Design of complex profile extrusion dies through numerical modeling

摘要

The achievement of a balanced flow is one of the major tasks encompassed in the design of profile extrusiondies [1]. For this purpose numerical modeling codes may be a very useful aid. The research teaminvolved in this work has been working during the last decade on the development of numerical toolsto aid the conception of extrusion dies [1,2]. The design code developed so far carries out the automaticsearch of a final geometry via an optimization routine coupled with geometry and mesh generators and a3D computational fluid dynamics (CFD) code based on the finite volume method (FVM). This CFD code isable to model the flow of polymer melts in confined channels, but is inadequate to deal with complexgeometries, since it is limited to structured meshes. This work describes the recent efforts made toenlarge the scope of the design procedures, that are currently focused on the development of a modelingcode able to deal with unstructured meshes. This code solves the continuity and linear momentum conservationequations, with generalized Newtonian fluids, using a SIMPLE based approach. This paperdescribes the developed numerical modelling code and its employment in a case study that involvesthe design of a medical catheter extrusion die, focused on the search of a balanced flow distribution.The results obtained show that the developed numerical code is able to deal with complex geometricalproblems, being thus a valuable tool to aid the design of extrusion dies to produce complex profiles.