Title: Statistics of spherical and anisotropic particles in strongly sheared flows

Author (Invited): Varghese Mathai, University of Massachusetts, Amherst

Abstract:

We study the translational and rotational statistics of a suspension of millimetric spheres and rigid fibers (1-4% volume fraction) in a strongly sheared turbulent Taylor-Couette flow. The presence of particles causes an increase in the global driving torque (drag) of the system. The fiber angular velocity statistics is strongly intermittent with wide-tailed distribution. The fibers retain a preferred orientation with the mean flow direction, for all studied Reynolds numbers, fiber concentrations, and locations. We model the particle's motion and orientation statistics and show that the preferential orientations are driven by the tendency of the particles to orient with respect to the local fluid strain and vorticity directions in the flow.