Numerical study on the vortex-induced vibration of a circular cylinder in viscoelastic fluids

The vortex-induced vibration (VIV) in a Newtonian fluid has been widely studied due to its significance in many industrial applications. However, it could be significantly affected by the addition of polymer. In this work, we investigate the viscoelastic effect on the VIV of a circular cylinder whose motion is confined in the cross-flow direction. The Arbitrary Lagrangian-Eulerian (ALE) based finite volume method is used to carry out the two-dimensional simulations at the Reynolds number (Re) range of 30-500. The nonlinear FENE-P model is used to characterize the polymeric viscoelastic fluids. The results show that the addition of polymers in a Newtonian fluid can suppress the VIV amplitude of the cylinder since the polymer can significantly modify the vortex pattern and inhibit the fluctuation in flow. Both higher Weissenberg Number (We) and larger maximum polymer extensibility can reinforce this tendency. Furthermore, the corresponding reduced velocity for the peak of maximum vibration amplitude increases as the increase of Weissenberg number. This is because that the viscoelasticity can reduce the characteristic frequency in the wake flow. Finally, the viscoelasticity can increase the critical Re of the structure vibrations implying a more stable flow.