The dynamics of a capsule in a wall-bounded oscillating shear flow
2014 (English)Report (Other academic)
The motion of an initially spherical capsule in a wall-bounded oscillating shear flow is studied via an accelerated boundary integral implementation. Neo-Hookean model is used as the constitutive law of the membrane of capsule. The lateral migration velocity of the capsule varies non-monotonically with its capillary number. It is negatively related with the initial height of the capsule above the wall. A positive correlation between the lateral migration velocity and normal stress difference is identified. The correlation becomes strongest for the capsule with the highest lateral migration velocity. For a fixed capillary number, the lateral migration velocity decreases linearly with the frequency of oscillating shear, and approaches an asymptotic value of zero for high frequency. The deformation of capsule displays a wave-like variation in time and its frequency is twice that of the underlying shear. A phase delay is observed between the variation of capsule deformation with that of the oscillatory flow, more pronounced for a more deformable capsule.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:kth:diva-142673OAI: oai:DiVA.org:kth-142673DiVA: diva2:704185
FunderSwedish Research Council
QC 201403112014-03-112014-03-112014-03-13Bibliographically approved