scholarly journals Improvement of Self-Starting Capabilities of Vertical Axis Wind Turbines with New Design of Turbine Blades

2021 ◽  
Vol 13 (7) ◽  
pp. 3854
Author(s):  
Samuel Mitchell ◽  
Iheanyichukwu Ogbonna ◽  
Konstantin Volkov
Keyword(s):  
Wind Turbine ◽  
Cfd Simulation ◽  
Tangential Force ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Coefficient Of Performance ◽  
Small Range ◽  
Vertical Axis Wind Turbine ◽  
A Minor

A lift-driven vertical axis wind turbine (VAWT) generates peak power when it is rotating at high tip-speed ratios (TSR), at which time the blades encounter angles of attack (AOA) over a small range from zero to 30 degrees. However, its ability to self-start is dependent upon its performance at low TSRs, at which time the blades encounter a range of AOAs from zero to 180 degrees. A novel vented aerofoil is presented with the intention of improving the performance of a lift-driven VAWT at low TSRs without hampering the performance of the wind turbine at high TSRs. Computational fluid dynamics (CFD) simulation is used to predict the aerodynamic characteristics of a new vented aerofoil based on the well documented NACA0012 profile. Simulations are performed using the SST turbulence model. The results obtained show a reduction in the coefficient of tangential force (the force that generates torque on the wind turbine) at low AOAs (less than 90 degrees) of no more than 30%, while at high AOAs (more than 90 degrees) an improvement in the tangential force of over 100% is observed. Using a simple momentum based performance prediction model, these results suggest that this would lead to an increase in torque generation by a theoretical three-bladed VAWT of up to 20% at low TSRs and a minor reduction in coefficient of performance of up to 9% at TSR of 2 and closer to 1% at higher TSRs.

Computational Analysis of Airfoil Merging and its Effect on Performance of Lift Based Vertical Axis Wind Turbine

2016 ◽  
Author(s):  
Akshay Basavaraj
Keyword(s):  
Reynolds Number ◽  
Wind Turbine ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Low Wind Speed ◽  
Naca 0012 ◽  
Selection Of

In regions of low wind speed, overcoming the starting torque of a Vertical Axis Wind Turbine (VAWT) becomes a challenge aspect. In order to overcome this adversity, careful selection of airfoils for the turbine blades becomes a priority. This paper tries to address the issue utilizing an approach wherein by observing the effect of merging two airfoils. Two airfoils which are of varying camber and thickness are merged and their aerodynamic characteristics are evaluated using the software XFOIL 6.96. For a variation in angle of attack from 0 to 90°, aerodynamic analysis is done in order to observe the behavior of one quarter of the entire VAWT cycle. An objective function is developed so as to observe the maximum possible torque generated by these airfoils at Reynolds number varying from 15,000–120,000. Due to change in the value of CL observed at Low Reynolds Number using commercial CFD softwares, multiple objective functions are utilized to observe the behavior over a range of Reynolds number. An experimental co-relation between the cut-in velocity and the lift-coefficient of the airfoils is developed in order to predict the cut-in velocity of the interpolated airfoils. The airfoils used for this paper are NACA 0012, NACA 0018, FX 66 S196, Clark Y (smooth), PT 40, SD 7032, A 18, SD 7080, SG 6043 and SG 6040.

scholarly journals 2D CFD Simulation Study on the Performance of Various NACA Airfoils

CFD letters ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 38-50
Author(s):  
Mark Jason Thomas Loutun ◽  
Djamal Hissein Didane ◽  
Mohd Faizal Mohideen Batcha ◽  
Kamil Abdullah ◽  
Mas Fawzi Mohd Ali ◽  
...  
Keyword(s):  
Energy Source ◽  
Wind Turbine ◽  
Computational Models ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
The Other ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine

The wind is an energy source that has the properties of a clean, free, and readily available energy source. However, the efficiency of the existing rotors used to harness wind power is still not satisfactory. Thus, in this current study, the development and aerodynamic performance investigation of ten NACA airfoils comprising of five symmetrical and five non-symmetrical airfoils have been analyzed through the computational fluids dynamic (CFD) simulation approach. The main motive of this study was to investigate the aerodynamic performance of NACA airfoils to be used on a vertical axis wind turbine (VAWT), which will assist in further understanding the physics of the interaction between airflow and the wind turbine blades. The simulation was performed using two-dimensional computational models based on an unsteady state K-omega Shear Stress Transport (SST) turbulence model. This study covers a parametric study based on the variations of tip-speed ratios and constant wind velocity. The aerodynamic performances are evaluated in terms of torque, torque coefficient, and also power coefficient. The performance of NACA0018 was found to be the best among the other airfoils with a power coefficient of 0.3. NACA0010 displayed the lowest power coefficient among the other airfoils but had a more extensive operating range compared to the other airfoils. However, for non-symmetrical NACA airfoils, NACA2421 scored the highest power coefficient, followed by NACA4412. It was also found that most of the non-symmetrical NACA airfoils can operate at a higher range of tip-speed ratios compared to the symmetrical NACA airfoils.

