Comparison of CFD Simulation to UAS Measurements for Wind Flows in Complex Terrain: Application to the WINSENT Test Site

• Published in: Energies (Basel) Vol. 12; no. 10; p. 1992
• Main Authors: Asmae El Bahlouli, Rautenberg, Alexander, Schön, Martin, Kjell zum Berge, Bange, Jens, Knaus, Hermann
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 24.05.2019
• Subjects: Aerodynamics; Aircraft; Alternative energy sources; Atmospheric boundary layer; Boundary conditions; Boundary layers; Calibration; Canopies; Cell size; complex terrain; Computational fluid dynamics; Computer applications; Computer simulation; Coriolis force; Design of experiments; design of experiments (DoE); Downstream effects; Escarpments; Finite volume method; Fluid dynamics; Fluid flow; Forests; Horizontal cells; Hydrodynamics; Inclination angle; Investigations; Kinetic energy; Leaf area; Leaf area index; Model testing; Navier-Stokes equations; Reynolds averaged Navier-Stokes method; Rotor blades; Rotor blades (turbomachinery); Simulation; Thermal stratification; Topography; Transport equations; Turbines; Turbulence; Turbulence models; Turbulent flow; Unmanned aerial vehicles; Unmanned aircraft; unmanned aircraft system (UAS); unsteady Reynolds averaged Navier-Stokes (URANS); Velocity; Wakes; Wind measurement; Wind power; Wind profiles; wind simulation; Europe; Germany
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en12101992

This investigation presents a modelling strategy for wind-energy studies in complex terrains using computational fluid dynamics (CFD). A model, based on an unsteady Reynolds Averaged Navier-Stokes (URANS) approach with a modified version of the standard k-ε model, is applied. A validation study based on the Leipzig experiment shows the ability of the model to simulate atmospheric boundary layer characteristics such as the Coriolis force and shallow boundary layer. By combining the results of the model and a design of experiments (DoE) method, we could determine the degree to which the slope, the leaf area index, and the forest height of an escarpment have an effect on the horizontal velocity, the flow inclination angle, and the turbulent kinetic energy at critical positions. The DoE study shows that the primary contributor at a turbine-relevant height is the slope of the escarpment. In the second step, the method is extended to the WINSENT test site. The model is compared with measurements from an unmanned aircraft system (UAS). We show the potential of the methodology and the satisfactory results of our model in depicting some interesting flow features. The results indicate that the wakes with high turbulence levels downstream of the escarpment are likely to impact the rotor blade of future wind turbines.