Model Tests for a Floating Wind Turbine on Three Different Floaters

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Bonjun J. Koo ◽  
Andrew J. Goupee ◽  
Richard W. Kimball ◽  
Kostas F. Lambrakos
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Model Tests ◽  
Experimental Comparison ◽  
Floating Platform ◽  
Scaled Model ◽  
Advantages And Disadvantages ◽  
Floating Wind Turbine ◽  
Floating Platforms

Wind energy is a promising alternate energy resource. However, the on-land wind farms are limited by space, noise, and visual pollution and, therefore, many countries build wind farms near the shore. Until now, most offshore wind farms have been built in relatively shallow water (less than 30 m) with fixed tower type wind turbines. Recently, several countries have planned to move wind farms to deep water offshore locations to find stronger and steadier wind fields as compared to near shore locations. For the wind farms in deeper water, floating platforms have been proposed to support the wind turbine. The model tests described in this paper were performed at MARIN (maritime research institute netherlands) with a model setup corresponding to a 1:50 Froude scaling. The wind turbine was a scaled model of the national renewable energy lab (NREL) 5 MW horizontal axis reference wind turbine supported by three different generic floating platforms: a spar, a semisubmersible, and a tension-leg platform (TLP). The wave environment used in the tests is representative of the offshore in the state of Maine. In order to capture coupling between the floating platform and the wind turbine, the 1st bending mode of the turbine tower was also modeled. The main purpose of the model tests was to generate data on coupled motions and loads between the three floating platforms and the same wind turbine for the operational, design, and survival seas states. The data are to be used for the calibration and improvement of the existing design analysis and performance numerical codes. An additional objective of the model tests was to establish the advantages and disadvantages among the three floating platform concepts on the basis of the test data. The paper gives details of the scaled model wind turbine and floating platforms, the setup configurations, and the instrumentation to measure motions, accelerations, and loads along with the wind turbine rpm, torque, and thrust for the three floating wind turbines. The data and data analysis results are discussed in the work of Goupee et al. (2012, “Experimental Comparison of Three Floating Wind Turbine Concepts,” OMAE 2012-83645).

Model Tests for a Floating Windturbine on Three Different Floaters

2012 ◽  
Author(s):  
Bonjun Koo ◽  
Andrew J. Goupee ◽  
Kostas Lambrakos ◽  
Richard W. Kimball
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Model Tests ◽  
Floating Platform ◽  
Scaled Model ◽  
Advantages And Disadvantages ◽  
Near Shore ◽  
Set Up ◽  
Floating Platforms

Wind energy is a promising alternate energy resource. However, the on-land wind farms are limited by space, noise, and visual pollution, and therefore many countries build wind farms near shore. Up to now, most of offshore wind farms have been built in relatively shallow water (less than 30m) with fixed tower type wind turbines. Recently, several countries plan to move wind farms to deep water offshore locations to find stronger and steadier wind fields as compared to near shore locations. For the wind farms in deeper water, floating platforms have been proposed to support the wind turbine. The model tests described in this paper were performed at MARIN (Maritime Research Institute Netherlands) with a model set-up corresponding to a 1:50 Froude scaling. The wind turbine was a scaled model of the National Renewable Energy Lab (NREL) 5MW, horizontal axis reference wind turbine supported by three different generic floating platforms: a spar, a semi-submersible and a tension-leg platform (TLP). The wave environment used in the tests is representative of the offshore in the state of Maine. In order to capture coupling between the floating platform and the wind turbine, the 1st bending mode of the turbine tower was also modeled. The main purpose of the model tests was to generate data on coupled motions and loads between the three floating platforms and the same wind turbine for the operational, design, and survival seas states. The data are to be used for calibration and improvement of existing design analysis and performance numerical codes. An additional objective of the model tests was to establish advantages and disadvantages among the three floating platform concepts on the basis of test data. The paper gives details of the scaled model wind turbine and floating platforms, the set-up configurations, and the instrumentation to measure motions, accelerations and loads as well as wind turbine rpm, torque and thrust for the three floating wind turbines. The data and data analysis results are the subject of another paper in this conference [1].

