Full Reynolds-averaged Navier–Stokes (RANS) simulations of the flow in the near wake of a three-bladed horizontal-axis wind turbine are presented. The simulations, which are based on the model experiments in controlled conditions (MEXICO) experiment and include the complete rotor, nacelle, and tower show good agreement with experimental data, with 4% difference relative to measured flow properties. The flow properties in the near wake are detailed for both uniform and nonuniform flow conditions. The effects of increasing tip-speed ratio and a yawed inflow of 30 deg are studied. The full RANS simulations are used to support the development of an immersed wind turbine model at ETH Zurich. This model allows for modeling of the wake evolution and interactions in wind farms, for multiple turbines, with substantially reduced computational effort.

This work examines the effect of flow inclination on the performance of a stand-alone wind turbine and of wind turbines operating in the wakes of upstream turbines. The experimental portion of this work, which includes performance and flowfield measurements, is conducted in the ETH dynamically-scaled wind turbine test facility, with a wind turbine model that can be inclined relative to the incoming flow. The performance of the wind turbine is measured with an in-line torquemeter, and a 5-hole steady-state probe is used to detail the inflow and wake flow of the turbine. Measurements show that over a range of tip-speed ratios of 4–7.5, the power coefficient of a wind turbine with an incoming flow of 15 deg inclination decreases on average by 7% relative to the power coefficient of a wind turbine with a noninclined incoming flow. Flowfield measurements show that the wake of a turbine with an inclined incoming flow is deflected; the deflection angle is approximately 6 deg for an incoming flow with 15 deg inclination. The measured wake profiles are used as inflow profiles for a blade element momentum code in order to quantify the impact of flow inclination on the performance of downstream wind turbines. In comparison to the case without inclination in the incoming flow, the combined power output of two aligned turbines with incoming inclined flow decreases by 1%, showing that flow inclination in complex terrain does not significantly reduce the energy production.

Full RANS simulations of the flow in the near wake of a three-bladed horizontal-axis wind turbine are presented. The simulations, which are based on the MEXICO experiment and include the complete rotor, nacelle and tower, show good agreement with experimental data, with 4% difference relative to measured flow properties. The flow properties in the near wake are detailed for both uniform and non-uniform flow conditions. The effects of increasing tip-speed ratio and of yawed inflow of 30° are studied. The full RANS simulations are used to support the development of an immersed wind turbine model at ETH Zurich. This model allows for modeling of the wake evolution and interactions in wind farms, for multiple turbines, with substantially reduced computational effort.

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