Performance Prediction of flow induced vibration and energy capture for VIVACE converter improved by maglev in ultra-low velocity zones

Using flow-induced vibration (FIV) for low-velocity ocean current energy generation is an effective approach. Due to the poor vibration performance of oscillators supported by metal springs in ultra-low flow velocity zones, leaving a significant gap in studies in ultra-low flow velocity zones. This study found that replacing metal springs with a maglev system to support the oscillator results in better flow-induced vibration characteristics in low flow velocity zones. It is speculated to perform better in ultra-low flow velocity zone. Therefore, this study employs maglev-supported oscillators to investigate flow-induced vibration in ultra-low flow velocity zones, which holds significant implications for deep-sea power generation research. This study uses the Reynolds-Averaged Navier-Stokes (RANS) method and the equivalent magnetic charge method to develop a coupled model of a flow-induced vibration system and a maglev system. Numerical simulations are conducted to research the effects of magnetic forces on the FIV characteristics and energy capture efficiency of the oscillator in ultra-low velocity zones. This study found a transition velocity at U = 0.3 m/s. When the flow velocity increases to this transition velocity, the vibration state of the oscillator in certain conditions changes. It is found that among the oscillators supported by maglev with a magnetic spacing of 4.2D, the oscillator with a mass ratio of 1.798 achieves the highest energy capture efficiency at this transition velocity, the highest energy capture efficiency of the oscillator is 18.974 %.