Performance Enhancement of Horizontal Axis Wind Turbine Using Numerical Techniques

Ansys Fluent ◽

Design Requirements ◽

Nrel Phase Vi

Abstract Wind turbines are one of the most prominent and popular sources of renewable energy, of which, horizontal axis wind turbines (HAWT) are the majorly chosen design for wind machines. These turbines rotate about the horizontal axis which is parallel to the ground. They comprise of aerodynamic blades (generated from the desired airfoil), that may be twisted or tapered as per the design requirements. The blades are attached to a rotor which is located either upwind or downwind. To help wind the orientation of the turbines, the upwind rotors have a tail vane, while the downwind rotors are coned which in turn help them to self-orient. One of the major reasons for the popularity of the horizontal wind turbine, is its ability to generate a larger amount of electricity for a given amount of wind. Due to its popularity, the enhancement in the design of HAWTs, is a major focus area for research. In the present study, a scaled-down CFD model of the NREL Phase VI was validated against the numerical and experimental data. The model used had a dual blade rotor and applied the S809 airfoil. The simulations were carried out using a rotating mesh in ANSYS Fluent. Validation was carried out for 3 velocities — 7m/s, 10m/s and 20m/s. Once validation was carried out, turbine was modified with the addition of vortex generators, in the form of cylindrical protrusions that reduce flow separation.

Analysis on Aerodynamic Performance of Horizontal Axis Wind Turbine Based on Nonlinear Wake Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.448-453.1716 ◽

2013 ◽

Vol 448-453 ◽

pp. 1716-1720

Author(s):

Rui Yang ◽

Jiu Xin Wang ◽

Sheng Long Zhang

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Optimization Design ◽

Aerodynamic Performance ◽

Horizontal Axis ◽

Wake Vortex ◽

Wake Model ◽

Induced Velocity

A computational method based on nonlinear wake model was established for horizontal axis wind turbines aerodynamic performance prediction. This method makes use of finite difference method to solve the integral differential equation of the model, the induced velocity of wake vortex can be calculated from equations and compared with the induced velocity of wake vortex in linear model. The comparison between the calculated results of wind turbine under axis flow condition, including tip vortex geometry and aerodynamic performance, and available experimental data shows that this method is suitable for wind turbine aerodynamic performance analysis. Finally, a series of numerical calculations were made to investigate the change of wake geometry and aerodynamic performance of the wind turbine when yawing and pitch angle increasing, which provide foundations for aerodynamic optimization design of horizontal axis wind turbines.

Observation of the Starting and Low Speed Behavior of Small Horizontal Axis Wind Turbine

Journal of Wind Energy ◽

10.1155/2014/527198 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Sikandar Khan ◽

Kamran Shah ◽

Izhar-Ul-Haq ◽

Hamid Khan ◽

Sajid Ali ◽

...

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Horizontal Axis ◽

Wind Speeds ◽

Starting Time ◽

Speed Range ◽

Starting Torque ◽

High Angles Of Attack

This paper describes the starting behavior of small horizontal axis wind turbines at high angles of attack and low Reynolds number. The unfavorable relative wind direction during the starting time leads to low starting torque and more idling time. Wind turbine models of sizes less than 5 meters were simulated at wind speed range of 2 m/s to 5 m/s. Wind turbines were modeled in Pro/E and based on the optimized designs given by MATLAB codes. Wind turbine models were simulated in ADAMS for improving the starting behavior. The models with high starting torques and less idling times were selected. The starting behavior was successfully improved and the optimized wind turbine models were able to produce more starting torque even at wind speeds less than 5 m/s.

