Design and Aero-Elastic Simulation of a 5MW Floating Vertical Axis Wind Turbine

2012 ◽  
Author(s):  
Luca Vita ◽  
Uwe S. Paulsen ◽  
Helge A. Madsen ◽  
Per H. Nielsen ◽  
Petter A. Berthelsen ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Waves ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
The European Union ◽  
Vertical Axis Wind Turbine ◽  
Floating Platform ◽  
Mooring Lines ◽  
Sea Bed

This paper deals with the design of a 5MW floating offshore Vertical Axis Wind Turbine (VAWT). The design is based on a new offshore wind turbine concept (DeepWind concept), consisting of a Darrieus rotor mounted on a spar buoy support structure, which is anchored to the sea bed with mooring lines [1]. The design is carried out in an iterative process, involving the different sub-components and addressing several conflicting constraints. The present design does not aim to be the final optimum solution for this concept. Instead, the goal is to have a baseline model, based on the present technology, which can be improved in the future with new dedicated technological solutions. The rotor uses curved blades, which are designed in order to minimize the gravitational loads and to be produced by the pultrusion process. The floating platform is a slender cylindrical structure rotating along with the rotor, whose stability is achieved by adding ballast at the bottom. The platform is connected to the mooring lines with some rigid arms, which are necessary to absorb the torque transmitted by the rotor. The aero-elastic simulations are carried out with Hawc2, a numerical solver developed at Risø-DTU. The numerical simulations take into account the fully coupled aerodynamic and hydrodynamic loads on the structure, due to wind, waves and currents. The turbine is tested in operative conditions, at different sea states, selected according to the international offshore standards. The research is part of the European project DeepWind (2010–2014), which has been financed by the European Union (FP7-Future Emerging Technologies).

scholarly journals On mooring line tension and fatigue prediction for offshore vertical axis wind turbines: A comparison of lumped mass and quasi-static approaches

2018 ◽  
Vol 42 (2) ◽  
pp. 97-107 ◽  
Author(s):  
D Cevasco ◽  
M Collu ◽  
CM Rizzo ◽  
M Hall
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Line Tension ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Vertical Axis Wind Turbine ◽  
Lumped Mass ◽  
Vertical Axis Wind Turbines

Despite several potential advantages, relatively few studies and design support tools have been developed for floating vertical axis wind turbines. Due to the substantial aerodynamics differences, the analyses of vertical axis wind turbine on floating structures cannot be easily extended from what have been already done for horizontal axis wind turbines. Therefore, the main aim of the present work is to compare the dynamic response of the floating offshore wind turbine system adopting two different mooring dynamics approaches. Two versions of the in-house aero-hydro-mooring coupled model of dynamics for floating vertical axis wind turbine (FloVAWT) have been used, employing a mooring quasi-static model, which solves the equations using an energetic approach, and a modified version of floating vertical axis wind turbine, which instead couples with the lumped mass mooring line model MoorDyn. The results, in terms of mooring line tension, fatigue and response in frequency have been obtained and analysed, based on a 5 MW Darrieus type rotor supported by the OC4-DeepCwind semisubmersible.

scholarly journals Alternative Mooring Systems for a Very Large Offshore Wind Turbine Supported by a Semisubmersible Floating Platform

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Jinsong Liu ◽  
Lance Manuel
Keyword(s):  
Wind Turbine ◽  
Integrated System ◽  
Offshore Wind ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
System Response ◽  
Mooring System ◽  
Floating Platform ◽  
Mooring Lines ◽  
Wind Speeds

As offshore wind turbines supported on floating platforms extend to deep waters, the various effects involved in the dynamics, especially those resulting from the influence of moorings, become significant when predicting the overall integrated system response. The combined influence of waves and wind affect motions of the structure and induce tensile forces in mooring lines. The investigation of the system response under misaligned wind-wave conditions and the selection of appropriate mooring systems to minimize the turbine, tower, and mooring system loads is the subject of this study. We estimate the 50-year return response of a semisubmersible platform supporting a 13.2 MW wind turbine as well as mooring line forces when the system is exposed to four different wave headings with various environmental conditions (wind speeds and wave heights). Three different mooring system patterns are presented that include 3 or 6 mooring lines with different interline angles. Performance comparisons of the integrated systems may be used to define an optimal system for the selected large wind turbine.

