Deliverable 2.2 - Validation Report of QBlade-Ocean

For the detailed validation and verification of the capabilities of QBlade-Ocean in work package 2 (WP2) of FLOATECH, a detailed definition of the three considered models was recently presented in Deliverable 2.1 [1]. This document can be seen as a continuation of that work as the three aero-hydro-elastic models within QBlade-Ocean were thoroughly validated against experimental results and other state-of-the-art aero-servo-hydro-elastic simulation codes with complex load cases. As a first check, the models were validated in static and decay tests to assure that their natural frequencies and damping coefficients align. Secondly, regular and irregular wave only load cases were carried out to isolate the hydrodynamic response and quantify the hydrodynamic accuracy of QBlade-Ocean. Finally, combined irregular wave with turbulent wind load cases were analysed in order to obtain insight into the accuracy of QBlade- Ocean in complex load cases where aero-, hydro-, servo- and structural dynamics concurrently play a significant role. Of the simulated models, two include experimental validation: the upscaled 10 MW SOFTWIND experimental turbine mounted on a spar floater and the upscaled 5 MW OC5 experimental turbine mounted on a semi-submersible floater. Both models were additionally set up in the open-source software OpenFAST to, on the one hand, compare the performance of both software tools and on the other hand, as a preparatory step for a full-scale code-to-code comparison with the aim of uncertainty identification between the codes occurring later in WP2. The third model – the DTU 10MW Reference Wind Turbine mounted on the Hexafloat floater – is used for numerical validation against the established commercial code DeepLines Wind™ which was used during the design process of the floater by the company SAIPEM. The present document includes results of a selected set of load cases that demonstrate the capabilities of QBlade-Ocean compared to experimental results and the considered numerical codes. Links to the updated QBlade-Ocean models as well as the OpenFAST model are provided in the relevant sections of each model