Nonlinear Rheology of FENE Dumbbell with Friction-Reduction: Analysis of Brownian Force Intensity through Comparison of Extensional and Shear Viscosities
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- Watanabe Hiroshi
- Institute for Chemical Research, Kyoto University
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- Matsumiya Yumi
- Institute for Chemical Research, Kyoto University
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- SATO Takeshi
- Institute for Chemical Research, Kyoto University
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Abstract
<p>Normalized extensional and shear viscosities, ηE/ηE0 and η/η0 with the subscript “0” standing for quantities in the linear viscoelastic (LVE) regime, are theoretically analyzed for the FENE-dumbbell in the presence of isotropic friction-reduction under flow. The basic parameters in the analysis are the friction reduction factor rζ = ζsf/ζeq, FENE factor rκ = κsf/κeq, and the Brownian force intensity factor rB = Bsf/Beq, with ζ and κ being the bead friction coefficient and spring strength of the dumbbell, B denoting the intensity of the Brownian force acting on the bead, and the subscripts “sf” and “eq” standing for the quantities under steady flow and at equilibrium, respectively: Beq = 2ζeqkBT with kBT being the thermal energy, according to the fluctuation-dissipation theorem valid at equilibrium. The normalized viscosities were found to be analytically expressed as ηE/ηE0 = (rB/rκ){1−2(rζ/rκ)Wi}−1{1+(rζ/rκ)Wi}−1 and η/η0 = (rB/rκ), with Wi being the Weissenberg number defined with respect to the LVE relaxation time. Both ηE/ηE0 and η/η0 are proportional to the rB factor, so that comparison of these quantities allows us to characterize the intensity of the Brownian force Bsf under flow. For example, for a test case of power-law decay of rζ with Wi, the above expressions of ηE/ηE0 and η/η0 suggested a relationship 2ζsfkBT < Bsf < 2ζeqkBT <br>View PDF for the rest of the abstract</p>
Journal
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- Nihon Reoroji Gakkaishi
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Nihon Reoroji Gakkaishi 48 (5), 259-269, 2020-12-15
The Society of Rheology, Japan
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Keywords
Details 詳細情報について
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- CRID
- 1391131406305597184
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- NII Article ID
- 130007968928
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- NII Book ID
- AN00198812
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- ISSN
- 21864586
- 03871533
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- NDL BIB ID
- 031205427
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- Text Lang
- en
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- Data Source
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- JaLC
- NDL
- Crossref
- CiNii Articles
- KAKEN
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- Abstract License Flag
- Disallowed