Comparison of Morphing Wing Stategies Based upon Aircraft Performance Impacts

Joshi, Shailendra P.; Tidwell, Zeb; Crossley, William A.

doi:10.2514/6.2004-1722

Cited by 68 publications

(41 citation statements)

References 3 publications

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“…Starting from the need of wings to fly, passing by the different airfoil designs and recently, the emerging need for morphing wings [1]. In the aeronautical field, morphing is a technology that increases the aircraft's performance by manipulating its geometrical characteristics [2][3][4]. Morphing technology of wings can be divided into the following three categories; in-plane (span, sweep and chord), out-of-plane (twist, dihedral and bending) and airfoil (camber and thickness) morphing [5].…”

Section: Introductionmentioning

confidence: 99%

Effect of the Backward-Facing Step Location on the Aerodynamics of a Morphing Wing

Mishriky

Walsh

2016

Aerospace

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Over the last decade, aircraft morphing technology has drawn a lot of attention in the aerospace community, because it is likely to improve the aerodynamic performance and the versatility of aircraft at different flight regimes. With the fast paced advancements in this field, a parallel stream of research is studying different materials and designs to develop reliable morphing skins. A promising candidate for a viable morphing skin is the sliding skin, where two or more rigid surfaces remain in contact and slide against each other during morphing. The overlapping between each two panels create a backward-facing step on the airfoil surface which has a critical effect on the aerodynamics of the wing. This paper presents a numerical study of the effect of employing a backward-facing step on the suction side of a National Advisory Committee for Aeronautics (NACA) 2412 airfoil at a high Reynolds number of 5.9 × 10 6 . The effects of the step location on the lift coefficient, drag coefficient and critical angle of attack are studied to find a favorable location for the step along the chord-wise direction. Results showed that employing a step on the suction side of the NACA 2412 airfoil can adversely affect the aforementioned aerodynamic properties. A drop of 21.1% in value of the lift coefficient and an increase of 120.8% in the drag coefficient were observed in case of a step located at 25% of the chord length. However, these effects are mitigated by shifting the step location towards the trailing edge. Introducing a step on the airfoil caused the airfoil's thickness to change, which in turn has affected the transition point of the viscous boundary layer from laminar to turbulent. The location of the step, prior or post the transition point, has a noteworthy effect on the pressure and shear stress distribution, and consequently on the values of the lift and drag coefficients.

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Section: Introductionmentioning

confidence: 99%

Effect of the Backward-Facing Step Location on the Aerodynamics of a Morphing Wing

Mishriky

Walsh

2016

Aerospace

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“…If the wing of a small aircraft or MAV could be controlled in a similar manner, the morphing would allow for multiple tasks to be achieved, so that the wing could change to increase lift to carry loads, increase the lift to drag ratio for maximum efficiency, and create an asymmetric lift distribution for rolling and turning maneuvers. [3][4][5] Whg reS,snc. 'the FIsx pir,.I dga Already different attempts at morphing wings have indicated that morphing would allow a single aircraft to serve a multitude of functions.…”

Section: Introductionmentioning

confidence: 98%

“…'the FIsx pir,.I dga Already different attempts at morphing wings have indicated that morphing would allow a single aircraft to serve a multitude of functions. [3][4][5] Perhaps the most well known morphing wing aircraft is the F-14 Tomcat, which has a variable geometry wing that changes the sweep angle according to the Mach number it is flying at. Prior to the F-14, NASA and the USAF were investigating the use of a Mission Adaptive Wing (MAW) on the F-111 fighter, which incorporates a continuous, smooth wing profile with an automatic control system to change the camber for the best aerodynamic efficiency at a given flight speed (Fig.…”

Section: Introductionmentioning

confidence: 99%

Analysis of bat wings for morphing

2008

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The morphing of wings from three different bat species is studied using an extension of the Weissinger method. To understand how camber affects performance factors such as lift and lift to drag ratio, XFOIL is used to study thin (3% thickness to chord ratio) airfoils at a low Reynolds number of 100,000. The maximum camber of 9% yielded the largest lift coefficient, and a mid-range camber of 7% yielded the largest lift to drag ratio. Correlations between bat wing morphology and flight characteristics are covered, and the three bat wing planforms chosen represent various combinations of morphological components and different flight modes. The wings are studied using the extended Weissinger method in an "unmorphed" configuration using a thin, symmetric airfoil across the span of the wing through angles of attack of 0°-15°. The wings are then run in the Weissinger method at angles of attack of -2° to 12° in a "morphed" configuration modeled after bat wings seen in flight, where the camber of the airfoils comprising the wings is varied along the span and a twist distribution along the span is introduced. The morphed wing configurations increase the lift coefficient over 1000% from the unmorphed configuration and increase the lift to drag ratio over 175%. The results of the three different species correlate well with their flight in nature.

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“…This category is the least represented in the body of literature on morphing aircraft. Pioneering work in this field has been carried out by William Crossley and co-workers starting from the early 2000s to this decade [10][11][12][13][14][15][16][17][18]. A dedicated morphing aircraft design software based on a composition of existing tools has been developed by the research group of Sergio Ricci [19,20].…”

Section: Introductionmentioning

confidence: 99%

On the Importance of Morphing Deformation Scheduling for Actuation Force and Energy

Breuker¹,

Werter²

2016

Aerospace

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Abstract:Morphing aircraft offer superior properties as compared to non-morphing aircraft. They can achieve this by adapting their shape depending on the requirements of various conflicting flight conditions. These shape changes are often associated with large deformations and strains, and hence dedicated morphing concepts are developed to carry out the required changes in shape. Such intricate mechanisms are often heavy, which reduces, or even completely cancels, the performance increase of the morphing aircraft. Part of this weight penalty is determined by the required actuators and associated batteries, which are mainly driven by the required actuation force and energy. Two underexposed influences on the actuation force and energy are the flight condition at which morphing should take place and the order of the morphing manoeuvres, also called morphing scheduling. This paper aims at highlighting the importance of both influences by using a small Unmanned Aerial Vehicle (UAV) with different morphing mechanisms as an example. The results in this paper are generated using a morphing aircraft analysis and design code that was developed at the Delft University of Technology. The importance of the flight condition and a proper morphing schedule is demonstrated by investigating the required actuation forces for various flight conditions and morphing sequences. More importantly, the results show that there is not necessarily one optimal flight condition or morphing schedule and a tradeoff needs to be made.

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Comparison of Morphing Wing Stategies Based upon Aircraft Performance Impacts

Cited by 68 publications

References 3 publications

Effect of the Backward-Facing Step Location on the Aerodynamics of a Morphing Wing

Effect of the Backward-Facing Step Location on the Aerodynamics of a Morphing Wing

Analysis of bat wings for morphing

On the Importance of Morphing Deformation Scheduling for Actuation Force and Energy

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