Numerical Simulation Of Flow Field Of Wind Farm Based On Actuator Disk Model

Wake effect of wind turbines lead to velocity deficit and turbulence intensity increase,which cause the power losses and fatigue load increase of the wind turbine downstream and affect the economic benefits of the wind farm eventually.it is of practical significance to study the wakes effect.Computational Fluid Dynamics(CFD)is an important method for numerical simulation of the wake field of wind turbines and wind farms.The meshing is difficult for the full rotor model according to the complex geometry of blades,tower and the nacelle,which needed a plenty of computational resources,making it hardly realize the wind field numerical simulation of wind turbine clusters and wind farms.The actuator model can be used to simulate the flow field of wind turbine groups and wind farms due to its simple structure and certain accuracy.The numerical simulations of the flow field for single wind turbine and wind farm are studied based on the actuator disc model.First of all,the actuator disc model of single wind turbine is established by adding volume momentum source.Furthermore,the numerical simulation of the wind field flow field under different atmospheric stability is carried out.The power of wind turbines at the same period were compared to verify the effectiveness of the actuator disk model.The main contents and conclusions are as follows:(1)Numerical simulation of wake flow field of single wind turbine based on actuator disc modelThe structured mesh model of actuator disc was established.RANS numerical simulation was carried out.The actuator disc model in the flow field was realized by adding the volume momentum source,the CFD results were validated by comparing with wind tunnel test data and the Jensen wake model at different positions downstream of the rotor,the reliability of the actuator disc model in the simulation study of the far-wake field of the wind turbine is verified.(2)Study of numerical simulation of wind farm wake flow fieldBased on the lidar wind measurement data and wind turbines power data of the wind farm located in the northwest of China,the physical model of the wind turbines based on actuator disc is established.The DBSCAN algorithm is used to select the wind turbines which power output is normal state.The simulation based on the actuator disc model under different atmospheric stability was carried out.The power data of simulation was compared with the actual output power and the Jensen wake model,the Larsen wake model,the Ishihara wake model,which verify the effectiveness of the actuator disc model.