A Novel Structural Form of Semi-Submersible Platform for a Floating Offshore Wind Turbine with Hydrodynamic Performance Analysis

2013 ◽  
Vol 477-478 ◽  
pp. 109-113
Author(s):  
Bin Bin Lai ◽  
Cheng Bi Zhao ◽  
Xiao Ming Chen ◽  
You Hong Tang ◽  
Wei Lin
Keyword(s):  
Wind Turbine ◽  
Wind Farm ◽  
Wind Waves ◽  
Simulation Method ◽  
Offshore Wind ◽  
Hydrodynamic Performance ◽  
Offshore Wind Turbine ◽  
Structural Form ◽  
Floating Platform ◽  
Floating Offshore Wind Turbine

With the mature of floating offshore wind turbine technology, floating wind farm building in the deep sea becomes an inevitable trend. In the design of floating offshore wind turbine, the change of structural form is the main factor influencing hydrodynamic performance. This research, taking a typical sea condition in China's coastal areas as the object of study, designs a novel semi-submersible foundation for NREL 5 MW offshore wind turbine in 200 m deep water. In the design, deep-draft buoys structures are used to reduce the force of waves on the floating offshore, while damping structures are used to optimize the stability of wind turbine and reduce the heave amplitude. By means of numerical simulation method, the hydrodynamic performance of semi-submersible support is studied. Meanwhile, the response amplitude operators (RAOs) and the wave response motions of platform are calculated. The results in time domain indicate that the floating wind turbine system can keep safe and survive in the harsh sea condition, coupling wind, waves and currents. It is showed that the designed semi-submersible support of platform has excellent hydrodynamic performance. This change of structural form may serve as a reference on the development of offshore wind floating platform.

A New Ballasted Floating Support for Offshore Wind Turbine

2014 ◽  
Author(s):  
Yann Poirette ◽  
Timothée Perdrizet ◽  
Jean Christophe Gilloteaux ◽  
Alice Pourtier ◽  
Claude Mabile
Keyword(s):  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Platform ◽  
Floating Structures ◽  
Marine Energy ◽  
Sea Bed ◽  
Wide Range ◽  
Circular Platform ◽  
Design Options

In the framework of the developments of renewable marine energy and especially offshore wind energy, different design options of floating support have already been presented in the community such as barge-type, spar-type or semi-submersible-type floating structures. In the present paper, a study conducted by IFPEN is presented in order to design of a new floating platform concept dedicated to a multi-megawatt wind turbine. The design of the concept consists in a circular platform ballasted with water and concrete, anchored to the sea bed through a spread mooring system and designed to accommodate a multi-megawatt (in the range of 5 to 8 MW) offshore wind turbine. The paper focuses on the methodology used in the conceptual and preliminary design phases and then on the major results obtained on the performance of the concept for a wide range of design load cases. The results, at current level, show that the concept is viable and interesting, and that the design can be improved further while requiring some additional validation.

scholarly journals ESwift: Smart and Self-Stabilizing Water-Wind Floating Turbine

2019 ◽  
Author(s):  
Minh N. Doan ◽  
Mehdi Badri ◽  
Trung B. Tran ◽  
Yuriko Kai
Keyword(s):  
Vertical Axis ◽  
Construction Cost ◽  
Offshore Wind ◽  
Conceptual System ◽  
Vertical Axis Wind Turbine ◽  
Floating Platform ◽  
Mooring Lines ◽  
Horizontal Axis Wind Turbines ◽  
Marine Hydrokinetic ◽  
Novel Concept

