Numerical Simulation Of The Wind Turbine Wake Based On Actuator Disc Model

Wind turbine wake effects are the most common issues in wind farms, which affect the electric energy production. Nowadays, in China, wind farms are growing fast, the output power of a single wind turbine is getting bigger and bigger. Therefore, it is practical significant to study wake characters and laws.The common CFD methods cost lots of computing resource, and the time consumption is large. It is very difficult for CFD methods when there are many wind turbines in a wind farm which is simulated. Therefore, actuator discs are used instead of wind turbines. The function includes volume momentum source to avoid simulating real blades. The computation is reduced, and the time consumption becomes small. It’s suitable for engineering applications.In this paper, the study of actuator is carried out in two steps. First of all, the actuator disc method with uniform induction factor is studied. In this method, axial induction factor is uniform, and tangential induction factor is ignored, on the whole actuator disc. Different values of induction factors are used in two computations, the pressure and wake flow fields are compared. The results and measured data are basically the same. In the position2.5D, there is a little different between computation results and measured data. It is affected by the hub and blade roots.Second, the actuator discs with variable factors are studied. The axial induction factor and tangential induction factor are computed with momentum blade element theory. In this method, discs with different induction factor along radius are used. The wake flow fields are analyzed qualitatively. Then, using this method, two wind turbines along the wind direction are simulated, with different distances between two turbines. The effects of downstream turbine are deeply analyzed, which is caused by the upstream one.