The motion of a deforming capsule through a corner
2015 (English)In: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 770, 374-397 p.Article in journal (Refereed) Published
A three-dimensional deformable capsule convected through a square duct with a corner is studied via numerical simulations. We develop an accelerated boundary integral implementation adapted to general geometries and boundary conditions. A global spectral method is adopted to resolve the dynamics of the capsule membrane developing elastic tension according to the neo-Hookean constitutive law and bending moments in an inertialess flow. The simulations show that the trajectory of the capsule closely follows the underlying streamlines independently of the capillary number. The membrane deformability, on the other hand, significantly influences the relative area variations, the advection velocity and the principal tensions observed during the capsule motion. The evolution of the capsule velocity displays a loss of the time-reversal symmetry of Stokes flow due to the elasticity of the membrane. The velocity decreases while the capsule is approaching the corner, as the background flow does, reaches a minimum at the corner and displays an overshoot past the corner due to the streamwise elongation induced by the flow acceleration in the downstream branch. This velocity overshoot increases with confinement while the maxima of the major principal tension increase linearly with the inverse of the duct width. Finally, the deformation and tension of the capsule are shown to decrease in a curved corner.
Place, publisher, year, edition, pages
2015. Vol. 770, 374-397 p.
biological fluid dynamics, boundary integral methods, capsule/cell dynamics
IdentifiersURN: urn:nbn:se:kth:diva-142671DOI: 10.1017/jfm.2015.157ISI: 000354190500011ScopusID: 2-s2.0-84927128753OAI: oai:DiVA.org:kth-142671DiVA: diva2:704159
FunderSwedish Research CouncilEU, European Research Council, simcomics-280117; 2013-CoG-616186Swedish e‐Science Research Center
QC 20150609. Updated from manuscript to article in journal.2014-03-112014-03-112015-06-09Bibliographically approved