Fluid Structure Interaction using beam models

Nowadays, significant developments of wind power technology are achieved in Europe, in alignment with the rising need for sustainability in electrical energy generation. With the upscaling of the wind turbines, aeroelastic effects start to play a major role in the simulations that cater to the design and evaluation of Floating Offshore Wind Turbines (FOWTs). Traditional Computational Fluid Dynamics (CFD) approaches treat the wind turbines as rigid models, but blade deflections do have a noticeable impact on the turbine performance and should be taken into account. In the design stage and evaluation, Fluid Structure Interactions (FSI) simulations tackle this issue using structural models to capture the deformations of the FOWTs, while still achieving reasonable computational costs. ReFRESCO, MARIN’s multi-phase viscous flow solver focused on maritime applications, has an FSI module that supports several FEM elements but has been tested for solid and shell elements only. In the pre-processing stage any package can be used (most of the time ANSYS) for FEM modelling. For rotor blades, beam models are considered to be a reliable option and the dependency to an external FEM package can be avoided. This paper discusses the development of a beam solver, capable of static and modal analysis. Verification & Validation of the stand-alone solver is done using a benchmark test-case. Another benchmark case is used for verification of ReFRESCO-BeamSolver coupling in an FSI setting.