Non-linear Stokes drag of spherical particles in a nematic solvent
Abstract
We present a numerical calculation for the Stokes drag of a particle in a nematic solvent. Due to the radial anchoring of the molecules at the particle surface and a uniform director field at infinity, the particle is accompanied by a hyperbolic point defect which gives rise to the so-called dipole configuration. We write the Ericksen-Leslie equation in a reduced form emphasizing the importance of the Ericksen number Er. Due to the coupling between director and velocity field, we find a highly non-linear Stokes drag. We discuss it in terms of an effective viscosity and as a function of Er. Director field and stream line patterns add to the understanding of our results. Finally, we suggest that the non-linear Stokes drag should be observable in a falling-ball experiment.
- Publication:
-
EPL (Europhysics Letters)
- Pub Date:
- January 2002
- DOI:
- 10.1209/epl/i2002-00541-0
- Bibcode:
- 2002EL.....57...60S
- Keywords:
-
- 61.30.Dk;
- 47.50.+d;
- 83.10.-y;
- Continuum models and theories of liquid crystal structure;
- Fundamentals and theoretical