A Comparison of Two Coupled Model of Dynamics for Offshore Floating Vertical Axis Wind Turbines (VAWT)

2014 ◽  
Author(s):  
Michael Borg ◽  
Kai Wang ◽  
Maurizio Collu ◽  
Torgeir Moan
Keyword(s):  
Wind Turbines ◽  
Coupled Model ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Design Codes ◽  
Vertical Axis Wind Turbines ◽  
Complex Simulation ◽  
Floating Offshore Wind Turbines ◽  
Horizontal Axis Wind Turbines ◽  
Engineering Models

As part of the deployment of floating offshore wind turbines (FOWTs) in deep sea, robust coupled dynamic design codes based on engineering models are being developed to investigate the behaviour of FOWTs in the offshore environment. The recent re-emerging interest in vertical axis wind turbines (VAWTs) for floating foundation applications has resulted in a number of design codes being developed concurrently by different researchers. In this study, two such design codes for floating VAWTs developed at Cranfield University and the Norwegian University of Science and Technology are compared through a series of increasingly complex simulation load cases. A floating VAWT design was specified to be used in this study. The rotor is based on the Darrieus Troposkein shape and is the same used within the DeepWind VAWT spar concept, with a 5MW rated capacity. The floating support structure is a semi-submersible that is being used in the Offshore Code Collaboration Continuation (OC4) Phase II project for floating horizontal axis wind turbines. A series of load cases were set out to assess and compare the two different design codes. A comparison of the performance of the two design tools is presented, illustrating their level of maturity and areas of improvement.

Optimal Placement of Horizontal- and Vertical-Axis Wind Turbines in a Wind Farm for Maximum Power Generation Using a Genetic Algorithm

2011 ◽  
Author(s):  
Xiaomin Chen ◽  
Ramesh Agarwal
Keyword(s):  
Genetic Algorithm ◽  
Wind Turbines ◽  
Wind Farm ◽  
Optimization Problem ◽  
Vertical Axis ◽  
Optimal Placement ◽  
Vertical Axis Wind Turbines ◽  
Wake Effects ◽  
Horizontal Axis Wind Turbines ◽  
Wake Model

In this paper, we consider the Wind Farm layout optimization problem using a genetic algorithm. Both the Horizontal–Axis Wind Turbines (HAWT) and Vertical-Axis Wind Turbines (VAWT) are considered. The goal of the optimization problem is to optimally place the turbines within the wind farm such that the wake effects are minimized and the power production is maximized. The reasonably accurate modeling of the turbine wake is critical in determination of the optimal layout of the turbines and the power generated. For HAWT, two wake models are considered; both are found to give similar answers. For VAWT, a very simple wake model is employed.

Vertical axis wind turbine operation in icing conditions: A review study

2021 ◽  
pp. 0309524X2110618
Author(s):  
Syed Abdur Rahman Tahir ◽  
Muhammad Shakeel Virk
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Electricity Production ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
Horizontal Axis Wind Turbines ◽  
Promising Solution ◽  
Review Study ◽  
Accretion Physics

Vertical Axis Wind Turbine (VAWT) can be a promising solution for electricity production in remote ice prone territories of high north, where good wind resources are available, but icing is a challenge that can affect its optimum operation. A lot of research has been made to study the icing effects on the conventional horizontal axis wind turbines, but the literature about vertical axis wind turbines operating in icing conditions is still scarce, despite the importance of this topic. This paper presents a review study about existing knowledge of VAWT operation in icing condition. Focus has been made in better understanding of ice accretion physics along VAWT blades and methods to detect and mitigate icing effects.

scholarly journals Design and Testing of a LUT Airfoil for Straight-Bladed Vertical Axis Wind Turbines

2018 ◽  
Vol 8 (11) ◽  
pp. 2266 ◽  
Author(s):  
Shoutu Li ◽  
Ye Li ◽  
Congxin Yang ◽  
Xuyao Zhang ◽  
Qing Wang ◽  
...  
Keyword(s):  
Wind Turbines ◽  
Lift Coefficient ◽  
Pressure Coefficient ◽  
Vertical Axis ◽  
Reynolds Numbers ◽  
Optimization Method ◽  
Geometrical Parameters ◽  
Vertical Axis Wind Turbines ◽  
University Of Technology ◽  
Horizontal Axis Wind Turbines

The airfoil plays an important role in improving the performance of wind turbines. However, there is less research dedicated to the airfoils for Vertical Axis Wind Turbines (VAWTs) compared to the research on Horizontal Axis Wind Turbines (HAWTs). With the objective of maximizing the aerodynamic performance of the airfoil by optimizing its geometrical parameters and by considering the law of motion of VAWTs, a new airfoil, designated the LUT airfoil (Lanzhou University of Technology), was designed for lift-driven VAWTs by employing the sequential quadratic programming optimization method. Afterwards, the pressure on the surface of the airfoil and the flow velocity were measured in steady conditions by employing wind tunnel experiments and particle image velocimetry technology. Then, the distribution of the pressure coefficient and aerodynamic loads were analyzed for the LUT airfoil under free transition. The results show that the LUT airfoil has a moderate thickness (20.77%) and moderate camber (1.11%). Moreover, compared to the airfoils commonly used for VAWTs, the LUT airfoil, with a wide drag bucket and gentle stall performance, achieves a higher maximum lift coefficient and lift–drag ratios at the Reynolds numbers 3 × 105 and 5 × 105.

