Effects of the Hydroturbine Array Arrangement in Guanmen Channel on Tidal Current Movement Characteristics
The efficient use of tidal current energy can alleviate the energy shortage in some offshore islands.However,the operation of tidal current hydroturbine array will change the structure of tidal flow characteristics,causing changes in local hydrodynamic characteristics,and thus having an influence on the power efficiency,in order to explore the tidal flow impacts of staggered hydroturbine array layout,a model is established based on Delft 3D.First,nested grids are used to stimulate the hydrodynamic properties of tides in the Zhoushan Archipelago and Guanmen Channel.Then,to simulate the interaction between tidal hydroturbine array and the spatial structure of tidal flow,the porous disc approach is used.The results show that the array layout can significantly reduce the flow velocity of the tidal current hydroturbine and its wake,and cause an increase in the flow velocity in the upper and lower edge areas of the vertical blades.The water level in the upstream direction of the tidal current hydroturbine rises,and the maximum difference in backwater at maximum flood and ebb reaches 10 cm.The bed shear stress at the bottom of the tidal current hydroturbine and between the turbines increases,while the shear stress in the wake region decreases.With a reduction of 54.03%during low water slack in the wake region,the wake overlapping lowers the bed shear stress,the increase in bed shear stress on both sides of the array layout can reach 177.93%.In the future development of tidal energy,a comprehensive assessment of potential changes in tidal flow characteristics should be conducted following the array layout.Optimization of array layout is essential to minimize environmental impact.