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A numerical study of the effect of fibre stiffness on the rheology of sheared flexible fibre suspensions

  • JINGSHU WU (a1) and CYRUS K. AIDUN (a1)

Abstract

A recently developed particle-level numerical method is used to simulate flexible fibre suspensions in Newtonian simple shear flow. In this method, the flow is computed on a fixed regular ‘lattice’ using the lattice Boltzmann method, where each solid particle, or fibre in this case, is mapped onto a Lagrangian frame moving continuously through the domain. The motion and orientation of the fibre are obtained from Newtonian dynamics equations. The effect of fibre stiffness on the rheology of flexible fibre suspensions is investigated and a relation for the relative viscosity is obtained. We show that fibre stiffness (bending ratio, BR) has a strong impact on rheology in the range BR < 3. The relative viscosity increases significantly as BR decreases. These results show that the primary normal stress difference has a minimum value at BR ~ 1. The primary normal stress difference for slightly deformable fibres reaches a minimum and increases significantly as BR decreases below one. The results are explained based on Batchelor's relation for non-Brownian suspensions.

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Corresponding author

Email address for correspondence: cyrus.aidun@me.gatech.edu

References

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A numerical study of the effect of fibre stiffness on the rheology of sheared flexible fibre suspensions

  • JINGSHU WU (a1) and CYRUS K. AIDUN (a1)

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