Experimental Comparison of Three Floating Wind Turbine Concepts

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Andrew J. Goupee ◽  
Bonjun J. Koo ◽  
Richard W. Kimball ◽  
Kostas F. Lambrakos ◽  
Habib J. Dagher
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Operating Conditions ◽  
Scale Model ◽  
Experimental Comparison ◽  
System Response ◽  
Advantages And Disadvantages ◽  
Floating Wind Turbine ◽  
Wind Resource

Beyond many of Earth's coasts exists a vast deepwater wind resource that can be tapped to provide substantial amounts of clean, renewable energy. However, much of this resource resides in waters deeper than 60 m where current fixed bottom wind turbine technology is no longer economically viable. As a result, many are looking to floating wind turbines as a means of harnessing this deepwater offshore wind resource. The preferred floating platform technology for this application, however, is currently up for debate. To begin the process of assessing the unique behavior of various platform concepts for floating wind turbines, 1/50th scale model tests in a wind/wave basin were performed at the Maritime Research Institute Netherlands (MARIN) of three floating wind turbine concepts. The Froude scaled tests simulated the response of the 126 m rotor diameter National Renewable Energy Lab (NREL) 5 MW, horizontal axis Reference Wind Turbine attached via a flexible tower in turn to three distinct platforms, these being a tension leg-platform, a spar-buoy, and a semisubmersible. A large number of tests were performed ranging from simple free-decay tests to complex operating conditions with irregular sea states and dynamic winds. The high-quality wind environments, unique to these tests, were realized in the offshore basin via a novel wind machine, which exhibited low swirl and turbulence intensity in the flow field. Recorded data from the floating wind turbine models include rotor torque and position, tower top and base forces and moments, mooring line tensions, six-axis platform motions, and accelerations at key locations on the nacelle, tower, and platform. A comprehensive overview of the test program, including basic system identification results, is covered in previously published works. In this paper, the results of a comprehensive data analysis are presented, which illuminate the unique coupled system behavior of the three floating wind turbines subjected to combined wind and wave environments. The relative performance of each of the three systems is discussed with an emphasis placed on global motions, flexible tower dynamics, and mooring system response. The results demonstrate the unique advantages and disadvantages of each floating wind turbine platform.

Progressive Drifting of Floating Wind Turbines in a Wind Farm

2009 ◽  
Author(s):  
Hideyuki Suzuki ◽  
Masaru Kurimoto ◽  
Yu Kitahara ◽  
Yukinari Fukumoto
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
Wind Farms ◽  
Floating Platform ◽  
Allowable Limit ◽  
Main Research ◽  
Analysis And Design ◽  
Floating Wind Turbine ◽  
Wide Range

A wide range of platform types have been investigated for a floating wind turbine. Most of the research projects on a floating wind turbine assume that a land based wind turbine is to be installed on a platform with minimum modification to reduce the overall cost. For this reason, allowable limit of a motion of wind turbine is limited to lower value, for example, five degrees for static inclination and one to two degrees for pitching motion. So far analysis and design of motion characteristics of the platform have been main research concern. One key research area less focused is floating platform related risk. If the wind energy would be one of the major sources of power supply, wind farms which are comprised of large number of floating wind turbines must be deployed in the ocean. Wind turbines will be closely spaced in a wind farm so that installation cost should be minimized. In such an arrangement, a wind turbine accidentally started drifting has some possibility to collide or contact with the moorings of neighboring wind turbines and might cause progressive drifting of wind turbines. This paper present investigation of scenario of progressive drifting of floating wind turbines and evaluate risk of the scenario. Quantitative risk of several arrangements of wind farms is estimated. Effect of arrangement of wind turbines in a wind farm and safety factor used in design moorings is discussed.

Experimental Comparison of Three Floating Wind Turbine Concepts

2012 ◽  
Author(s):  
Andrew J. Goupee ◽  
Bonjun Koo ◽  
Richard W. Kimball ◽  
Kostas F. Lambrakos ◽  
Habib J. Dagher
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Operating Conditions ◽  
Scale Model ◽  
Experimental Comparison ◽  
System Response ◽  
Advantages And Disadvantages ◽  
Floating Wind Turbine ◽  
Wind Resource

Beyond many of the Earth’s coasts exist a vast deepwater wind resource that can be tapped to provide substantial amounts of clean, renewable energy. However, much of this resource resides in waters deeper than 60 m where current fixed bottom wind turbine technology is no longer economically viable. As a result, many are looking to floating wind turbines as a means of harnessing this deepwater offshore wind resource. The preferred floating platform technology for this application, however, is currently up for debate. To begin the process of assessing the relative advantages of various platform concepts for floating wind turbines, 1/50th scale model tests in a wind/wave basin were performed at MARIN (Maritime Research Institute Netherlands) of three floating wind turbine concepts. The Froude scaled tests simulated the behavior of the 126 m rotor diameter NREL (National Renewable Energy Lab) 5 MW, horizontal axis Reference Wind Turbine attached via a flexible tower in turn to three distinct platforms, these being a tension leg-platform, a spar-buoy and a semi-submersible. A large number of tests were performed ranging from simple free-decay tests to complex operating conditions with irregular sea states and dynamic winds. The high-quality wind environments, unique to these tests, were realized in the offshore basin via a novel wind machine which exhibited low swirl and turbulence intensity in the flow field. Recorded data from the floating wind turbine models include rotor torque and position, tower top and base forces and moments, mooring line tensions, six-axis platform motions and accelerations at key locations on the nacelle, tower, and platform. A comprehensive overview of the test program, including basic system identification results, is covered in an associated paper in this conference. In this paper, the results of a comprehensive data analysis are presented which illuminate the unique coupled system behavior of the three floating wind turbines subjected to combined wind and wave environments. The relative performance of each of the three systems is discussed with an emphasis placed on global motions, flexible tower dynamics and mooring system response. The results demonstrate the unique advantages and disadvantages of each floating wind turbine platform.