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.

FloVAWT: Progress on the Development of a Coupled Model of Dynamics for Floating Offshore Vertical Axis Wind Turbines

2013 ◽  
Author(s):  
Maurizio Collu ◽  
Michael Borg ◽  
Andrew Shires ◽  
Feargal P. Brennan
Keyword(s):  
Experimental Data ◽  
Wind Turbines ◽  
Three Dimensional ◽  
Coupled Model ◽  
Vertical Axis ◽  
Potential Method ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
Wind Profiles ◽  
Gyroscopic Effects

In the present article, progress on the development of an aero-hydro-servo-elastic coupled model of dynamics for floating Vertical Axis Wind Turbines (VAWTs) is presented, called FloVAWT (Floating Vertical Axis Wind Turbine). Aerodynamics is based on Paraschivoiu’s Double-Multiple Streamtube (DMST) model [1] [2], relying on blade element momentum (BEM) theory, but also taking into account three-dimensional effects, dynamic stall, and unsteady wind profiles and platform motions. Hydrodynamics is modelled with a time domain seakeeping model [3], based on hydrodynamic coefficients estimated with a frequency analysis potential method. In this first phase of the research program, the system is considered a rigid body. The mooring system is represented through a user defined force-displacement relationship. Due to the lack of experimental data on offshore floating VAWTs, the model has initially been validated by taking each module separately and comparing it against known experimental data, showing good agreement. The capabilities of the program are illustrated through a case study, giving an insight on the relative importance of aerodynamics loads and gyroscopic effects with respect to hydrodynamic load effects.

STATE OF THE ART OF SMALL WIND ENERGY ANALYSING DIFFERENT CONTROLS

10.6036/10376 ◽  
2022 ◽  
Vol 97 (1) ◽  
pp. 11-11
Author(s):  
MARLON GALLO TORRES ◽  
ENEKO MOLA SANZ ◽  
IGNACIO MUGURUZA FERNANDEZ DE VALDERRAMA ◽  
AITZOL UGARTEMENDIA ITURRIZAR ◽  
GONZALO ABAD BIAIN ◽  
...  
Keyword(s):  
Wind Turbines ◽  
State Of The Art ◽  
Vertical Axis ◽  
Energy Conversion Efficiency ◽  
Horizontal Axis ◽  
Prevailing Wind ◽  
Vertical Axis Wind Turbines ◽  
Axis Of Rotation ◽  
Horizontal Axis Wind Turbines ◽  
Installation Cost

There are two wind turbine topologies according to the axis of rotation: horizontal axis, "Horizontal Axis Wind Turbines" (HAWT) and vertical axis, "Vertical Axis Wind Turbines" (VAWT) [2]. HAWT turbines are used for high power generation as they have a higher energy conversion efficiency [2]. However, VAWTs are used in mini wind applications because they do not need to be oriented to the prevailing wind and have lower installation cost.

scholarly journals Aerodynamic Simulations for Floating Darrieus-Type Wind Turbines with Three-Stage Rotors

Inventions ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 18
Author(s):  
Mohamed Amine Dabachi ◽  
Abdellatif Rahmouni ◽  
Eugen Rusu ◽  
Otmane Bouksour
Keyword(s):  
Wind Energy ◽  
Wind Turbines ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Cost Effective ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Critical Parameters ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbines

Growing energy demand is causing a significant decrease in the world’s hydrocarbon stock in addition to the pollution of our ecosystem. Based on this observation, the search for alternative sorts of energy to fossil fuels is being increasingly explored and exploited. Wind energy is experiencing a very important development, and it offers a very profitable opportunity for exploitation since the wind is always available and inexhaustible. Several technical solutions exist to exploit wind energy, such as floating vertical axis wind turbines (F-VAWTs), which provide an attractive and cost-effective solution for exploiting higher resources of offshore wind in deep water areas. Recently, the use of the Darrieus vertical axis wind turbine (VAWT) offshore has attracted increased interest because it offers significant advantages over horizontal axis wind turbines (HAWTs). In this context, this article presents a new concept of floating Darrieus-type straight-bladed turbine with three-stage rotors. A double-multiple stream tube (DMST) model is used for aerodynamic simulations to examine several critical parameters, including, solidity turbine, number of blades, rotor radius, aspect ratio, wind velocity, and rotor height. This study also allows to identify a low solidity turbine (σ = 0.3), offering the best aerodynamic performance, while a two-bladed design is recommended. Moreover, the results also indicate the interest of a variable radius rotor, as well as the variation of the height as a function of the wind speed on the aerodynamic efficiency.

