Numerical simulation of the two-degree-of-freedom vortex induced vibration of a circular cylinder at Reynolds number of O(104∼105)

Abstract

Vortex induced vibration (VIV) is of practical interest since it can result in the fatigue damage of structures, so has been a highly researched topic during the past few decades. The present study employs the unsteady Reynolds-Averaged-Navier–Stokes (URANS) equations combined with the shear-stress transport (SST) k-ω turbulence model to carry out the numerical simulation of the two-degree-of-freedom (2DOF) VIV at Reynolds number of O(104∼105). The present numerical method is validated through the comparison of the numerically and experimentally obtained response amplitude, lock-in frequency and hydrodynamic force, and the obtained vortex shedding modes are demonstrated. Based on the numerical model, this study parametrically investigates the effect of the Reynolds number, mass-damping ratio on the 2DOF VIV. The results indicate that the changes of the Reynolds number in the range of 104∼105 seem to have little effect on the VIV, and the maximum non-dimensional amplitude of the cross-flow (CF) VIV keeps close to 1.5. The in-line (IL) VIV is more sensitive to the Reynolds number than CF VIV. Additionally, with the increase of the mass-damping ratio, the peak of the CF non-dimensional amplitude in 2DOF VIV decreases, and its difference with that in 1DOF VIV decreases.