CFD Simulations on the NTNU Wind Turbine Rotor and Comparison with Experiments

The present work aims to prove the efficiency of the finite volume TAU-DLR software for CFD (computational fluid dynamics) calculations on small wind turbines rotors. CFD simulations were carried out on the NTNU wind turbine rotor and the computational results were compared with experiments. Three different tip speed ratios λ (where λ is the ratio between the local flow velocity at the tip and the incoming flow speed) corresponding to different operational conditions have been simulated and analyzed. λ = 6: Design conditions. In this case the blades were designed to produce a nearly constant pressure drop across the rotor. λ = 3: The turbine is here operating in fully stalled conditions. λ = 10: the power produced is roughly the same as for λ = 3, but the thrust coefficients are significantly different. In this case the internal part of the turbine operates as a propeller. Results relative to rotor loads, power production and thrust force show good agreement with the experiments and the results from the near wake computations are in partial agreement with the experiments, proving the TAU-DLR code to be a suitable tool for CFD calculations on wind turbine rotors.