Establishing a robust testing approach for displacement measurement on a rotating horizontal-axis wind turbine

Wind Energy Science ◽

10.5194/wes-3-301-2018 ◽

2018 ◽

Vol 3 (1) ◽

pp. 301-311

Author(s):

Nadia Najafi ◽

Allan Vesth

Keyword(s):

Wind Turbine ◽

Camera Calibration ◽

Wind Turbines ◽

Calibration Method ◽

Horizontal Axis ◽

Tracking Algorithm ◽

Displacement Measurement ◽

Damage And Failure ◽

Abstract. Health monitoring by conventional sensors like accelerometers or strain gauges becomes challenging for large rotating structures due to the issues with feasibility, sensing and data transmission. In addition, acceleration measurements have low capability of presenting very small frequencies, which happen very often for large structures (for instance, frequencies between 0.2 and 0.5 Hz in horizontal-axis wind turbines). By contrast, displacement measurement using stereo vision is rapid, non-contacting and distributed over the structure. The sensors are cheaper and more easily applied to many places on the object to be measured. Horizontal-axis wind turbines are one of the most important large rotating structures and need to be measured and monitored in time to prevent damage and failure, and the blade tip position is one of the key parameters to measure in order to prevent the blade hitting the turbine tower. This paper presents a clearly described and easily applicable procedure for measuring the displacement on the components of a rotating horizontal-axis wind turbine with stereophotogrammetry. Paper markers have been applied on the rotor and tower of a scaled-down horizontal-axis wind turbine model in the workshop and the displacement measurement method has been demonstrated by measuring displacement during operation. The method is mainly developed in two parts: (1) camera calibration and (2) tracking algorithm. We introduce an efficient camera calibration method for measurement in large fields of view, which has always been a challenge. This method is easy and practical and offers better accuracy compared with 2-D traditional camera calibration. The tracking algorithm also works successfully and is able to track the points during rotation within the measurement time. Finally, the accuracy analysis has been conducted and has shown better accuracy of the new calibration method compared with 2-D traditional camera calibration.

Robust Design of Horizontal Axis Wind Turbines Using Taguchi Method

Volume 6B: Energy ◽

10.1115/imece2015-52093 ◽

2015 ◽

Cited By ~ 3

Author(s):

Singiresu S. Rao

Keyword(s):

Taguchi Method ◽

Wind Turbine ◽

Robust Design ◽

Wind Turbines ◽

Horizontal Axis ◽

Parameter Design ◽

Energy Output ◽

Momentum Theory ◽

The robust design of horizontal axis wind turbines, including both parameter and tolerance designs, is presented. A simple way of designing robust horizontal axis wind turbine systems under realistic conditions is outlined with multiple design variables, multiple objectives, and multiple constraints simultaneously by using the traditional Taguchi method and its extensions. The performance of the turbine is predicted using the axial momentum theory and the blade element momentum theory. In the parameter design stage, the energy output of the turbine is maximized using the Taguchi method and an extended penalty-based Taguchi method is proposed to solve constrained parameter design problems. Using an appropriate set of tolerance settings of the parameters, the tolerance design problem is formulated so as to yield an economical design while ensuring a minimal variability in the performance of the wind turbine. The present work provides a simple and economical approach for the robust optimal design of horizontal axis wind turbines.

Effect of Wind Shear to Horizontal Axis Wind Turbine Aerodynamic

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.521.99 ◽

2014 ◽

Vol 521 ◽

pp. 99-103

Author(s):

Ling Zhang ◽

Hui Xia Sheng ◽

Da Fei Guo

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Wind Shear ◽

Numerical Study ◽

Three Dimensional ◽

Horizontal Axis ◽

Power Calculation ◽

And Performance

A three-dimensional unsteady numerical study of the streaming flow field of the1.2 MW horizontal axis wind turbines which operation in the 11.26 m/s under the uniform wind and the shear wind have been carried out in this paper. according to the simulation results to understand the effect of uniform flow and the dynamic wind shear flow to the output power of wind turbine and the aerodynamics. results showed that: Under the uniform wind,Wind turbine power calculation values are in good agreement with the design value ,Wind turbines under the influence of wind shear can lead to change in load and performance on the surface of the blade.