Model Tests of a Spar-Type Floating Wind Turbine Under Wind/Wave Loads

2015 ◽  
Author(s):  
Fei Duan ◽  
Zhiqiang Hu ◽  
Jin Wang
Keyword(s):  
Wind Turbine ◽  
Model Test ◽  
Wind Wave ◽  
Wave Model ◽  
Offshore Structures ◽  
Model Tests ◽  
Wave Loads ◽  
Scaled Model ◽  
Floating Wind Turbine ◽  
Wave Effects

Wind power has great potential because of its clean and renewable production compared to the traditional power. Most of the present researches for floating wind turbine rely on the hydro-aero-elastic-servo simulation codes and have not been exhaustively validated yet. Thus, model tests are needed and make sense for its high credibility to master the kinetic characters of floating offshore structures. The characters of kinetic responses of the spar-type wind turbine are investigated through model test research technique. This paper describes the methodology for wind/wave model test that carried out at Deepwater Offshore Basin in Shanghai Jiao Tong University at a scale of 1:50. A Spar-type floater was selected to support the wind turbine in this test and the model blade was geometrically scaled down from the original NREL 5 MW reference wind turbine blade. The detail of the scaled model of wind turbine and the floating supporter, the test set-up configuration, the mooring system, the high-quality wind generator that can create required homogeneous and low turbulence wind, and the instrumentations to capture loads, accelerations and 6 DOF motions are described in detail, respectively. The isolated wind/wave effects and the integrated wind-wave effects on the floating wind turbine are analyzed, according to the test results.

Progressive Drift of Moored Floating Wind Turbines in a Wind Farm: Improved Mooring Capacity Model

2011 ◽  
Author(s):  
Hideyuki Suzuki ◽  
Yu Kitahara ◽  
Yukinari Fukumoto
Keyword(s):  
Wind Turbine ◽  
Safety Factor ◽  
Wind Turbines ◽  
Wind Farm ◽  
Wind Farms ◽  
Floating Platform ◽  
Main Research ◽  
Electric Power Supply ◽  
Analysis And Design ◽  
Wide Range

A wide range of platform concepts have been investigated for a floating wind turbine. So far analysis and design of motion characteristics of the platform is main research concern. One key research area less focused is floating platform related risk. If the wind energy would be one of the major sources of electric power supply, wind farms which are comprised of large number of floating wind turbines must be deployed in the ocean. Wind turbines are relatively closely arranged in a wind farm. In such an arrangement, a wind turbine accidentally started drifting will have some possibility to collide with floater and moorings of neighboring moored floating wind turbines, and might initiate another drift which might cause progressive drifting of wind turbines. In the previous report, a scenario of progressive drifting of wind turbines was investigated and associated risk was formulated. Quantitative risk of several arrangements of wind farm was estimated. Effects of arrangement of wind turbines in a wind farm and safety factor used in the design of moorings is discussed. Probability of initial drift was evaluated analyzing past records of accidents and design of mooring. In this research, strength of mooring system was modeled more precisely and probabilistic model was developed considering aged deterioration. Risk of progressive drifting was evaluated and safety factor required to realize a acceptable risk of a wind farm was discussed.

Guideline for Offshore Floating Wind Turbine Structures

2010 ◽  
Author(s):  
Knut O. Ronold ◽  
Vigleik L. Hansen ◽  
Marte Godvik ◽  
Einar Landet ◽  
Erik R. Jo̸rgensen ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Oil And Gas Industry ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Technical Requirements ◽  
Floating Wind Turbine ◽  
Floating Offshore Wind Turbines ◽  
Offshore Floating Wind Turbine

Floating offshore wind turbines is a field undergoing major development. Several companies and research institutes worldwide are engaged in research programs, pilot projects and even planning of commercial floating wind farms. Developing standards for design of floating wind turbine structures and a framework for prevailing rules are crucial and necessary for the industry to continue to grow. Det Norske Veritas (DNV) is an international provider of offshore standards for both the oil and gas industry and the wind energy industry. The standard DNV-OS-J101 “Design of Offshore Wind Turbine Structures” provides principles, technical requirements and guidance for design, construction and in-service inspection of offshore wind turbine structures. As a first step towards updating this standard to fully cover floating wind turbine structures, a DNV Guideline for Offshore Floating Wind Turbines has been established. This development is based on identification of current floating wind turbine concepts and the guideline includes an evaluation of what is required to make DNV-OS-J101 suitable for floating wind turbine structures. This paper presents the highlights of the new DNV Guideline for Offshore Floating Wind Turbine Structures.

