scholarly journals Model Test of a 1:8-Scale Floating Wind Turbine Offshore in the Gulf of Maine1

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Anthony M. Viselli ◽  
Andrew J. Goupee ◽  
Habib J. Dagher
Keyword(s):  
Wind Turbine ◽  
Physical Model ◽  
Test Data ◽  
Model Test ◽  
Test Site ◽  
Full Scale ◽  
Scale Construction ◽  
Offshore Wind ◽  
Testing Effort ◽  
Floating Wind Turbine

A new floating wind turbine platform design called VolturnUS developed by the University of Maine uses innovations in materials, construction, and deployment technologies such as a concrete semisubmersible hull and a composite tower to reduce the costs of offshore wind. These novel characteristics require research and development prior to full-scale construction. This paper presents a unique offshore model testing effort aimed at derisking full-scale commercial projects by providing scaled global motion data, allowing for testing of materials representative of the full-scale system, and demonstrating full-scale construction and deployment methods. A 1:8-scale model of a 6 MW semisubmersible floating wind turbine was deployed offshore Castine, ME, in June 2013. The model includes a fully operational commercial 20 kW wind turbine and was the first grid-connected offshore wind turbine in the U.S. The testing effort includes careful selection of the offshore test site, the commercial wind turbine that produces the correct aerodynamic thrust given the wind conditions at the test site, scaling methods, model design, and construction. A suitable test site was identified that produced scaled design load cases (DLCs) prescribed by the American Bureau of Shipping (ABS) Guide for Building and Classing Floating Offshore Wind Turbines. A turbine with a small rotor diameter was selected because it produces the correct thrust load given the wind conditions at the test site. Some representative data from the test are provided in this paper. Model test data are compared directly to full-scale design predictions made using coupled aeroelastic/hydrodynamic software. Scaled VolturnUS performance data during DLCs show excellent agreement with full-scale predictive models. Model test data are also compared directly without scaling against a numerical representation of the 1:8-scale physical model for the purposes of numerical code validation. The numerical model results compare favorably with data collected from the physical model.

Model Test of a 1:8 Scale Floating Wind Turbine Offshore in the Gulf of Maine

2014 ◽  
Author(s):  
Anthony M. Viselli ◽  
Andrew J. Goupee ◽  
Habib J. Dagher
Keyword(s):  
Wind Turbine ◽  
Physical Model ◽  
Test Data ◽  
Model Test ◽  
Test Site ◽  
Full Scale ◽  
Scale Construction ◽  
Offshore Wind ◽  
Testing Effort ◽  
Floating Wind Turbine

A new floating wind turbine platform design called VolturnUS developed by the University of Maine uses innovations in materials, construction, and deployment technologies such as a concrete semi-submersible hull and a composite tower to reduce the costs of offshore wind. These novel characteristics require research and development prior to full-scale construction. This paper presents a unique offshore model testing effort aimed at de-risking full-scale commercial projects by providing properly scaled global motion data, allowing for implementation of full-scale structural materials, and demonstrating full-scale construction and deployment methods. The model is a 1:8-scale model of a 6MW semi-submersible floating wind turbine and was deployed offshore Castine, Maine, USA in June, 2013. The model uses a fully operational turbine and was the first grid connected offshore wind turbine in the Americas. The testing effort includes careful treatment of the offshore test site, scaling methods, model design, and construction. A suitable test site was identified that provides the correct proportions of wind and wave loading in order to simulate design load cases prescribed by the American Bureau of Shipping Standard for Building and Classing Floating Offshore Wind Turbines. Sample model test data is provided. Model test data is directly compared to full-scale design predictions made using coupled aeroelastic/ hydrodynamic software. VolturnUS performance data from scaled extreme sea states show excellent agreement with predictive models. Model test data are also compared to a numerical representation of the physical model for the purposes of numerical code validation. The numerical model results compare very favorably with data collected from the physical model.

