Optimization and characterization of a magnetically levitated subsystem for VIVACE-based ocean current energy conversion

This study presents a magnetically levitated Vortex-Induced Vibration for Aquatic Clean Energy (VIVACE) system designed to harvest energy efficiently from low-velocity ocean currents. The magnetic levitation subsystem, serving as a nonlinear stiffness element, critically determines the system's vibration and energy conversion performance. Experiments and numerical simulations were conducted to investigate the effects of magnetic field intensity (H) and magnet spacing (MS) on vibration response and energy harvesting efficiency. Results show that higher magnetic field intensity enhances vibration amplitude and power output, while larger magnet spacing reduces vibration frequency and improves adaptability under fluctuating flow conditions. Conversely, smaller magnet spacing yields superior vibration performance in stable flow environments. The optimal configuration was achieved at H = 2085Gs and MS = 3.4D, where the system reached a natural frequency of 1.72 Hz, a peak power output of 0.282 W, and a maximum efficiency of 10.41% at U = 0.5 m/s. These findings establish design guidelines for adaptive maglev-supported VIVACE systems and provide a theoretical basis for efficient ocean current energy conversion in low-velocity marine environments.