Shape oscillations of elastic particles in shear flow.
J Mech Behav Biomed Mater
; 62: 534-544, 2016 09.
Article
em En
| MEDLINE
| ID: mdl-27294284
ABSTRACT
Particle suspensions are common to biological fluid flows; for example, flow of red- and white-blood cells, and platelets. In medical technology, current and proposed methods for drug delivery use membrane-bounded liquid capsules for transport via the microcirculation. In this paper, we consider a 3D linear elastic particle inserted into a Newtonian fluid and investigate the time-dependent deformation using a numerical simulation. Specifically, a boundary element technique is used to investigate the motion and deformation of initially spherical or spheroidal particles in bounded linear shear flow. The resulting deformed shapes reveal a steady-state profile that exhibits a 'tank-treading' motion for initially spherical particles. Wall effects on particle trajectory are seen to include a modified Jeffrey׳s orbit for spheroidal inclusions with a period that varies inversely with the strength of the shear flow. Alternately, spheroidal inclusions may exhibit either a 'tumbling' or 'trembling' motion depending on the initial particle aspect ratio and the capillary number (i.e., ratio of fluid shear to elastic restoring force). We find for a capillary number of 0.1, a tumbling mode transitions to a trembling mode at an aspect ratio of 0.87 (approx.), while for a capillary number of 0.2, this transition takes place at a lower aspect ratio. These oscillatory modes are consistent with experimental observations involving similarly shaped vesicles and thus serves to validate the use of a simple elastic constitutive model to perform relevant physiological flow calculations.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Suspensões
/
Resistência ao Cisalhamento
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Elasticidade
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Eritrócitos
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Leucócitos
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article