Experimental Study on Performance of Vertical Axis Wind Turbine with NACA 4-Digital Series of Blades

2012 ◽  
Vol 488-489 ◽  
pp. 1055-1061 ◽  
Author(s):  
W.C. Hsieh ◽  
J.M. Miao ◽  
C.C. Lai ◽  
C.S. Tai
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Free Stream ◽  
Rotation Speed ◽  
Vertical Axis ◽  
Free Stream Velocity ◽  
Stream Velocity ◽  
Test Model ◽  
Vertical Axis Wind Turbine ◽  
Blade Section

The experimental studies of output power performances of a vertical-axis-wind-turbine (VAWT) had been conducted in suction-type low speed wind tunnel with various free stream velocity. Torque and rotation speed of blades were measured by using torque meter and optical detector to analyze the effect of blade-section shape on the performance of wind turbine. The test model of experiments in the research was H-rotor VAWT. Three shapes of the NACA 4-digital series blade-section, NACA0022, NACA6404, and NACA6422 were taken in this work. Effects of thickness and camber of blade-section, blade numbers, and blade setting angles on the performance of VAWT have been analyzed in detail. The results show that NACA6422 blade-section has rotation speed of 42% higher than that of NACA0022 when the free stream velocity is below 12 m/s and the blade numbers are 4-blade type. Wind turbines with NACA6422 blades also showed that about 10% higher output power than that of NACA0022 blades among the tested range of free stream velocity. Results indicated that wind turbine with blades of anti-symmetric and thick blade-section was generally more suitable for applying to VAWT. All results of this study can be used the optimization design of VAWT blades in further.

scholarly journals Effect of Auxiliary Blade on Aerodynamic Characteristics of Vertical Axis Wind Turbine by Numerical Simulation

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Yan Li ◽  
Chang Zhao ◽  
Chunming Qu ◽  
Shouyang Zhao ◽  
Fang Feng ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Relative Thickness ◽  
Power Characteristics ◽  
Blade Section ◽  
Static Conditions ◽  
Static Torque

In order to improve the aerodynamic characteristics of the Straight-bladed Vertical Axis Wind Turbine (SB-VAWT), a rotor structure with auxiliary blade installed behind the main blade was proposed in this study. To investigate the effects of relative thickness and the fixing angle of the auxiliary blade on aerodynamic characteristics of SB-VAWT, numerical simulations were carried out. Two shapes of NACA 4-digital series blade-section, NACA0018 and NACA0024, were selected as the main blades in this work. Effects of relative thickness and fixing angles of auxiliary blade on the aerodynamic performance of SB-VAWT had been analyzed in detail, which had 5 kinds of relative thickness and 3 kinds of fixing angles combined into 13 working conditions. And the main blades and the auxiliary blades were also decided as the NACA series airfoil with five kinds of relative thickness. Three kinds of fixing angle of auxiliary blade installed behind main blade were used including 0°, 5°, and 10°. The simulations included the output power coefficients, the static torque coefficients, and the flow fields around the main blade and auxiliary blade for both the dynamic and static conditions at some typical azimuth angles. The results show that the auxiliary blade with certain relative thickness and fixing angle can improve the output power characteristics and static torque characteristics of SB-VAWT, which can also provide research reference for improving the performance of VAWT.

scholarly journals Design and Contruction of Vertical Axis Wind Turbine Triple-Stage Savonius Type as the Alternative Wind Power Plant

KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 172
Author(s):  
Tedy Harsanto ◽  
Haryo Dwi Prananto ◽  
Esmar Budi ◽  
Hadi Nasbey
Keyword(s):  
Wind Speed ◽  
Power Plant ◽  
Wind Turbine ◽  
Wind Power ◽  
Output Power ◽  
Vertical Axis ◽  
Wind Power Plant ◽  
Vertical Axis Wind Turbine ◽  
Low Wind Speed ◽  
Simple Materials

<p>A vertical axis wind turbine triple-stage savonius type has been created by using simple materials to generate electricity for the alternative wind power plant. The objective of this research is to design a simple wind turbine which can operate with low wind speed. The turbine was designed by making three savonius rotors and then varied the structure of angle on the three rotors, 0˚, 90˚ and 120˚. The dimension of the three rotors are created equal with each rotor diameter 35 cm and each rotor height 19 cm. The turbine was tested by using blower as the wind sources. Through the measurements obtained the comparisons of output power, rotation of turbine, and the level of efficiency generated by the three variations. The result showed that the turbine with angle of 120˚ operate most optimally because it is able to produce the highest output power and highest rotation of turbine which is 0.346 Watt and 222.7 RPM. </p><p><strong>Keywords</strong>: Output power; savonius turbine; triple-stage; the structure of angle</p>

scholarly journals Numerical and Experimental Efficiency Evaluation of a Counter-Rotating Vertical Axis Wind Turbine

2018 ◽  
Vol 8 (4) ◽  
pp. 3282-3286
Author(s):  
I. Malael ◽  
V. Dragan
Keyword(s):  
Wind Turbine ◽  
Free Stream ◽  
Experimental Tests ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Sliding Mesh ◽  
Momentum Coefficient ◽  
Fluent Software ◽  
Two Stages

This paper investigates the concept of a concentric counter-rotating vertical axis wind turbine (VAWT), consisting of a two stage vertical H-type turbine with three blades on each stage. The model has an inner and an outer stage, rotating in opposition to each other. Both numerical and experimental tests have been performed in order to validate this new concept. Numerical analysis is based on the use of 2.5-dimensional, unsteady simulations using a DOF type of analysis which allows for the two stages to self-adjust their rotation speed. Sliding mesh conformal interfaces are defined between these subdomains to minimize numerical artifacts such as artificial relations or entropy changes. Fully turbulent URANS were carried out in Ansys Fluent software. One key outcome was the momentum coefficient for each stage at different tip wind speed values. Another, more qualitative, outcome is the analysis of vortex shedding, impingement and overall interaction between the stages at different positions and scenarios. Ultimately, the numerical results have been validated using a scaled experimental device which was analyzed in the wind tunnel at different free stream speeds.

