A numerical study of the motion of a neutrally buoyant cylinder in two dimensional shear flow

• The numerical results are validated by comparisons with existing results.
• Power laws of the angular speed of a disk versus Rep are obtained.
• New equilibrium positions of the disk in shear ow are discussed.

In this paper, we investigate the motion of a neutrally buoyant cylinder of circular or elliptic shape in two dimensional shear flow of a Newtonian fluid by direct numerical simulation. The numerical results are validated by comparisons with existing theoretical, experimental and numerical results, including a power law of the normalized angular speed versus the particle Reynolds number. The centerline between two walls is an expected equilibrium position of the cylinder mass center in shear flow. A new result on the equilibrium position has been obtained. When placing the particle away from the centerline initially, the cylinder migrates to an equilibrium position between the centerline and the wall for higher Reynolds numbers. This new equilibrium position is caused by the interplay between the slip velocity, the Magnus force, and the wall effect.