Numerical Investigation of Modified Bach Type Vertical Axis Wind Turbine

2016 ◽  
Vol 852 ◽  
pp. 551-557 ◽  
Author(s):  
R. Sarath Kumar ◽  
T. Micha Premkumar ◽  
Sivamani Seralathan ◽  
T. Mohan
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Flow Behaviour ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Vertical Axis Wind Turbine ◽  
Navier Stokes Equation ◽  
Ansys Fluent ◽  
Improved Performance ◽  
And Performance

This study evaluates the performance and flow behaviour over the modified Bach type Vertical Axis Wind Turbine. A two dimensional unsteady state analysis is carried out in this study. The unsteady Reynolds Averaged Navier-Stokes equation and the turbulence equation corresponding to SST k-ω turbulence model are solved using commercial software ANSYS FLUENT 13. A grid independence study is performed to choose optimum mesh elements. The simulation is carried out and performance parameters like power coefficient and torque coefficient are calculated. The results are compared with the available experimental data for validation purpose and these matched with numerical values. An improved performance of around 37% Cp is observed for modified Bach type over simple Savonius rotor. Moreover, a brief analysis of flow behaviour over the rotor is studied.

Performance Improvements for a Vertical Axis Wind Turbine by Means of Gurney Flap

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Yan Yan ◽  
Eldad Avital ◽  
John Williams ◽  
Jiahuan Cui
Keyword(s):  
Wind Turbine ◽  
Stokes Equations ◽  
Numerical Study ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Performance Improvements ◽  
Gurney Flap

Abstract A numerical study was carried out to investigate the effects of a Gurney flap (GF) on the aerodynamics performance of the NACA 00 aerofoil and an associated three-blade rotor of a H-type Darrieus wind turbine. The flow fields around a single aerofoil and the vertical axis wind turbine (VAWT) rotor are studied using unsteady Reynolds-averaged Navier–Stokes equations (URANS). The height of GF ranges from 1% to 5% of the aerofoil chord length. The results show that the GF can increase the lift and lift-to-drag ratio of the aerofoil as associated with the generation of additional vortices near the aerofoil trailing edge. As a result, adding a GF can significantly improve the power coefficient of the VAWT at low tip speed ratio (TSR), where it typically gives low power production. The causing mechanism is discussed in detail, pointing to flow separation and dynamic stall delay.

Simulation Study on the Performance of Vertical Axis Wind Turbine

2013 ◽  
Vol 465-466 ◽  
pp. 270-274 ◽  
Author(s):  
N. Afzanizam Samiran ◽  
A.A. Wahab ◽  
Mohd Sofian ◽  
N. Rosly
Keyword(s):  
Output Power ◽  
Flow Characteristic ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Savonius Rotor ◽  
Torque Coefficient

The present study considered the design improvement of Savonius rotor, in order to increase the efficiency of output power. An investigation was conducted to study the effect of geometrical configuration on the performance of the rotor in terms of coefficient of torque, coefficient of power and power output. Modification of conventional geometry has been designed by combining the effect of number of blades and shielding method. CFD simulation was conducted to analyze the flow characteristic and calculate the torque coefficient of all the rotor configurations. The continuity and Reynolds Averaged Navier-Stokes (RANS) equations and realizable k-ε epsilon turbulence model are numerically solved by commercial software Ansys-Fluent 14.0. The results obtained by transient and steady method for the conventional two bladed Savonius rotor are in agreement with those obtained experimentally by other authors and this indicates that the methods can be successfully applied for such analysis. The modified 3 and 4 bladed rotors with hybrid shielding method gave the highest maximum power coefficient which 0.37 at TSR 0.5 and output power exceed 4 watts with rotor dimensions of 0.2m width and 0.2m height. This blade configuration also is the best configuration by several percentages compared to the other model from the previous study

scholarly journals Studi simulasi penggunaan airfoil naca 6412 sebagai sudu pada turbin angin crossflow melalui pemodelan CFD 2 dimensi

2018 ◽  
Vol 13 (1) ◽  
pp. 28
Author(s):  
Muhammad Ivan Fadhil Hendrawan ◽  
Dominicus Danardono ◽  
Syamsul Hadi
Keyword(s):  
Wind Turbine ◽  
Constant Velocity ◽  
Cross Flow ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Tip Speed Ratio ◽  
Blade Number

