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

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.

Modeling and Numerical Simulation for the Newly Designed Four Cavity Blades Vertical Axis Wind Turbine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.554.536 ◽

2014 ◽

Vol 554 ◽

pp. 536-540

Author(s):

Kadhim Suffer ◽

Ryspek Usubamatov ◽

Ghulam Abdul Quadir ◽

Khairul Azwan Ismail

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Urban Areas ◽

Fluid Dynamic ◽

Turbulence Models ◽

Vertical Axis ◽

The Individual

The last years have proved that Vertical Axis Wind Turbines (VAWTs) are more suitable for urban areas than Horizontal Axis Wind Turbines (HAWTs). To date, very little has been published in this area to assess good performance and lifetime of VAWTs either in open or urban areas. The main goal of this current research is to investigate numerically the aerodynamic performance of a newly designed cavity type vertical axis wind turbine having four blades. In the current new design the power generated depends on the drag force generated by the individual blades and interactions between them in a rotating configuration. For numerical investigation, commercially available computational fluid dynamic CFD software GAMBIT and FLUENT were used. In this numerical analysis the Shear Stress Transport (SST) k-ω turbulence model is used which is better than the other turbulence models available as suggested by some researchers. The computed results show good agreement with published experimental results.

Aerodynamic improvement of Darrieus wind turbine

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/897/1/012001 ◽

2021 ◽

Vol 897 (1) ◽

pp. 012001

Author(s):

Oleg Goman ◽

Andrii Dreus ◽

Anton Rozhkevych ◽

Krystyna Heti

Keyword(s):

Reynolds Number ◽

Wind Turbine ◽

Wind Turbines ◽

Structural Reliability ◽

Vertical Axis ◽

Vertical Wind ◽

Integral Approach ◽

Calculation Algorithm ◽

Abstract Until recently, vertical-axis wind turbines are less extensively developed in wind energetics. At the same time, there are a number of advantages in turbines of such type like their independence from the change of wind direction, lower levels of aerodynamic and infrasound noises, higher structural reliability (compared to horizontal engines), etc. With these advantages, vertical-axis wind turbines demonstrate promising capacities. Inter alia, the productiveness of such turbines can be refined through the aerodynamic improvement of the structure and comprehensive optimization of the rotor geometry. The main purpose of the presented paper is to aerodynamically improve vertical wind turbine in order to increase the efficiency of wind energy conversion into electricity. Within the framework of the classical theory of impulses, this article presents a study of the effect of variation in Reynolds number on the general energy characteristics of a vertical-axis wind turbine with two blades. The integral approach makes it possible to use a single-disk impulse model to determine the main specific indicators of the system. The power factor was calculated based on the obtained value of the shaft torque factor, which in turn was determined by numerically integrating the total torque generated by the wind turbine. To calculate the test problem, we used the classic NACA airfoils: 0012, 0015, 0018 and 0021. The proposed calculation algorithm makes it possible not to indicate the Reynolds number and corresponding aerodynamic coefficients at the beginning of the calculation, but to recalculate it depending on the relative speed, position of the airfoil and the linear speed of the airfoil around the circumference. Proposed modern design techniques can be helpful for optimization of vertical wind turbines.

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

Investigation of vertical axis wind turbine airfoil performance in rain

10.1177/0957650917721776 ◽

2017 ◽

Vol 232 (2) ◽

pp. 181-194 ◽

Cited By ~ 3

Author(s):

Zhenlong Wu ◽

Yihua Cao

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Meteorological Condition ◽

Vertical Axis ◽

Turbine Performance ◽

Practical Design ◽

Wind Turbine Airfoil ◽

Naca 0015

Rainfall is a common meteorological condition that wind turbines may encounter and by which their performance may be affected. This paper comprehensively investigates the effects of rainfall on a NACA 0015 airfoil which is commonly used in vertical axis wind turbines. A CFD-based Eulerian–Lagrangian multiphase approach is proposed to study the static, rotating, and oscillating performances of the NACA 0015 airfoil in rainy conditions. It is found that for the different airfoil movements, the airfoil performance can seriously be deteriorated in the rain condition. Rain also causes premature boundary layer separations and more severe flow recirculations than in the dry condition. These findings seem to be the first open reports on rain effects on wind turbine performance and should be of some significance to practical design.

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

Wind Engineering ◽

10.1177/0309524x18756962 ◽

2018 ◽

Vol 42 (2) ◽

pp. 97-107 ◽

Cited By ~ 1

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 ◽

Lumped Mass ◽

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.

