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(19) TZZ ¥__T (11) EP 2 731 867 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: B64C 23/06 (2006.01) 09.09.2015 Bulletin 2015/37 (86) International application number: (21) Application number: 12737212.6 PCT/EP2012/002986 (22) Date of filing: 16.07.2012 (87) International publication number: WO 2013/007396 (17.01.2013 Gazette 2013/03) (54) WINGTIP DEVICE OF A WING, AND ALSO A WING WITH SUCH A WINGTIP DEVICE FLÜGELSPITZENVORRICHTUNG EINES FLÜGELS UND FLÜGEL MIT EINER SOLCHEN FLÜGELSPITZENVORRICHTUNG DISPOSITIF DE BOUT D’AILE D’UNE AILE, ET ÉGALEMENT AILE DOTÉE D’UN DISPOSITIF DE BOUT D’AILE (84) Designated Contracting States: (72) Inventors: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB • THEURICH, Frank GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO 27798 Hude (DE) PL PT RO RS SE SI SK SM TR • HIMISCH, Jan 38114 Braunschweig (DE) (30) Priority: 14.07.2011 DE 102011107251 14.07.2011 US 201161507689 P (74) Representative: UEXKÜLL & STOLBERG Patentanwälte (43) Date of publication of application: Beselerstrasse 4 21.05.2014 Bulletin 2014/21 22607 Hamburg (DE) (73) Proprietor: Airbus Operations GmbH (56) References cited: 21129 Hamburg (DE) WO-A1-2008/061739 US-A- 4 598 885 US-A- 4 674 709 Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 2 731 867 B1 Printed by Jouve, 75001 PARIS (FR) 1 EP 2 731 867 B1 2 Description 1 a reduction of the drag of the wingtip device and/or of the wing during flight operations, or [0001] The invention concerns a wingtip device of a wing, and also a wing with such a wingtip device. 1 by means of the inventive solution, an advanta- [0002] From WO 08-061739 A a wing with a wingtip 5 geous compromise between reduction of the drag of device is of known art. In general the gradient of drag the overall wingtip device and the effect of the loads. reduction with increasing wing loads reduces with in- creasing height of the wingtip device, so that increasing [0006] Inaccordance with one example of embodiment the height of the wingtip device is not effective. The object the ancillary wing sections in form, size, location and po- of the invention is to provide a wingtip device, and also 10 sition are provided on the wingtip device such that the a wing with such a wingtip device, with which the gradient ancillary wing sections on a wingtip device compared with of drag reduction with increasing wing loads can be con- a wingtip device without ancillary wing sections exert only figured in a particularly favourable manner. a relatively small influence on the drag during flight op- [0003] This object is achieved with the features of the erations, but exert a considerable influence on the global independent claims. Further forms of embodiment are 15 load distribution over the whole wing, to which the wingtip specified in the subsidiary claims that are dependent on device is attached. the independent claims. [0007] The inventive solution is in particular advanta- [0004] The inventive wingtip device can in general be geous if it is applied to wings with a relatively low stiffness, attached to a wing, or to a wing-like component of an since then the influence of the inventively provided an- aircraft. The wing-like component, which in what follows 20 cillary wing sections on the global load distribution is par- is abbreviated to "wing", can be a wing, a tailplane, a ticularly advantageous. By virtue of the development of stabiliser, or also a canard, wherein the sweep of the further aerodynamic loads as a function of the configu- wing can be positive or negative. By means of the inven- ration and position of the respective ancillary wing sec- tive solution of a wingtip device attached to a wing, or a tions, the ancillary wing sections contribute to the load main winglet with at least two ancillary wing sections, or 25 redistribution on the wing. ancillary wing parts, or ancillary winglets, or auxiliary win- [0008] In particular, the difference in wing flexing be- glets arranged on the wing, the aerodynamic drag of the tween the case of steady-state cruise flight that is of in- overall wingtip device during flight operations can be re- terest in terms of drag, and the increased flexing that duced, and/or the loads acting on the overall wingtip de- occurs during flight manoeuvres that are of interest for vice can be reduced compared with wingtip devices of 30 dimensioning the structure, is exploited by means of the known art. The inventive wingtip device can reduce the inventive solution. By means of the inventive ancillary loads that occur under flight conditions that are relevant wing sections it is possible to adjust the local loadings for the structural design of the wing. The length of an and load distribution on the wing in these flight conditions ancillary wing section is thereby clearly less than the such that the maximum loads occurring on the wing are length of the wingtip device, and in particular is less by 35 reduced and the wing can therefore be built with a lower a half. By this means, with matching and optimisation of weight. the number and/or size and/or position and/or location [0009] In accordance with one aspect of the invention of the at least two ancillary wing sections on the wingtip a wingtip device is provided for a wing that has an inner device, it is possible to achieve a gradient of drag reduc- end and an outer end and in which the local dihedral tion that is greater than the gradient of the increasing40 angle of the wingtip device increases or reduces from loads on the wing or wingtip device as a result of aero- the inner end to the outer end, with a pressure-side flow dynamic loading. surface and a suction-side flow surface with reference to [0005] A wing with an inventive wingtip device, i.e. the an assumed prime incident flow direction. In accordance inventive wingtip device, can be optimised by matching with the invention provision is made that at least two an- and optimisation of the number and/or size and/or posi- 45 cillary wing sections are arranged on the wingtip device, tion and/or location of the at least two ancillary wing sec- projecting away from the flow surface of the wingtip de- tions on the wingtip device, wherein in particular a reduc- vice. The ancillary wing sections are thereby configured tion of the total drag at a given wing loading and/or a and arranged on the wingtip device such that in a prede- reduction of the wingtip device loading and/or wing load- termined manner these generate loads acting on the ing as a result of external aerodynamic loads can be50 wingtip device, and thus also on the wing to which the achieved without any particular effect on the total drag wingtip device is attached. of the wing wingtip device and can be adjusted in a tar- [0010] In accordance with one form of embodiment of geted and advantageous manner. In this regard the fol- the invention at least one ancillary wing section is, or two lowing can in particular be achieved: of the ancillary wing sections are, arranged on the wingtip 55 device such that the attachment region of the ancillary 1 a reduction of the loading and/or load distribution wing section to the wingtip device, i.e. the interface be- on the wingtip device and/or on the wing ensuing as tween ancillary wing section and the wingtip device, is a result of aerodynamic loads and/or predominantly located on the respective flow surface 2 3 EP 2 731 867 B1 4 pointing in the local thickness direction of the wingtip de- that the central plane of the ancillary wing section is in- vice, which in what follows can also be called the suction clined at an angle of less than 30 degrees with respect surface, or is located on the flow surface pointing away to the local thickness direction of the local wingtip device from the local thickness direction of the wingtip device, coordinates system. which in what follows can also be called the pressure 5 [0017] In accordance with a further inventive form of surface. embodiment of the wingtip device provision can be made [0011] In particular provision is thereby made that, with that the in particular inventively defined local central reference to a section through the wingtip device in the plane of the ancillary wing section is incli ned at an angle YZ-plane, at least one ancillary wing section is arranged of less than 30 degrees relative to the local thickness on that side of the wingtip device that in general has con- 10 direction of the local wingtip device coordinates system, vex curvature. This form of embodiment is in particular at least within a region of up to 85 % of the length of the advantageous for aerodynamic reasons, since the span ancillary wing section. of the wing is increased, and by this means the induced [0018] Also in accordance with an inventive form of drag can be reduced.
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