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

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

Energy ◽

10.1016/j.energy.2019.06.066 ◽

2019 ◽

Vol 182 ◽

pp. 1202-1221 ◽

Cited By ~ 3

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

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

Volume 2: Symposia, Parts A, B, and C ◽

10.1115/fedsm2003-45625 ◽

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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S0503-3-5 A study of blade surface flow of horizontal axis wind turbine

The proceedings of the JSME annual meeting ◽

10.1299/jsmemecjo.2010.2.0_121 ◽

2010 ◽

Vol 2010.2 (0) ◽

pp. 121-122

Author(s):

Yasunari KAMADA ◽

Takao MAEDA ◽

Junsuke MURATA ◽

Satoshi MATSUDA ◽

Thibault MATHIEU ◽

...

Keyword(s):

Wind Turbine ◽

Surface Flow ◽

Horizontal Axis ◽

Blade Surface ◽

Horizontal Axis Wind Turbine

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Measurements of separating boundary layer and wake of an airfoil using laser Doppler velocimetry

10.2514/6.1985-181 ◽

1985 ◽

Cited By ~ 4

Author(s):

A. NAKAYAMA

Keyword(s):

Boundary Layer ◽

Laser Doppler Velocimetry ◽

Laser Doppler ◽

Doppler Velocimetry

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Bubble-Induced Unsteadiness on A Wind Turbine Airfoil

Journal of Solar Energy Engineering ◽

10.1115/1.1510525 ◽

2002 ◽

Vol 124 (4) ◽

pp. 335-344 ◽

Cited By ~ 17

Author(s):

E. A. Mayda ◽

C. P. van Dam

Keyword(s):

Wind Turbine ◽

Aerodynamic Force ◽

Horizontal Axis ◽

Horizontal Axis Wind Turbine ◽

Airfoil Surface ◽

Laminar Separation ◽

Surface Pressure Distribution ◽

Horizontal Axis Wind Turbines ◽

Wind Turbine Airfoil ◽

Force Characteristics

The effect of laminar separation bubbles on the surface pressure distribution and aerodynamic force characteristics of a horizontal axis wind turbine airfoil is studied numerically. The NREL S809 airfoil for stall-controlled horizontal-axis wind turbines is analyzed at a chord Reynolds number of 1.0×106. For all flow conditions involving laminar separation in the present study, bubble-induced vortex shedding is observed. This flow phenomenon causes significant oscillations in the airfoil surface pressures and, hence, in the airfoil-generated aerodynamic forces. The computed time-averaged pressures compare favorably with wind-tunnel measurements.

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