AbstractThe simulation aimed to understand the effect of the angle of blade number and blade number of vertical axis wind turbine with cross flow runner to enhance the performance of wind turbine. The turbine had 20, 22, and 24 number of blades. Simulation was done in 2D analysis using ANSYS-Fluent. Tip speed ratio was varied in range of 0,1-0,5 with constant velocity inlet 2 m/s. The effect of blade numbers to torque and power coefficient were analyzed and compared. It had been found that the best power coefficient were 0,5 at tip speed ratio 0,3.

scholarly journals Experimental Study of the Performance of a Novel Vertical-Axis Wind Turbine

2020 ◽  
Vol 10 (8) ◽  
pp. 2902
Author(s):  
James Agbormbai ◽  
Weidong Zhu
Keyword(s):  
Wind Turbine ◽  
Pressure Difference ◽  
Free Stream ◽  
Vertical Axis ◽  
Inviscid Flow ◽  
Momentum Equation ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Vertical Axis Wind Turbine ◽  
Bernoulli’S Equation

Basic equations for estimating the aerodynamic power captured by the Anderson vertical-axis wind turbine (AVAWT) are derived from a solution of Navier–Stokes (N–S) equations for a baroclinic inviscid flow. In a nutshell, the pressure difference across the AVAWT is derived from the Bernoulli’s equation—an upshot of the integration of the Euler’s momentum equation, which is the N–S momentum equation for a baroclinic inviscid flow. The resulting expression for the pressure difference across the AVAWT rotor is plotted as a function of the free-stream speed. Experimentally determined airstream speeds at the AVAWT inlet and outlet, coupled with corresponding free-stream speeds, are used in estimating the aerodynamic power captured. The aerodynamic power of the AVAWT is subsequently used in calculating its aerodynamic power coefficient. The actual power coefficient is calculated from the power generated by the AVAWT at various free-stream speeds and plotted as a function of the latter. Experimental results show that at all free-stream speeds and tip-speed ratios, the aerodynamic power coefficient of the AVAWT is higher than its actual power coefficient. Consequently, the power generated by the AVAWT prototype is lower than the aerodynamic power captured, given the same inflow wind conditions. Besides the foregoing, the main purpose of this experiment is to investigate the technical feasibility of the AVAWT. This proof of concept enables the inventor to commercialize the AVAWT.

scholarly journals Performance Analysis of a H-Darrieus Wind Turbine for a Series of 4-Digit NACA Airfoils

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3196 ◽  
Author(s):  
Krzysztof Rogowski ◽  
Martin Otto Laver Hansen ◽  
Galih Bangga
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Point Of View ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Vertical Axis Wind Turbine ◽  
Wide Range ◽  
Sst Turbulence Model ◽  
Lift And Drag ◽  
Blade Loads

The purpose of this paper is to estimate the H-Darrieus wind turbine aerodynamic performance, aerodynamic blade loads, and velocity profiles downstream behind the rotor. The wind turbine model is based on the rotor designed by McDonnell Aircraft Company. The model proposed here consists of three fixed straight blades; in the future, this model is planned to be developed with controlled blades. The study was conducted using the unsteady Reynolds averaged Navier–Stokes (URANS) approach with the k-ω shear stress transport (SST) turbulence model. The numerical two-dimensional model was verified using two other independent aerodynamic approaches: a vortex model and the extended version of the computational fluid dynamics (CFD) code FLOWer. All utilized numerical codes gave similar result of the instantaneous aerodynamic blade loads. In addition, steady-state calculations for the applied airfoils were also made using the same numerical model as for the vertical axis wind turbine (VAWT) to obtain lift and drag coefficients. The obtained values of lift and drag force coefficients, for a Reynolds number of 2.9 million, agree with the predictions of the experiment and XFOIL over a wide range of angle of attack. A maximum rotor power coefficient of 0.5 is obtained, which makes this impeller attractive from the point of view of further research. Research has shown that, if this rotor were to work with fixed blades, it is recommended to use the NACA 1418 airfoil instead of the original NACA 0018.

scholarly journals Experimental Study of the Performance of A Novel Vertical Axis Wind Turbine

2019 ◽  
Author(s):  
James Agbormbai ◽  
Weidong Zhu
Keyword(s):  
Wind Turbine ◽  
Pressure Difference ◽  
Free Stream ◽  
Vertical Axis ◽  
Inviscid Flow ◽  
Momentum Equation ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Wind Condition ◽  
Vertical Axis Wind Turbine

