Speaker
Bernhard Mehlig
(Gothenburg University)
Description
The dynamics of a very small particle suspended in a fluid
flow is simple: the centre-of-mass is advected by the fluid
velocity, and the angular dynamics is determined by the
sequence of fluid-velocity gradients that the particle
experiences. For larger particles inertial effects may
become important. Particle inertia is relatively
straightforward to treat and there has recently been
substantial progress in understanding its effect upon the
dynamics of particles in flows [1]. The effect of fluid
inertia, by contrast, is more difficult to describe. In this
talk I will review what is known about the effect of weak
fluid inertia upon the translational and angular motion of
particles in flows. I will describe new results on the
effects of weak fluid inertia on the rotation of neutrally
buoyant spheroidal particles in a simple shear flow [2,3]
[1] K. Gustavsson and B. Mehlig, Statistical models for
spatial patterns of heavy particles in turbulence, submitted
to Adv. Phys. (2016)
[2] J. Einarsson, F. Candelier, F. Lundell, J.R. Angilella,
and B. Mehlig, Rotation of a spheroid in a simple shear at small
Reynolds number, Phys. Fluids 27, 063301 (2015)
[3] T. Rosen, J. Einarsson, A. Nordmark, C. K. Aidun, F.
Lundell, and B. Mehlig, Numerical analysis of the angular
motion of a neutrally buoyant spheroid in shear flow at
small Reynolds numbers, Phys. Rev. E 92, 063022 (2015)