The unsteady aerodynamics of floating wind turbine under platform pitch motion

2018 ◽  
Vol 232 (8) ◽  
pp. 1019-1036 ◽  
Author(s):  
Xin Shen ◽  
Ping Hu ◽  
Jinge Chen ◽  
Xiaocheng Zhu ◽  
Zhaohui Du
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Degrees Of Freedom ◽  
Unsteady Aerodynamics ◽  
Aerodynamic Performance ◽  
Floating Platform ◽  
Pitch Motion ◽  
Floating Wind Turbine ◽  
Fixed Base ◽  
Turbine Rotors

The aerodynamic performance of floating platform wind turbines is much more complex than fixed-base wind turbines because of the flexibility of the floating platform. Due to the extra six degrees-of-freedom of the floating platform, the inflow of the wind turbine rotors is highly influenced by the motions of the floating platform. It is therefore of interest to study the unsteady aerodynamics of the wind turbine rotors involved with the interaction of the floating platform induced motions. In the present work, a lifting surface method with a free wake model is developed for analysis of the unsteady aerodynamics of wind turbines. The aerodynamic performance of the NREL 5 MW floating wind turbine under the prescribed floating platform pitch motion is studied. The unsteady aerodynamic loads, the transient of wind turbine states, and the instability of the wind turbine wakes are discussed in detail.

Influence of the Rotor Characterization on the Motion of a Floating Wind Turbine

2015 ◽  
Author(s):  
Sébastien Gueydon ◽  
Guillaume Venet ◽  
Gerson Fernandes
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Rotation Speed ◽  
Model Tests ◽  
Full Scale ◽  
Aerodynamic Damping ◽  
Common Solution ◽  
Floating Wind Turbine ◽  
Wave Basin ◽  
Low Reynolds

It is useful to complement model tests of a floating wind turbine with simulations mimicking the scaled-down turbine. Standard engineering tools have some short-comings to model a rotor at the very low Reynolds that Froude scaled wind and rotor’s rotation speed impose. The flow around an airfoil at the scale of a wave basin brings new distinct challenges than at full scale. The capacity of standard engineering tools for the design of wind turbines to capture this complexity may be questioned. Therefore, work-around solutions need to be proposed. This paper looks at a common solution that consists of optimizing the load coefficients of the rotor to reproduce the measured rotor loads. 3 variants of optimizations are applied to a semisubmersible floating wind turbine at scale 1/50th, the DeepCwind semisubmersible platform. The effects of the differences between these 3 methods on the motions of the floater in waves and wind are analyzed. In the absence of a controller for the rotor, no significant differences related to the induced aerodynamic damping was noticed, but an offset in the motion related to a thrust deficit was observed.

Model Test Data Correlations With Fully Coupled Hull/Mooring Analysis for a Floating Wind Turbine on a Semi-Submersible Platform

2014 ◽  
Author(s):  
Bonjun Koo ◽  
Andrew J. Goupee ◽  
Kostas Lambrakos ◽  
Ho-Joon Lim
Keyword(s):  
Wind Turbine ◽  
Model Test ◽  
Model Tests ◽  
Test Results ◽  
Scaled Model ◽  
Floating Wind Turbine ◽  
Mooring Dynamics ◽  
Set Up ◽  
Fully Coupled ◽  
Turbine Model

The DeepCwind floating wind turbine model tests were performed at MARIN (Maritime Research Institute Netherlands) with a model set-up corresponding to a 1:50 Froude scaling. In the model tests, the wind turbine was a scaled model of the National Renewable Energy Lab (NREL) 5MW, horizontal axis reference wind turbine supported by three different generic floating platforms: a spar, a semi-submersible and a tension-leg platform (TLP) (Ref. [1] and [2]). This paper presents validation of the MLTSIM-FAST [3] code with DeepCwind semi-submersible wind turbine model test results. In this integrated program, the turbine tower and rotor dynamics are simulated by the subroutines of FAST [4], and the hydrodynamic loads and mooring system dynamics are simulated by the subroutines of MLTSIM. In this study, fully coupled hull/mooring dynamics and second-order difference-frequency response are included in MLTSIM-FAST. The analysis results are systematically compared with model test results and show good agreement.

Sign in / Sign up

Export Citation Format

Share Document