Improved nonlinear fluid model in rotating flow

doi:10.1007/s10483-012-1633-x

摘要/Abstract

摘要： The pseudoplastic circular Couette flow (CCF) in annuli is investigated. The viscosity is dependent on the shear rate that directly affects the conservation equations solved by the spectral method in the present study. The pseudoplastic model adopted here is shown to be the suitable representative of nonlinear fluids. Unlike the previous studies, where only the square of the shear rate term in the viscosity expression is considered to ease the numerical manipulations, in the present study, the term containing the quadratic power is also taken into account. The curved streamlines of the CCF can cause the centrifugal instability leading to toroidal vortices, known as the Taylor vortices. It is further found that the critical Taylor number becomes lower as the pseudoplastic effect increases. The comparison with the existing measurements on the pseudoplastic CCF results in good agreement.

关键词: pseudoplastic, circular Couette flow (CCF), toroidal vortex, spectral method, theory of materials with elastic range, elastic-plastic constitutive relation, back stress

Abstract: The pseudoplastic circular Couette flow (CCF) in annuli is investigated. The viscosity is dependent on the shear rate that directly affects the conservation equations solved by the spectral method in the present study. The pseudoplastic model adopted here is shown to be the suitable representative of nonlinear fluids. Unlike the previous studies, where only the square of the shear rate term in the viscosity expression is considered to ease the numerical manipulations, in the present study, the term containing the quadratic power is also taken into account. The curved streamlines of the CCF can cause the centrifugal instability leading to toroidal vortices, known as the Taylor vortices. It is further found that the critical Taylor number becomes lower as the pseudoplastic effect increases. The comparison with the existing measurements on the pseudoplastic CCF results in good agreement.

Key words: pseudoplastic, circular Couette flow (CCF), toroidal vortex, spectral method, theory of materials with elastic range, elastic-plastic constitutive relation, back stress

中图分类号:

O373

N. ASHRAFI;H. KARIMI-HAGHIGHI. Improved nonlinear fluid model in rotating flow[J]. Applied Mathematics and Mechanics (English Edition), 2012, 33(11): 1419-1430.

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