New System for the Acceleration of the Airflow in Wind Turbines

Recent Patents on Mechanical Engineering ◽

10.2174/2212797612666190311154747 ◽

2019 ◽

Vol 12 (2) ◽

pp. 158-167

Author(s):

Alejandro Alonso-Estébanez ◽

Pablo Pascual-Muñoz ◽

Felipe P. Alvarez Rabanal ◽

Daniel Castro-Fresno ◽

Juan J. Del Coz Díaz

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Horizontal Axis ◽

The Earth ◽

Air Stream ◽

Free Air ◽

Prevailing Wind Direction ◽

Wind Resource

Background: This patent is based on the wind industry technology called Diffuser Augmented Wind Turbines (DAWTs). This technology consists of a horizontal axis wind turbine, which is housed inside a duct with diverging section in the direction of the free air stream. In this paper, a review of preceding patents related to this technology is carried out. Objective: This paper presents an innovative patent to improve the performance of horizontal axis wind turbines. In particular, this system is aimed at improving the performance of those turbines that otherwise might not be installed due to the low wind resource existing at certain locations. Methods: The most innovative elements of this patent are: (1) the semi-spherical grooves, which are mechanized on the surface of the two diffusers in order to guarantee a more energetic boundary layer; (2) the coaxial diffuser, which is located downwind following the first diffuser in order to increase the suction effect on the air mass close to the inlet; (3) the coaxial rings located around the first diffuser outlet, which are used to deflect the external airflow toward the turbine wake; and (4), the selforientating system to orientate the system by the prevailing wind direction. Results: An application of the patent for increasing the power generated by a horizontal axis wind turbine with three blades is presented. The patent is designed and its performance is evaluated by using a Computational Fluid Dynamics code. The numerical results show that this system rises the airflow going through the rotor of the turbine. Conclusion: The patented device is an original contribution aimed at enabling a more profitable installation of wind turbines in places where the wind resource is insufficient because of the wind shear caused both by the proximity of the earth and the obstacles on the earth surface.

Establishing a robust testing approach for displacement measurement on a rotating horizontal axis wind turbine

10.5194/wes-2017-49 ◽

2017 ◽

Cited By ~ 1

Author(s):

Nadia Najafi ◽

Allan Vesth

Keyword(s):

Wind Turbine ◽

Camera Calibration ◽

Wind Turbines ◽

Calibration Method ◽

Horizontal Axis ◽

Tracking Algorithm ◽

Displacement Measurement ◽

Large Field ◽

Abstract. Health monitoring by conventional sensors like accelerometers or strain gauges becomes challenging for large rotating structures due to the feasibility, sensing and data transmission. In addition acceleration measurements have low capability in presenting very small frequencies which happen so often for large structures (For instance frequencies between 0.2 and 0.5 Hz in horizontal axis wind turbines). By contrast the displacement measurement using stereo vision is rapid, non-contacting and also distributed over the structure. The sensors are cheaper and easier to be applied in many places on the object to be measured. Horizontal axis wind turbines are one of the important large rotating structures which need to be measured and monitored in time to prevent damage and failure and the blade tip position is one of the key parameters to measure to prevent blade hitting the turbine tower. This paper presents a well-defined procedure for measuring the displacement on the components of a rotating horizontal axis wind turbine (HAWT) with stereo photometry. Paper markers have been applied on the rotor and tower of a scaled down HAWT model in the workshop and the displacement measurement method has been demonstrated by measuring displacement during operation. The method is mainly developed in two parts: (1) the camera calibration and (2) tracking algorithm. We introduce an efficient camera calibration method for measurement in the large field of views that has always been a challenge. This method is easy and practical and offers better accuracy compared with 2D traditional camera calibration. The tracking algorithm also worked quite successfully and kept tracking the points during rotation within the measurement time.Finally the accuracy analysis has been conducted and has shown the better accuracy of the new calibration method compared with 2D traditional camera calibration.

Blade design for horizontal axis wind turbine: 3D model.

