Mampaey F

Abstract: The features of two variants of the Finite Volume Method, which both employ a structured grid, are briefly discussed. The first method (Hybrid) in based on a rectangular grid in which some elements may contain two different materials. In the second method (BFC), the mesh becomes deformed as the vertices of the control volumes are moved to the geometry boundary. Here too, the elements or control volumes, may be internally mixed with two materials. Both techniques have been applied to construct meshes for three casting geometries for which experimental data exist. Because of the mesh deformation in the BFC method, casting geometries may be enmeshed correctly using few control volumes. In these circumstances, the CPU time required for mold filling can be reduced by two orders of magnitude as compared to the classical Finite Difference Method (FDM). The other important benefit of both Finite Volume Methods, is the ability to mesh thin inclined walls accurately without the harmful zigzag approximation typical for the FDM. Since BFC and Hybrid enmeshments can correctly model a casting geometry irrespectively of the fineness of the discretization, mold filling results do not depend on the mesh size as in case of the FDM. Thermal simulations obtained with the BFC method produce results that are in good agreement with experimental data. Examples are given for two different castings. However, this result relies more on accurate material data than on the ability to construct correct geometrical models.

Keywords: Casting process, Finite volume, Method for simulation, Practical examples, Simulation.