Design of a 10MW Wind Turbine Rotor Blade for Testing of a Scaled-down Floating Offshore Support Structure

Abstract

Floating offshore wind energy is being widely implemented in deep-water sites thanks to its numerous advantages, which among others include the access to stronger and undisturbed wind resources. In addition, considering the fast-paced growth in size and power generating capacity of offshore wind turbines, the designs of floating foundations need to be continuously improved. Therefore, proper testing (at model-scale) is necessary.

To achieve this, several factors need to be taken into account. For instance, down-scaling for testing of floating structures brings challenges due to the so-called Reynolds effects, which degrade the aerodynamic response of the mounted turbine. Likewise, the rotation of the blades and the motions of the platform as a result of its interaction with waves, have an impact on the wind inflow acting upon the rotor. Thereby, modifying its instantaneous performance.

This Master thesis, carried out in cooperation with MARIN (Maritime Research Institute Netherlands), focuses on developing a reliable methodology that renders in the design of a scaled-down thrust-matched 10MW wind turbine rotor blade, for its further implementation in the testing of a floating offshore support structure.

For this purpose, the aforementioned effects are investigated, and a suitable set of design tools is selected and coupled, in order to realise an optimised blade geometry. For predicting the wind turbine behaviour, this implementation relies on the Blade Element Momentum Theory. Furthermore, the resulting blade's aerodynamic performance is validated using ReFRESCO (MARIN’s in-house CFD code), against the non-dimensional parameters of the DTU 10MW reference wind turbine.