scholarly journals Parametric study of flapwise and edgewise vibration of horizontal axis wind turbine blades

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110508
Author(s):  
Hamza Diken ◽  
Saeed Asiri
Keyword(s):  
Wind Turbine ◽  
Natural Frequency ◽  
Pitch Angle ◽  
Natural Frequencies ◽  
Slenderness Ratio ◽  
Ritz Method ◽  
Lagrange Function ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Small Pitch

In this paper, flapwise and edgewise vibrations of a horizontal axis wind turbine (HAWT) blade are studied. Rayleigh-Ritz method is used in which; orthogonal mode functions of the Euler-Bernoulli beam having fixed-free boundary are introduced into the Lagrange function and then the dynamic equations are derived. Effect of gravity, pitch angle, centrifugal stiffening, and rotary inertia are considered. Nondimensional equations are obtained by defining nondimensional parameters like; natural frequency, blade rotation, slenderness ratio, and simple pendulum frequency. The stiffness term of the natural frequency has two speed dependent elements and it is shown that, for small pitch angles, flapwise natural frequencies of the blade are increased by the increasing blade speed while the edgewise natural frequencies of the blade are decreased with the increasing blade speed. Pitch angle values ranging from 0° to 15° has negligible effect on the nondimensional natural frequencies of the blade up to the nondimensional blade speed of 4. Since the natural frequencies are the function of the blade speed, rotor critical speeds should be calculated with Campbell diagrams. Vibrational response of the blade tip to the gravity is dominant and much greater than that of the wind speed in the edgewise and flapwise vibration.

scholarly journals Airfoil optimization for small horizontal axis wind turbine

2021 ◽  
Vol 19 ◽  
pp. 505-510
Author(s):  
Cristhian Leonardo Pabón Rojas ◽  
◽  
Carlos Andrés Trujillo Suarez ◽  
Juan Carlos Serrano Rico ◽  
Elkin Gregorio Flórez Serrano ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Pitch Angle ◽  
Horizontal Axis ◽  
Middle Zone ◽  
Horizontal Axis Wind Turbine ◽  
Airfoil Optimization ◽  
Low Wind Speed ◽  
Gradient Based ◽  
Blade Element

In order to take advantage of the low wind speed found in the Colombian territory, a gradient-based optimization process (GBA) of 2 airfoils is carried out, using the Xfoil software to evaluate the interactions. The shapes chosen will be destined for the root and for the middle zone of a blade for a small horizontal axis wind turbine (sHAWT). The blade will be created from the calculation of the chord and pitch angle with the blade element momentum methodology (BEM) and the SHAWT will be tested by CFD software to check its performance. As a preliminary result, a root-bound airfoil has been obtained with a higher performance than the airfoil used as a bases.

Modal Analysis of the 1.5MW Wind Turbine Tower

2013 ◽  
Vol 712-715 ◽  
pp. 1494-1500
Author(s):  
Bi Feng Cao ◽  
Hui Yu
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Excitation Frequency ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Finite Element Software ◽  
Wind Turbine Tower ◽  
Tower Model

The paper uses the finite element software ANSYS to establish a 1.5 MW horizontal-axis wind turbine tower model as an example and works on the modal analysis. The modal analysis takes into account the totalmass of wind rotor and nacelle and assumes the bottom of the wind turbine tower is fully constrained. The result shows that the natural frequency of the 1.5MW wind turbine tower is not coincident with the excitation frequency of the wind turbine, and the wind turbine can operate stably at the design condition.

scholarly journals Effect of blade pitch angle on the aerodynamic characteristics of a twisted blade horizontal axis wind turbine based on numerical simulations

2021 ◽  
Vol 12 (1) ◽  
pp. 511
Author(s):  
Rajendra Roul ◽  
Awadhesh Kumar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Angular Velocity ◽  
Wind Turbine ◽  
Pitch Angle ◽  
Aerodynamic Characteristics ◽  
Horizontal Axis ◽  
Performance Parameters ◽  
Horizontal Axis Wind Turbine ◽  
The Impact

The present work includes a study of the impact of varying pitch angles and angular velocity on the performance parameters of a horizontal axis wind turbine using computational fluid dynamics. Simulations have been made using commercial Ansys 15 software. Seven pitch angles are chosen for study, i.e., 0° , 5 ° , 10° , 15° , 20° , 25° , and 28°, and two angular velocity values of 1.57 rad/sec and 2.22 rad/sec are used for simulation. The turbulence model used is shear stress transport (SST) K-ω. A detailed study of the influence of pitch angle on the aerodynamic characteristics of the wind turbine is highlighted. Performance parameters like torque and power have been found to exhibit random variability with a change in wind velocity and pitch angle. The verification of computational fluid dynamics (CFD) with the standard empirical formula is highlighted. The best pitch angle is noted for the best power coefficient.

scholarly journals Comparative study: Pitch angle variation for making power curve and search maximum power of horizontal axis wind turbine

2020 ◽  
Author(s):  
Langlang Gumilar ◽  
Arif Nur Afandi ◽  
Quota Alief Sias ◽  
Wahyu Sapto Nugroho ◽  
Mokhammad Sholeh ◽  
...  
Keyword(s):  
Comparative Study ◽  
Wind Turbine ◽  
Pitch Angle ◽  
Horizontal Axis ◽  
Maximum Power ◽  
Power Curve ◽  
Horizontal Axis Wind Turbine ◽  
Angle Variation

scholarly journals Wake Effect of a Horizontal Axis Wind Turbine on the Performance of a Downstream Turbine

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2395 ◽  
Author(s):  
Haojun Tang ◽  
Kit-Ming Lam ◽  
Kei-Man Shum ◽  
Yongle Li
Keyword(s):  
Wind Turbine ◽  
Tangential Velocity ◽  
Streamwise Velocity ◽  
Horizontal Axis ◽  
Wake Flow ◽  
Wake Effect ◽  
Horizontal Axis Wind Turbine ◽  
Small Pitch ◽  
Swept Area ◽  
Wake Characteristics

This paper presents wind tunnel tests on the wake characteristics of a three-blade horizontal axis wind turbine and the wake effect on the performance of a downstream turbine. For a single turbine model, the performance was determined and this was followed by measurement of the wind characteristics including velocities, turbulence intensities, and correlation in the wake flow field. Subsequently, taking two horizontal axis wind turbines in a tandem arrangement into account, their performance was tested and the aerodynamic mechanism was discussed. The results showed that the upstream turbine with blades set at a small pitch angle provided smaller disturbance to the flow, but as the blade turned faster, larger changes in the velocity and the turbulence intensity occurred in its wake due to the more frequent disturbance of the wind turbine. The correlation of wake velocities in the turbine swept area also obviously decreased from the free-stream situation. For the downstream turbine, the output power loss largely depended on the wake characteristics of the upstream turbine, which was closely related to lower wind velocities or higher turbulence intensities. The decrease in correlation of the streamwise velocity within the blade swept area is accompanied by the increased correlation of the tangential velocity, which may be beneficial to the downstream turbine’s performance.

Withdrawal: Computations of Aerodynamic Behaviour of Small Horizontal Axis Wind Turbine with NACA4418 airfoil

2019 ◽  
Author(s):  
Essam E. Khalil ◽  
Gamal E. ElHarriri ◽  
Eslam E. AbdelGhany ◽  
Moemen E. Farghaly
Keyword(s):  
Wind Turbine ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine
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