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Three‐dimensional finite element analysis of polymeric fluid flow in an extrusion die. Part I: Entrance effect
Author(s) -
Wen ShuHeng,
Liu TaJo,
Tsou JenqDer
Publication year - 1994
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760341008
Subject(s) - die (integrated circuit) , extrusion , materials science , mechanics , inlet , flow (mathematics) , reynolds number , flow visualization , finite element method , volumetric flow rate , secondary flow , mechanical engineering , turbulence , physics , composite material , thermodynamics , engineering , nanotechnology
The Galerkin finite element method has been applied to study the three‐dimensional flow field of power‐law fluids inside an extrusion die. Two inlet designs, i.e., center‐fed and end‐fed, have been considered. The effects of inertial force as represented by the Reynolds number Re , inlet geometry, and the power‐law index n on lateral flow uniformity and vortex formation in the entrance region have been examined. A flow visualization technique has been carried out to experimentally verify the theoretical prediction of the three‐dimensional flow field inside a die. It has been found that increasing Re or decreasing n will deteriorate flow uniformity. Depending on the direction of the inlet jet stream, the inertial force may create a flow peak in the central region of a center‐fed die, or the maximum flow rate will appear close to the end of the die for an end‐fed die. For highly shear‐thinning fluids, lower flow rates are always observed close to the end of the dies. It is concluded that creating a plug flow in the inlet tube of the extrusion die is advantageous for both center‐fed and end‐fed designs.