The Aerodynamic Analysis of Helical-Type VAWT With Semi Empirical and CFD Method

2019 ◽  
Author(s):  
Ying Guo ◽  
Liqin Liu ◽  
Xinxin Lv ◽  
Yougang Tang
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Structural Parameters ◽  
Vertical Axis ◽  
Empirical Method ◽  
Parameter Analysis ◽  
Vertical Axis Wind Turbine ◽  
Parameters Analysis ◽  
Cfd Method ◽  
Semi Empirical

Abstract Comparing to Φ-type and H-type VAWT (Vertical Axis Wind Turbine), the amplitude changes of the aerodynamics acting on Helical-type VAWT are much smaller, so Helical-type VAWT has advantages in steady output power and avoiding fatigue of structure. Considering the characteristic of helical-type VAWT, this paper modifies the semi empirical method of calculating aerodynamic loads and compares with CFD results. A comparison is presented between CFD results and experiment results to confirm the model used in CFD. Single parameter analysis and muti-parameters analysis are carried out to study the influence of structural parameters on the dynamic torque. Based on an objective output power as 5MW, the parameters of wind turbine are adjusted, and optimal values of these parameters are determined.

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 Development of a Computational System to Improve Wind Farm Layout, Part I: Model Validation and Near Wake Analysis

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 940 ◽  
Author(s):  
Rafael Rodrigues ◽  
Corinne Lengsfeld
Keyword(s):  
Wind Turbine ◽  
Pitch Angle ◽  
Wind Farm ◽  
Free Stream ◽  
Free Stream Velocity ◽  
Speed Ratio ◽  
Stream Velocity ◽  
Near Wake ◽  
Tip Speed Ratio ◽  
Wind Farm Layout

The first part of this work describes the validation of a wind turbine farm Computational Fluid Dynamics (CFD) simulation using literature velocity wake data from the MEXICO (Model Experiments in Controlled Conditions) experiment. The work is intended to establish a computational framework from which to investigate wind farm layout, seeking to validate the simulation and identify parameters influencing the wake. A CFD model was designed to mimic the MEXICO rotor experimental conditions and simulate new operating conditions with regards to tip speed ratio and pitch angle. The validation showed that the computational results qualitatively agree with the experimental data. Considering the designed tip speed ratio (TSR) of 6.6, the deficit of velocity in the wake remains at rate of approximately 15% of the free-stream velocity per rotor diameter regardless of the free-stream velocity applied. Moreover, analysis of a radial traverse right behind the rotor showed an increase of 20% in the velocity deficit as the TSR varied from TSR = 6 to TSR = 10, corresponding to an increase ratio of approximately 5% m·s−1 per dimensionless unit of TSR. We conclude that the near wake characteristics of a wind turbine are strongly influenced by the TSR and the pitch angle.

scholarly journals Far-wake meandering induced by atmospheric eddies in flow past a wind turbine

2018 ◽  
Vol 846 ◽  
pp. 190-209 ◽  
Author(s):  
X. Mao ◽  
J. N. Sørensen
Keyword(s):  
Wind Turbine ◽  
Strouhal Number ◽  
Large Scale ◽  
Free Stream ◽  
Stokes Equations ◽  
Wind Farms ◽  
Free Stream Velocity ◽  
Immersed Boundary ◽  
Stream Velocity ◽  
Actuator Disc

A novel algorithm is developed to calculate the nonlinear optimal boundary perturbations in three-dimensional incompressible flow. An optimal step length in the optimization loop is calculated without any additional calls to the Navier–Stokes equations. The algorithm is applied to compute the optimal inflow eddies for the flow around a wind turbine to clarify the mechanisms behind wake meandering, a phenomenon usually observed in wind farms. The turbine is modelled as an actuator disc using an immersed boundary method with the loading prescribed as a body force. At Reynolds number (based on free-stream velocity and turbine radius) $Re=1000$, the most energetic inflow perturbation has a frequency $\unicode[STIX]{x1D714}=0.8$–2, and is in the form of an azimuthal wave with wavenumber $m=1$ and the same radius as the actuator disc. The inflow perturbation is amplified by the strong shear downstream of the edge of the disc and then tilts the rolling-up vortex rings to induce wake meandering. This mechanism is verified by studying randomly perturbed flow at $Re\leqslant 8000$. At five turbine diameters downstream of the disc, the axial velocity oscillates at a magnitude of more than 60 % of the free-stream velocity when the magnitude of the inflow perturbation is 6 % of the free-stream wind speed. The dominant Strouhal number of the wake oscillation is 0.16 at $Re=3000$ and keeps approximately constant at higher $Re$. This Strouhal number agrees well with previous experimental findings. Overall the observations indicate that the well-observed stochastic wake meandering phenomenon appearing far downstream of wind turbines is induced by large-scale (the same order as the turbine rotor) and low-frequency free-stream eddies.

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