1:52 Scale Testing of the First US Commercial Scale Floating Wind Turbine, VolturnUS: Testing Overview and the Evolution of Scale Model Testing Methods

2017 ◽  
Author(s):  
Matthew J. Fowler ◽  
Andrew J. Goupee ◽  
Christopher Allen ◽  
Anthony Viselli ◽  
Habib Dagher
Keyword(s):  
Model Test ◽  
Wind Wave ◽  
Model Testing ◽  
Model Tests ◽  
Scale Model ◽  
Test Facility ◽  
Ocean Engineering ◽  
Floating Platform ◽  
Design Validation ◽  
Floating Offshore Wind Turbines

Over the past 6 years, the University of Maine (UMaine) has been an active contributor in research and scale-model testing of floating offshore wind turbines (FOWTs). This paper serves to share the evolution of UMaine’s scale-model testing pedigree by exploring the various test campaigns at a high level, culminating with the design validation of the VolturnUS floating platform. These model test campaigns have each provided key insights into the behavior of FOWT platforms as well as improving the ability to perform model tests of FOWTs. In 2011, the UMaine-led DeepCwind Consortium carried out 1/50-scale model tests of a generic tension leg platform (TLP), a semi-submersible (semi), and a spar-buoy (spar) floating platform at the Maritime Research Institute Netherlands (MARIN) test facility. The designs were Froude-scaled and supported a scaled version of the 5-MW National Renewable Energy Laboratory (NREL) offshore research turbine. Data from these tests has been used extensively for numerical simulation validation efforts using NREL’s computer-aided engineering software FAST and laid the foundation for UMaine’s design efforts on VolturnUS. In 2013, UMaine conducted another test campaign at MARIN using the original semi-submersible from 2011 with an improved turbine as well as a 1:50-scale model of the VolturnUS concrete semi-submersible design. The improved DeepCwind semi-submersible data is currently being utilized in the validation of a large number of other analysis codes as part of the International Energy Agency’s OC5 project. In 2015, UMaine opened its own Wind/Wave test facility, the Alfond Wind/Wave Ocean Engineering Laboratory (W2). Utilizing this new facility, UMaine tested the 1:50-scale model DeepCwind semi-submersible, repeating the tests from MARIN, to validate the experimental equipment and procedures as well as demonstrate the capability of the W2. In 2016 UMaine carried out testing of a 1:52-scale model of the 100% design of the VolturnUS with a 6-MW topside as a final design validation to support the US Department of Energy-supported, full-scale Aqua Ventus demonstration project scheduled to be connected to the grid in 2019. A newly designed 6-MW scale model turbine was used in this test and the performance-matched turbine design methodology is described. Selected results from the test campaign and preliminary numerical comparisons are discussed as well as key lessons learned from the model test campaigns are presented.

Physical Model Testing of the TetraSpar Demo Floating Wind Turbine Prototype

2019 ◽  
Author(s):  
Michael Borg ◽  
Anthony Viselli ◽  
Christopher K. Allen ◽  
Matthew Fowler ◽  
Christoffer Sigshøj ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Numerical Models ◽  
Model Testing ◽  
Offshore Wind ◽  
Scale Model ◽  
Test Facility ◽  
Hydrodynamic Characteristics ◽  
Ocean Engineering ◽  
Floating Wind Turbine ◽  
Floating Offshore Wind Turbines

Abstract As part of the process of deploying new floating offshore wind turbines, scale model testing is carried out to de-risk and verify the design of novel foundation concepts. This paper describes the testing of a 1:43 Froude-scaled model of the TetraSpar Demo floating wind turbine prototype that shall be installed at the Metcentre test facility, Norway. The TetraSpar floating foundation concept consists of a floater tetrahedral structure comprising of braces connected together through pinned connections, and a triangular keel structure suspended below the floater by six suspension lines. A description of the experimental setup and program at the Alfond W2 Ocean Engineering Lab at University of Maine is given. The objective of the test campaign was to validate the initial design, and contribute to the development of the final demonstrator design and numerical models. The nonlinear hydrodynamic characteristics of the design are illustrated experimentally and the keel suspension system is shown to satisfy design criteria.

