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Comparison of two numerical methods for the solution of non‐Newtonian flow in ducts
Author(s) -
Liu TaJo,
Lin HoMay,
Hong ChinNan
Publication year - 1988
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.1650080707
Subject(s) - finite element method , non newtonian fluid , power law fluid , newtonian fluid , mathematics , mechanics , bingham plastic , generalized newtonian fluid , viscosity , shear rate , physics , rheology , thermodynamics
Two numerical methods, the Galerkin finite element method (FEM) and the boundary‐fitted co‐ordinate transformation method (BFCTM), have been applied to solve inelastic non‐Newtonian fluid flow in ducts of irregular cross‐section. Three representative fluid models, namely the power‐law, the Ellis and the Bingham models, have been analysed. The application of the FEM is straightforward, while for the BFCTM the accurate estimation of viscosity on the duct boundary and the proper mesh adjustment appear to be critical for generating convergent solutions. A detailed comparison of the two numerical methods in terms of volumetric flow rate, axial velocity, shear rate, viscosity and CPU time is given. Both methods can generate accurate solutions of velocity over a wide range of variables, but the FEM requires much less computing time to reach the same level of accuracy. Only the BFCTM can be used to approximate shear rate and viscosity with reasonable accuracy.