scholarly journals Numerical Study of Nacelle Wind Speed Characteristics of a Horizontal Axis Wind Turbine under Time-Varying Flow

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3993 ◽  
Author(s):  
Xiaodong Wang ◽  
Yunong Liu ◽  
Luyao Wang ◽  
Lin Ding ◽  
Hui Hu
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Wake Flow ◽  
Horizontal Axis Wind Turbine ◽  
Inlet Flow ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Speed Condition ◽  
Simulation Results

Nacelle wind speed transfer function (NTF) is usually used for power prediction and operational control of a horizontal axis wind turbine. Nacelle wind speed exhibits high instability as it is influenced by both incoming flow and near wake of a wind turbine rotor. Enhanced understanding of the nacelle wind speed characteristics is critical for improving the accuracy of NTF. This paper presents Reynolds-averaged Navier–Stokes (RANS) simulation results obtained for a multi-megawatt wind turbine under both stable and dynamic incoming flows. The dynamic inlet wind speed varies in the form of simplified sinusoidal and superposed sinusoidal functions. The simulation results are analyzed in time and frequency domains. For a stable inlet flow, the variation of nacelle wind speed is mainly influenced by the blade rotation. The influence of wake flow shows high frequency characteristics. The results with stable inlet flow show that the reduction of the nacelle wind speed with respect to the inlet wind speed is overestimated for low wind speed condition, and underestimated for high wind speed condition. Under time-varing inflow conditions, for the time scale and fluctuation amplitude subject to the International Electrotechnical Commission (IEC) standard, the nacelle wind speed is mainly influenced by the dynamic inflow. The variation of inflow can be recovered by choosing a suitable low pass filter. The work in this paper demonstrates the potential for building accurate NTF based on Computational Fluid Dynamics (CFD) simulations and signal analysis.

scholarly journals Investigation of an Innovative Rotor Modification for a Small-Scale Horizontal Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2649 ◽  
Author(s):  
Artur Bugała ◽  
Olga Roszyk
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Airflow Distribution

This paper presents the results of the computational fluid dynamics (CFD) simulation of the airflow for a 300 W horizontal axis wind turbine, using additional structural elements which modify the original shape of the rotor in the form of multi-shaped bowls which change the airflow distribution. A three-dimensional CAD model of the tested wind turbine was presented, with three variants subjected to simulation: a basic wind turbine without the element that modifies the airflow distribution, a turbine with a plano-convex bowl, and a turbine with a centrally convex bowl, with the hyperbolic disappearance of convexity as the radius of the rotor increases. The momentary value of wind speed, recorded at measuring points located in the plane of wind turbine blades, demonstrated an increase when compared to the base model by 35% for the wind turbine with the plano-convex bowl, for the wind speed of 5 m/s, and 31.3% and 49% for the higher approaching wind speed, for the plano-convex bowl and centrally convex bowl, respectively. The centrally convex bowl seems to be more appropriate for higher approaching wind speeds. An increase in wind turbine efficiency, described by the power coefficient, for solutions with aerodynamic bowls was observed.

Optimal Design of Horizontal Axis Wind Turbine Blades

2008 ◽  
Author(s):  
Ohad Gur ◽  
Aviv Rosen
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Design Method ◽  
Turbine Blades ◽  
Horizontal Axis ◽  
Optimization Strategy ◽  
Wind Turbine Blades ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Design Variables

The optimal aerodynamic design of Horizontal Axis Wind Turbine (HAWT) is investigated. The Blade-element/Momentum model is used for the aerodynamic analysis. In the first part of the paper a simple design method is derived, where the turbine blade is optimized for operation at a specific wind speed. Results of this simple optimization are presented and discussed. Besides being optimized for operation at a specific wind speed, without considering operation at other wind speeds, the simple model is also limited in the choice of design goals (cost functions), design variables and constraints. In the second part of the paper a comprehensive design method that is based on a mixed numerical optimization strategy, is presented. This method can handle almost any combination of: design goal, design variables, and constraints. Results of this method are presented, compared with the results of the simple optimization, and discussed.

scholarly journals Experimental investigations of winglet effects on blade geometry of small horizontal axis wind turbine rotors