An experimental study of the optimal design parameters of a wind power tower used to improve the performance of vertical axis wind turbines

Advances in Mechanical Engineering ◽

10.1177/1687814018799543 ◽

2018 ◽

Vol 10 (9) ◽

pp. 168781401879954

Author(s):

Soo-Yong Cho ◽

Sang-Kyu Choi ◽

Jin-Gyun Kim ◽

Chong-Hyun Cho

Keyword(s):

Experimental Study ◽

Optimal Design ◽

Wind Turbine ◽

Wind Power ◽

Wind Turbines ◽

Vertical Axis ◽

Power Coefficient ◽

Design Parameters ◽

In order to augment the performance of vertical axis wind turbines, wind power towers have been used because they increase the frontal area. Typically, the wind power tower is installed as a circular column around a vertical axis wind turbine because the vertical axis wind turbine should be operated in an omnidirectional wind. As a result, the performance of the vertical axis wind turbine depends on the design parameters of the wind power tower. An experimental study was conducted in a wind tunnel to investigate the optimal design parameters of the wind power tower. Three different sizes of guide walls were applied to test with various wind power tower design parameters. The tested vertical axis wind turbine consisted of three blades of the NACA0018 profile and its solidity was 0.5. In order to simulate the operation in omnidirectional winds, the wind power tower was fabricated to be rotated. The performance of the vertical axis wind turbine was severely varied depending on the azimuthal location of the wind power tower. Comparison of the performance of the vertical axis wind turbine was performed based on the power coefficient obtained by averaging for the one periodic azimuth angle. The optimal design parameters were estimated using the results obtained under equal experimental conditions. When the non-dimensional inner gap was 0.3, the performance of the vertical axis wind turbine was better than any other gaps.

Development and Application of a Simulation Tool for Vertical and Horizontal Axis Wind Turbines

Volume 8: Supercritical CO2 Power Cycles; Wind Energy; Honors and Awards ◽

10.1115/gt2013-94979 ◽

2013 ◽

Cited By ~ 5

Author(s):

David Marten ◽

Juliane Wendler ◽

Georgios Pechlivanoglou ◽

Christian Navid Nayeri ◽

Christian Oliver Paschereit

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Vertical Axis ◽

Turbine Rotor ◽

Horizontal Axis ◽

First Case ◽

Lift And Drag ◽

The Impact

A double-multiple-streamtube vertical axis wind turbine simulation and design module has been integrated within the open-source wind turbine simulator QBlade. QBlade also contains the XFOIL airfoil analysis functionalities, which makes the software a single tool that comprises all functionality needed for the design and simulation of vertical or horizontal axis wind turbines. The functionality includes two dimensional airfoil design and analysis, lift and drag polar extrapolation, rotor blade design and wind turbine performance simulation. The QBlade software also inherits a generator module, pitch and rotational speed controllers, geometry export functionality and the simulation of rotor characteristics maps. Besides that, QBlade serves as a tool to compare different blade designs and their performance and to thoroughly investigate the distribution of all relevant variables along the rotor in an included post processor. The benefits of this code will be illustrated with two different case studies. The first case deals with the effect of stall delaying vortex generators on a vertical axis wind turbine rotor. The second case outlines the impact of helical blades and blade number on the time varying loads of a vertical axis wind turbine.

The Straight-Bladed Morphing Vertical Axis Wind Turbine

ASME 2016 Power Conference ◽

10.1115/power2016-59192 ◽

2016 ◽

Author(s):

David MacPhee ◽

Asfaw Beyene

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Low Cost ◽

Vertical Axis ◽

Power Coefficient ◽

Pitch Control ◽

Control Schemes ◽

Novel Concept

Blade pitch control has been extremely important for the development of Horizontal-Axis Wind Turbines (HAWTs), allowing for greater efficiency over a wider range of operational regimes when compared to rigid-bladed designs. For Vertical-Axis Wind Turbines (VAWTs), blade pitching is inherently more difficult due to a dependence of attack angle on turbine armature location, shaft speed, and wind speed. As a result, there have been very few practical pitch control schemes put forward for VAWTs, which may be a major reason why this wind turbine type enjoys a much lower market share as compared to HAWTs. To alleviate this issue, the flexible, straight-bladed vertical-axis turbine is presented, which can passively adapt its geometry to local aerodynamic loadings and serves as a low-cost blade pitch control strategy increasing efficiency and startup capabilities. Using two-dimensional fluid-structure action simulations, this novel concept is compared to an identical rigid one and is proven to be superior in terms of power coefficient due to decreased torque minima. Moreover, due to the flexible nature of the blades, the morphing turbine achieves less severe oscillatory loadings. As a result, the morphing blade design is expected to not only increase efficiency but also system longevity without additional system costs usually associated with active pitch control schemes.

