A Parametric Study of Trailing Edge Flap Implementation on Three Different Airfoils Through an Artificial Neuronal Network

Trailing edge flaps (TEFs) are high-lift devices that generate changes in the lift and drag coefficients of an airfoil. A large number of 2D simulations are performed in this study, in order to measure these changes in aerodynamic coefficients and to analyze them for a given Reynolds number. Three different airfoils, namely NACA 0012, NACA 64(3)-618, and S810, are studied in relation to three combinations of the following parameters: angle of attack, flap angle (deflection), and flaplength. Results are in concordance with the aerodynamic results expected when studying a TEF on an airfoil, showing the effect exerted by the three parameters on both aerodynamic coefficients lift and drag. Depending on whether the airfoil flap is deployed on either the pressure zone or the suction zone, the lift-to-drag ratio, CL/CD, will increase or decrease, respectively. Besides, the use of a larger flap length will increase the higher values and decrease the lower values of the CL/CD ratio. In addition, an artificial neural network (ANN) based prediction model for aerodynamic forces was built through the results obtained from the research.

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Effect of Blade Cambering on Dynamic Stall in View of Designing Vertical Axis Turbines

Journal of Fluids Engineering ◽

10.1115/1.4039235 ◽

2018 ◽

Vol 140 (6) ◽

Cited By ~ 17

Author(s):

Pablo Ouro ◽

Thorsten Stoesser ◽

Luis Ramírez

Keyword(s):

Vertical Axis ◽

Dynamic Stall ◽

Hysteresis Cycle ◽

Aerodynamic Coefficients ◽

Pitching Motion ◽

Large Eddy ◽

Naca 0012 ◽

Drag Ratio ◽

Lift To Drag Ratio ◽

Good Agreement

This paper presents large eddy simulations (LESs) of symmetric and asymmetric (cambered) airfoils forced to undergo deep dynamic stall due to a prescribed pitching motion. Experimental data in terms of lift, drag, and moment coefficients are available for the symmetric NACA 0012 airfoil and these are used to validate the LESs. Good agreement between computed and experimentally observed coefficients is found confirming the accuracy of the method. The influence of foil asymmetry on the aerodynamic coefficients is analyzed by subjecting a NACA 4412 airfoil to the same flow and pitching motion conditions. Flow visualizations and analysis of aerodynamic forces allow an understanding and quantification of dynamic stall on both straight and cambered foils. The results confirm that cambered airfoils provide an increased lift-to-drag ratio and a decreased force hysteresis cycle in comparison to their symmetric counterparts. This may translate into increased performance and lower fatigue loads when using cambered airfoils in the design of vertical axis turbines (VATs) operating at low tip-speed ratios.

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Design and experimental analysis of morphing wing based on biomimicry

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i2.33.14160 ◽

2018 ◽

Vol 7 (3.3) ◽

pp. 239

Author(s):

Mugeshwaran A ◽

Guru Prasad Bacha ◽

Rajkumar S

Keyword(s):

Gear Ratio ◽

Machining Process ◽

Control Surface ◽

Cad Model ◽

Morphing Wing ◽

Lift And Drag ◽

Naca 0012 ◽

Drag Ratio ◽

Lift To Drag Ratio ◽

Aluminum Material

In this paper narrate about the study of aerodynamics in the multi-section morphing wing variation of baseline configuration to camber con-figuration. In particularly NACA 0012, section tried to morph as NACA 9312 camber section to achieve the lift to drag ratio in the flight condition based on the bio-mimicry. The CAD model and fabricated morphing wing in geometry scale of 20 cm chord and a 36 cm wing-span, with aluminum material ribs divided into 6 sections. Each section was able to rotate approximately 6 degrees without causing a discon-tinuity in the wing surface and also in order avoid the control surface based on the bio mimicry the morphing wing was designed and tested. DC-motor located at main spar with the two equal gear ratio the rib section used to morph the wing through the linear mechanical linkages. The aluminum ribs section are made through the EDM-Wire cut machining process for capable to actuate the morphing wing. In each sec-tion morphing wing can able provide up to 10 percent variation in the symmetrical airfoil to the cambered airfoil. The experimental test of the morphing was carried out in the cascade tunnel by force balancing method and the lift and drag output are compared.

