Development of a new simulation method of mold filling based on a body-fitted coordinate system

A new numerical model has been developed for the simulation of mold filling in curved-shape mold cavities. In the present method, the SIMPLE scheme was adopted to solve the momentum transport and the VOF (Volume of Fluid) method to trace the free surface in mold filling processes. In order to improve the solution accuracy in modeling mold filling with curved-shape and thin-walled mold cavities, the body-fitted-coordinate (BFC) concept, known as the most effective method to predict a flow field in a curved-shape cavity, was adopted. The governing equations for fluid flow were transformed based on the BFC concept, The nonstaggered mesh and the momentum interpolation method were used which are essential for the BFC method. In addition, the standard VOF method was modified for the treatment of free surface in the BFC system. The standard DAFA (donor and acceptor flux approximation) method was also revised as a suitable form to the BFC system. In order to verify the present SIMPLE-BFC-VOF method, several examples on mold filling problems having curved-shape mold cavities were simulated, and the results were compared with the experimental results and other simulation methods. It is concluded that the present method can be used as an effective simulation method for the simulation of mold filling in thin-walled and curved-shape mold cavities.