A 3-DIMENSIONAL BOUNDARY-ELEMENT APPROACH TO CONFINED FREE-SURFACE FLOW AS APPLIED TO DIE-CASTING

A three-dimensional boundary-element method is proposed for the numeri cal simulation of confined free surface flow problems. Although the me thod is applicable to viscous and inviscid flows, the present formulat ion will be limited to potential flow, including transient and nonline ar waves in cavities of general shape. The emphasis in this study, how ever, will be on the flow driven by a plunger in cylindrical cavities, typically as it arises in the shot sleeve of a die casting machine. U nlike most existing (two-dimensional) Lagrangian formulations, the pre sent method is based on a mixed Eulerian-Lagrangian formulation whereb y the partially filled cavity is discretized into volume elements that deform along and with the plunger movement. The fluid, at any time, o ccupies part of the cavity, and the domain of computation thus changes as the fluid flows within the cavity. At each time step, the solution is obtained using boundary element discretization and an explicit (Eu ler) time stepping scheme. Numerical results will be given for both re ctangular and cylindrical cavities. (C) 1998 Elsevier Science Ltd. All rights reserved.