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

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

Measurement of Unsteady Aerodynamics Load on the Blade of Field Horizontal Axis Wind Turbine

2007 ◽  
Author(s):  
Takao Maeda ◽  
Yasunari Kamada ◽  
Keita Naito ◽  
Yuu Ouchi ◽  
Masayoshi Kozawa
Keyword(s):  
Wind Turbine ◽  
Pressure Distribution ◽  
Mode Frequency ◽  
Horizontal Axis ◽  
Strain Gauges ◽  
Aerodynamic Forces ◽  
Horizontal Axis Wind Turbine ◽  
Blade Root ◽  
Blade Section ◽  
Mechanical Moment

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.

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

Energy ◽  
2019 ◽  
Vol 183 ◽  
pp. 341-357 ◽  
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

scholarly journals Flow Characteristics Study of Wind Turbine Blade with Vortex Generators

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hao Hu ◽  
Xin-kai Li ◽  
Bo Gu
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Horizontal Axis ◽  
Vortex Generators ◽  
Propeller Shaft ◽  
Horizontal Axis Wind Turbine ◽  
Separation Line ◽  
Blade Root ◽  
Pneumatic Power ◽  
Large Wind

The blade root flow control is of particular importance to the aerodynamic characteristic of large wind turbines. The paper studies the feasibility of improving blade pneumatic power by applying vortex generators (VGs) to large variable propeller shaft horizontal axis wind turbines, with 2 MW variable propeller shaft horizontal axis wind turbine blades as research object. In the paper, three cases of VGs installation are designed; they are scattered in different chordwise position at the blade root, and then they are calculated, respectively, with CFD method. The results show that VGs installed in the separation line upstream, with the separation line of the blade root as a benchmark, show a better effect. Pneumatic power of blades increases by 0.6% by installing VGs. Although the effect on large wind turbines is not obvious, there is a space for optimization.

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

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.

The effect of the boundary layer on the wake of a horizontal axis wind turbine

Energy ◽  
2019 ◽  
Vol 182 ◽  
pp. 1202-1221 ◽  
Author(s):  
Nima Sedaghatizadeh ◽  
Maziar Arjomandi ◽  
Richard Kelso ◽  
Benjamin Cazzolato ◽  
Mergen H. Ghayesh
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine

Experimental Study on the Performance and Flow Characteristics of a Small Horizontal Axis Wind Turbine (HAWT)

2003 ◽  
Author(s):  
Isaac Gutierrez ◽  
Atsushi Okajima ◽  
Takahiro Kiwata ◽  
Shigeo Kimura ◽  
Yoshitaro Wakisaka
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Separation Bubble ◽  
Flow Characteristics ◽  
Field Tests ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Horizontal Axis Wind Turbine ◽  
Oil Film

With the aim of getting basic data to increase the efficiency of a small horizontal axis wind turbine (HAWT) systems, the wind tunnel experiments were carried out to observe flow characteristics of rotating blades of the turbine, using the oil-film visualization technique, and to measure turbine performance. Flow visualization allowed the identification of laminar flow, laminar separation bubble formation, flow reattachment, turbulent boundary layer, and turbulent separation. The complex patterns on the rotating blade surface were confirmed by the oil-film visualization method and identified. When the trip-tape was employed for control of the blade boundary layer, the efficiency was not significantly improved. Field-tests of this turbine were performed also, and averages of wind speed and net power were calculated from the field measured data using the bins method and were compared with wind tunnel performance tests. The results of field-tests showed for this small HAWT that the highest power coefficient value was 30%.

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