Curved Vortex Filaments in Free Vortex Wake Analysis of Floating Wind Turbines

Floating offshore wind turbines experience complex aerodynamic phenomena due to additional Degrees-of-Freedom (DOF) and transient flow field conditions, which common aerodynamic modeling techniques based on momentum balance methods are not capable of taking into account. Free Vortex Methods (FVM) represent an alternative approach based on potential flow theory and capture the physics of the flow field more precisely with reasonable computational costs, but only recently have gained importance even though they have been state-of-the-art in helicopter research for decades. The focus of this study by Beyer et al. [1] is the development, validation and application of a curved Vortex Filament Model (VFM). In contrast to commonly used straight-line segments, this higher-order approach simulates the local curvature of the wake more accurately resulting in an increase in computational efficiency because fewer and larger curved elements can be used to represent a vortex filament .