Abstract
In this study, the new computational fluid dynamics (CFD) porous disk (PD) wake model was proposed in order to accurately predict the time-averaged wind speed deficits in the wind turbine wake region formed on the downstream side by the 2-MW wind turbine operating at a wind speed of 10 m/s. We use the concept of forest canopy model as a new CFD PD wake model, which has many research results in the meteorological field. In the forest canopy model, an aerodynamic resistance is added as an external force term to all governing equations (Navier–Stokes equations) in the streamwise, spanwise, and vertical directions. Therefore, like the forest model, the aerodynamic resistance is added to the governing equations in the three directions as an external force term in the CFD PD wake model. In addition, we have positioned the newly proposed the LES using the CFD PD wake model approach as an intermediate method between the engineering wake model (empirical/analytical wake model) and the LES combined with actuator disk (AD) or actuator line (AL) models. The newly proposed model is intended for use in large-scale offshore wind farms (WFs) consisting of multiple wind turbines. In order to verify the validity of the new method, the optimal model parameter CRC was estimated by comparison with the time-averaged wind speed database in the wind turbine wake region with fully resolved geometries, combined with unsteady Reynolds-averaged Navier–Stokes (RANS) equations, implemented using the ANSYS(R) CFX(R) software. Here, product names (mentioned herein) may be trademarks of their respective companies. As a result, in the range from x = 5D of the near wake region to x = 10D of the far wake region, by selecting model parameter CRC, it was clarified that it is possible to accurately evaluate the time-averaged wind speed deficits at those separation distances. We also examined the effect of the spatial grid resolution using the CFD PD wake model that is proposed in the present study, clarifying that the spatial grid resolution has little effect on the simulation results shown here.
Highlights
With the operation of wind turbines, a deficit of wind speed and temporal and spatial fluctuations are formed behind the wind turbines
In the forest canopy model, an aerodynamic resistance is added as an external force term to all governing equations (Navier–Stokes equations) in the streamwise, spanwise, and vertical direction
Ordera to support the practical wind disk farm design wind energy/wind as an intermediate method between the engineering wake model farm developers, we propose a new large-eddy simulation (LES) method using the porous disk (PD) wake model approach and the LES combined with actuator disk (AD) or actuator line (AL) models
Summary
With the operation of wind turbines, a deficit of wind speed and temporal and spatial fluctuations are formed behind the wind turbines (see Figure 1). The method with the highest prediction accuracy is using fully resolved geometries combined with computational fluid dynamics (CFD) simulations [7] In this method, the structures of the rotating wind turbine blades, nacelle, tower, etc. Are modeled in detail by the CFD approach of unsteady Reynolds-averaged Navier–Stokes (RANS) modeling and large-eddy simulation (LES) In these approaches, in order to faithfully reproduce the rotation of the wind turbine blade, special techniques such as the advanced generation of computational grids and a sliding mesh approach are required. The target wind turbine is only 2-MW This is because the accurate prediction results of this wind speed class have a very important impact on the evaluation of the feasibility of offshore wind power generation. CFX(R), a comparison with wind tunnel experiments using a wind turbine scale model component in the streamwise direction will be denoted by U-velocity.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
