Investigation of a bio-inspired lift-enhancing effector on a 2D airfoil

The effect of rotation has been investigated with emphasis on the impact of blade geometry on the “correction factor” in stall models. The data used came from field tests and wind tunnel experiments performed by the National Renewable Energy Laboratory and were restricted to the steady-state nonyawed conditions. Three blade layouts were available; a blade with constant chord without twist (phase II), a blade with constant chord and twist (phases III and IV), and a tapered blade with twist (phase VI). Effects due to twist and taper were determined from comparison of c n between the different blade layouts. The formulation of the stall model was rewritten so that the measured c n values could be used without reference to 2D airfoil performance. This enabled a direct comparison of the normal force characteristics between the four blade stations of the selected blade configurations. In particular, the correction term f used in stall models for rotational effects was analyzed. The comparison between the test results with a straight and a twisted blade showed that a relation for twist + pitch is required in f . In addition, a dependency offon the angle-of-attack was identified in the measurements and it is recommended that this dependency be incorporated in the stall models.

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An investigation of unsteady 3D effects on trailing edge flaps

10.5194/wes-2016-48 ◽

2016 ◽

Author(s):

Eva Jost ◽

Annette Fischer ◽

Galih Bangga ◽

Thorsten Lutz ◽

Ewald Krämer

Keyword(s):

Trailing Edge ◽

Trailing Vortices ◽

Trailing Edge Flaps ◽

Negative Effect ◽

3D Effects ◽

Computational Fluid Dynamics Cfd ◽

Trailing Edge Flap ◽

The Impact ◽

2D Airfoil ◽

High Influence

Abstract. The present study investigates the impact of unsteady and viscous 3D aerodynamic effects on a wind turbine blade with trailing edge flap by means of Computational Fluid Dynamics (CFD). Harmonic oscillations are simulated on the DTU 10 MW rotor with a morphing flap of 10 % chord extent ranging from 70 % to 80 % blade radius. The deflection frequency is varied in the range between 1 p and 6 p. To quantify 3D effects, rotor simulations are compared to 2D airfoil computations and the 2D theory by Theodorsen. A significant influence of trailing and shed vortex structures has been found which leads to an amplitude reduction and hysteresis of the lift response in the flap section with regard to the deflection signal. For the 3D rotor results greater amplitude reductions and a less pronounced hysteresis is observed compared to the 2D airfoil case. Blade sections neighboring the flap experience however an opposing impact and hence partly compensate the negative effect of trailing vortices in the flap section in respect to integral loads. The comparison to steady flap deflections at the 3D rotor revealed the high influence of dynamic inflow effects.

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Prediction of Glaze Ice Accretion on 2D Airfoil

Journal of the Korean Society for Aeronautical & Space Sciences ◽

10.5139/jksas.2010.38.8.747 ◽

2010 ◽

Vol 38 (8) ◽

pp. 747-757 ◽

Cited By ~ 2

Author(s):

Chan-Kyu Son ◽

Se-Jong Oh ◽

Kwan-Jung Yee

Keyword(s):

Ice Accretion ◽

2D Airfoil

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Modal Analysis of Transonic Shock Buffet on 2D Airfoil

2018 Fluid Dynamics Conference ◽

10.2514/6.2018-2910 ◽

2018 ◽

Cited By ~ 3

Author(s):

Lior Poplingher ◽

Daniella E. Raveh

Keyword(s):

Modal Analysis ◽

Transonic Shock ◽

2D Airfoil

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Conclusions From the Comparisons of Numerous 2D Airfoil Computations With Experiments

ASME 2002 Wind Energy Symposium ◽

10.1115/wind2002-34 ◽

2002 ◽

Cited By ~ 1

Author(s):

F. Bertagnolio ◽

N. N. So̸rensen ◽

J. Johansen ◽

P. Fuglsang

Keyword(s):

Wind Turbine ◽

Numerical Results ◽

Panel Method ◽

Navier Stokes ◽

Flow Properties ◽

2D Airfoil

The aim of this work is two-fold. Firstly, 28 sets of airfoil (widely used for wind turbine applications) measurements were compared with numerical results from a 2D Navier-Stokes solver and a panel method code. These results have been collected into an airfoil catalogue that has been separately published. Secondly, based on the previous results, criterions for evaluating the airfoils are derived. Thereby, the performance of the Navier-Stokes solver is evaluated. Further analysis of the results determines geometrical and flow properties that may cause problems when computing airfoil flows with a Navier-Stokes solver, and some recommendations are given.

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Conclusions from the comparisons of numerous 2D airfoil computations with experiments

10.2514/6.2002-34 ◽

2002 ◽

Cited By ~ 1

Author(s):

F. Bertagnolio ◽

N. Sorenson ◽

J. Johansen ◽

P. Fuglsang

Keyword(s):

2D Airfoil

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Research on Design Methods and Aerodynamics Performance of CQU-DTU-B21 Airfoil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.455-456.1486 ◽

2012 ◽

Vol 455-456 ◽

pp. 1486-1490

Author(s):

Jin Chen ◽

Jiang Tao Cheng ◽

Wen Zhong Shen

Keyword(s):

Wind Turbine ◽

Design Theory ◽

Low Noise ◽

Design Methods ◽

Wind Tunnels ◽

Power Performance ◽

Noise Emission ◽

Turbine Airfoils ◽

2D Airfoil ◽

Airfoil Self Noise

This paper presents the design methods of CQU-DTU-B21 airfoil for wind turbine. Compared with the traditional method of inverse design, the new method is described directly by a compound objective function to balance several conflicting requirements for design wind turbine airfoils, which based on design theory of airfoil profiles, blade element momentum (BEM) theory and airfoil Self-Noise prediction model. And then an optimization model with the target of maximum power performance on a 2D airfoil and low noise emission of design ranges for angle of attack has been developed for designing CQU-DTU-B21 airfoil. To validate the optimization results, the comparison of the aerodynamics performance by XFOIL and wind tunnels test respectively at Re=3×106 is made between the CQU-DTU-B21 and DU93-W-210 which is widely used in wind turbines.

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