Analysis of liquid metal flow in die casting

Abstract A new approach is developed for analyzing liquid metal flow in die casting which, compared with conventional methods, greatly shortens the time required to calculate a solution. Instead of modeling the usually thin die casting cavity as a general three-dimensional fluid region, the governing equations are integrated through the cavity thickness, creating an equivalent two-dimensional theory that describes the motion of the liquid metal in terms of a bulk velocity and a pressure resultant. The liquid metal is represented as an inviscid, incompressible fluid. This makes it possible to introduce a two-dimensional velocity potential on the cavity surface and avoid an explicit solution for pressure. The arbitrary jump in potential that may occur when two flow fronts meet is accommodated by using discontinuous finite elements. The cavity gas displaced by the advancing metal front is assumed to compress adiabatically as an ideal gas. The method allows for generally curved, branched cavities, venting of the cavity gas, energy dissipation at gates, and a variable injection speed. A number of example problems are considered which illustrate the performance of the analysis under several geometric and process conditions.