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
2013 ◽  
Vol 291-294 ◽  
pp. 425-428 ◽  
Author(s):  
Mohammad Moshfeghi ◽  
Kun Lu ◽  
Yong Hui Xie

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.


2020 ◽  
Vol 5 (4) ◽  
pp. 1771-1792
Author(s):  
Rodrigo Soto-Valle ◽  
Sirko Bartholomay ◽  
Jörg Alber ◽  
Marinos Manolesos ◽  
Christian Navid Nayeri ◽  
...  

Abstract. In this paper, a method to determine the angle of attack on a wind turbine rotor blade using a chordwise pressure distribution measurement was applied. The approach used a reduced number of pressure tap data located close to the blade leading edge. The results were compared with the measurements from three external probes mounted on the blade at different radial positions and with analytical calculations. Both experimental approaches used in this study are based on the 2-D flow assumption; the pressure tap method is an application of the thin airfoil theory, while the probe method applies geometrical and induction corrections to the measurement data. The experiments were conducted in the wind tunnel at the Hermann Föttinger Institut of the Technische Universität Berlin. The research turbine is a three-bladed upwind horizontal axis wind turbine model with a rotor diameter of 3 m. The measurements were carried out at rated conditions with a tip speed ratio of 4.35, and different yaw and pitch angles were tested in order to compare the approaches over a wide range of conditions. Results show that the pressure tap method is suitable and provides a similar angle of attack to the external probe measurements as well as the analytical calculations. This is a significant step for the experimental determination of the local angle of attack, as it eliminates the need for external probes, which affect the flow over the blade and require additional calibration.


2019 ◽  
Vol 9 (3) ◽  
pp. 482 ◽  
Author(s):  
Guangxing Wu ◽  
Lei Zhang ◽  
Ke Yang

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.


Author(s):  
Ambadas Menghare

Abstract: Within the current years wind power is extensively taken into consideration and applied as one of the most promising renewable electricity assets. In the recent studies have a look at, aerodynamic analysis of horizontal axis turbine is achieved with the aid of using cfd. Blades which can be often possible for industrial grade wind turbines embody a directly span-wise profile in conjunction with airfoil fashioned go sections. Wind tunnel test is applied in order to check aerodynamic efficiency wind turbine blade. The goal of this study is to design a wind turbine. The layout manner includes the choice of the sun machine for max efficiency and wind turbine kind and the determination of the blade airfoil, pitch attitude distribution along the radius, and chord duration distribution along the radius. The pitch angle and chord period distributions are optimized primarily based on conservation of angular momentum and principle of aerodynamic forces on an airfoil. Blade element momentum (BEM) principle is first derived then used to conduct a parametric observe to be able to determine if the optimized values of blade pitch and chord period create the maximum green blade geometry. This work includes a discussion of the most important parameters in wind turbine blade layout to maximize efficiency. Keywords: Wind Turbine, HAWT, BEM Theory, Parametric Study, Maximization of efficiency etc.


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.


2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.


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