Visión electrónica ◽

10.14483/22484728.14400 ◽

2019 ◽

Vol 13 (1) ◽

pp. 135-143

Author(s):

David Esteban Albadan Molano ◽

Jorge Enrique Salamanca Céspedes

Keyword(s):

Wind Energy ◽

Wind Turbine ◽

Wind Turbines ◽

3D Model ◽

Horizontal Axis ◽

Computer Assisted ◽

Blade Design ◽

Computer Assisted Design ◽

Wind energy is one of the best important sources of renewable energy and an excellent alternative for the transition to sustainable energy that the planet earth needs. The wind energy is contained in the air particles in movement, forming kinetic energy. This energy could be transformed into another type of energy such as electricity, through the use of wind turbines. It is known that horizontal axis wind turbines are more efficient energetically, the power output of a horizontal axis wind turbine depends of it aerodynamic performance; therefore, the correct geometric design of the propeller is essential for an optimum wind turbine. This article analyzes the most relevant aspects in the design of a wind propeller, using MATLAB® software to illustrate its behavior, suggests an ideal airfoil for wind applications to use in the 3D modeling of the blades using the computer assisted design, this blades has been built with a 3D printer.

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

Fast CFD Simulation of Horizontal Axis Wind Turbines

10.1115/gt2010-22724 ◽

2010 ◽

Author(s):

Fabio De Bellis ◽

Luciano A. Catalano ◽

Andrea Dadone

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Cfd Simulation ◽

Flow Distribution ◽

Horizontal Axis ◽

Wall Functions ◽

Mesh Topology ◽

Numerical Predictions ◽

Time Required

The numerical simulation of horizontal axis wind turbines (HAWT) has been analysed using computational fluid dynamics (CFD) with the aim of obtaining reliable but at the same time affordable wind turbine simulations, while significantly reducing required overall resources (time, computational power, user skills), for example in an optimization perspective. Starting from mesh generation, time required to extract preliminary aerodynamic predictions of a wind turbine blade has been shortened by means of some simplifications, i.e.: fully unstructured mesh topology, reduced grid size, incompressible flow assumption, use of wall functions, commercial available CFD package employment. Ansys Fluent software package has been employed to solve Reynolds Averaged Navier Stokes (RANS) equations, and results obtained have been compared against NREL Phase VI campaign data. The whole CFD process (pre-processing, processing, postprocessing) has been analysed and the chosen final settings are the result of a trade-off between numerical accuracy and required resources. Besides the introduced simplifications, numerical predictions of shaft torque, forces and flow distribution are in good agreement with experimental data and as accurate as those calcuted by other more sophisticated works.

Performance Enhancement Analysis of a Horizontal Axis Wind Turbine by Vortex Trapping Cavity

Journal of Energy Resources Technology ◽

10.1115/1.4052980 ◽

2021 ◽

pp. 1-13

Author(s):

Khaoula Qaissi ◽

Omer A Elsayed ◽

Mustapha Faqir ◽

Elhachmi Essadiqi

Keyword(s):

Wind Turbine ◽

Performance Enhancement ◽

Lift Coefficient ◽

Separated Flow ◽

National Renewable Energy Laboratory ◽

Wake Region ◽

High Twist ◽

Wind Speeds ◽

Nrel Phase Vi

Abstract A wind turbine blade has the particularity of containing twisted and tapered thick airfoils. The challenge with this configuration is the highly separated flow in the region of high twist. This research presents a numerical investigation of the effectiveness of a Vortex Trapping Cavity (VTC) on the aerodynamics of the National renewable Energy laboratory (NREL) Phase VI wind turbine. First, simulations are conducted on the S809 profile to study the fluid flow compared to the airfoil with the redesigned VTC. Secondly, the blade is simulated with and without VTC to assess its effect on the torque and the flow patterns. The results show that for high angles of incidence at Rec=106, the lift coefficient increases by 10% and the wake region appears smaller for the case with VTC. For wind speeds larger than 10 m/s, the VTC improves the torque by 3.9%. This is due to the separation that takes place in the vicinity of the VTC and leads to trapping early separation eddies inside the cell. These eddies roll up forming a coherent laminar vortex structure, which in turn sheds periodically out of the cell. This phenomenon favourably reshapes excessive flow separation, reenergizes the boundary layer and globally improves blade torque.