In April 2019, a team of Keio University and Bucknell University students was assembled to participate in Ericsson Innovation Awards with a novel concept for generating renewable energy. This conceptual system consists of a vertical axis wind turbine, a crossflow marine hydrokinetic turbine, a floating platform integrated with a quadcopter system, and three to four temporary mooring lines with ship-type anchors. The proposed designed aims to offer solutions to two current problems of floating offshore wind energy: high construction cost of floating platforms and difficulties in maintenance of mooring lines. The combination of two vertical-axis turbines into a single floating platform would enable the system, namely ESwift, to extract energy from both wind and current resources. Additionally, due to the utilization of vertical axis turbines, the center of gravity of the proposed concept is significantly lower with respect to water level, compared to that of existing floating horizontal axis wind turbines, which would potentially reduce the floater's size and construction cost. Lastly, the integrated quadcopter mechanism would assist the floater in terms of stability and mobility, and enables an array of ESwifts to automatically rearrange for maximal energy generation. The authors hope that readers would find the idea described in this open access letter worth pursuing and would further develop and commercialize the ESwift concept.

A Method for Modeling of Floating Vertical Axis Wind Turbine

2013 ◽  
Author(s):  
Kai Wang ◽  
Torgeir Moan ◽  
Martin Otto Laver Hansen
Keyword(s):  
Wind Turbine ◽  
Dynamic Equilibrium ◽  
Vertical Axis ◽  
Economic Feasibility ◽  
Vertical Axis Wind Turbine ◽  
Floating Platform ◽  
Time Step ◽  
Mooring Lines ◽  
Platform Motion ◽  
Novel Concept

It is of interest to investigate the potential advantages of floating vertical axis wind turbine (FVAWT) due to its economical installation and maintenance. A novel 5MW vertical axis wind turbine concept with a Darrieus rotor mounted on a semi-submersible support structure is proposed in this paper. In order to assess the technical and economic feasibility of this novel concept, a comprehensive simulation tool for modeling of the floating vertical axis wind turbine is needed. This work presents the development of a coupled method for modeling of the dynamics of a floating vertical axis wind turbine. This integrated dynamic model takes into account the wind inflow, aerodynamics, hydrodynamics, structural dynamics (wind turbine, floating platform and the mooring lines) and a generator control. This approach calculates dynamic equilibrium at each time step and takes account of the interaction between the rotor dynamics, platform motion and mooring dynamics. Verification of this method is made through model-to-model comparisons. Finally, some dynamic response results for the platform motion are presented as an example for application of this method.

Three-dimensional computational fluid dynamic analysis of a large-scale vertical axis wind turbine

2021 ◽  
pp. 0309524X2110379
Author(s):  
Brian Hand
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Speed Ratio ◽  
Offshore Wind Turbine ◽  
Vertical Axis Wind Turbine ◽  
Computational Fluid Dynamics Analysis ◽  
Torque Coefficient

The vertical axis wind turbine (VAWT) configuration has many advantages for an offshore wind turbine Installation. In this paper, the three dimensional (3D) computational fluid dynamics analysis of a large-scale 5 MW VAWT is conducted. At the optimum tip-speed ratio (TSR), the VAWT maximum inline force was 75% larger than the maximum lateral force. It was found the dynamic stall effects cause the VAWT flow field to become increasingly asymmetrical at the mid-span plane, when the TSR is reduced. The attachment of end plates to the blade tips, resulted in a performance improvement during the upwind phase with the average blade torque coefficient in this range being increased by 4.71%. Conversely, during the blade downwind phase a reduction in performance was found due to the increase in drag from the end plates and the average blade torque coefficient in this phase was reduced by 23.1%.

Conceptual Design of a Floating Support Structure and Mooring System for a Vertical Axis Wind Turbine

2012 ◽  
Author(s):  
Petter Andreas Berthelsen ◽  
Ivar Fylling ◽  
Luca Vita ◽  
Uwe S. Paulsen
Keyword(s):  
Wind Turbine ◽  
Conceptual Design ◽  
Optimization Problems ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Mooring System ◽  
Vertical Axis Wind Turbine ◽  
Support Structure