Development of a New Federally Funded Wind/Wave/Towing Basin to Support the Offshore Renewable Energy Industry

2017 ◽  
Author(s):  
Alexander Cole ◽  
Matthew Fowler ◽  
Razieh Zangeneh ◽  
Anthony Viselli
Keyword(s):  
Renewable Energy ◽  
Wave Energy ◽  
Wind Wave ◽  
Model Testing ◽  
Scale Model ◽  
Test Facility ◽  
Resistance Testing ◽  
High Quality ◽  
Directional Wave ◽  
Wave Maker

This paper presents technical details for a unique newly constructed model testing facility for offshore renewable energy devices and other structures established through federal and state funding. The University of Maine (UMaine) has been an active contributor to research in the field of floating offshore wind turbine (FOWT) design and scale-model testing for the past 6 years. Due to a lack of appropriate test facilities in the United States, UMaine has led multiple 1:50 scale-model tests of FOWT platforms internationally, leading to the motivation to design and build a state-of-the-art test facility at UMaine which includes high-quality wind generation with waves and towing capabilities. In November of 2015, UMaine opened the Alfond Wind/Wave Ocean Engineering Laboratory (W2) at the Advanced Structures and Composites Center. This facility, shown in Figure 1, contains a 30m long x 9m wide x 0-4.5m variable floor depth test basin with a 16-paddle wave maker at one end and a parabolic wave attenuating beach at the other. This basin is unique in that it integrates a rotatable open-jet wind tunnel over the basin that is capable of simulating high-quality wind fields in excess of 10 m/s over a large test area. Since opening, the W2 has provided testing for various scale-model FOWT designs, oil and gas vessels such as a scale-model floating production storage and offloading (FPSO) vessel, and a large number of wave energy conversion (WEC) devices in support of the Department of Energy’s (DOE) Wave Energy Prize. In addition to scalemodel testing, the W2 facility supports a wide range of model construction equipment including a 2.0m x 4.0m x 0.1m tall 3D CNC waterjet, a 3m long x 1.5m wide x 1.4m tall 5-axis CNC router, and an additive manufacturing facility housing a 0.6m x 0.6m x 0.9m 3D printer. To expand the capability of W2, a towing system is currently being designed to operate in conjunction with the multi-directional wave maker, which is shown in Figure 5. This equipment will provide bi-directional towing for a variety of applications. In addition to standard resistance testing, the broad aspect ratio of the basin provides reduced blockage effects while the multi-directional wave maker allows for tow testing a large number of wave environments and headings. The moving floor enables intermediate to shallow water tow tank tests, which are important for capturing the wave kinematics applicable to coastal environments, while the relatively deep water depths support testing of large structures such as tidal turbines and tow-out operations for THE 30th AMERICAN TOWING TANK CONFERENCE WEST BETHESDA, MARYLAND, OCTOBER 2017 2 large offshore structures such as wind and wave floating energy platforms. To test the capabilities of this system, UMaine is constructing a 1:50-scale model of the David Taylor Model Basin (DTMB) 5415 to perform commissioning tests. The towing system is planned to be operational in 2018.

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.

CFD Analysis on Similarity Criteria of Hydrodynamic Characteristics for Gravity-Installed Anchors

2019 ◽  
Author(s):  
Jiancai Gao ◽  
Haixiao Liu
Keyword(s):  
Model Testing ◽  
Model Tests ◽  
Similarity Criteria ◽  
Scale Model ◽  
Hydrodynamic Characteristics ◽  
Cfd Analysis ◽  
Cfd Simulations ◽  
Tests Of Gravity ◽  
Free Falling ◽  
Reduced Scale

Abstract For reduced-scale model tests of gravity-installed anchors (GIAs), it is of great significance to extrapolate the testing results to prototype. This highlights the necessity of investigation of similarity criteria. The present work aims to find the similarity criteria of three prioritized hydrodynamic characteristics including VT, HP, and Cd for GIAs during installation in water through CFD simulations. In the present study, free falling processes of different reduced-scale T98 anchor models and prototype anchor is simulated, from which VT, HP, and Cd are extracted and analyzed to get the fitting curves for these three characteristics over reduced-scale λ. Based on these curves, hydrodynamic characteristics for prototype and other reduced-scale model can be extrapolated from model testing results. And, the researching procedure in this paper sets an example and reference to study about similarity criteria for other hydrodynamic characteristics.

