Effects of hydrodynamic interaction on fibre suspension

Yamanoi, M.¹ and Maia, J^.1

¹ I3N,Department of Polymer Engineering, University of Minho, Portugal

Fibres are used in industry as fillers in polymer matrices to control rheological properties, process conditions, quality of products and so on. There are some theories for rigid fibre dispersion; commonly used theories are based on the Jeffery model, with an evolution function of orientation and a constitutive equation. These models are normally modified to be applied to semi-dilute concentrations with fibre-fibre interactions. The first simulation research on this subject, treating dynamics of flexible fibre under flows, was done by PSM (particle simulation method)[1,2], where fibres are modelled as connected beads. Between adjacent beads, stretch force, bending and torsion torques are considered. It is possible to simulate fibre behaviour under flow by solving translational and rotational equations of motion with non-slip restriction between adjacent beads, which is important for producing tumbling phenomena. Still now, the effect of hydrodynamic interaction on fibre behaviours and rheological properties is not well known. This research focuses on fibre aspect ratio and flexibility. Fibres are modelled as a series of beads, following PSM and hydrodynamic interactions [3] are considered. The effects on hydrodynamic interaction on flexible fibres under flows will be demonstrated.

[1] S. Yamamoto and T. Matsuoka, J. Chem. Phys. 98 (1993) 644-650.

[2] S. Yamamoto and T. Matsuoka, J. Chem. Phys. 102 (1995) 2254-2260.

[3] R. J. Phillips, J. F. Brady and G. Bossis, Phys. Fluids 31 (1988) 3462-3472.