This paper deals with the conceptual design of a floating support structure and mooring system for a 5MW vertical axis offshore wind turbine. The work is carried out as part of the DeepWind project, where the main objective is to investigate the feasibility of a floating vertical axis offshore wind turbine. The DeepWind concept consists of a Darrieus rotor mounted on a spar buoy support structure. The conceptual design is carried out in an iterative process, involving the different subcomponents. The present work is part of the first design iteration and the objective is to find a feasible floating support structure and mooring system for the DeepWind concept. The conceptual design is formulated as an optimization problem: Starting with an initial configuration, the optimization procedure tries to find a cheaper solution while satisfying a set of design requirements. This approach utilizes available response analysis programs for mooring system forces and vessel motions, and combines this with a gradient search method for solution of nonlinear optimization problems with arbitrary constraints. Two different mooring system configurations are considered: Chain systems with 3 and 6 lines, respectively.

scholarly journals Physical Modelling of Offshore Wind Turbine Foundations for TRL (Technology Readiness Level) Studies

2021 ◽  
Vol 9 (6) ◽  
pp. 589
Author(s):  
Subhamoy Bhattacharya ◽  
Domenico Lombardi ◽  
Sadra Amani ◽  
Muhammad Aleem ◽  
Ganga Prakhya ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Prior Experience ◽  
Physical Modelling ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Foundation Design ◽  
Offshore Wind Turbines ◽  
Sea Bed ◽  
Geological Conditions

Offshore wind turbines are a complex, dynamically sensitive structure due to their irregular mass and stiffness distribution, and complexity of the loading conditions they need to withstand. There are other challenges in particular locations such as typhoons, hurricanes, earthquakes, sea-bed currents, and tsunami. Because offshore wind turbines have stringent Serviceability Limit State (SLS) requirements and need to be installed in variable and often complex ground conditions, their foundation design is challenging. Foundation design must be robust due to the enormous cost of retrofitting in a challenging environment should any problem occur during the design lifetime. Traditionally, engineers use conventional types of foundation systems, such as shallow gravity-based foundations (GBF), suction caissons, or slender piles or monopiles, based on prior experience with designing such foundations for the oil and gas industry. For offshore wind turbines, however, new types of foundations are being considered for which neither prior experience nor guidelines exist. One of the major challenges is to develop a method to de-risk the life cycle of offshore wind turbines in diverse metocean and geological conditions. The paper, therefore, has the following aims: (a) provide an overview of the complexities and the common SLS performance requirements for offshore wind turbine; (b) discuss the use of physical modelling for verification and validation of innovative design concepts, taking into account all possible angles to de-risk the project; and (c) provide examples of applications in scaled model tests.

Coupled Dynamic Analysis for Multi-Unit Floating Offshore Wind Turbine in Maximum Operational and Survival Conditions

2015 ◽  
Author(s):  
H. K. Jang ◽  
H. C. Kim ◽  
M. H. Kim ◽  
K. H. Kim
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Time Domain ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Random Waves ◽  
Mooring Lines ◽  
Floating Offshore Wind Turbine ◽  
Coupled Dynamic Analysis ◽  
Floating Offshore Wind Turbines

Numerical tools for a single floating offshore wind turbine (FOWT) have been developed by a number of researchers, while the investigation of multi-unit floating offshore wind turbines (MUFOWT) has rarely been performed. Recently, a numerical simulator was developed by TAMU to analyze the coupled dynamics of MUFOWT including multi-rotor-floater-mooring coupled effects. In the present study, the behavior of MUFOWT in time domain is described through the comparison of two load cases in maximum operational and survival conditions. A semi-submersible floater with four 2MW wind turbines, moored by eight mooring lines is selected as an example. The combination of irregular random waves, steady currents and dynamic turbulent winds are applied as environmental loads. As a result, the global motion and kinetic responses of the system are assessed in time domain. Kane’s dynamic theory is employed to formulate the global coupled dynamic equation of the whole system. The coupling terms are carefully considered to address the interactions among multiple turbines. This newly developed tool will be helpful in the future to evaluate the performance of MUFOWT under diverse environmental scenarios. In the present study, the aerodynamic interactions among multiple turbines including wake/array effect are not considered due to the complexity and uncertainty.

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