Recycle of resin-based analogue material for geo-mechanical model test

2018 ◽  
Vol 37 (2) ◽  
pp. 142-148
Author(s):  
Fan Pengxian ◽  
Wang Jiabo ◽  
Shi Yehui ◽  
Wang Derong ◽  
Tan Jinzhong ◽  
...  
Keyword(s):  
Model Test ◽  
Mechanical Model ◽  
Large Scale ◽  
Economic Benefits ◽  
Model Tests ◽  
Scale Model ◽  
Large Scale Model ◽  
Cyclic Utilization ◽  
The Cost ◽  
Recycled Material

Analogue materials are widely used to simulate prototype rocks in geo-mechanical model tests. The large amounts of solid waste generated by a large-scale model test has always posed problems for studies. The re-use of analogue materials can significantly reduce the cost of geo-mechanical model tests and the resulting environmental problems. However, despite the environmental and economic benefits, there have been few reports on the re-use of analogue materials. In this work, a recycling method for a resin-based analogue material is studied experimentally. More than 300 samples were prepared and tested. By adding a certain amount of resin in solution form to the recycled material, regenerated samples with properties consistent with those of the samples prior to recycling were obtained. Based on a comparative analysis of the test data, an equation is proposed for the calculation of the appropriate amount of resin addition in the recycling process. Thus, a simple and effective recycling method is established for a resin-based analogue material. Verification was performed by independent tests on three group samples with different proportions, and the possibility of repeated recycling was also confirmed. The proposed recycling method makes the cyclic utilization of resin-based analogue material possible and is helpful for reducing the cost and pollution of geo-mechanical model tests.

Pipeline plough performance in sand waves. Part 1: model testing

2010 ◽  
Vol 47 (1) ◽  
pp. 49-64 ◽  
Author(s):  
Mark Fraser Bransby ◽  
Michael Brown ◽  
Andrew Hatherley ◽  
Keith Lauder
Keyword(s):  
Model Testing ◽  
Model Tests ◽  
Scale Model ◽  
Soil Conditions ◽  
Small Scale ◽  
Offshore Pipelines ◽  
Sand Waves ◽  
Increased Risk ◽  
Small Scale Model ◽  
Spoil Heaps

Offshore pipelines are often buried in the seabed by ploughing a trench, placing the pipe at the base, and then backfilling. The ploughing operation is critical in terms of cost and project time, with increased risk due to uncertain soil conditions or geohazards. One problem that can be encountered is the presence of sand waves or megaripples on the seabed surface. This may affect the progress of the plough, prevent the plough from generating a level trench or modify the size of the spoil heaps for backfilling. These aspects have been investigated by conducting a series of small-scale model tests in the laboratory. These have revealed information about the plough kinematics and the resulting trench conditions when ploughing in sand waves with different wavelengths and amplitudes. It is shown that it may be possible to plough through regions of sand waves and estimate likely plough performance by knowing the sand wavelength and amplitude relative to the plough size.

Model Testing for Vortex Induced Motions of Spar Platforms

2004 ◽  
Author(s):  
Mehernosh Irani ◽  
Lyle Finn
Keyword(s):  
Gulf Of Mexico ◽  
Model Test ◽  
State Of The Art ◽  
Model Testing ◽  
Model Tests ◽  
The State ◽  
Test Results ◽  
Test Set ◽  
Vortex Induced Vibrations ◽  
Set Up

The state-of-the art in model testing for Vortex Induced Vibrations (VIV) of Spars is presented. Important issues related to Spar VIV model testing are highlighted. The parameters that need to be modeled including hull geometry, strake configuration, mass and mooring properties and, considerations of test set-up and instrumentation are discussed. Results are presented from model tests of an as-built Spar deployed in the Gulf of Mexico. It is shown that the model test results compare well with the VIV responses measured in the field.

