Investigating the influence of dimensional scaling on aerodynamic characteristics of wind turbine using CFD simulation

Wind turbines are used in a variety of applications with different performance requirements. Investigating the influence of scaling on wind turbine characteristics can pave the way to utilize the experience gained from a smaller turbine for a larger one. In this paper, the effects of wind turbine size on aerodynamic characteristics of a rotor blade are examined using CFD simulation. NREL phase VI wind turbine rotor was simulated in order to validate the results and ensure the accuracy of the CFD model. A 2 MW wind turbine was then chosen as a large turbine and a scaled down model of its rotor was simulated numerically. The results of the simulation were introduced to Similarity Theory relations in order to predict the aerodynamic characteristics of the 2 MW wind turbine. The 2 MW turbine was also simulated and the results of the simulation were compared to predictions of Similarity Theory. It was observed that the results of the simulation completely follow the values predicted by Similarity Theory. Both Similarity Theory predictions and simulation results demonstrated that the torque increases with the cube of change in rotor diameter whereas the thrust value and aerodynamic forces grow with the square of change in diameter.