HeLoFOW tank testing: to study the elastic behaviour of floating wind turbines

Numerous simulators for floating wind turbine behaviour have been developed over the last decade. The vast majority of these models are based on a multi-body formulation where the floating wind turbine is represented by a set of interconnected deformable and rigid bodies. The blades, tower, rotor shaft and anchor lines are generally considered deformable, while the platform and the floating support are assumed to be rigid. While this approach may be adequate for medium power rotors, recently developed 10-15 MW rotors will require larger foundations for which the hydro-elastic effects are expected to become more pronounced.

To meet this new design challenge, the LHEEA wanted to extend the capabilities of its current floating wind turbine simulator. To this end, the WEAMEC HeLoFOW project aims to develop a hydro-elastic solver for the calculation of structural loads on floating wind turbine foundations. This work consists in combining an "in-house" hydrodynamic solver, based on an unsteady potential theory, with a structural solver based on a finite element formulation.

The next phase - experimental validation - was carried out in the Hydrodynamic and Ocean Engineering Tank at Centrale Nantes between December 2020 and January 2021. The tests were based on a segmented model of a SPAR floating foundation. The rotor forces are represented by the SOFTWIND emulation system. These tests took place at the same time as lab classes for the Ocean specialisation of the Centrale Nantes engineering programme. Students were thus able to take part in the test campaign in real conditions.
 
The experimental results are now being analysed, and will be of great value to the community and the development of very high-power floating wind turbines, thus contributing to the ongoing optimisation of offshore energy production from wind turbines.

This project is carried out as part of WEAMEC and benefits from funding from the Pays de la Loire Region and the ERDF. INNOSEA and the Norwegian University of Science and Technology (NTNU) are partners in this project.
 

• Learn more about HeLoFOW: https://www.weamec.fr/en/projets/helofow/