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.

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.

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.

scholarly journals Double multiple stream tube theory coupled with dynamic stall and wake correction for aerodynamic investigation of vertical axis wind turbine

2020 ◽  
Vol 23 (4) ◽  
pp. 771-780
Author(s):  
Anh Ngoc VU ◽  
Ngoc Son Pham
Keyword(s):  
Wind Turbine ◽  
Shape Function ◽  
Vertical Axis ◽  
Transformation Method ◽  
Aerodynamic Performance ◽  
Dynamic Stall ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Stream Tube ◽  
Aerodynamic Investigation

This study describes an effectively analytic methodology to investigate the aerodynamic performance of H vertical axis wind turbine (H-VAWT). An in-house code based on double multiple stream tube theory (DMST) coupled with dynamic stall and wake correction is implemented to estimate the power coefficient. Design optimization of airfoil shape is conducted to study the influences of the dynamic stall and turbulent wakes. Airfoil shape is universally investigated by using the Class/Shape function transformation method. The airfoil study shows that the upper curve tends to be less convex than the lower curve in order to extract more energy of the wind upstream and generate less drag of the blade downstream. The optimal results show that the power coefficient increases by 6.5% with the new airfoil shape.

Numerical Analysis of a Rooftop Vertical Axis Wind Turbine

2011 ◽  
Author(s):  
N. Cristobal Uzarraga-Rodriguez ◽  
A. Gallegos-Mun˜oz ◽  
J. Manuel Riesco A´vila
Keyword(s):  
Numerical Analysis ◽  
Wind Turbine ◽  
Numerical Study ◽  
Vertical Axis ◽  
Turbine Rotor ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh ◽  
Mesh Model

A numerical analysis of a rooftop vertical axis wind turbine (VAWT) for applications in urban area is presented. The numerical simulations were developed to study the flow field through the turbine rotor to analyze the aerodynamic performance characteristics of the device. Three different blade numbers of wind turbine are studied, 2, 3 and 4, respectively. Each one of the models was built in a 3D computational model. The effects generated in the performance of turbines by the numbers of blades are considered. A Sliding Mesh Model (SMM) capability was used to present the dimensionless form of coefficient power and coefficient moment of the wind turbine as a function of the wind velocity and the rotor rotational speed. The numerical study was developed in CFD using FLUENT®. The results show the aerodynamic performance for each configuration of wind turbine rotor. In the cases of Rooftop rotor the power coefficient increases as the blade number increases, while in the case of Savonius rotor the power coefficient decrease as the blades number increases.

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.

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

scholarly journals Analysis of the suitability of using the selected wind turbine blades for wind power appliances based on numerical analyses

2018 ◽  
Vol 46 ◽  
pp. 00006
Author(s):  
Krzysztof Pytel ◽  
Szymon Szpin ◽  
Wiktor Hudy ◽  
Małgorzata Piaskowska–Silarska ◽  
Stanisław Gumuła
Keyword(s):  
Wind Turbine ◽  
Wind Power ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Numerical Analyses ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
Wind Speeds ◽  
Air Stream

The aim of this study was a comparative analysis of the suitability of the use of airfoil for wind power. Based on numerical analyses and analytical methods, information on the power factor was obtained. The analyses were carried out for the wind turbine blades and rotors of a vertical axis wind turbine. The tests were performed for the constructed profile and compared with the profile DU 06-W-200 used in the construction of a wind turbine rotors. A vertical axis wind turbine model equipped with designed blade profiles was prepared. The main predicted purpose of the device is to supply electricity to the household. The blade profile models were prepared and then a numerical analysis was performed using the CFD application. The obtained results for given wind speeds and types of profiles were compared with each other. The conducted research allowed to determine the sense of applying the unaudited profile based on the determined value of wind turbine power coefficient. Studies have shown that the accurate preparation of the optimal rotor blade with respect to flow of air stream strongly influences the characteristics of the wind turbine.

Swept Blade for Performance Improvement on a Vertical Axis Wind Turbine

2020 ◽  
Author(s):  
Jie Su ◽  
Yaoran Chen ◽  
Dai Zhou ◽  
Zhaolong Han ◽  
Yan Bao
Keyword(s):  
Wind Turbine ◽  
Wind Farm ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Static Pressure Distribution ◽  
Low Wind Speed ◽  
Turbine Wake ◽  
Wind Turbine Wake

Abstract The vertical axis wind turbine (VAWT) is considered an important device to utilize the renewable and sustainable wind energy. However, the relatively lower power coefficient has hampered its development. Therefore, this paper attempts to investigate the effect of swept blade employed in a VAWT on the enhancement in aerodynamic performance. A series of swept blades were studied in a small VAWT rotor, and the RANS SST k-ω turbulence model was utilized to simulate the flow field. The numerical model was validated against experimental data, and the aerodynamic performance was investigated with respect to force coefficients, vorticity distribution, static pressure distribution, and wind turbine wake, respectively. The results indicated that the swept blade could effectively increase power outputs by about 20% for the wind turbine. By reducing the drag coefficient, a high lift-drag ratio was achieved. And this configuration prevented the blade from suffering severe dynamic stall. Besides, the swept blade changed the distribution of low wind speed area in the wind turbine wake, which should be considered in the wind farm. It was concluded that this work provided a new way for the practical design and optimization of wind turbine.

Aerodynamic Performance Evaluation of a Novel Savonius-Style Wind Turbine Under an Oriented Jet

2014 ◽  
Author(s):  
Sukanta Roy ◽  
Prasenjit Mukherjee ◽  
Ujjwal K. Saha
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Small Scale ◽  
Practical Applications ◽  
Wind Speeds ◽  
Energy Applications

The Savonius-style wind turbine, a class of vertical axis wind turbines, can be a viable option for small scale off-grid electricity generation in the context of renewable energy applications. A better self-starting capability at low wind speeds is one of the major advantages of this turbine. However, as reported in open literature, the power coefficient of the conventional design is found to be inferior as compared to its counterparts. In this regard, a new blade design has been developed. In the present investigation, the aerodynamic performance of this newly designed turbine is assessed under an oriented jet. This is affected by installing deflectors upstream of the turbine blades. The intention of this study is to maximize the utilization of wind energy at the exhaust systems of several practical applications. Experiments are carried out in a low speed wind tunnel at a wind speed of 6.2 m/s. The gradual loads applied to the turbine, and the corresponding rotational speeds are recorded. Power and torque coefficients are calculated at various mechanical loads. Further, all the estimated data are corrected by a suitable correction factor to account for the wind tunnel blockage effects. The results obtained are compared with the experimental data of modified Bach and conventional designs. The results have shown a significant improvement in the performance of newly designed Savonius-style wind turbine under the concentrated and oriented jet.

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