Investigation of Self-Starting Capability of Vertical Axis Wind Turbines Using a Computational Fluid Dynamics Approach

Journal of Solar Energy Engineering ◽

10.1115/1.4004705 ◽

2011 ◽

Vol 133 (4) ◽

Cited By ~ 34

Author(s):

Alexandrina Untaroiu ◽

Houston G. Wood ◽

Paul E. Allaire ◽

Robert J. Ribando

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Wind Turbine ◽

Wind Turbines ◽

Vertical Axis ◽

Mesh Deformation ◽

Operating Speed ◽

Turbine Performance

Vertical axis wind turbines have always been a controversial technology; claims regarding their benefits and drawbacks have been debated since the initial patent in 1931. Despite this contention, very little systematic vertical axis wind turbine research has been accomplished. Experimental assessments remain prohibitively expensive, while analytical analyses are limited by the complexity of the system. Numerical methods can address both concerns, but inadequate computing power hampered this field. Instead, approximating models were developed which provided some basis for study; but all these exhibited high error margins when compared with actual turbine performance data and were only useful in some operating regimes. Modern computers are capable of more accurate computational fluid dynamics analysis, but most research has focused on horizontal axis configurations or modeling of single blades rather than full geometries. In order to address this research gap, a systematic review of vertical axis wind-power turbine (VAWT) was undertaken, starting with establishment of a methodology for vertical axis wind turbine simulation that is presented in this paper. Replicating the experimental prototype, both 2D and 3D models of a three-bladed vertical axis wind turbine were generated. Full transient computational fluid dynamics (CFD) simulations using mesh deformation capability available in ansys-CFX were run from turbine start-up to operating speed and compared with the experimental data in order to validate the technique. A circular inner domain, containing the blades and the rotor, was allowed to undergo mesh deformation with a rotational velocity that varied with torque generated by the incoming wind. Results have demonstrated that a transient CFD simulation using a two-dimensional computational model can accurately predict vertical axis wind turbine operating speed within 12% error, with the caveat that intermediate turbine performance is not accurately captured.

Volume 5: Industrial and Cogeneration; Microturbines and Small Turbomachinery; Oil and Gas Applications; Wind Turbine Technology ◽

Aerodynamic Measurements on a Vertical Axis Wind Turbine in a Large Scale Wind Tunnel

10.1115/gt2010-23512 ◽

2010 ◽

Author(s):

L. Battisti ◽

L. Zanne ◽

S. Dell’Anna ◽

V. Dossena ◽

B. Paradiso ◽

...

Keyword(s):

Wind Tunnel ◽

Flow Field ◽

Wind Turbine ◽

Wind Turbines ◽

Large Scale ◽

Fluid Dynamic ◽

Vertical Axis ◽

Aerodynamic Optimization ◽

This paper presents the first results of a wide experimental investigation on the aerodynamics of a vertical axis wind turbine. Vertical axis wind turbines have recently received particular attention, as interesting alternative for small and micro generation applications. However, the complex fluid dynamic mechanisms occurring in these machines make the aerodynamic optimization of the rotors still an open issue and detailed experimental analyses are now highly recommended to convert improved flow field comprehensions into novel design techniques. The experiments were performed in the large-scale wind tunnel of the Politecnico di Milano (Italy), where real-scale wind turbines for micro generation can be tested in full similarity conditions. Open and closed wind tunnel configurations are considered in such a way to quantify the influence of model blockage for several operational conditions. Integral torque and thrust measurements, as well as detailed aerodynamic measurements were applied to characterize the 3D flow field downstream of the turbine. The local unsteady flow field and the streamwise turbulent component, both resolved in phase with the rotor position, were derived by hot wire measurements. The paper critically analyses the models and the correlations usually applied to correct the wind tunnel blockage effects. Results evidence that the presently available theoretical correction models does not provide accurate estimates of the blockage effect in the case of vertical axis wind turbines. The tip aerodynamic phenomena, in particular, seem to play a key role for the prediction of the turbine performance; large-scale unsteadiness is observed in that region and a simple flow model is used to explain the different flow features with respect to horizontal axis wind turbines.

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

Energies ◽

10.3390/en14165140 ◽

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 ◽

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.