Aerodynamic simulation of rough and eroded blades, AEP effect and mitigation using low drag vortex generators
Abstract. Blade roughness depositions or blade erosion have an unquestionably effect over blade aerodynamics and wind turbine power production. This work is focused on the simulation using Computational Fluid Dynamics (CFD) of the NACA 633418 airfoil with high roughness values and with different erosion typologies (pits and extreme losses of material). The CFD code used is OpenFOAM v8 and different technologies are selected to create the meshes to capture properly geometries' defects (ICEMCFD and ANSYS Workbench).
This study goes a step further by using low drag Vortex Generators (VGs) to mitigate the roughness and erosion harmful effects. Low drag VGs are compared with conventional ones and afterwards 3D blade sections are computed with roughness and erosion incorporating low drag VGs to evaluate the blade performance recovery achieved by the use of VGs. Finally, the impact of the different configurations (rough, eroded, rough + VG and eroded + VG) over Annual Energy Production (AEP) is evaluated on a virtual 2.5 MW wind turbine. The most important finding of the work presented in this paper is that AEP losses due to the existence of blade surface roughness or erosion can be recovered from the use of VGs up to 1.5 %.
Viewed (geographical distribution)