Sedimentation in viscous fluids: flexible filaments and boundary effects

IAM Seminar
March 22, 2016 7:30 pm

Speaker:  Saverio E. Spagnolie, University of Wisconsin-Madison

URL for Speaker:

Location:  ESB 4133

Intended Audience:  Public

The deformation and transport of elastic filaments in viscous fluids play central roles in many biological and technological processes. Compared with the well-studied case of sedimenting rigid rods, the introduction of filament compliance may cause a significant alteration in the long-time sedimentation orientation and filament geometry. In the weakly flexible regime, a multiple-scale asymptotic expansion is used to obtain expressions for filament translations, rotations and shapes which match excellently with full numerical simulations. In the highly flexible regime we show that a filament sedimenting along its long axis is susceptible to a buckling instability. Embedding the analytical results for a single filament into a mean-field theory, we show how flexibility affects a well established concentration instability in a sedimenting suspension. Related topics will make cameo appearances, from a zoology of dynamics of settling bodies near walls to a new traction boundary integral equation for viscous fluid-body interactions.

Note this is a joint event with the SCAIM seminar, and the usual sushi lunch will be provided.