VolturnUS 1:8: Conclusion of 18-Months of Operation of the First Grid-Connected Floating Wind Turbine Prototype in the Americas

2015 ◽  
Author(s):  
Anthony M. Viselli ◽  
Andrew J. Goupee ◽  
Habib J. Dagher ◽  
Christopher K. Allen
Keyword(s):  
Wind Turbine ◽  
Large Data ◽  
Full Scale ◽  
Offshore Wind ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Data Set ◽  
Floating Offshore Wind Turbine ◽  
The Past ◽  
Floating Wind Turbine

This paper presents an overview of the successful conclusion of 18 months of testing the first grid-connected floating offshore wind turbine prototype in the Americas. The prototype, called VolturnUS 1:8, was installed off Castine, Maine, USA. The prototype is a 1:8 scale prototype and serves to de-risk the deployment of a full-scale 6MW turbine. VolturnUS utilizes innovations in materials, construction, and deployment technologies such as a concrete semi-submersible hull and an advanced composite tower to reduce the costs of offshore wind. The prototype unit was designed following the American Bureau of Shipping (ABS) “Guide for Building and Classing Floating Offshore Wind Turbine Installations”. Froude scaling was used in designing the 1:8-scale VolturnUS prototype so that the motions of the prototype in the relatively protected site represent those of the full-scale unit in an open site farther offshore. During the past year, a comprehensive instrumentation package monitored key performance characteristics of the platform during operational, extreme, and survival storm conditions. Data collected include: wind speed, turbine power, rotor angular frequency, blade pitch, torque, acceleration; tower bending moment, 6 DOF accelerations at tower top and base, mooring line tensions, and wave elevation at the platform. During the past year the prototype has experienced many environments representative of scaled ABS design conditions including operational wind and sea-states, 50-year sea states and 500-year survival sea states. This large data set provides a unique view of a near full-scale floating wind turbine subjected to its prescribed environmental conditions. Inspections of the concrete hull following removal provided confirmation of material durability. Marine growth measurements provide data for future design efforts.

VolturnUS 1:8-Scale FRP Floating Wind Turbine Tower: Analysis, Design, Testing and Performance

2014 ◽  
Author(s):  
Andrew C. Young ◽  
Steve Hettick ◽  
Habib J. Dagher ◽  
Anthony M. Viselli ◽  
Andrew J. Goupee
Keyword(s):  
Wind Turbine ◽  
The United States ◽  
Pilot Scale ◽  
Full Scale ◽  
Lessons Learned ◽  
Offshore Wind ◽  
Floating Platform ◽  
Floating Wind Turbine ◽  
Wind Turbine Tower ◽  
Analysis Design

In May of 2013 the VolturnUS 1:8 floating semi-submersible wind turbine was successfully deployed off the coast of Castine, Maine, making the unit the first grid connected offshore turbine in the United States. The VolturnUS 1:8 structure features a 20 kW turbine, a post-tensioned and reinforced concrete semi-submersible base and a fiber reinforced plastic (FRP) tower (E-glass and polyester resin). The VolturnUS 1:8 structure is a geometrically 1:8-scale of a 6 MW floating turbine design and is used to demonstrate the feasibility of both the concrete base and FRP tower and validate the performance of the structure in a scaled environment. Data collected from the deployed 1:8-scale structure will be used for modeling and simulating the behavior of the system at full-scale. The effort was led by the University of Maine’s Advanced Structures and Composites Center (UMaine) and a consortium of industry partners, including FRP manufacturer Ershigs, Inc. An overview of the process and methodology used in the analysis, design and testing of the 1:8 scale FRP floating wind turbine tower is presented. The use of an FRP tower on a floating wind turbine platform offers the benefits of reduced tower mass and maintenance requirements and has the potential to further reduce hull mass by lowering the global center of gravity of the structure. An FRP tower for use on the UMaine semi-submersible concrete VolturnUS 1:8 platform was developed that meets all strength and serviceability criteria and is robust enough to withstand the loading from both wind and waves. An overview of the tower loads analysis and FAST modeling, tower structural design, structural proof testing and preliminary analysis of performance are presented. The VolturnUS 1:8 wind turbine tower is the first time FRP materials have been used in an offshore wind tower application. Further, the methodologies and procedures that were developed in the design of the pilot-scale tower are directly applicable to the design and analysis of composite wind turbine towers at the full-scale level. These “lessons learned” are already in use as Ershigs and UMaine work to design a full-scale composite tower over 80 meters tall for use on the VolturnUS platform with a 6MW wind turbine. The results of the 1:8-scale program demonstrate the successful use of an FRP wind turbine tower on a floating platform and highlights the potential for the use of an FRP tower at the full-scale (6 MW) level.

