Numerical investigation of wake dynamics of a rotating cylinder undergoing vortex-induced vibration in turbulent flow

This study analyzes the wake dynamics and flow physics of vortex-induced vibration of a rotating circular cylinder at a Reynolds number of 10 000. A direct forcing immersed boundary method coupled with a large eddy simulation is employed to resolve the interaction between the rotating vibrating cylinder and the surrounding turbulent flow. The effects of rotation rate, Reynolds number, and three dimensional wake structures on vibration amplitude and vortex shedding modes are systematically analyzed. The results confirmed that cylinder rotation causes flow separation and wakes to become more asymmetric and strength alternating lift forces, thereby enhancing the vibration response. The evolution of unsteady lift and drag forces governs the onset, growth, and suppression of vortex-induced vibration of a rotating cylinder. As the rotation rate increases, the vibration response transitions from a strongly coupled vibration regime at a rotation rate 0 to a weakened, partially decoupled state at a rotation rate 2 and ultimately to a regime, where vortex shedding is largely suppressed and the fluid–structure interaction vanishes at a rotation rate 2.5. The phase relationship between transverse displacement and lift force is in phase at low reduced velocities but becomes out of phase at the onset of the upper branch for the rotation rate between 0 and 1.5. However, higher rotation rates of 2 and 2.5 maintain an in-phase response over a wider range of reduced velocities. Additionally, the mechanical energy transfer from the fluid to the vibrating rotating cylinder increases as the rotation rate increases from 0 to 2, while the rotation rate of 2.5 nearly suppresses the energy transfer. In general, the findings show that cylinder rotation is an effective mechanism of controlling vortex-induced vibration through wake modification and energy transfer, providing much insight into the enhancement and suppression of vibration in rotating bluff body configurations.