Simulation Study for Optimization Design on Vertical Axis Wind Turbine blades

2019 ◽  
Vol 3 (1) ◽  
pp. 136-145
Author(s):  
Arie S. Pangemanan ◽  
Houtman P. Siregar ◽  
Maman Suryaman
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Optimization Design ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Angle Of Attack ◽  
Vertical Axis ◽  
Evaluation Study ◽  
Vertical Axis Wind Turbine ◽  
Drag Ratio

In this article is conducted research to harness wind energy which is firstly generated by vehicle / truck that is runing on the public road highway. To take advantage of wind energy of the moving truck is designed, otherwise advisor had some ideas during the proposal defense change into fixed vertical axis wind turbine. The purpose of this evaluation study is to get optimization for the design blades of the vertical axis fixed wind turbine and finding the best blades installed and angle of attack will result in highest lift/drag ratio. While other test parameters such as air pressure, wind speed and others are held constant. In this evaluation study the angle of attack are used ranging begin from 45 and until 90 degrees. Evaluation result showed that the best blades install and angle of attack that gives the best lift/drag ratio is 5 blades at AoA ninety degree. Blades diameter of the designed wind turbine are 0.35 m and the number of blades which is the best in analytical of CFD techniques in the designed wind turbine are five pieces. The speed of the wind which is used to test the blades is 8 m/s on turbine rotation 80 rpm. The evaluation study has suceeded to do parametric optimization of the turbine blades. The optimised blades have been ready to re-designed assamble with another componens of the wind turbine to construct the prototype but there some problems / handicaps during the changes the prootype of turbine from movable to fixed wind turbine. The assambled vertical axial wind turbine postponed to further be tested in order to know its performance. CFD simulation has been performed with ten different VAWT designed models. Moving mesh and fluid flow simulation have been developed in CFD software FLUENT. The findings of these numerical simulations provided pressure contour, velocity contour, C D or C L

Effect of Solidity on Performance of Vertical Axis Wind Turbine Using Constant Chord Reynolds Number

2021 ◽  
Author(s):  
Anirudh P ◽  
Ratna Kishore Velamati ◽  
Srinath K S ◽  
Unnikrishnan D
Keyword(s):  
Reynolds Number ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Coefficient Of Performance ◽  
Vertical Axis Wind Turbine ◽  
Number Range ◽  
Turbine Performance ◽  
The Impact

Abstract The demand for wind turbines has increased ever since fossil fuels showed signs of quick depletion. Among wind turbines, Vertical Axis Wind Turbine (VAWT) is compact, produces less noise, is omnidirectional, resilient to turbulent flow, and is easy to maintain. The power generated by a VAWT is a function of a non-dimensional geometric parameter known as solidity (s), which is a function of turbine diameter (D), blade chord (c) and the number of blades (n). The present work analyses the impact of solidity (0.12 and 0.18) as a complete non-dimensional parameter on wind turbine performance. Each parameter of solidity is varied, keeping any one of the parameters constant and numerically studied for its performance across a range of tip speed ratios (TSR). For each solidity, six different combinations of VAWT geometric parameters were analyzed. In all the cases, the chord Reynolds number is kept constant. CFD simulation was performed on the Darrieus H-type (NACA0018 airfoil) VAWT. Two dimensional (2D) computational domains are used to study the effect on the turbine’s performance as the solidity studied is less than 0.4. Unsteady Reynolds-Averaged Navier-strokes (URANS) equation is used to solve the CFD model using ANSYS Fluent 19.1 with 4-equation transition SST k-ω for turbulence modelling. The comprehensive study of the turbine performance keeping the turbine operation within a constant Re number range shows the Coefficient of Performance (Cp) overlaps for a given solidity.

