Experimental and numerical analysis of a TLP floating offshore wind turbine

Abstract

This paper describes an experimental and numerical investigation of the Iberdrola TLP wind turbine concept, TLPWIND, in realistic wind and wave conditions. The TLP was coupled to the NREL 5 MW reference turbine and was designed to operate in a water depth of 70 m. The test campaign included free oscillation tests, tests in regular and irregular waves and simulated wind conditions. A Software-in-the-loop approach was adopted to account for the time-varying aerodynamic forces produced by the turbine during the physical experiments. The effect of wind was found to have a significant contribution to the overall response of the platform whilst variation in wave conditions was found to have a relatively small effect on the platform response. A comparison of results from physical and numerical simulations show that, the numerical predictions from FAST were very close to the results obtained from the experiments in some cases, but in other cases the numerical model failed to accurately predict the platform response. The results from both studies show the benefits of such TLP structures in terms of motions which are vital to obtain a high power output from a floating offshore wind turbine

Uncertainty in the Physical Testing of Floating Wind Energy Platforms’ Accuracy versus Precision

“…As the physical testing of FOWTs is relatively new, a standardised approach has yet to emerge and thus a quantification of experimental uncertainty is often absent from the relevant literature. For example, in [8][9][10][11], experimental uncertainty was not addressed, whilst in [12][13][14][15][16][17], comparisons between numerical and physical data were presented, which can be considered a measure of experimental accuracy, but with no assessment of experimental precision.…”

Study on the Coupled Dynamic Responses of a Submerged Floating Wind Turbine under Different Mooring Conditions

“…The hydrodynamic coefficients, such as the added mass, potential damping, hydrostatic restoring stiffness and wave excitation force transfer function, were calculated in frequency domain using the potential-based 3D diffraction/radiation code HydroD/Wadam and then applied in time domain using the convolution technique. Then these hydrodynamic coefficients were fed to the HydroDyn module in FAST [9]. MAP++ was used to model the mooring system.…”

“…At the intermediate water depth, the bottom-fixed foundations will no longer be economically feasible. A variety of FOWT concepts have been proposed in the last two decades, such as spar, semi-submersible and tension leg platforms (TLPs) [7][8][9][10]. Several of these concepts have already outgrown the prototype status and will go into pre-serial production shortly, such as the WindFloat semi-submersible, SWAY [11][12][13].…”

Dynamic and structural performances of offshore floating wind turbines in turbulent wind flow

“…Li et al (2018b) measured the dynamic response of a semisubmersible floating wind turbine in experimental environment, and a free-rotation method was proposed to correct the Reynolds number dissimilitude. Oguz et al (2018) investigated the dynamics of a TLP floating wind turbine with both numerical and experimental methods. Apart from model test research, numerical simulation technology is also widely adopted by many researchers.…”