Unexpected Particle Motions in Viscous Fluids Undergoing Oscillatory Rotation

When
Start: 01/24/2018 - 4:15pm
End  : 01/24/2018 - 5:15pm

Category
Colloquium

Speaker
Ali Nadim (CGU)

Abstract

In this joint work with former doctoral student Shujing "Flora" Xu, we investigate theoretically the effect of the Coriolis force on the motion of a suspended particle in a viscous fluid undergoing rotation. In normal centrifugation, a particle which is denser than the surrounding fluid is "thrown" away from the rotation axis. However, we find that when the rotation is oscillatory, through a combination of viscous drag and the Coriolis force, dense particles may actually migrate toward the rotation axis for certain parameter regimes. We analyze the nonlinear dynamical system describing the particle trajectories using the method of averaging and derive the criterion for such "counter-centrifugation." We also use numerical simulations to verify our predictions. For details, see Xu and Nadim, Physics of Fluids, 28, 021302 (2016).

 

Where
Freeberg Forum, LC 62, Kravis Center, CMC