scholarly journals Aerodynamic analysis of backward swept in HAWT rotor blades using CFD

2018 ◽  
Vol 7 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Mohammad Sadegh Salari ◽  
Behzad Zarif Boushehri ◽  
Mehrdad Boroushaki

The aerodynamical design of backward swept for a horizontal axis wind turbine blade has been carried out to produce more power at higher wind velocities. The backward sweep is added by tilting the blade toward the air flow direction. Computational Fluid Dynamics (CFD) calculations were used for solving the conservation equations in one outer stationary reference frame and one inner rotating reference frame, where the blades and grids were fixed in reference to the rotating frame. The blade structure was validated using Reynolds Averaged Navier-Stokes (RANS) solver in a test case by the National Renewable Energy Laboratory (NREL) VI blades results. Simulation results show considerable agreement with the NREL measurements. Standard K-ε turbulence model was chosen for simulations and for the backward swept design process. A sample backward sweep design was applied to the blades of a Horizontal Axis Wind Turbine (HAWT) rotor, and it is obtained that although at the lower wind velocities the output power and the axial thrust of the rotor decrease, at the higher wind velocities the output power increases while the axial thrust decreases. The swept blades have shown about 30 percent increase in output power and about 12 percent decrease in thrust at the wind speed of 14 m/s.Article History: Received June 23rd 2018; Received in revised form Sept 16th 2018; Accepted October 1st 2018; Available onlineHow to Cite This Article: Salari, M.S., Boushehri, B.Z. and Boroushaki, M. (2018). Aerodynamic Analysis of Backward Swept in HAWT Rotor Blades Using CFD. International Journal of Renewable Energy Development, 7(3), 241-249.http://dx.doi.org/10.14710/ijred.7.3.241-249

2021 ◽  
Vol 1 (1) ◽  
pp. 24-29
Author(s):  
Najma Safienatin Najah ◽  
Arief Muliawan ◽  
Febria Anita

A horizontal axis wind turbine design research has been carried out using an inverter. This study aims to generate the output power generated by the generator through an inverter. So that the use of an inverter can turn on the 10 watt lamp. From the research results obtained turbine rotation varied between 1357 rpm to 2415 rpm producing a generator voltage of 3.05 volts to 4.61 volts and generator currents 32mA up to 49 mA. The inverter produces a voltage of 16.57 volts up to 20.46 volts and an inverter current of 0.60 amperes up to 0.48 amperes. The greater the rotation of the wind turbine turbine, the greater the generator voltage generated and so is the voltage of the inverter. While the current will increase as the turbine rotation increases and the inverse of the inverter current will decrease as the turbine rotation increases.


Author(s):  
Ibtissem Barkat ◽  
Abdelouahab Benretem ◽  
Fawaz Massouh ◽  
Issam Meghlaoui ◽  
Ahlem Chebel

This article aims to study the forces applied to the rotors of horizontal axis wind turbines. The aerodynamics of a turbine are controlled by the flow around the rotor, or estimate of air charges on the rotor blades under various operating conditions and their relation to the structural dynamics of the rotor are critical for design. One of the major challenges in wind turbine aerodynamics is to predict the forces on the blade as various methods, including blade element moment theory (BEM), the approach that is naturally adapted to the simulation of the aerodynamics of wind turbines and the dynamic and models (CFD) that describes with fidelity the flow around the rotor. In our article we proposed a modeling method and a simulation of the forces applied to the horizontal axis wind rotors turbines using the application of the blade elements method to model the rotor and the vortex method of free wake modeling in order to develop a rotor model, which can be used to study wind farms. This model is intended to speed up the calculation, guaranteeing a good representation of the aerodynamic loads exerted by the wind.


Author(s):  
P. Venkaiah ◽  
B. K. Sarkar

Abstract The advantages of renewable energy sources are available freely in nature, inexhaustible, produce either no or little pollution and low gestation period. Among all renewable energy sources, wind energy has become one of the leading resources for power production in the world as well as in the India. According to WWEA, the wind turbine installation capacity in the world has been reached over 539.291GW by the end of 2017. The entire wind power installed capacity by the end of 2017 covers more than 5% of global demand of electricity. In India, the present wind power installation capacity on October, 2017 was over 32.7GW and wind energy contribution is 55% of the total renewable energy capacity in the country. Inspite of having sharp growth rate in wind in India, only a fraction of wind energy has been tapped until now out of 302 GW wind potential which is available above 100 m height on shore. Practical horizontal axis wind turbine converts kinetic energy in the wind into useful energy by using airfoil blades. Blade element momentum (BEM) theory becomes very popular due to its simplicity in mathematical calculation as well as accuracy. Hydraulic pitch actuation system has certain advantages due to its versatility, ability to produce constant force and torque irrespective of the disturbances outside of the system, ease and accuracy of control, simplicity, safety and economy. In the present study a semi rotary actuator has been utilized for turbine pitch actuation. In order to extract maximum power from available wind, fractional order PID controller (FOPID) has been developed for pitch control of wind turbine rotor blade. The performances of PID as well as FOPID controller have been compared with available wind data. The performance of FOPID controller was satisfactory compare to PID controller.