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Lift-to-Drag Ratio Improvement of a Supersonic Transport with Leading-Edge and Trailing-Edge Flaps

JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES ◽

10.2322/jjsass.51.551 ◽

2003 ◽

Vol 51 (597) ◽

pp. 551-558 ◽

Cited By ~ 1

Author(s):

Dong-Youn Kwak ◽

Katsuhiro Miyata ◽

Masayoshi Noguchi ◽

Kenichi Rinoie

Keyword(s):

Leading Edge ◽

Trailing Edge ◽

Supersonic Transport ◽

Trailing Edge Flaps ◽

Drag Ratio ◽

Lift To Drag Ratio

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Design of Shape Memory Alloy Actuated Deformable Airfoil for Subsonic Flight

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.334-335.1105 ◽

2007 ◽

Vol 334-335 ◽

pp. 1105-1108

Author(s):

R.C.K. Leung ◽

Alan Kin Tak Lau ◽

S.F. Yu

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Power Budget ◽

Sma Actuators ◽

Flight Vehicles ◽

Lift And Drag ◽

Naca 0012 ◽

Drag Ratio ◽

Aerodynamic Surfaces ◽

Lift To Drag Ratio

Aerodynamic surfaces for subsonic flight vehicles are usually designed primarily with the cruise condition in mind. With this objective in mind, the design of these aerodynamic surfaces, which usually exist as airfoils on the vehicles, are in general suboptimal for actual situation because they must be used for takeoff, landing, and maneuver in addition to cruise condition [1]. Therefore, it would be always desirable to design an airfoil with the ability to adapt to its current flow condition and alter its shape to remain the efficiency at any speed. The present paper reports a design of an airfoil with NACA 0012 profile which aims to deform the airfoil shape under the actuation the shape memory alloy (SMA) actuators embedded in it. The SMA actuators design to alter the aerodynamic lift and drag in a subsonic flow. The feasibility of the design is examined and discussed in the light of the change in lift to drag ratio and the power budget of the actuation.

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Optimal Design of Wind Turbines Using BIAS, A Method of Multipliers Code

14th Design Automation Conference ◽

10.1115/detc1988-0026 ◽

1988 ◽

Author(s):

B. D. Vick ◽

W. Wrigglesworth ◽

L. B. Scott ◽

K. M. Ragsdell

Keyword(s):

Optimal Design ◽

Rough Surface ◽

Wind Turbines ◽

Lift Coefficient ◽

Power Coefficient ◽

Method Of Multipliers ◽

High Lift ◽

Small Wind Turbines ◽

Drag Ratio ◽

Lift To Drag Ratio

Abstract A method has been developed and is demonstrated which determines the chord and twist distribution for a wind turbine with maximum power coefficient. Only small wind turbines (less than 10 kilowatts) are considered in this study, but the method could be used for larger wind turbines. Glauert determined a method for estimating the chord and twist distribution that will maximize the power coefficient if there is no drag. However, the method proposed here determines the chord and twist distribution which will maximize the power coefficient with the effect of drag included. Including drag in the analysis does not significantly affect the Glauert chord and twist distribution for airfoils with a high lift coefficient at the maximum lift to drag ratio. However, if the airfoil has a fairly low lift coefficient at its maximum lift to drag ratio due to its shape or a rough surface then significant improvement can be obtained in power coefficient by altering the Glauert chord and twist distribution according to the method proposed herein.

