The wake interaction phenomenon among wind turbines has a great influence on aerodynamic power output, wind speed deficit turbulence stress and wake vortex structure, which indicates that more attention should be placed on the wake interaction for the optimal arrangement of wind farm. In this present study, firstly a numerical validation of aerodynamics for the two offset model wind turbines using actuator line model and CFD technique. The results obtained from the present simulations are compared to the data from the experiment "Blind Test 3" and other simulation models. Based on the simulations results, the present study shows good agreement with the experimental results. Then considering the uniform inflow condition, the complex phenomenon of wake interaction in wind farm containing fourteen wind turbines is simulated using a numerical method. Large eddy simulations combined with an actuator line model are conducted in the in-house CFD code FOWT-UALM-SJTU Solver. The motivation for this work is to create a sound methodology for performing the simulation of large wind farms. To better understand the wake interaction phenomenon, the aerodynamic power coefficients and basic features of both the near and far wake, including the distribution characteristics of the mean wake velocity and vortex structures are studied in detail.
With the rapid development of wind energy technology, wind turbines have showed the rapid increase in both the total number of wind turbines installed and the maximum wind power capacity, increasing number of wind farms are built around the world (Jeon, 2013). Wind farms composed of large capacity wind turbines will become the future trend of development of wind energy (Abderrazzaq and Hahn, 2006). Wind turbines built in clusters will inevitably be affected by the wake of upstream and neighboring turbines. The wake interaction among wind turbines will lead to the decreased inflow wind velocity and increased turbulence intensity (Sanderse, 2011). Decreased total production of power and increased levels of fatigue loads are imposed on the turbines in the wind farm due to the phenomenon of wake interaction. Therefore, numerical simulations of wind farm containing multiple wind turbines are carried out to study characteristics of aerodynamic power and the significant wake interference effect, which have very important scientific significance and practical reference value for the wind farm layout optimization.
