Browsing by Author "Mendikoa, I"
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Item NAUTILUS-DTU10 MW Floating Offshore Wind Turbine at Gulf of Maine: Public numerical models of an actively ballasted semisubmersible: Public numerical models of an actively ballasted semisubmersible(2018-10-10) Galván, J; Sánchez-Lara, M J; Mendikoa, I; Pérez-Morán, G; Nava, V; Rodríguez-Arias, R; RENOVABLES OFFSHORE; Tecnalia Research & InnovationThis study presents two numerical multiphysics models of the NAUTILUS-10 floating support structure mounting the DTU10 MW Reference Wind Turbine at Gulf of Maine site, and analyses its dynamics. With the site conditions and the FAST model of the onshore turbine as the starting point, the floating support structure: tower, floating substructure with its corresponding active ballast system and station keeping system, was designed by NAUTILUS. The numerical models were developed and the onshore DTU wind energy controller was tuned to avoid the resonance of the operating FOWT by TECNALIA, in the framework of H2020 LIFES50+ project. This concept and its subsystems are fully characterised throughout this paper and implemented in opensource code, FAST v8.16. Here, the mooring dynamics are solved using MoorDyn, and the hydrodynamic properties are computed using HydroDyn. Viscous effects, not captured by radiation-diffraction theory, are modelled using two different approaches: (1) through linear and quadratic additional hydrodynamic damping matrices and (2) by means of Morison elements. A set of simulations (such as, decay, wind only and broadband irregular waves tests) were carried out with system identification purposes and to analyse the differences between the two models presented. Then, a set of simulations in stochastic wind and waves were carried out to characterise the global response of the FOWT.Item OC6 Phase I: Investigating the underprediction of low-frequency hydrodynamic loads and responses of a floating wind turbine: Investigating the underprediction of low-frequency hydrodynamic loads and responses of a floating wind turbine(2020-09-21) Gueydon, S; Bachynski, E; Wang, L; Jonkman, J; Alarcón, D; Amet, E; Beardsell, A; Bonnet, P; Boudet, B; Brun, C; Chen, Z; Féron, M; Forbush, D; Galinos, C; Galvan, J; Gilbert, P; Gómez, J; Harnois, V; Haudin, F; Hu, Z; Dreff, J Le; Leimeister, M; Lemmer, F; Li, H; Mckinnon, G; Mendikoa, I; Moghtadaei, A; Netzband, S; Oh, S; Pegalajar-Jurado, A; Nguyen, M Q; Ruehl, K; Schünemann, P; Shi, W; Shin, H; Si, Y; Surmont, F; Trubat, P; Qwist, J; Wohlfahrt-Laymann, S; Robertson, A N; RENOVABLES OFFSHOREPhase I of the OC6 project is focused on examining why offshore wind design tools underpredict the response (loads/motion) of the OC5-DeepCwind semisubmersible at its surge and pitch natural frequencies. Previous investigations showed that the underprediction was primarily related to nonlinear hydrodynamic loading, so two new validation campaigns were performed to separately examine the different hydrodynamic load components. In this paper, we validate a variety of tools against this new test data, focusing on the ability to accurately model the low-frequency loads on a semisubmersible floater when held fixed under wave excitation and when forced to oscillate in the surge direction. However, it is observed that models providing better load predictions in these two scenarios do not necessarily produce a more accurate motion response in a moored configuration.