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

2012 ◽  
Author(s):  
Heather R. Martin ◽  
Richard W. Kimball ◽  
Anthony M. Viselli ◽  
Andrew J. Goupee
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Model Testing ◽  
Full Scale ◽  
Scale Model ◽  
Horizontal Axis Wind Turbine ◽  
Wind Turbine Aerodynamics ◽  
Floating Wind Turbine ◽  
Floating Offshore Wind Turbines ◽  
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 model validation. As the development of floating wind turbine technology progresses in order to capture the vast deepwater 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 one to accurately simulate 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 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 MARIN’s (Maritime Research Institute Netherlands) Offshore Basin which tested the 126 m rotor diameter NREL (National Renewable Energy Lab) horizontal axis wind turbine atop three floating platforms: a tension-leg platform, a spar-buoy and a semi-submersible. The results demonstrate the methodology’s ability to adequately simulate full scale global response of floating wind turbine systems.

Hybrid Model Tests for Floating Offshore Wind Turbines

2019 ◽  
Author(s):  
Maxime Thys ◽  
Alessandro Fontanella ◽  
Federico Taruffi ◽  
Marco Belloli ◽  
Petter Andreas Berthelsen
Keyword(s):  
Wind Tunnel ◽  
Real Time ◽  
Hybrid Model ◽  
Wind Turbines ◽  
Ocean Basin ◽  
Model Testing ◽  
Model Tests ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines

Abstract Model testing of offshore structures has been standard practice over the years and is often recommended in guidelines and required in certification rules. The standard objectives for model testing are final concept verification, where it is recommended to model the system as closely as possible, and numerical code calibration. Model testing of floating offshore wind turbines is complex due to the response depending on the aero-hydro-servo-elastic system, but also due to difficulties to perform model tests in a hydrodynamic facility with correctly scaled hydrodynamic, aerodynamic and inertial loads. The main limitations are due to the Froude-Reynolds scaling incompatibility, and the wind generation. An approach to solve these issues is by use of hybrid testing where the system is divided in a numerical and a physical substructure, interacting in real-time with each other. Depending on the objectives of the model tests, parts of a physical model of a FOWT can then be placed in a wind tunnel or an ocean basin, where the rest of the system is simulated. In the EU H2020 LIFES50+ project, hybrid model tests were performed in the wind tunnel at Politecnico di Milano, as well as in the ocean basin at SINTEF Ocean. The model tests in the wind tunnel were performed with a physical wind turbine positioned on top of a 6DOF position-controlled actuator, while the hydrodynamic loads and the motions of the support structure were simulated in real-time. For the tests in the ocean basin, a physical floater with tower subject to waves and current was used, while the simulated rotor loads were applied on the model by use of a force actuation system. The tests in both facilities are compared and recommendations on how to combine testing methodologies in an optimal way are discussed.

scholarly journals Scale-model test for disposal pit of high-level radioactive waste and theoretical evaluation of self-sealing of bentonite-based buffers

2020 ◽  
Vol 57 (4) ◽  
pp. 608-615
Author(s):  
Hideo Komine
Keyword(s):  
Radioactive Waste ◽  
Model Test ◽  
Experimental Work ◽  
Model Tests ◽  
Interstitial Space ◽  
Scale Model ◽  
Theoretical Evaluation ◽  
High Level Radioactive Waste ◽  
High Level

Bentonite is attracting greater attention in Japan and some other countries as a buffer for use in repositories of high-level radioactive waste (HLW). Bentonite-based buffers for HLW disposal are expected, because of their swelling deformation, to fill spaces between buffers and walls of disposal pits or between buffers and waste containers designated as overpack. Bentonite has a self-sealing capability. This study conducts scale-model tests simulating the relation between the buffer and interstitial space. It also investigates the validity of theoretical equations for swelling presented by Komine and Ogata (published in 2003 and 2004) to evaluate buffer self-sealing capabilities by comparing calculated and experimentally obtained results of scale-model tests. Results of the experimental work and calculations described herein highlight bentonite’s self-sealing capability and demonstrate the high applicability of these Komine and Ogata equations to quantify filling of interstitial spaces by bentonite-based buffer swelling.

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