scholarly journals Fluctuations of angle of attack and lift coefficient and the resultant fatigue loads for a large Horizontal Axis Wind turbine

2017 ◽  
Vol 114 ◽  
pp. 904-916 ◽  
Author(s):  
Abdolrahim Rezaeiha ◽  
Ricardo Pereira ◽  
Marios Kotsonis
Keyword(s):  
Wind Turbine ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Fatigue Loads

scholarly journals Development and Validation of Aerodynamic Measurement on a Horizontal Axis Wind Turbine in the Field

2019 ◽  
Vol 9 (3) ◽  
pp. 482 ◽  
Author(s):  
Guangxing Wu ◽  
Lei Zhang ◽  
Ke Yang
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Near Field ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Engineering Thermophysics ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Sideslip Angle

Aerodynamic measurement on horizontal axis wind turbines in the field is a challenging research topic and also an essential research method on the aerodynamic performance of blades in real atmospheric inflow conditions. However, the angle of attack is difficult to determine in the field due to the unsteadiness and unevenness of the inflow. To study the measuring and analyzing method of angle of attack in the field, a platform was developed based on a 100 kW wind turbine from the Institute of Engineering Thermophysics (IET) in China in this paper. Seven-hole probes were developed and installed at the leading edge to measure the inflow direction, static and total pressure at the near field. Two data reducing processes, sideslip angle correction, and induced velocity correction, were proposed to determine the effective angle of attack based on the inflow data measured by probes. The aerodynamic measurement platform was first validated by the comparison with wind tunnel results. Then some particular aerodynamic phenomenon in the field were discussed. As a result, the angle of attack varies quasi-periodically with the rotation of the rotor, which is caused by the yaw angle of the inflow. The variation of angle of attack induces dynamic response of a clockwise hysteresis loop in lift coefficient. The dynamic response is the main source of a dispersion of instantaneous lift coefficients with a standard deviation of 0.2.

scholarly journals Numerical investigation of stall characteristics for winglet blade of a horizontal axis wind turbine

2021 ◽  
Vol 321 ◽  
pp. 03004
Author(s):  
Shalini Verma ◽  
Akshoy Ranjan Paul ◽  
Anuj Jain ◽  
Firoz Alam
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Numerical Investigation ◽  
Turbulence Intensity ◽  
Geometric Modeling ◽  
Cfd Simulation ◽  
Lift Coefficient ◽  
Horizontal Axis ◽  
Renewable Energy Resources ◽  
Horizontal Axis Wind Turbine

Wind energy is one of the renewable energy resources which is clean and sustainable energy and the wind turbine is used for harnessing energy from the wind. The blades are the key components of a wind turbine to convert wind energy into rotational energy. Recently, wingtip devices are used in the blades of horizontal axis wind turbine (HAWT), which decreases the vortex and drag, while increases the lift and thereby improve the performance of the turbine. In the present study, a winglet is used at the tip of an NREL phase VI wind turbine blade. Solidworks, Pointwise, and Ansys-Fluent are used for geometric modeling, computational grid generation, and CFD simulation, respectively. The computational result obtained using SST k-ω turbulence modeling is well validated with the experimental data of NREL at 5 and 7 m/s of wind speeds. Numerical investigation of stall characteristics is carried out for wingleted blade at higher turbulence intensity (21% and 25%) and angle of attack (00 to 300 at 50 intervals) at 7 m/s wind speed. The result found that wingletd blade delay stall to 150 for both the cases of turbulence intensity. Increasing the turbulence intensity increases the lift coefficient at stall angle but drag coefficient also increases and thus a lower aerodynamic performance (CL/CD ratio = 13) is obtained. Wingleted blade improves the performance as the intensity of vortices is smaller compared to baseline blade

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 Techniques for the Determination of Local Dynamic Pressure and Angle of Attack on a Horizontal Axis Wind Turbine

10.2172/61151 ◽  
1995 ◽  
Author(s):  
Derek E. Shipley ◽  
Mark S. Miller ◽  
Michael C. Robinson ◽  
Marvin W. Luttges ◽  
David A. Simms
Keyword(s):  
Wind Turbine ◽  
Dynamic Pressure ◽  
Angle Of Attack ◽  
Horizontal Axis ◽  
Local Dynamic ◽  
Horizontal Axis Wind Turbine

A New Method for Horizontal Axis Wind Turbine Angle of Attack Determination

2013 ◽  
Vol 291-294 ◽  
pp. 425-428 ◽  
Author(s):  
Mohammad Moshfeghi ◽  
Kun Lu ◽  
Yong Hui Xie
Keyword(s):  
Wind Turbine ◽  
High Velocity ◽  
Normal Force ◽  
Data Extraction ◽  
Angle Of Attack ◽  
Horizontal Axis ◽  
New Method ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Nrel Phase Vi

This paper proposes a new method for horizontal axis wind turbine (HAWT) angle of attack (AOA) determination. Despite common circular planes for data extraction, here, data is extracted on rectangular planes. NREL Phase VI is used for validation of the method. Results show that even in a high velocity wind the proposed plane can be an appropriate choice. Furthermore, the average radial distributions of axial and tangential induction factors are calculated based on the velocity values at the planes. Moreover, local normal force coefficients are calculated and then, the local AOA are compared with 2D results and other 3D values for different wind speeds.

