The offshore wind energy market is growing rapidly globally. To be more competitive in the energy market, the levelized cost of energy (LCOE) of offshore wind farms needs to be further reduced. However, currently, popular tools for wind farm modeling are based on simplified models either for near-wake or for far-wake regions due to the difficulties of resolving them simultaneously. This simplification could result in large uncertainties in predictions of the power extraction of the wind farms. Further, for floating offshore wind turbines (FOWT), floater motions will also affect the airflow around the turbine and eventually affect the power output of the wind farm. To address these issues, tools with a higher level of accuracy must be developed for modeling the multi-scale airflow in offshore wind farms.
In the present study, we focus on the aerodynamic forces and the turbine-generated wakes of two parked turbines in a tandem configuration, as can be found in wind farms under unfavorable conditions. Model-scale simulations of the MARIN Stock Wind Turbine (MSWT) are performed. The CFD simulations with fully resolved rotor geometries are performed using MARIN's in-house CFD code ReFRESCO. The absolute formulation method (AFM) is leveraged to model the two rotating wind turbines. The k − ω SST turbulence model is adopted in the incompressible Reynolds Averaged Navier-Stokes (RANS) simulations.
The aerodynamic forces and wakes of single turbine cases are analyzed and compared to those of two tandemly arrayed turbines.
In order to achieve carbon neutrality in the coming decades, electricity generation from renewable sources, including wind, will need to increase several times. Both onshore and offshore wind farms have been constructed or planned worldwide to meet this increasing demand. However, wind turbines in a wind farm could be operating in the wakes of upstream turbines. This is unfavorable because wakes generated from the upstream turbines will, in general, decrease the wind speed and increase turbulence levels comparing to the upstream conditions, and this is also known as the wake effect. This wake effect could potentially increase fatigue loading on the downstream turbines while reducing their power extraction from the wind. Therefore, to minimize the energy loss within wind farms, a detailed understanding of wind turbine wakes is of particular interest to researchers.