Abstract: A method of actively acquiring energy from tidal current by a rotating vibration cylinder is proposed. The user-defined function based on Fluent software is used to solve the lifting force of the rotating vibration cylinder, and the dynamic grid technology is applied to numerically simulating study the flow energy obtained by the rotating vibration cylinder at a certain speed. Firstly, according to the test results, the numerical simulation results are confirmed, and it shows that the maximum lift coefficient and the average drag coefficient are consistent with the test results. Secondly, the effects of phase difference, amplitude ratio and rotation amplitude on the energy efficiency of the rotating vibration cylinder are analyzed. The results show that the energy utilization rate of the rotating vibration cylinders with the same amplitude ratio and the same rotation amplitude gradually increases first and then decreases with the phase difference; in the effective energy range, the greater the amplitude ratio, the higher the energy efficiency of the rotating vibration cylinder with the same phase difference and the same rotating amplitude ratio; with the increase of the rotation amplitude, the energy utilization rate of the rotating vibration cylinder with the same pha se difference and the same amplitude ratio gradually increases and then decreases. The energy utilization rate is highest when the phase difference is 243 degree, the rotation amplitude is 3 and the amplitude ratio is 2.0.

Key words: tidal current energy, rotating vibrating cylinder, amplitude ratio, energy utilization rate, phase difference