title: Lateral migration of flexible fibers in Poiseuille flow between two parallel planar solid walls.
abstract: Dynamics of non-Brownian flexible fibers in Poiseuille flow between two parallel planar solid walls is evaluated from the Stokes equations which are solved numerically by the multipole method. Fibers migrate towards a critical distance from the wall zc, which depends significantly on the fiber length N and bending stiffness A. This effect can be used to sort fibers. Three types of accumulation are found, depending on a shear-to-bending parameter Γ. In the first type, stiff fibers deform only a little and accumulate close to the wall, where their tendency to drift away from the channel is balanced by the repulsive hydrodynamic interaction with the wall. In the second type, flexible fibers deform significantly and accumulate far from the wall. In both types, the fiber shapes at the accumulation positions are repeatable, while in the third type, they are very compact and non-repeatable. The difference between the second and third accumulation types is a special case of the difference between the regular and irregular modes for the dynamics of migrating fibers. At the regular mode, far from walls, the fiber tumbling frequency satisfies Jeffery's expression, with the local shear rate and the aspect ratio close to N.
authors.affiliation: Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawińskiego 5B, 02-106 Warsaw, Poland.
authors.forename: Agnieszka M
authors.initials: AM
authors.lastname: Słowicka
authors.forename: Eligiusz
authors.initials: E
authors.lastname: Wajnryb
authors.forename: Maria L
authors.initials: ML
authors.lastname: Ekiel-Jeżewska
references.citation: Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Nov;82(5 Pt 1):050803
references.pmid: 21230428
references.citation: Phys Rev Lett. 2013 Mar 8;110(10):108104
references.pmid: 23521303
references.citation: Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Aug;74(2 Pt 1):021907
references.pmid: 17025472
references.citation: Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Jul;84(1 Pt 1):011902
references.pmid: 21867208
references.citation: Phys Rev Lett. 2007 Mar 2;98(9):098301
references.pmid: 17359205
references.citation: Phys Rev Lett. 2007 Aug 3;99(5):058303
references.pmid: 17930802
references.citation: Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Jul;82(1 Pt 1):011802
references.pmid: 20866639
references.citation: J Chem Phys. 2012 Jan 28;136(4):044904
references.pmid: 22299916
references.citation: Phys Rev Lett. 2012 Jan 20;108(3):038103
references.pmid: 22400789
references.citation: J Chem Phys. 2011 Oct 28;135(16):165101
references.pmid: 22047266
references.citation: J Chem Phys. 2005 Mar 1;122(9):094902
references.pmid: 15836176
references.citation: Phys Rev Lett. 2001 Nov 5;87(19):198301
references.pmid: 11690460
references.citation: J Chem Phys. 2010 Oct 28;133(16):164905
references.pmid: 21033821
references.citation: Phys Rev Lett. 2006 Sep 22;97(12):128301
references.pmid: 17026005