Effect of Trailing-Edge Flap Deflection on a Symmetric Airfoil Over a Wavy Ground

2018 ◽  
Vol 141 (6) ◽  
Author(s):  
V. Tremblay-Dionne ◽  
T. Lee
Keyword(s):  
Experimental Investigation ◽  
Pitching Moment ◽  
Cyclic Variation ◽  
Trailing Edge ◽  
Opposite Trend ◽  
Aerodynamic Properties ◽  
Trailing Edge Flap ◽  
Flap Deflection ◽  
Naca 0015

The effect of trailing-edge flap (TEF) deflection on the aerodynamic properties and flowfield of a symmetric airfoil over a wavy ground was investigated experimentally. This Technical Brief is a continuation of Lee and Tremblay-Dionne (2018, “Experimental Investigation of the Aerodynamics and Flowfield of a NACA 0015 Airfoil Over a Wavy Ground,” ASME J. Fluids Eng., 140(7), p. 071202) in which an unflapped airfoil was employed. Regardless of the flap deflection, the cyclic variation in the sectional lift Cl and pitching moment Cm coefficients over the wavy ground always persists. The Cm also has an opposite trend to Cl. The flap deflection, however, produces an increased maximum and minimum Cl and Cm with a reduced fluctuation compared to their unflapped counterparts. The Cd increase outperforms the Cl increase, leading to a lowered Cl/Cd of the flapped airfoil.

Trailing-Edge Flap Control of Dynamic Pitching Moment

AIAA Journal ◽  
2007 ◽  
Vol 45 (7) ◽  
pp. 1688-1694 ◽  
Author(s):  
P. Gerontakos ◽  
T. Lee
Keyword(s):  
Pitching Moment ◽  
Trailing Edge ◽  
Trailing Edge Flap

Numerical and Experimental Investigation of Trailing Edge Flap Performance on a Model Wind Turbine

2018 ◽  
Author(s):  
David Marten ◽  
Sirko Bartholomay ◽  
George Pechlivanoglou ◽  
Christian Nayeri ◽  
Christian O. Paschereit ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Wind Turbine ◽  
Trailing Edge ◽  
Trailing Edge Flap

Influence of Flap Deflection Angle on Wind Turbine Airfoil with Trailing Edge Flaps

2014 ◽  
Vol 977 ◽  
pp. 222-227
Author(s):  
Ya Lei Jia ◽  
Zhong He Han ◽  
Fu You Li ◽  
Ya Kai Bai ◽  
Ji Xuan Wang
Keyword(s):  
Wind Turbine ◽  
Deflection Angle ◽  
Aerodynamic Performance ◽  
Main Body ◽  
Trailing Edge ◽  
Trailing Edge Flaps ◽  
Wind Turbine Airfoil ◽  
Trailing Edge Flap ◽  
Flap Deflection ◽  
Drag Ratio

To improve the ability of capturing the wind energy of wind turbine and shorten the design period is of great importance to designing wind turbine blade. The article established S809 airfoil model with trailing edge flaps, The gap of the frontal subject and trailing edge flap adopt uniform gap structure, this structure will reduce the influence of the gap on aerodynamic characteristics.Using the k-ω Two equation turbulence model , the article calculated aerodynamic performance of S809 with 10% chord length trailing edge flaps under different deflecting angles. Results show that gap between the main body and trailing edge flap has little effect on airfoil aerodynamic performance, however, the deflection Angle of Trailing edge flap have great affect on airfoil aerodynamic performance, when deflection Angle of trailing edge flap is 14 ° degrees ,the lift-to-drag ratio is the largest.

Experimental investigation of the ground effect on a wing without/with trailing edge flap

2020 ◽  
Vol 52 (4) ◽  
pp. 045504
Author(s):  
Khalida Sekhoune Özden ◽  
İlyas Karasu ◽  
Mustafa Serdar Genç
Keyword(s):  
Experimental Investigation ◽  
Ground Effect ◽  
Trailing Edge ◽  
Trailing Edge Flap

Trailing-edge flap flow control for dynamic stall

2011 ◽  
Vol 115 (1170) ◽  
pp. 493-503 ◽  
Author(s):  
R. B. Green ◽  
E. A. Gillies ◽  
Y. Wang
Keyword(s):  
Lower Surface ◽  
Rotor Blades ◽  
Surface Shape ◽  
Dynamic Stall ◽  
Limiting Factors ◽  
Trailing Edge ◽  
Oscillatory Dynamic ◽  
Trailing Edge Flap ◽  
Flap Deflection ◽  
Motion Profile

Abstract Results of a series of oscillatory dynamic stall tests of a rotor aerofoil fitted with a pulsed, trailing-edge flap are presented. Flap deflection amplitude, motion profile, duration and starting phase were investigated to assess the potential of the flap for mitigating the adverse effects of dynamic stall, which is one of the limiting factors for rotor blades on the retreating side of a helicopter rotor. The tests were a continuation of the investigations by Ref. 1 who used a computational fluid dynamics method on a symmetric NACA section, and our results broadly confirm their conclusions by experimental test, using a modern rotor section. The results presented in this paper also confirm the observations from experimental work by Refs 2 and 3, which were undertaken at lower Reynolds number and with a larger flap. In the present study, the flap mitigates the high negative pitching moment and negative pitch damping seen in dynamic stall by strong suction being generated over the aerofoil lower surface, and it is the modification to the lower surface shape by the flap that creates this effect. The dynamic stall vortex acts to enhance the lower surface suction, and careful flap phasing and flap motion profile shaping can make the control more effective.

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