Analysis of FOWT dynamics in 2-DOF hybrid HIL wind tunnel experiments. (1st January 2020)

• Record Type: Journal Article
• Authors: Bayati, I.; Facchinetti, A.; Fontanella, A.; Taruffi, F.; Belloli, M.
• Is Part Of: Ocean engineering. Volume 195(2020)
• Publication Date: 2020-01-01
• Subjects: Floating offshore wind turbine -- Wind tunnel testing -- Hardware in the loop testing -- Hybrid testing -- Model validation -- Hydrodynamics; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2019.106717
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: This paper presents the main results of experimental hybrid/HIL wind tunnel tests of the National Renewable Energy Laboratory (NREL) 5 MW wind turbine coupled with the DeepCwind semi-submersible floating platform. Experiments in still water and in irregular waves without wind are compared to corresponding FAST simulations in order to assess the effectiveness of the proposed HIL methodology and to highlight the main sources of uncertainty. Tests are repeated under three wind conditions, corresponding to different wind turbine operating points, to evaluate the effect of the aerodynamic force field on the overall system response. Experimental results are compared to the output of FAST simulations to investigate its prediction capability with respect to the influence of unsteady aerodynamic loads on the FOWT dynamics. Highlights: Hybrid/hardware-in-the-loop wind tunnel setup for floating offshore wind turbines. Detailed and critical analysis of the capability of a reduced order hybrid/HIL (2DoF). No-wind tests were performed to extensively compare the FOWT behavior as reproduced by the HIL system against corresponding reference numerical simulation. Tests with wind have shown that aerodynamic loads have the the strongest effect on the platform response in correspondence of the system natural frequencies and in the linear wave excitation range. A variable correlation between loads and platform motion is registered at the platform resonant frequencies for different operating conditions. This translates into a variable damping.