2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Ali M. Abdelsalam ◽  
W. A. El-Askary ◽  
M. A. Kotb ◽  
I. M. Sakr

Abstract This article aims to study numerically the effect of curvature of linear blade profile on the performance of small-scale horizontal axis wind turbine (SSHAWT). Rotors with two curvature types, f forward angles 5 deg, 10 deg, 15 deg, 20 deg, 30 deg, and 45 deg and backward angles −5 deg, −10 deg, and −15 deg, are investigated. Furthermore, three curvature positions of r/R = 0.8, 0.9, and 0.95 are studied. The numerical simulations are performed on rotors of radius 0.5 m at different wind speeds. The results are compared with straight rotor of linear profiles of chord and twist, which is considered as base rotor. It is found that the rotor with forward curvature of 5 deg and r/R = 0.9 has the highest power coefficient compared with the other rotors. At the peak performance, the proposed rotor reduces the axial thrust by about 12.5% compared with the base rotor. The flow behavior represented by the streamlines contours is also discussed. In such case, the separation approximately disappeared for the tip speed ratios of 5 and 6, which is responsible for the performance peak.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4983 ◽  
Author(s):  
Miguel Sumait Sy ◽  
Binoe Eugenio Abuan ◽  
Louis Angelo Macapili Danao

Wind energy is one of the fastest growing renewable energy sources, and the most developed energy extraction device that harnesses this energy is the Horizontal Axis Wind Turbine (HAWT). Increasing the efficiency of HAWTs is one important topic in current research with multiple aspects to look at such as blade design and rotor array optimization. This study looked at the effect of wingtip devices, a split winglet, in particular, to reduce the drag induced by the wind vortices at the blade tip, hence increasing performance. Split winglet implementation was done using computational fluid dynamics (CFD) on the National Renewable Energy Lab (NREL) Phase VI sequence H. In total, there are four (4) blade configurations that are simulated, the base NREL Phase VI sequence H blade, an extended version of the previous blade to equalize length of the blades, the base blade with a winglet and the base blade with split winglet. Results at wind speeds of 7 m/s to 15 m/s show that adding a winglet increased the power generation, on an average, by 1.23%, whereas adding a split winglet increased it by 2.53% in comparison to the extended blade. The study also shows that the increase is achieved by reducing the drag at the blade tip and because of the fact that the winglet and split winglet generating lift themselves. This, however, comes at a cost, i.e., an increase in thrust of 0.83% and 2.05% for the blades with winglet and split winglet, respectively, in comparison to the extended blade.


2012 ◽  
Vol 608-609 ◽  
pp. 658-661
Author(s):  
Xian Yi ◽  
Kun Chen ◽  
Kai Chun Wang ◽  
Hong Lin Ma

A design approach of ice detection system for wind turbine is presented in this paper. Basic steps for design are proposed. Numerical arithmetic used for design configuration and shape of the icing prober is given. The arithmetic is composed of the Multiple Reference Frame (MRF) method to calculate flowfield of air, a Lagrangian method to compute droplet trajectories and a technique for fast computing ice accretion. Icing prober configuration for a 1.5 MW horizontal axis wind turbine is then obtained with the approach. The state of wind turbine icing can be reflected by the prober in real time. All these achievements build a good base for future research.


Author(s):  
Antonio Velazquez ◽  
R. Andrew Swartz

Horizontal axis wind turbine (HAWTs) structures, throughout the years, have presumed to be of relatively simple construction, but wind-induced aerodynamic vibrations, wind-field conditions, and power requirements tend to lead to the need for increasingly complicated designs. One phenomenon that requires special attention is the gyroscopic or Coriolis effect. In general, blades design codes are written to optimize for lightness and slenderness, but also to withstand excitations at high frequency. As a result, gyroscopic motion derives as a nonlinear dynamic condition in the out-of-plane direction that is difficult to characterize by means of the well-known vibrational theory that has been established for their design and analysis. The present study develops and presents a probabilistic analysis of the precession — gyroscopic — effects of a wind turbine model developed for tapered-swept cross-sections of nt degree with nonlinear variations of mass and geometry along the body of the blade. A dynamic orthogonal decoupling method is utilized to successfully perform the aeroelastic analysis by decoupling the damped-gyroscopic equations of motion, as a result of the addition of Rayleigh damping — symmetric proportional mass and stiffness — within the linear system in study. Results are valid for yaw-free rotor configurations by means of unknown and random (though bounded) yaw rates. Simultaneously, those results can easily be expanded for yaw-controlled mechanisms. The yaw-free assumption presents a higher risk of potential reliability expectations, given the stochastic impairment of the gyroscopic nature that is present for out-of-plane axis motions, requiring special attention at higher frequencies. This impairment becomes particularly troublesome for blade profiles with tapered-swept cross-section variations. This uncertainty can be minimized by incorporating a mathematical framework capable of characterizing properly the yaw action such that gyroscopic effects can be fully interpreted and diagnosed. In summary, the main goal is to decipher the complexity of gyroscopic patterns of flexible rotor blades with complex shape configurations, but also to provide substantial elements to successfully approach yaw-mechanics of tapered-swept rotor blades.


1994 ◽  
Vol 116 (2) ◽  
pp. 287-292 ◽  
Author(s):  
Yukimaru Shimizu ◽  
Takaya Yoshikawa ◽  
Shinji Matsumura

This paper describes the experimental results of output power augmentation of a horizontal axis wind turbine with a tip vane. In order to find the relationship between the performance of the turbine and the configuration of the tip vane, various types and sizes were used. It was found that V-type and S-type tip vanes can improve turbine performance. Also, the dimensions of V- and S-type tip vanes were investigated. The maximum improvement achieved was a 25 percent increase in power in an existing wind turbine without a tip vane.


Sign in / Sign up

Export Citation Format

Share Document