Comparative study on the wake description using actuator disc model with increasing level of complexity

Abstract

The present work evaluates the benefits obtained when different levels of geometric and aerodynamic information of wind turbine blades are included in the actuator disc (AD) model, progressively increasing its descriptive capabilities. A novel AD model is presented, equivalent in precision to the AD coupled with the blade element momentum method, but avoiding the need to modify the CFD code by the use of a pre-calculated table. It is compared against three classical AD models, particularly aiming at the simulation of the wind farm wake interaction. The NREL-5MW reference wind turbine is adopted as test case, and configurations with single and two shifted wind turbines are analyzed.

Processing of offshore measurement data for multi-fidelity wake model performance assessments

“…The wake models to be assessed include the NO Jensen [10], TurboPark [11], Gaussian [12] and cumulative curl [13]. The CFD model applies the k-ε-f P turbulence model to the wind turbines that are simulated by actuator discs [14,15]. Due to the varying inputs required by these models, both flow and power production data are required for the evaluation dataset.…”

Transient phenomena study in wind energy by means of LES simulations: impact of wind direction changes

“…Also, the wind direction for yawing is calculated equally. After that, the unperturbed upstream velocity U ∞ is interpolated from a previously calibrated table that links U ∞ and U d [19]. Once U ∞ is obtained, the thrust coefficient, C T , is extracted from the wind turbine curve C T − U ∞ and total thrust is calculated as…”

On the Accuracy of Predicting Wind-Farm Blockage

“…Near the wind-farm wake a refinement zone is created with an horizontal cell size of 𝐷∕12. Additional mesh refinement zones are placed near each turbine, with an horizontal cell size of 𝐷∕24, following the findings of the mesh-sensitivity analyses in [50,53]. The vertical cell size grows from a wall cell size of 0.0139𝐷 close to the turbines towards 𝐷∕6 at the top of the domain.…”

“…The turbine is modelled using an AD model with the thrust imposed according to a calibration curve, relating the inflow wind speed to the disc-averaged velocity. The calibration procedure is performed [50,53] for an isolated turbine in the middle of the wind tunnel. As 𝐶 𝑇 is constant for this wind turbine, this procedure is done for a single wind speed and the obtained induction factor is assumed to be valid for the rest of the inflow velocities.…”