scholarly journals Recent Development in the Design of Wind Deflectors for Vertical Axis Wind Turbine: A Review

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5140
Author(s):  
Altaf Hussain Rajpar ◽  
Imran Ali ◽  
Ahmad E. Eladwi ◽  
Mohamed Bashir Ali Bashir
Keyword(s):  
Wind Turbines ◽  
Vertical Axis ◽  
Optimization Techniques ◽  
Rotor Blades ◽  
Power Coefficient ◽  
Potential Contribution ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
Horizontal Axis Wind Turbines ◽  
Network Costs

Developments in the design of wind turbines with augmentation are advancing around the globe with the goal of generating electricity close to the user in built-up areas. This is certain to help lessen the power generation load as well as distribution and transmission network costs by reducing the distance between the user and the power source. The main objectives driving the development and advancement of vertical-axis wind turbines are increasing the power coefficient and the torque coefficient by optimizing the upstream wind striking on the rotor blades. Unlike horizontal-axis wind turbines, vertical axis turbines generate not only positive torque but also negative torque during operation. The negative torque generated by the returning blade is a key issue for vertical-axis wind turbines (VAWTs) that is counterproductive. Installation of wind deflectors for flow augmentation helps to reduce the negative torque generated by the returning blades as well as enhance the positive torque by creating a diversion in the upstream wind towards the forwarding blade during operation. This paper reviews various designs, experiments, and CFD simulations of wind deflectors reported to date. Optimization techniques for VAWTs incorporating wind deflectors are discussed in detail. The main focus of the review was on the installation position and orientation of the deflectors and their potential contribution to increasing the power coefficient. Topics for future study are suggested in the conclusion section of the paper.

scholarly journals Floating Offshore Vertical Axis Wind Turbines: Opportunities, Challenges and Way Forward

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8000
Author(s):  
Abel Arredondo-Galeana ◽  
Feargal Brennan
Keyword(s):  
Wind Turbines ◽  
Deep Water ◽  
Wind Farm ◽  
Structural Integrity ◽  
Wind Farms ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Small Scale ◽  
Offshore Wind Farms ◽  
Vertical Axis Wind Turbines

The offshore wind sector is expanding to deep water locations through floating platforms. This poses challenges to horizontal axis wind turbines (HAWTs) due to the ever growing size of blades and floating support structures. As such, maintaining the structural integrity and reducing the levelised cost of energy (LCoE) of floating HAWTs seems increasingly difficult. An alternative to these challenges could be found in floating offshore vertical axis wind turbines (VAWTs). It is known that VAWTs have certain advantages over HAWTs, and in fact, some small-scale developers have successfully commercialised their onshore prototypes. In contrast, it remains unknown whether VAWTs can offer an advantage for deep water floating offshore wind farms. Therefore, here we present a multi-criteria review of different aspects of VAWTs to address this question. It is found that wind farm power density and reliability could be decisive factors to make VAWTs a feasible alternative for deep water floating arrays. Finally, we propose a way forward based on the findings of this review.

Experimental Investigation of Overlap and Blockage Effects on Three-Bucket Savonius Rotors

2007 ◽  
Vol 31 (5) ◽  
pp. 363-368 ◽  
Author(s):  
A. Biswas ◽  
R. Gupta ◽  
K.K. Sharma
Keyword(s):  
Wind Turbines ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Experimental Investigations ◽  
Small Scale ◽  
Correction Factors ◽  
Vertical Axis Wind Turbines ◽  
Horizontal Axis Wind Turbines ◽  
Blockage Correction ◽  
Model Rotor

Savonius vertical axis wind turbines (VAWT) have advantages over horizontal axis wind turbines (HAWT), such as simple construction, acceptance of wind from any direction without orientation, self-starting, inexpensive etc. These advantages make it a viable proposition for small-scale applications in developing countries. In spite of the above advantages, VAWT are not gaining popularity mainly because of their poor efficiency. Hence, a three-bucket Savonius model rotor, having 8 cm bucket diameter and 20 cm height, was designed, fabricated, and tested in a sub-sonic wind tunnel. Provisions for variations of ‘blade’ overlap were included. Experiments were conducted for overlap conditions in the range of 16% to 35%. From the experimental investigations, power-coefficients (Cp) were calculated with and without blockage correction factors for tunnel interference. In both analyses, the power-coefficient increased if there was overlap, with an optimum value at 20% overlap of 47% without blockage correction, and 38% with blockage correction.

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