Study On Mechanism Of VIV In Tidal Current Energy Conversion Device

Tidal current energy as a green renewable energy, its substainability, high energyand rich reserves, become broad prospects for development of the field. The turbine isa mainsteam form of tidal current energy conversion devices. Due to the energydensity of tidal current energy is proportional to the velocity, it has to increase thescale of tidal current energy conversion devices in areas of low tidal current velocity.It needs higher requirement of water depth as well as. The turbine needs a highervelocity of tidal current to start to generate electricity at the same time. It is difficultto achieve the energy conversion effectively in areas of low tidal current velocity. Theprinciple of VIV for generation electricity is a suitable way of tidal current energyconversion devices in areas of low tidal current velocity. But the principles of VIV forelectricity generation is still in its infancy, and not thorough enough in its study. Inthis paper, through the theoretical methods, numerical simulation and Model tests tostudy the hydrodynamic characteristics of vortex-induced vibration in tidal currentenergy conversion device.This paper summarizes the study of VIV for energy generation of tidal currentenergy conversion devices. It masters the key parameters that affect the response ofVIV and the latest progresses. The empirical model of VIV, fluid force decompositionmodel, is used to establish the motion equation of VIV. Solving the equations of VIV,the VIV response vibration frequency and amplitude are received. Combination ofempirical data and formula, based on solving the equations of motion of VIV, the VIVprediction modal is established. Combination of results of theoretical analysis andprediction modal, it determines the parameters of VIV coupling modal ofexperimental prototype, then design a model experimental prototype. In numericalsimulation, the forced movement of a cylinder in flow, observes the lift and dampingcoefficient curve convergence and obtains the frequency ratio of resonance. Inexperimental methods, it studys the VIV motion of elastic supported cylinder in velocity, the coefficient of elasticity and spring combinations aspects.In this paper, it studys the principles of generation of VIV in tidal current energyconversion device, reveals the match relationship of VIV parameters. It providesreference and guidance of the study of VIV hydrodynamic characteristics and lays atheoretical foundation for designing a model experimental prototype.