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The Dassault Mirage G

The Aeronautical Journal ◽

10.1017/s0001924000051162 ◽

1969 ◽

Vol 73 (708) ◽

pp. 1027-1028

Author(s):

Henri Deplante

Keyword(s):

Leading Edge ◽

Variable Geometry ◽

Relative Thickness ◽

Trailing Edge ◽

High Lift ◽

Profound Knowledge ◽

Subsonic Speed ◽

Trailing Edge Flaps ◽

Leading Edge Slats

The interest of wings with variable sweepback springs directly from pure commonsense and appeals to no profound knowledge of aerodynamics for its justification. To realise the advantage of variable geometry, it is enough to know that only a wing of small relative thickness is capable of good performance at supersonic speeds and that by increasing the sweepback from 20° to 70° the thickness of a wing is divided by about 2. In the advanced position, the wing offers its full span to the airstream and with high-lift devices in action (leading-edge slats and trailing-edge flaps combined), the aeroplane can develop the considerable lift necessary for take-off and landing as well as for break-through and for slow approach. Wings still advanced but slats, flaps and undercarriage retracted, the aeroplane is in excellent maximum fineness condition for protracted cruising at subsonic speed or for a long wait. As soon as transonic (Mach No of more than 0-8) or supersonic speeds are in question, the wings are progressively folded back.

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Roughness Sensitivity Considerations for Thick Rotor Blade Airfoils

Journal of Solar Energy Engineering ◽

10.1115/1.1624614 ◽

2003 ◽

Vol 125 (4) ◽

pp. 468-478 ◽

Cited By ~ 93

Author(s):

R. P. J. O. M. van Rooij ◽

W. A. Timmer

Keyword(s):

Turbine Blades ◽

Leading Edge ◽

Lower Surface ◽

Vortex Generators ◽

Wind Turbine Blades ◽

High Lift ◽

Edge Roughness ◽

Proper Design ◽

Drag Ratio ◽

Lift To Drag Ratio

In modern wind turbine blades, airfoils of more than 25% thickness can be found at mid-span and inboard locations. At mid-span, aerodynamic requirements dominate, demanding a high lift-to-drag ratio, moderate to high lift and low roughness sensitivity. Towards the root, structural requirements become more important. In this paper, the performance for the airfoil series DU FFA, S8xx, AH, Risø and NACA are reviewed. For the 25% and 30% thick airfoils, the best performing airfoils can be recognized by a restricted upper-surface thickness and an S-shaped lower surface for aft-loading. Differences in performance of the DU 91-W2-250 (25%), S814 (24%) and Risø-A1-24 (24%) airfoils are small. For a 30% thickness, the DU 97-W-300 meets the requirements best. Reduction of roughness sensitivity can be achieved both by proper design and by application of vortex generators on the upper surface of the airfoil. Maximum lift and lift-to-drag ratio are, in general, enhanced for the rough configuration when vortex generators are used. At inboard locations, 2-D wind tunnel tests do not represent the performance characteristics well because the influence of rotation is not included. The RFOIL code is believed to be capable of approximating the rotational effect. Results from this code indicate that rotational effects dramatically reduce roughness sensitivity effects at inboard locations. In particular, the change in lift characteristics in the case of leading edge roughness for the 35% and 40% thick DU airfoils, DU 00-W-350 and DU 00-W-401, respectively, is remarkable. As a result of the strong reduction of roughness sensitivity, the design for inboard airfoils can primarily focus on high lift and structural demands.

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Stress and Shape Analysis of a Paraglider Wing

Journal of Applied Mechanics ◽

10.1115/1.3627315 ◽

1965 ◽

Vol 32 (4) ◽

pp. 771-780 ◽

Cited By ~ 4

Author(s):

Robert W. Fralich

Keyword(s):

Structural Analysis ◽

Shape Analysis ◽

Numerical Results ◽

Internal Stresses ◽

Flexible Wing ◽

Aerodynamic Pressure ◽

Drag Forces ◽

Lift And Drag ◽

Drag Ratio ◽

Lift To Drag Ratio

A combined aerodynamic-structural analysis is made which is based on the assumption that the sail is flexible and has freedom to take the shape which the aerodynamic pressure and the internal stresses dictate. Numerical results were obtained for Newtonian impact aerodynamic theory and were compared with published results obtained for a rigid idealization of the paraglider wing. It was found that the assumed rigid idealization did not approximate the shape of a flexible wing well and led to significant errors in the lift and drag forces and the lift-to-drag ratio. The new calculations provide a basis for design of paragliders for hypersonic flight.

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