Flapwise and Edgewise Blade Loads Analysis of HAWT Rotor by Using Fluid-Oscillation Coupled Calculation Model

2011 ◽  
Author(s):  
Yutaka Hasegawa ◽  
Yusuke Takagi ◽  
Junsuke Murata ◽  
Koji Kikuyama
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Calculation Model ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Aerodynamic Loads ◽  
Coupled Calculation ◽  
Fluid Oscillation ◽  
Fatigue Loads ◽  
Inflow Conditions

A horizontal axis wind turbine suffers fluctuating aerodynamic loads, which result in oscillations of the rotor blades. Since the blade oscillation has considerable effects on the blade fatigue life, the influence on the fatigue loads from the interaction between the aerodynamic loads and the structural oscillations should be considered in the design process of the wind turbine rotor. The objective of this work is to analyze the aerodynamic effects on the fatigue loads of rotor blade due to structural oscillation and inflow conditions, by using numerical calculation method. This paper explains a calculation model which can estimate the aerodynamic loads on the rotor blade of the horizontal axis wind turbine in the inflow conditions with the turbulence and yawed misalignment. The fluid-oscillation coupled calculation has been performed for the geometry of the NREL test turbine. The calculated results are compared with the experimental results to evaluate the validity of the calculation model.

scholarly journals Design and Fabrication of Small Horizontal axis wind Turbine Rotors at Low Reynolds Number

2019 ◽  
Vol 8 (12) ◽  
pp. 4454-4463 ◽  
Keyword(s):  
Reynolds Number ◽  
Wind Turbine ◽  
Low Reynolds Number ◽  
Angle Of Attack ◽  
Horizontal Axis ◽  
Speed Ratio ◽  
Horizontal Axis Wind Turbine ◽  
Tip Speed Ratio ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This research paper presents a design and fabrication of 100 Watt small horizontal axis wind turbine with 0.24 m and 0.35 m rotor radius and tip speed ratio varies from 2 to 10 was designed and development for operated at low wind speed with Low Reynolds number. In this paper, a new airfoil profile was designed and developed, it’s denoted by MK115. The numerical and experimental analysis for 6 airfoils using Xfoil software was conducted with a view to evaluating the lift-to-drag ratio and angle of attack by means of the SD7024, SG6043, NACA2412, S1210, E213, and New Airfoil (MK115) tested. In simulation, new MK115 airfoil was the most convenient airfoil to start high energy production for low-wind applications, on the Reynolds number 25000, 50000, 75000, and 100000 in improved airfoil (MK115) tests an Open type wind tunnel. An Xfoil analysis to obtain further data on the flow characteristics was also conducted. (MK115) airfoil have CLmax of 0.92, 1.25, 1.69, 1.67 at Re=25k, 50k, 75k and 100k for an angle of attack is equal to 100 .A maximum lift to drag ratio (Cl/Cd) of 7,16,50,63 at Re=25k, 50k, 75k and 100k for New airfoil (MK115) at angle of attack (α) =40 , 40 , 80 , 80 . SG6043, NACA2412, E214, SD7034, S1210 and MK115 (New airfoil) have the Maximum Cp=0.37, 0.36, 0.4, 0.39, 0.44, and 0.44 at tip speed ratio (λ) =6 for Reynolds number is equal to 100000. MK115, Maximum Torque obtained 0.9744 Nm, 1.389 Nm and 2.4866 Nm at blade angle =0, 15 and 30 degrees respectively. Power coefficient (Cp) =0.51, 0.5, 0.46, and 0.4 at Rotor shaft angle=00 , 50 , 100 , and 150 respectively for the new airfoil results.

scholarly journals Horizontal axis wind turbine modelling and data analysis by multilinear regression

2020 ◽  
Vol 11 (2) ◽  
pp. 447-464
Author(s):  
Paulaiyan Tittus ◽  
Paul Mary Diaz
Keyword(s):  
Regression Analysis ◽  
Wind Turbine ◽  
Lift Coefficient ◽  
Operating Conditions ◽  
Horizontal Axis ◽  
Design Parameters ◽  
Multilinear Regression ◽  
Horizontal Axis Wind Turbine ◽  
Multilinear Regression Analysis ◽  
Turbine Performance

Abstract. The modelling of each horizontal axis wind turbine (HAWT) differs due to variation in operating conditions, dynamic parameters, and components. Thus, the choice of profiles also varies for specific applications. So for the better choice of profiles, the wind turbine performance is analysed for different parameters and working conditions. The efficiency of HAWTs mainly depends on the blade, which in turn is related to the profile of the blade, blade orientation, and tip size. Hence, the main aim of the present work is to evaluate the performance of HAWTs for three different blade tip sizes and six different blade twist angles for three major NACA (National Advisory Committee for Aeronautics) airfoils. A statistical analysis is also carried out to find the influence of different performance parameters such as drag, lift, vorticity, and normal force. The static design parameters are considered based on the available literature. A three-bladed offshore HAWT is adopted as the research object in the study. Data visualization using star glyphs and sunray plots is performed, along with multilinear regression analysis. From the multilinear regression analysis and reliable empirical correlations, it is known that drag coefficient and lift coefficient parameters have less significance in contrast to the other parameters which have more significance in the regression model. The different results obtained in terms of parametric coefficients provide an effective way to generate appropriate airfoil profiles for given HAWTs. Thus, the study helps to achieve better turbine performance, and it serves as a benchmark for future studies on HAWTs.

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