2021 ◽  
Author(s):  
Manoj Kumar Chaudhary ◽  
◽  
S. Prakash ◽  
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Lift Coefficient ◽  
Research Work ◽  
Operating Conditions ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Experimental Investigations ◽  
Horizontal Axis Wind Turbine ◽  
Blade Geometry

In this research work, the investigation and optimization of small horizontal axis wind turbine blade at low wind speed is pursued. The experimental blades were developed using the 3D printing additive manufacturing technique. The airfoils E210, NACA2412, S1223, SG6043, E216, NACA4415, SD7080, SD7033, S1210 and MAF were tested at the wind speed of 2-6 m/s. The airfoils and optimum blade geometry were investigated with the aid of the Xfoil software at Reynolds number of 100,000. The initial investigation range included tip speed ratios from 3 to 10, solidity from 0.0431 – 0.1181 and angle of attacks from 2o to 20o. Later on these parameters were varied in MATLAB and Xfoil software for optimization and investigation of the power coefficient, lift coefficient, drag coefficient and lift to drag ratio. The cut-in wind speed of the rotors was 2 and 2.5 m/s with the winglet-equipped blades and without winglets. It was found that the E210, SG6043, E216 NACA4415 and MAF airfoil displayed better performance than the NACA 2412, S1223, SD7080, S1210 & SD7003 for the geometry optimized for the operating conditions and manufacturing method described.

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.

scholarly journals Parametric study of a horizontal axis wind turbine with similar characteristics to those of the Villonaco wind power plant

2021 ◽  
Vol 2 (2) ◽  
pp. 51
Author(s):  
Santiago Sánchez ◽  
Victor Hidalgo ◽  
Martin Velasco ◽  
Diana Puga ◽  
P. Amparo López-Jiménez ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Energy Production ◽  
Electrical Energy ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Electrical Energy Production ◽  
Python Programming ◽  
Selection Of

<p class="JAREAbstract">The present paper focuses on the selection of parameters that maximize electrical energy production of a horizontal axis wind turbine using Python programming language. The study takes as reference turbines of Villonaco wind field in Ecuador. For this aim, the Blade Element Momentum (BEM) theory was implemented, to define rotor geometry and power curve. Furthermore, wind speeds were analyzed using the Weibull probability distribution and the most probable speed was 10.50 m/s. The results were compared with mean annual energy production of a Villonaco’s wind turbine to validate the model. Turbine height, rated wind speed and rotor radius were the selected parameters to determine the influence in generated energy. Individual increment in rotor radius and rated wind speed cause a significant increase in energy produced. While the increment in turbine’s height reduces energy generated by 0.88%.</p>

scholarly journals Influence of the Heights of Low-Level Jets on Power and Aerodynamic Loads of a Horizontal Axis Wind Turbine Rotor

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 132 ◽  
Author(s):  
Xuyao Zhang ◽  
Congxin Yang ◽  
Shoutu Li
Keyword(s):  
Wind Speed ◽  
Power Spectrum ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Aerodynamic Loads ◽  
Low Level ◽  
Low Level Jets ◽  
Inflow Conditions ◽  
Swept Area

The influence of the heights of low-level jets (LLJs) on the rotor power and aerodynamic loads of a horizontal axis wind turbine were investigated using the fatigue, aerodynamics, structures, and turbulence code. The LLJ and shear inflow wind fields were generated using an existing wind speed spectral model. We found that the rotor power predicted by the average wind speed of the hub height is higher than the actual power in relatively weak and shallow LLJ inflow conditions, especially when the LLJ height is located inside the rotor-swept area. In terms of aerodynamic loads, when the LLJ height is located inside the rotor-swept area, the root mean square (RMS) rotor thrust coefficient and torque coefficient increase, while the RMS rotor unbalanced aerodynamic load coefficients, including lateral force, longitudinal force, tilt moment, and yaw moment, decreased. This means that the presence of both positive and negative wind shear in the rotor-swept area not only increases the rotor power but also reduces the unbalanced aerodynamic loads, which is beneficial to the operation of wind turbine. Power spectrum analysis shows no obvious difference in the power spectrum characteristics of the rotor torque and thrust in LLJ inflow conditions with different heights.

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