Dynamic Modelling of a Spar Buoy Wind Turbine

Abstract

In the present paper, the dynamic response of a spar buoy wind turbine under different wind and wave conditions is discussed. Physical model tests were performed at the Danish Hydraulic Institute (DHI) off-shore wave basin within the EU-Hydralab IV Integrated Infrastructure Initiative. The OC3-Hywind spar buoy was taken as reference prototype. A spar buoy model, 1:40 Froude-scaled, was tested using long crested regular and irregular waves, orthogonal (0 degrees) and oblique (20 degrees) to the structure. Here the results concerning regular waves, with incidence orthogonal to the structure, are presented; the selected tests considered rotating and non-rotating blades. Measurements of displacements, rotations, accelerations, forces response of the floating structure and at the mooring lines were carried out. Based on the observed data, FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy’s (DOE’s), National Renewable Energy Laboratory (NREL), was calibrated and verified. The numerical model takes into account the wave induced response and the effects of the mooring lines on the overall system. The adopted spar buoy has three equally spaced mooring lines that were modelled as quasi-static taut or catenary lines through MAP++ (static module) and MoorDyn (dynamic module) in the FAST simulation tool. The tensions along the fairleads of the three mooring lines were examined. At the end of the calibration procedure, the numerical model was successfully used to simulate the dynamic motions of the floating wind turbine under combinations of wind and sea states for the selected wave attacks. All data from the DHI tests were converted to full scale using Froude scaling before being analyzed.

Review of Recent Offshore Wind Turbine Research and Optimization Methodologies in Their Design

“…Another 1:40 model of OC3-Hywind spar was established in the DHI Offshore Wave Basin in Hørsholm (Denmark). Experimental results and numerical analysis of the FAST code were compared [37]. A numerical study was also developed for the coupled dynamics analysis of the Hywind spar design with a 5 MW turbine in the time domain, including aeroloading, blade-rotor dynamics and control, tower elastic responses, mooring dynamics, and platform motions [38].…”

Dynamic Loads and Response of a Spar Buoy Wind Turbine with Pitch-Controlled Rotating Blades: An Experimental Study

“…The spar buoy, as used in the previous experimental campaign [39], was composed of three main sections:…”

“…Experimental results are reported in [38], however in this campaign the wind loads were simulated through a static weight. These tests, carried out in the DHI Offshore Wave Basin in Hørsholm (Denmark), were preliminarily compared with the responses obtained through the FAST code [39].…”

Floating Offshore Renewable Energy Farms. A Life-Cycle Cost Analysis at Brindisi, Italy

“…Regarding the SS platform, several studies and projects are under development [3][4][5], and a review can be found in Liu et al (2016) [6], while for the TLP typology, most of the projects are still in the scale test phase [7][8][9][10]. Regarding the SB platform, several studies have been carried out in recent years on this typology [11][12][13][14][15] and in October 2017, the world's first floating wind farm, the 30 MW "Hywind Scotland," became operating (https://www.equinor.com). Recent reviews on floating wind turbines can be found in [16][17][18].…”