scholarly journals Study on the Motion Characteristics of 10 MW Superconducting Floating Offshore Wind Turbine Considering 2nd Order Wave Effect

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6070
Author(s):  
Youngjae Yu ◽  
Thanh Dam Pham ◽  
Hyunkyoung Shin ◽  
Kwangtae Ha
Keyword(s):  
Wind Turbine ◽  
Test Data ◽  
Model Test ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Strong Wind ◽  
Floating Offshore Wind Turbine ◽  
Simulation Results ◽  
Motion Characteristics

Recently, several countries have made commitments to move to a net-zero emission by the year 2050 in a response to climate change. Among various renewable energy systems to realize the target, wind energy system has been gaining much attention as a favorable alternative source to fossil fuel energy. In particular, many floating offshore wind turbines (FOWT) are expected to be installed because of vast installation resources without water depth limit conditions, stable and strong wind resources, relatively low constraints on noise emission, and space restriction compared to onshore wind turbines. In this study, a 10 MW superconducting floating offshore wind turbine was modeled with a 1/90 scale ratio and was experimentally tested at the Ocean Engineering Widetank of the University of Ulsan. The model calibration of the scaled model was performed with free decay test and showed a good correlation with simulation results calculated from FAST V8 of NREL. The motion characteristics of the 10 MW superconducting FOWT semi-submersible type platform was investigated under regular waves and irregular waves through the comparison of model test data and simulation results. The study on the motion characteristics of the model showed that the simulation considering the 2nd order wave effects to hydrodynamic forces and moments provided better accuracy close to the model test data.

Methodology for Wind/Wave Basin Testing of Floating Offshore Wind Turbines

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Heather R. Martin ◽  
Richard W. Kimball ◽  
Anthony M. Viselli ◽  
Andrew J. Goupee
Keyword(s):  
Wind Turbine ◽  
Model Test ◽  
Wind Turbines ◽  
Model Testing ◽  
Full Scale ◽  
Scale Model ◽  
Horizontal Axis Wind Turbine ◽  
Wind Turbine Aerodynamics ◽  
Floating Wind Turbine ◽  
Wave Basin

Scale-model wave basin testing is often employed in the development and validation of large-scale offshore vessels and structures by the oil and gas, military, and marine industries. A basin-model test requires less time, resources, and risk than a full-scale test, while providing real and accurate data for numerical simulator validation. As the development of floating wind turbine technology progresses in order to capture the vast deep-water wind energy resource, it is clear that model testing will be essential for the economical and efficient advancement of this technology. However, the scale model testing of floating wind turbines requires accurate simulation of the wind and wave environments, structural flexibility, and wind turbine aerodynamics and thus requires a comprehensive scaling methodology. This paper presents a unified methodology for Froude scale model testing of floating wind turbines under combined wind and wave loading. First, an overview of the scaling relationships employed for the environment, floater, and wind turbine are presented. Afterward, a discussion is presented concerning suggested methods for manufacturing a high-quality, low-turbulence Froude scale wind environment in a wave basin to facilitate simultaneous application of wind and waves to the model. Subsequently, the difficulties of scaling the highly Reynolds number–dependent wind turbine aerodynamics is presented in addition to methods for tailoring the turbine and wind characteristics to best emulate the full-scale condition. Lastly, the scaling methodology is demonstrated using results from 1/50th-scale floating wind turbine testing performed at the Maritime Research Institute Netherlands (MARIN) Offshore Basin. The model test campaign investigated the response of the 126 -m rotor diameter National Renewable Energy Lab (NREL) horizontal axis wind turbine atop three floating platforms: a tension-leg platform, a spar-buoy, and a semisubmersible. The results highlight the methodology's strengths and weaknesses for simulating full-scale global response of floating wind turbine systems.

