Experimental investigations of boundary layer impact on the airfoil aerodynamic forces of Horizontal Axis Wind Turbine in turbulent inflows

This paper describes an experimental field study of the rotor aerodynamics of wind turbines. The test wind turbine is a horizontal axis wind turbine, or: HAWT with a diameter of 10m. The pressure distributions on the rotating blade are measured with multi point pressure transducers. Sectional aerodynamic forces are analyzed from pressure distribution. Blade root moments are measured simultaneously by a pair of strain gauges. The inflow wind is measured by a three component sonic anemometer, the local inflow of the blade section are measured by a pair of 7 hole Pitot tubes. The relation between the aerodynamic moments on the blade root from pressure distribution and the mechanical moment from strain gauges is discussed. The aerodynamic moments are estimated from the sectional aerodynamic forces and show oscillation caused by local wind speed and direction change. The mechanical moment shows similar oscillation to the aerodynamic excepting the short period oscillation of the blade first mode frequency. The fluctuation of the sectional aerodynamic force triggers resonant blade oscillations. Where stall is present along the blade section, the blade’s first mode frequency is dominant. Without stall, the rotating frequency is dominant in the blade root moment.

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

Journal of Engineering Research ◽

10.36909/jer.10767 ◽

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.

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STRESS ANALYSIS PADA HORIZONTAL AXIS WIND TURBINE BLADE

POROS ◽

10.24912/poros.v12i1.682 ◽

2017 ◽

Vol 12 (1) ◽

pp. 41

Author(s):

Achmad Rachmad Tullah ◽

Made K Dhiputra ◽

G Soeharsono

Keyword(s):

Power Plant ◽

Wind Turbine ◽

Stress Analysis ◽

Turbine Blade ◽

Maximum Stress ◽

Wind Turbine Blade ◽

Horizontal Axis ◽

Centrifugal Forces ◽

Aerodynamic Forces ◽

Horizontal Axis Wind Turbine

Abstract: Nowadays wind turbine is used widely in many countries as power plant. When the wind turbine blade rotates there will be aerodynamic forces acting on the blade such as drag, lift, weight and centrifugal forces. When designing wind turbine blade it is necessary to test whether the blade can withstand the aerodynamic forces or not. Stress analysis is a feature that can predict stress acting on construction. Nowadays there are many stress analysis softwares that can be used to predict stress. In this research the stress analysis will be used by using autodesk inventor.The research purposes are to find the stress acting on the wind turbine blade and to get the maximum stress location.

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424 Clarification of Boundary Layer around Blade Root of Horizontal Axis Wind Turbine

The Proceedings of Conference of Tokai Branch ◽

10.1299/jsmetokai.2013.62.253 ◽

2013 ◽

Vol 2013.62 (0) ◽

pp. 253-254

Author(s):

Yosuke KAGISAKI ◽

Yasunari KAMADA ◽

Takao MAEDA ◽

Junsuke MURATA ◽

Daiki SUZUKI

Keyword(s):

Boundary Layer ◽

Wind Turbine ◽

Horizontal Axis ◽

Horizontal Axis Wind Turbine ◽

Blade Root

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Computational and Experimental Investigations on Small Horizontal Axis Wind Turbine for Household Applications

Techno-Societal 2016 ◽

10.1007/978-3-319-53556-2_7 ◽

2017 ◽

pp. 65-73

Author(s):

Gurushant Koulagi ◽

R. S. Hosmath ◽

Ajitkumar Madival ◽

P. P. Revankar

Keyword(s):

Wind Turbine ◽

Horizontal Axis ◽

Experimental Investigations ◽

Horizontal Axis Wind Turbine

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Coupled Dynamics of a Flexible Horizontal Axis Wind Turbine With Damaged Blades: Experimental and Numerical Validations

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4037529 ◽

2017 ◽

Vol 140 (2) ◽

Author(s):

M. A. Ben Hassena ◽

F. Najar ◽

S. Choura ◽

F. H. Ghorbel

Keyword(s):

