Aerodynamic effects of a folding wingtip to increase take-off, landing and cruise performance.

The main purpose of a folding wing tip is to allow aerodynamically efficient high aspect ratio wing. To allow a wing tip to move in flight is to alleviate the loads and achieve lower wing weight or enable wing span to maximize. Thus reduces the induced drag and improve fuel efficiency. The folding wing tip may include spring devices in order to provide an additional gust loads alleviation ability in flight. A wing without a winglet produces wingtip vortices which increases drag as the air from the bottom surface of the wing (high pressure) tries to move to the upper surface (low pressure). To avoid this and have less vortices a winglet is used, around which the flow is same on both surfaces. A folding wingtip can be set at an angle of 0° to have maximum cruise performance and aspect ratio. If the wingtip is set in the range of 15°-50° it can increase lift during take-off. This folding wingtip can access any airport in the world because if it is folded at an angle of 90°, it can meet the gate requirements and restrictions of any airport. To study the performance of this mechanism, the wing tip was designed by using CATIA V5 software. The analysis of the wingtip at different angle of attacks was done using ANSYS and XFLR 5 softwares.

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Preliminary investigation of use of flexible folding wing tips for static and dynamic load alleviation

The Aeronautical Journal ◽

10.1017/aer.2016.108 ◽

2016 ◽

Vol 121 (1235) ◽

pp. 73-94 ◽

Cited By ~ 19

Author(s):

A. Castrichini ◽

V. Hodigere Siddaramaiah ◽

D.E. Calderon ◽

J.E. Cooper ◽

T. Wilson ◽

...

Keyword(s):

Aspect Ratio ◽

Preliminary Investigation ◽

Aircraft Design ◽

Dynamic Loads ◽

Induced Drag ◽

Aeroelastic Model ◽

Static And Dynamic Loads ◽

Folding Wing ◽

Wing Tips ◽

Wing Tip

ABSTRACTA recent consideration in aircraft design is the use of folding wing-tips with the aim of enabling higher aspect ratio aircraft with less induced drag while also meeting airport gate limitations. This study investigates the effect of exploiting folding wing-tips in flight as a device to reduce both static and dynamic loads. A representative civil jet aircraft aeroelastic model was used to explore the effect of introducing a wing-tip device, connected to the wings with an elastic hinge, on the load behaviour. For the dynamic cases, vertical discrete gusts and continuous turbulence were considered. The effects of hinge orientation, stiffness, damping and wing-tip weight on the static and dynamic response were investigated. It was found that significant reductions in both the static and dynamic loads were possible. For the case considered, a 25% increase in span using folding wing-tips resulted in almost no increase in loads.

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Correction: Testing of Folding Wing-Tip for Gust Load Alleviation in High Aspect Ratio Wing

AIAA Scitech 2019 Forum ◽

10.2514/6.2019-1863.c1 ◽

2019 ◽

Author(s):

Ronald C. Cheung ◽

Djamel Rezgui ◽

Jonathan E. Cooper ◽

Thomas Wilson

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Folding Wing ◽

Gust Load Alleviation ◽

Wing Tip

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Testing of Folding Wing-Tip for Gust Load Alleviation in High Aspect Ratio Wing

AIAA Scitech 2019 Forum ◽

10.2514/6.2019-1863 ◽

2019 ◽

Cited By ~ 1

Author(s):

Ronald C. Cheung ◽

Djamel Rezgui ◽

Jonathan E. Cooper ◽

Thomas Wilson

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Folding Wing ◽

Gust Load Alleviation ◽

Wing Tip

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Preparation and Properties of Optically Transparent Chitin Nanofibers Sheet by Different Simple Mechanical Methods

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.2232 ◽

2013 ◽

Vol 634-638 ◽

pp. 2232-2237

Author(s):

Qin Qin Hu ◽

Da Gang Li ◽

Ai Jun Li ◽

Wen Biao Gu

Keyword(s):

High Pressure ◽

Tensile Strength ◽

Aspect Ratio ◽

High Aspect Ratio ◽

Mechanical Treatment ◽

High Pressure Homogenization ◽

Flexible Composites ◽

Mechanical Methods ◽

Optically Transparent ◽

Chitin Nanofibers

Chitin nanofibers were prepared from commercially available dried chitin powders by different simple mechanical methods under acid conditions after removal of minerals and proteins. The fibrillated chitin samples were observed by FE-SEM and there was a fine network structure formed by chitin nanofibes with a width of approximately 10-50 nm and high aspect ratio. The mechanical treatment under acid conditions was crucial to facilitate the fibrillation of chitin fibers into nanofibers. The high pressure homogenization in combination with grinding was used to obtain the most transparent chitin nanofibers sheet with a transmittance of 88.5% and tensile strength of 82.34MPa, and the sheet even had a Young’s modulus of 6.17GPa. Thus, chitin nanofibers provide excellent potential as reinforcement of transparent flexible composites to improve the properties of nanocomposites.

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Aerodynamic Characteristics of an Airborne Vertical Gradient Magnetic Measuring Probe on the Wing Tip of a High Aspect Ratio UAV with Low Speed

10.1109/icisce50968.2020.00329 ◽

2020 ◽

Author(s):

S. B. Jia ◽

S. J. Luo ◽

Y. Wang ◽

Y. L. Cui ◽

S. J. Guo ◽

...

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Vertical Gradient ◽

Aerodynamic Characteristics ◽

Low Speed ◽

Measuring Probe ◽

Magnetic Measuring ◽

Wing Tip

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Aircraft Configuration Improvement Study from Aerodynamic and Structure Standpoints

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.798.565 ◽

2015 ◽

Vol 798 ◽

pp. 565-570

Author(s):

Luciano Magno Fragola Barbosa ◽

Ricardo Luiz Utsch de Freitas Pinto ◽

Bernardo Oliveira Hargreaves

Keyword(s):

Finite Element ◽

Aspect Ratio ◽

High Aspect Ratio ◽

Load Distribution ◽

Structural Deformation ◽

Load Factor ◽

Aircraft Wing ◽

Induced Drag ◽

Vertical Displacements ◽

Lifting Line

In this work improvements on the geometry of a high aspect ratio aircraft wing are studied, in order to reduce the wing in-flight deformation, without changing the drag of the aircraft and without increasing the structural weight. For this, from a reference rectangular wing, one new wing with elliptical planform has been defined; and comparative analyses of loads and structural deformation have been made for the wings considered: the original rectangular wing and the new corresponding elliptical wing. The aerodynamic analysis is based on the lifting line approach. A computer routine is made by the authors based on this approach, to obtain both induced drag values and the load distribution of the two wings, the original one and the corresponding elliptical. Based on the loads, spars for the two wings have been defined, and in order to evaluate the vertical displacements in flight, a finite element routine have been used. The main result of this study is the comparison of the deformation of wings considered, subjected to the same load factor, and for the same aircraft mass. The results obtained are encouraging for further developments using the present methodology.

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