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Deep channel operating characteristics of a single screw extruder: Finite element predictions and experimental results for isothermal non‐Newtonian flow
Author(s) -
Choo K. P.,
Hami M. L.,
Pittman J. F. T.
Publication year - 1981
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.760210208
Subject(s) - materials science , plastics extrusion , isothermal process , finite element method , non newtonian fluid , mechanics , shear thinning , newtonian fluid , rheology , power law fluid , shear stress , composite material , elasticity (physics) , thermodynamics , physics
Finite element solutions are presented for developed, isothermal, power‐law flow in an extruder channel, based on a variational formulation in helical co‐ordinates. The success of the method in handling non‐Newtonian flow in a deep, highly‐curved channel is tested by comparison with experimental results. Operating characteristics were determired under virtually isothermal conditions for a screw with depth to diameter ratio 0.25 pumping an aqueous glucose solution containing high molecular weight hydroxyethyl cellulose. Shear stress and first normal stress differences of this solution were determined in a rheogoniometer. It was both highly shear‐thinning and elastic. Computed and experimental screw operating characteristics agree well, except near closed discharge, where effects due to viscous heating and elasticity are tentatively suggested.