Long-Term Global Performance Analysis of a Vertical-Axis Wind Turbine Supported on a Semi-Submersible Floating Platform

2015 ◽  
Author(s):  
Michael Borg ◽  
Lance Manuel ◽  
Maurizio Collu ◽  
Jinsong Liu
Keyword(s):  
Wind Turbine ◽  
Wind Wave ◽  
Vertical Axis ◽  
Design Tool ◽  
Vertical Axis Wind Turbine ◽  
Floating Platform ◽  
Short Term ◽  
Dynamics Simulations ◽  
The Eu

This study examines the long-term reliability analysis of a floating vertical axis wind turbine (VAWT) situated off the Portuguese coast in the Atlantic Ocean. The VAWT, which consists of a 5-MW 3-bladed H-type rotor developed as part of the EU-FP7 H2OCEAN project, is assumed to be mounted on the OC4 semi-submersible floating platform. Given metocean conditions characterizing the selected turbine site, a number of sea states are identified for which coupled dynamics simulations are carried out using the FloVAWT design tool. Short-term turbine load and platform motion statistics are established for individual sea states that are analysed. The long-term reliability yields estimates of 50-year loads and platform motions that takes into consideration response statistics from the simulations as well as the metocean (wind-wave) data and distributions. Results can be used to guide future floating VAWT designs.

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).

Metaheuristic Optimization of Dual-Element Vertical Axis Wind Turbine Using Genetic Algorithm

2019 ◽  
Author(s):  
Sushrut Kumar ◽  
Priyam Gupta ◽  
Raj Kumar Singh
Keyword(s):  
Genetic Algorithm ◽  
Wind Turbine ◽  
Optimization Technique ◽  
Vertical Axis ◽  
Single Element ◽  
Vertical Axis Wind Turbine ◽  
Invasive Weed ◽  
Metaheuristic Optimization ◽  
Attached Flow ◽  
Dynamics Simulations

Abstract This paper presents a framework for the optimization of Dual-Element Vertical Axis Wind Turbine (VAWT) Blade configurations for improvement in power generation. Multi-element nature of the turbine was specifically chosen as this configuration offers better-attached flow over a conventional single element H-type turbine. The framework was based on a genetic evolutionary algorithm which is a metaheuristic optimization technique based on the principle of survival of the fittest. The class of genetic algorithm used was Invasive Weed Optimization. The geometry of the turbine consists of a rotor with three sets of dual-element airfoil oriented symmetrically. Effective chord length and relative chord angle were taken as modifying parameters for generating new configurations. The fitness of each individual was evaluated by performing two-dimensional Computational Fluid Dynamics Simulations. OpenFOAM was used for performing numerical simulations. Qualitative data of torque, pressure, velocity, and turbulence kinetic energy of best configuration is shown. A considerable increase in torque in the final geometry. The model was found ideal for optimizing multi-element VAWT configuration.

A New Structure for Low Speed Wind Turbine in Built-Up Areas

2013 ◽  
Vol 860-863 ◽  
pp. 314-318
Author(s):  
Feng Ji ◽  
Xiao Jian Feng ◽  
Dong Liang Wang
Keyword(s):  
Growth Rate ◽  
Wind Turbine ◽  
Wind Velocity ◽  
Wind Turbines ◽  
Residential Building ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Low Speed

Traditional wind turbines are difficulty to work well in built-up areas due to wind conditions of low speed, turbulence and frequent changing direction. A long-term wind observation work has been done to understand the characteristics of urban wind by installing a small weather station on the balcony at top floor of a residential building. Based on the observation results, a new structure for low speed wind turbine in built-up areas was designed. This structure can be used for either horizontal axis wind turbine or vertical axis wind turbine. Some mesh models were established to simulate the effect through CFD software. In this structure, growth rate of wind velocity is about 1.25 times; wind turbulence converts to laminar; and yawing angel of turbine motor shafts neednt change any more. Prototype testing draws better conclusions: growth rate of wind velocity is more than 1.4 times. Therefore, traditional wind turbines can work well in built-up areas through this new structure.