The basic equation for estimating the aerodynamic power captured by an Anderson Vertical Axis Wind Turbine (AVAWT) is a solution of the Navier-Stokes(N-S) equations for a baroclinic, inviscid flow. In a nutshell, the pressure difference across the AVAWT is derived from Bernoulli’s equation; an upshot of the integration of the N-S momentum equation for a baroclinic inviscid flow, Euler’s momentum equation. The resulting expression for the pressure difference across the AVAWT rotor is plotted as a function of freestream speed. Experimentally determined airstream speeds at the AVAWT inlet and outlet, coupled with corresponding freestream speeds are used in estimating the aerodynamic power captured. The aerodynamic power is subsequently used in calculating the aerodynamic power coefficient of the AVAWT. The actual power coefficient is calculated from the power generated by the AVAWT at various free stream speeds and plotted as a function of the latter. Experimental results show that, at all free stream speeds and tip speed ratios, the aerodynamic power coefficient is higher than the actual power coefficient of the AVAWT. Consequently, the power generated by the AVAWT prototype is lower than the aerodynamic power captured, given the same inflow wind condition.

Rotor Design and Performance Study of a Vertical-Axis Wind Turbine Based on DMS

2013 ◽  
Vol 448-453 ◽  
pp. 1892-1896
Author(s):  
Rui Yang ◽  
Jin Long Li ◽  
Wei Wei Xia ◽  
Ting Ting Wang
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Aerodynamic Load ◽  
Vertical Axis Wind Turbine ◽  
Performance Study ◽  
Force Coefficient ◽  
Rotor Design ◽  
And Performance

Specifically address the design of a 5KW H-type vertical-axis wind turbine (H-VAWT) with NACA 0018 airfoil considering the factors that affect wind turbine power. The double-multiple streamtube (DMS) theoretical model is analyzed and summarized and calculated by Matlab. The 5KW H-type vertical axis wind turbines aerodynamic performance is calculated by the model written in Matlab. The curve of the power coefficient as a function of the tip-speed ratio and the curve of the normal force coefficient and the tangential farce as a function of the blade position is given by Matlab. From the curves we can see that upwind rotor aerodynamic load is larger, downwind rotor aerodynamic load is smaller and there is a serious flow retarding effect in the rotor downwind area.

scholarly journals Performance Enhancement of a Darrieus Vertical Axis Wind Turbine using Divergent Ducting System

2018 ◽  
Vol 25 (3) ◽  
pp. 58-66
Author(s):  
Abdullateef A. Jadallah ◽  
Sahar R. Farag ◽  
Jinan D. Hamdi
Keyword(s):  
Wind Turbine ◽  
Urban Areas ◽  
Performance Enhancement ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Opening Angle ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Low Wind Speed ◽  
Enhancement Method

Ducting system is an effective way to potentially augment the performance of wind turbine for applications in building architectures. This paper is aimed to study one of the possible enhancement method of the vertical axis wind turbine performance. It is characterized by adding divergent duct to facilitate imparting more flow rate. The divergent duct was designed and adapted with wind turbine. The system was modelled and simulated analytically and numerically. A computer program built in MATLAB 16 to simulate the performance of system. The performance and flow are also solved numerically using ANSYS-FLUENT 17.2. Two opening angles of the divergent -duct were employed to study the behavior of air flow through divergent duct and results were compared with base vertical axis wind turbine. The duct turbine with a straight wall type diffuser demonstrate power coefficient augmentation by 24.2% and 9.09% for opening angle 20 and 12 respectively. The optimum half opening angle was attained for the diffuser. The diffuser’s length of a half of the throat opening is recommended, and its angle of opening is 20. The diffuser was located in a stream-was direction that adequately aligned with the center of the vertical axis wind turbine. Results showed a reasonable influence on the performance of wind turbine. This technology may be used in gates and in urban areas with a relatively low wind speed regime.

scholarly journals An automated analysis process for vertical axis wind turbine

2015 ◽  
Vol 18 (4) ◽  
pp. 145-152
Author(s):  
Anh Ngoc Vu ◽  
Tung Nguyen Minh Huynh
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Automated Analysis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Analysis Process ◽  
Processing Data ◽  
Fluent Software ◽  
Meshing Process

This paper presents an automated process for analyzing the performance of vertical axis wind turbine (VAWT). The details of this process will be demonstrated, which include the airfoil geometry representation using CST method, a hybrid meshing process combining structured grids and unstructured grids, CFD calculation process and processing data results to calculate the power coefficient of VAWT. These processes are designed as separate modules. CFD methods used in this research is RANS 2D using Realizable k  turbulence model. Meshing process will be done on the GAMBIT software, the CFD calculations are done on commercial ANSYS FLUENT software and these processes are controlled by mathematical software MATLAB. The formulas used to calculate the power coefficient will be also introduced in this paper.

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.

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