Wind/Wave Basin Verification of a Performance-Matched Scale-Model Wind Turbine on a Floating Offshore Wind Turbine Platform

2014 ◽  
Author(s):  
Richard Kimball ◽  
Andrew J. Goupee ◽  
Matthew J. Fowler ◽  
Erik-Jan de Ridder ◽  
Joop Helder
Keyword(s):  
Wind Turbine ◽  
Model Test ◽  
Reynolds Numbers ◽  
Full Scale ◽  
Offshore Wind ◽  
Scale Model ◽  
Scaled Model ◽  
Turbine Performance ◽  
Wave Basin ◽  
The University

In 2011, the DeepCwind Consortium performed 1/50th-scale model tests on three offshore floating wind platforms at the Maritime Research Institute Netherlands (MARIN) using a geometrically scaled model of the National Renewable Energy Laboratory (NREL) 5 MW reference turbine. However, due to the severe mismatch in Reynolds number between full scale and model scale, the strictly Froude-scaled, geometrically-similar (geo-sim) wind turbine underperformed greatly, which required significant modification of test wind speeds to match key wind turbine aerodynamic loads, such as thrust. The conclusion from these prior efforts was to abandon a geometrically similar model turbine and use a performance-matched turbine model in its place, keeping mass and inertia properties properly scaled, but utilizing modified blade geometries to achieve required performance at the lower Reynolds numbers of the Froude scaled model. To this end, the University of Maine and MARIN worked in parallel to develop performance-matched turbines designed to emulate the full scale performance of the NREL 5 MW reference turbine at model scale conditions. An overview of this performance-matched wind turbine design methodology is presented and examples of performance-matched turbines are provided. The DeepCwind semi-submersible platform was retested at MARIN in 2013 using the MARIN Stock Wind Turbine (MSWT), which was designed to closely emulate the performance of the original NREL 5 MW turbine. This work compares the wind turbine performance of the MSWT to the previously used geometrically scaled NREL 5 MW turbine. Additionally, turbine performance testing of the 1/50th-scale MSWT was completed at MARIN and a 1/130th-scale model was tested at the University of Maine under Reynolds numbers corresponding to the Froude-scaled model test conditions. Results from these tests are provided to demonstrate effects on model test fidelity. Comparisons of the performance response of the geometrically matched turbine to the performance-matched turbines are also presented to illustrate the performance-matched turbine methodology. Lastly, examples of the fully dynamic floating system performance using the original geometrically scaled NREL 5 MW turbine and the MSWT are investigated to illustrate the implementation of the model test procedure as well as the effects of turbine performance on floater response. Using the procedures employed for the MARIN tests as a guide, the results of this work support the development of protocols for properly designing scale model wind turbines that emulate the full scale design for Froude-scale wind/wave basin tests of floating offshore wind turbines.

scholarly journals Dynamic Modeling of an Offshore Floating Wind Turbine for Application in the Mediterranean Sea

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 248
Author(s):  
Lorenzo Cottura ◽  
Riccardo Caradonna ◽  
Alberto Ghigo ◽  
Riccardo Novo ◽  
Giovanni Bracco ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Mediterranean Sea ◽  
Wind Farm ◽  
Reference Model ◽  
Wide Spectrum ◽  
Wind Farms ◽  
Offshore Wind ◽  
Floating Wind Turbine ◽  
The Mediterranean ◽  
Offshore Floating Wind Turbine

Wind power is emerging as one of the most sustainable and low-cost options for energy production. Far-offshore floating wind turbines are attractive in view of exploiting high wind availability sites while minimizing environmental and landscape impact. In the last few years, some offshore floating wind farms were deployed in Northern Europe for technology validation, with very promising results. At present time, however, no offshore wind farm installations have been developed in the Mediterranean Sea. The aim of this work is to comprehensively model an offshore floating wind turbine and examine the behavior resulting from a wide spectrum of sea and wind states typical of the Mediterranean Sea. The flexible and accessible in-house model developed for this purpose is compared with the reference model FAST v8.16 for verifying its reliability. Then, a simulation campaign is carried out to estimate the wind turbine LCOE (Levelized Cost of Energy). Based on this, the best substructure is chosen and the convenience of the investment is evaluated.

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