Long-Term Stochastic Dynamic Analysis of a Combined Floating Spar-Type Wind Turbine and Wave Energy Converter (STC) System for Mooring Fatigue Damage and Power Prediction

2014 ◽  
Author(s):  
Nianxin Ren ◽  
Zhen Gao ◽  
Torgeir Moan
Keyword(s):  
Wind Turbine ◽  
Fatigue Damage ◽  
Wave Energy ◽  
Wind Wave ◽  
Wave Energy Converter ◽  
Force Model ◽  
Stochastic Dynamic ◽  
Energy Converter ◽  
Short Term

In this work, a combined concept called Spar-Toru-Combination (STC) involving a spar-type floating wind turbine (FWT) and an axi-symmetric two-body wave energy converter (WEC) is considered. From the views of both long-term fatigue damage prediction of the mooring lines and the annual energy production estimation, a coupled analysis of wind-wave induced long-term stochastic responses has been performed using the SIMO-TDHMILL code in the time domain, which includes 79200 one-hour short term cases (the combination of 22 selected mean wind speeds * 15 selected significant wave heights * 12 selected spectral peak wave periods * 20 random seeds). The hydrodynamic loads on the Spar and Torus are estimated using potential theory, while the aerodynamic loads on the wind rotor are calculated by the validated simplified thrust force model in the TDHMILL code. Considering the long-term wind-wave joint distribution in the northern North Sea, the annual fatigue damage of the mooring line for the STC system is obtained by using the S-N curve approach and Palmgren-Miner’s linear damage hypothesis. In addition, the annual wind and wave power productions are also obtained by using hourly mean output power for each short-term condition and the joint wind-wave distribution.

scholarly journals Nonlinear Lifting Line Theory Applied to Vertical Axis Wind Turbines: Development of a Practical Design Tool

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
David Marten ◽  
Georgios Pechlivanoglou ◽  
Christian Navid Nayeri ◽  
Christian Oliver Paschereit
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Unsteady Aerodynamics ◽  
Vertical Axis ◽  
Design Tool ◽  
Offshore Wind ◽  
Vertical Axis Wind Turbine ◽  
Floating Structure ◽  
Horizontal Axis Wind Turbine ◽  
Lifting Line

Recently, a new interest in vertical axis wind turbine (VAWT) technology is fueled by research on floating support structures for large-scale offshore wind energy application. For the application on floating structures at multimegawatt size, the VAWT concept may offer distinct advantages over the conventional horizontal axis wind turbine (HAWT) design. As an example, VAWT turbines are better suited for upscaling, and at multimegawatt size, the problem of periodic fatigue cycles reduces significantly due to a very low rotational speed. Additionally, the possibility to store the transmission and electricity generation system at the bottom, compared to the tower top as in a HAWT, can lead to a considerable reduction of material logistics costs. However, as most VAWT research stalled in the mid 1990s, no sophisticated and established tools to investigate this concept further exist today. Due to the complex interaction between unsteady aerodynamics and movement of the floating structure, fully coupled simulation tools modeling both aero and structural dynamics are needed. A nonlinear lifting line free vortex wake (LLFVW) code was recently integrated into the open source wind turbine simulation suite qblade. This paper describes some of the necessary adaptions of the algorithm, which differentiates it from the usual application in HAWT simulations. A focus is set on achieving a high robustness and computational efficiency. A short validation study compares LLFVW results with those of a two-dimensional (2D) unsteady Reynolds-averaged Navier–Stokes (URANS) simulation.

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.

Model Test of a Novel Floating Vertical-Axis Wind Turbine Under Wind and Wave Joint Loads

2021 ◽  
Author(s):  
Hua-Dong Zheng ◽  
Xiang Yuan Zheng ◽  
Yu Lei
Keyword(s):  
Wind Turbine ◽  
Wind Wave ◽  
Dynamic Performance ◽  
Low Frequency ◽  
Vertical Axis ◽  
Ocean Basin ◽  
Physical Models ◽  
Dynamic Responses ◽  
Vertical Axis Wind Turbine ◽  
Joint Loads

Abstract Recently a floating vertical-axis wind turbine (VAWT) concept that integrates a VAWT with a steel fishing cage has been developed by leading authors. In order to fathom the kinetic characteristics and performance of this floater under wind and wave joint loads, a series of model tests have been carried out in the ocean basin located at Tsinghua Shenzhen International Graduate School. The wind generation system of this facility allows turbulent wind to be produced such that examination of wind-wave joint actions can be extended to a number of stochastic scenarios. With a scale of 1/40th, the physical models of the floating VAWT and the platform of a steel fishing cage are introduced first. Details are also given to instrumentations and measurement methods. Then, thrust-wind speed tests, free-decay tests, and basin wind-wave tests are respectively carried out to probe the primary dynamic performance of the floating system. The second-order hydrodynamic effects are observed in tests, but they play a secondary role in the response of VAWTs as compared to aerodynamic effects. The aerodynamic loads can induce the obvious low-frequency response at surge and pitch eigen-frequencies, while for heave motion response its contribution is smaller. Additionally, test results reveal that third-per-revolution (3P) effects are insignificant in the platform’s surge, pitch and heave dynamic responses.

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