Wind Turbine ◽

Modal Analysis ◽

Fem Analysis ◽

Element Model ◽

Horizontal Axis ◽

Experimental Investigations ◽

Horizontal Axis Wind Turbine ◽

State Response ◽

Proposed Model ◽

Additional Point

In this paper, we propose a new coupled dynamical model of a horizontal axis wind turbine (HAWT). The proposed model takes into consideration the dynamic coupling of the flexible tower with both bending and torsion of the flexible blades. This model also accounts for the dynamics of an additional point mass located in one of the blades to simulate a crack. In addition, a finite element model (FEM) analysis along with an experimental study is conducted in this research to validate the modal analysis of a HAWT prototype. Data from the analytical, numerical, and experimental investigations were collected and showed comparable findings. Using the analytical model, the modal analysis and the steady-state response of the HAWT prototype are performed for two configurations: with and without a crack. In this paper, we also propose a new model-based technique for the detection of cracks in the HAWT.

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Laser Doppler Velocimetry (LDV) measurements of airfoil surface flow on a Horizontal Axis Wind Turbine in boundary layer

Energy ◽

10.1016/j.energy.2019.06.150 ◽

2019 ◽

Vol 183 ◽

pp. 341-357 ◽

Cited By ~ 2

Author(s):

Qing'an Li ◽

Jianzhong Xu ◽

Takao Maeda ◽

Yasunari Kamada ◽

Shogo Nishimura ◽

...

Keyword(s):

Boundary Layer ◽

Wind Turbine ◽

Laser Doppler Velocimetry ◽

Surface Flow ◽

Horizontal Axis ◽

Laser Doppler ◽

Doppler Velocimetry ◽

Horizontal Axis Wind Turbine ◽

Airfoil Surface

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Rotational Augmentation of Horizontal Axis Wind Turbine Blade Aerodynamic Response

ASME 2002 Wind Energy Symposium ◽

10.1115/wind2002-29 ◽

2002 ◽

Cited By ~ 4

Author(s):

S. Schreck ◽

M. Robinson

Keyword(s):

Wind Turbine ◽

Surface Pressure ◽

Unsteady Aerodynamics ◽

Horizontal Axis ◽

Pressure Data ◽

Aerodynamic Forces ◽

Horizontal Axis Wind Turbine ◽

Pressure Distributions ◽

Rotating Blade ◽

Wind Tunnel Data

Surface pressure data were acquired using the NREL Unsteady Aerodynamics Experiment, a full-scale horizontal axis wind turbine, which was erected in the NASA Ames 80 ft × 120 ft wind tunnel. Data were collected first for a stationary blade, and then for a rotating blade with the turbine disk at zero yaw. Analyses compared aerodynamic forces and surface pressure distributions under rotating conditions against analogous baseline data acquired from the stationary blade. This comparison allowed rotational modifications to blade aerodynamics to be characterized in detail. Rotating conditions were seen to dramatically amplify aerodynamic forces, and radically alter surface pressure distributions. These and subsequent findings will more fully reveal the structures and interactions responsible for these flow field enhancements, and help establish the basis for formalizing comprehension in physics based models.

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A vertical-axis rotor as the adjusting system of a horizontal axis wind turbine

Czasopismo Techniczne ◽

10.37705/techtrans/e2020009 ◽

2020 ◽

pp. 1-14

Author(s):

Marcin Augustyn

Keyword(s):

Boundary Layer ◽

Wind Turbine ◽

Vertical Axis ◽

Computational Procedure ◽

Horizontal Axis ◽

The Self ◽

Main Rotor ◽

Aerodynamic Coefficients ◽

Horizontal Axis Wind Turbine ◽

Design Structure

The proposed self-adjusting mechanism consists of a carousel rotor with a vertical axis consisting of two kinematically connected flat blades. The torque of this rotor can change the position of the directing unit and additionally the position of the main propeller in order to direct the wind stream or save the main rotor when the wind is too strong. The theory, principles of operation, and the properties of the self-adjusting system were illustrated by formulas and graphs. Based on research conducted in a boundary layer wind tunnel, the values of the aerodynamic coefficients of the flat blades were determined, and then the power and propeller torque of the rotor were found as a function of the angle of wind attack. A computational procedure provides kinematical and force relations as well as the resulting torque diagrams of the rotor. An example of the use and the design structure of a self-adjusting unit in the case of a horizontal axis wind turbine is presented.

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