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Vortex formation in a dual‐cavity coat‐hanger die
Author(s) -
Lee KwongYang,
Wen ShuHeng,
Liu TaJo
Publication year - 1990
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.760301906
Subject(s) - vortex , materials science , viscoelasticity , reynolds number , elasticity (physics) , mechanics , power law , composite material , physics , turbulence , mathematics , statistics
The effects of cavity shapes, particularly the expansion and contraction angles, and the Theological properties of polymeric liquids on vortex formation in the cuter cavity of a dual‐cavity coat‐hanger die have been examined. For power‐law fluids, a vortex may appear in the expansion side of the outer cavity, and the size of the vortex is influenced by the expansion angle, the power‐law index, and the Reynolds number. Two viscoelastic fluids were used in the flow visualization experiment; for an aqueous polyacrylamide solution, a vortex may appear in the contraction side of the outer cavity and this vortex is influenced by the contraction angle and the fluid elasticity, but no vortex was observed for a Boger fluid.