region while the mass conservation equation is discretized in element. Two dimensionless parameters β_ν, β_s are defined to predict the free surface movement more accurately and mass conservation in the free surface regions is solved explicitly by using these parameters. Some numerical mold filling examples, namely die casting of a disk-like cavity and gravity casting of a curved gating system, showed promising results of the proposed technique.