Numerical Simulation of Vertical Axis Wind Turbine Blade Airfoil Performance

2014 ◽  
Vol 529 ◽  
pp. 173-177
Author(s):  
Li Hua Zhao ◽  
Ming Liu ◽  
Tie Lv ◽  
Xiao Qun Mei
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Simulation Software ◽  
Vertical Axis Wind Turbine ◽  
Variation Of Parameters ◽  
Wind Turbine Airfoil ◽  
And Performance

Research of blade airfoil aerodynamic characteristics is an important foundation for the vertical axis wind turbine aerodynamic design and performance analysis. CFD simulation software has been applied in this paper. Representative lift-type vertical axis wind turbine airfoil NACA0014, NACA2414, NACA4414, NACA6414, NACA8414 's aerodynamic simulation have been studied. Camber airfoil relative with the change in to the flow velocity is analyzed. At different angles of attack effect on the aerodynamic performance of wind turbines, variation of parameters for airfoil aerodynamic had been analyzed. It will help the optimal design of airfoils for vertical axis wind turbines.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

Numerical Studies on the Effect of Cambered Airfoil Blades on Self-Starting of Vertical Axis Wind Turbine Part 1: NACA 0012 and NACA 4415

2015 ◽  
Vol 787 ◽  
pp. 250-254 ◽  
Author(s):  
T. Micha Premkumar ◽  
Sivamani Seralathan ◽  
T. Mohan ◽  
N.N.P. Saran Reddy
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
Static Pressure Distribution ◽  
Numerical Studies ◽  
Airfoil Blades ◽  
Torque Values ◽  
Naca 0012

This is Part-1 of the two-part paper in considering the effect of cambered airfoil blades on self-starting of vertical axis wind turbine. Part 1 reports the numerical studies on self-starting of vertical axis wind turbine with comparative studies involving NACA 0012 and cambered airfoil NACA 4415. Part 2 of the paper deals with numerical studies of NACA 0018 and cambered air foil NACA 63415. Darrieus type VAWT is attracting many researchers attention for its inherent advantages and its diversified applications. However, a disadvantage is when the rotor is stationary, no net rotational forces arises, even at high-wind speed. The principal advantage of the vertical axis format is their ability to accept wind from any direction without yawing mechanism. However, self-starting capability is the major drawbacks. Moreover, literatures based on computational analysis involving the cambered airfoil are few only. The objective of this present study is to select the suitable airfoil blades on self-starting of VAWT at low-Reynolds number. The numerical studies are carried out to identify self-starting capability of the airfoil using CFD analysis by studying the flow field over the vertical axis wind turbine blades. The commercial CFD code, ANSYS CFX 13.0© was used for the present studies. Initially, the flow over NACA 0012 was simulated and analyzed for different angles of attacks and similarly carried out for NACA 4415. The contours of static pressure distribution and velocity as well as the force and torque were obtained. Even though the lift force for cambered airfoil NACA 4415 is higher, based on the torque values of the above blade profiles, asymmetrical airfoil NACA 0012 is found to be appropriate for self-starring of VAWT.

Effect of trailing edge dual synthesis jets actuator on aerodynamic characteristics of a straight-bladed vertical axis wind turbine

Energy ◽  
2022 ◽  
Vol 238 ◽  
pp. 121792
Author(s):  
Peilin Wang ◽  
Qingsong Liu ◽  
Chun Li ◽  
Weipao Miao ◽  
Shuai Luo ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Trailing Edge

scholarly journals Numerical Simulation of Aerodynamic Performance of Off-grid Small Vertical Axis Wind Turbine

2018 ◽  
Vol 53 ◽  
pp. 02004
Author(s):  
Qiuyun Mo ◽  
Jiabei Yin ◽  
Lin Chen ◽  
Weihao Liu ◽  
Li Jiang ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Velocity Fields ◽  
Compact Model ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
Rotation Domain ◽  
Rng Turbulence Model

In this paper, a 2D off-grid small compact model of vertical axis wind turbine was established. The sliding grid technology, the RNG turbulence model and the Coupld algorithm was applied to simulate the unsteady value of the model's aerodynamic performance. Through the analysis on the flow field at difference moments, the rules about velocity fields, vortices distributions and the wind turbine's total torque were obtained. The results show that: the speed around wind turbine blades have obvious gradient, and the velocity distribution at different times show large differences in the computional domain. In the rotating domain vorticity is large. With away from the rotation domain, vorticity reduced quickly. In the process of rotating for vertical axis wind turbine, the wind turbine's total torque showed alternating positive and negative changes.

Sign in / Sign up

Export Citation Format

Share Document