Numerical investigation of vortex-induced vibrations (VIV) of a rotating cylinder in in-line and cross-flow directions subjected to oscillatory flow

This study investigates vortex-induced vibration (VIV) generated by a rotating circular cylinder across various rotation rates (α = 0, 0.25, 0.50, 0.75, and 1) subjected to oscillatory flow through two-dimensional numerical simulations. Numerical simulations are performed for two Keulegan-Carpenter (KC) numbers, 5 and 10, at Reynolds number (Re) of 150. A wide range of Reduced Velocity (Vr) is considered, ranging from 1 to 20. The vibration amplitude in both inline and cross-flow directions is significantly affected by the rotation of the cylinder, as well as the KC number and Vr. Notably, the impact of rotation is more pronounced on cross-flow direction vibrations than on in-line direction vibrations. For a non-rotating cylinder (α = 0), the cross-flow direction vibration for both KC numbers nearly ceases after surpassing the critical value of reduced velocity: Vr = 6 for KC = 5 and Vr = 11 for KC = 10. In rotating cylinders (α ≠ 0), vibration amplitude becomes zero only at the critical reduced velocity, beyond which it increases and eventually stabilizes. It is also observed that rotation rates significantly influence VIV behavior, notably widening the lock-in range of Vr for rotating cylinders compared to non-rotating ones. The vortex shedding is significantly affected by the rotation and becomes asymmetric.