(123i) Lift Force on an Asymmetrically Rotating Particle in Confinement

If a particle with arbitrary shape steadily rotates and translates in a viscous fluid with small but finite Re, it will experience inertial forces due to the unsteady flow field created by the asymmetric rotation. Such unsteady inertial force due to the rotation of the particle can produce a lift force which can cause a lateral motion of the particle. The described force is stronger than Oseen or Saffman force and only exists when the body is translating and simultaneously rotating about an axis which is not its axis of symmetry.

In confined geometry, this force can be very prominent because of the rotational motion of the body under the influence of the local shear flow. In this talk, we will present a simple formalism to analyze this effect in presence of walls. We will specifically concentrate on the motion of a polymeric chain of spheres in a slit pore. We will consider a pressure driven parabolic flow between two parallel plates and present the effect of shear-induced rotation on the inertia-driven lateral migration of the particle away from the wall.