Enhancing energy harvesting from vortex-induced vibration in circular cylinders through semi-active turbulence control: Impact of synthetic jet velocity and reynolds number

Semi-Active Turbulent Control (SATC) implemented via synthetic-jet actuation intensifies vortex-induced vibrations (VIV) of a circular cylinder and increases recoverable energy for flow-induced harvesting. A coupled CFD-FSI framework resolves the wake-structure interaction and quantifies how SATC modifies vortex shedding and the resulting structural response, and the dominant shedding and vibration frequencies are identified using the Fast Fourier Transform. Simulations span R e = 27.3 × 10 3 − 109.5 × 10 3 for baseline and actuated cases with jet velocities of 1.0 − 5.0 m / s , and harvested power and efficiency are evaluated from the computed oscillatory dynamics. Without SATC, increasing Re elevates the vibration frequency and progressively detunes the system from lock-in, thereby reducing the transverse vibration amplitude. Moreover, once the frequency ratio exceeds unity, SATC retunes wake-induced forcing toward the natural-frequency band, restores synchronization, and markedly increases the harvested energy relative to the uncontrolled baseline. Overall, the results indicate that SATC provides an effective semi-active lever for boosting VIV-based renewable-energy extraction over a broad Reynolds-number range.