Numerical Simulation Of Hydrodynamic Filed And Erosion Or Deposition About Sediment In Jiangsu Rudong Wind Farm

With the arrival of the industrial age,the demands for energy are also escalating.Fossil energy such as coal,oil,and natural gas releases a large amount of polluting gases during the consumption process,which intensifies the pollution of the global environment.China has a large population,low per capita energy supply,and growing energy demand.Therefore,the development of clean energy is a major trend in the future.Jiangsu Province,with abundant wind energy resources,is located in an economically developed region on the east coast of China.Construction of offshore wind power project can effectively guarantee energy demand.With the deployment of fan pile foundations in the ocean,it is bound to have a certain degree of influence on the surrounding hydrodynamic fields.Simulating the hydrodynamic fields and erosion or deposition about sediment before and after the construction of this sea area can not only reflect the hydrodynamic characteristics of the researched area itself,but also be able to provide reasonable plans and recommendations for project construction.The MIKE numerical model was selected to perform the simulation calculation.In the process of model building,MapInfo was used to extract the shoreline from the coast of northern Jiangsu to Shandong Peninsula,and the grid required by the model was mapped by SMS software.The bathymetry data used the global topographic elevation data?ETOPO1?with a resolution of 1'provided by the National Oceanic and Atmospheric Administration?NOAA?.Meanwhile hydrodynamic parameters and sediment model parameters were determined.After the construction of the project,the 75 wind turbines in the sea area where the project is located were divided into 12 fan groups,including 4 fan groups in the shallow sea area and 4 fan groups in the middle water area.There were also 4 fan groups in the deep water area.Each fan group was generalized into a pier.The structural features of the pier were based on the structural characteristics of each fan pile and were set to have a two-kilometer diameter to stimulate the hydrodynamic field and sediment erosion and deposition in later process.Lastly,the application of Wang Rukai's formula and Han Haiqian's formula to a single fan pile foundation estimated that the maximum scouring depth.Before construction of the project,the results showed that there was no significant difference between the calculated data and measured data of tidal level and tidal current.Moreover,the relative error rate was basically below10%.During the high tide,the seawater in the eastern part of the East Yellow Sea entered the radial sandbar along the radial sandbar channel and during the ebb,the seawater flows along the radial sandbar off the shoreline.The characteristics of the currents in the sandbars were marked by the characteristics of the north-south boundary of the bamboo root-sandstone mud.In the East Yellow Sea region,there was a half-day tide-free M₂ tide-free point,and there was a full-day tide K₁ without a tide point.After the construction of the project,the average flow velocity of the current near the pile foundation tended to decrease,and the average flow velocity of the current near the pile base decreased more significantly.In the entire project area,the area where the velocity changed most was mainly distributed in the north area.The change in flow rate increased as the water depth increases.Affected by the pile foundation in the project area,the average flow velocity of the sea area near the outside of the project area in different tidal periods had also decreased,and the decrease rate was lower than the average velocity near the pile foundation.The annual erosion and deposition in the project sea area and its adjacent sea areas showed a trend of siltation,and sedimentation mainly occurred near the pile foundation.Further,sedimentation may occur at the highest depth in the central area and the depth of silt deposition in deep water was not large.