Hydrodynamic Performance Of Tidal Current Energy Generation Device Based On Wig

The development of new renewable energy is always a hot topic in the world.As a kind of renewable energy,tidal current energy has rich resources,which is very valuable to develop and utilize.This paper will study to improve the power efficiency of the oscillating hydrofoil power generation device with the ground effect,analyze the hydrofoil hydrodynamic performance and the surrounding flow field change when the ground effect occurs,discuss the principle of the ground effect,and investigate the influence of different parameters on the power efficiency,so as to provide a theoretical basis for the research and development of the power generation device.In this paper,STAR CCM + is used to simulate the energy acquisition process of the oscillating hydrofoil in the two-dimensional incompressible unsteady flow field at high Reynolds number.Based on the calculation results of single oscillating hydrofoil model,the parallel connection of multiple hydrofoils and the interaction between hydrofoil and wall are simulated.The calculation results show that the power efficiency of the double oscillating hydrofoil is slightly higher than that of the single oscillating hydrofoil.The analysis shows that the ground effect between the two hydrofoils increases the lift coefficient when the hydrofoil is close to each other,and then improves the power efficiency of the hydrofoil.The variation of power efficiency with the distance between hydrofoils is studied.With the decrease of the distance between hydrofoils,the power efficiency increases gradually.It is proposed that three or more hydrofoils in parallel can further improve the power efficiency.In this paper,the energy acquisition of hydrofoil with infinite walls and finite walls arranged up and down are discussed respectively.The infinite walls restrict the flow of water,so that the hydrofoil can fully obtain the flow energy through the swept area.At the same time,the lift coefficient of hydrofoil is improved in the whole cycle,so the power efficiency is significantly improved.Under the same incoming flow velocity,the power efficiency of the hydrofoil with the straight finite walls is lower than that of the single oscillating hydrofoil.Because of the blocking effect between the walls,the flow will partially go round outside to the walls.It is suggested that the finite wall with variable cross-section can be used as a guide to counteract the loss of water flow.