Airplane wingtip device
Technical field
The present invention relates to a kind of wingtip device of aircraft wing.
Background technology
When aircraft maintains normal flight, required lift is to lean on the difference of pressure of wing upper and lower surface to produce, existence due to upper and lower surface pressure reduction, near wing tip, wing lower surface air can stream upper surface, form wing tip whirlpool, cause the pressure reduction of wing tip near zone wing upper and lower surface to reduce, thereby cause the lift that this region produces to reduce.
For the problems referred to above, winglet (winglet) is set conventionally on aircraft wing wing tip again, the Main Function of this winglet is not increase under the prerequisite of wing length, improves actv. aspect ratio.The two dimensional effects of wing strengthens like this, and induced drag reduces, and lift increases, and 1ift-drag ratio improves.Secondly, the winglet wing tip whirlpool of can also dissipating, reduces trailing the threat of the flivver of flight.
Yet, once aircraft wing has installed winglet additional, increased the weight of winglet.Wing wing tip structure, in order to assemble the winglet more complicated that can become, also can increase some extra weight.Winglet increases wing wing root moment of flexure and shearing load, also will cause the increase of wing structure weight.And winglet designs badly, the stalling characteristic of aircraft, flutter characteristic be variation thereupon also.
According to the shape of wingtip device, there are in the world at present several classes: a kind of is wing tip sail, or deserve to be called trans winglet.The winglet of this style generally has the structure of syllogic, there is construction section, arc transition section and straight plate section, this wingtip device has obvious crooked fin, in actual applications, the 747-400 type aircraft that Boeing (Boeing) produces and A330 and the A340 series aircraft of space truck (AIRBUS) have all been used such wingtip device.When reequiping as Boeing 727, Boeing 757 and Boeing-767 aircraft, also this wingtip device can be installed in addition.
Another kind is triangle wing tip sail, and the wing tip sail of this form aloft uses in passenger vehicle A320 series, A310 and A380, and such wingtip device also can say the standard form of Airbus aircraft.
In addition, the newly-designed passenger plane of Boeing all replaces wing tip sail with special shark fin type wingtip device (raked winglet) as Boeing 777, Boeing 787, Boeing-747-8.
Although upper trans winglet and wing tip sail have obvious drag-reduction effect, no matter be winglet or wing tip sail, the moment of flexure of their wing roots is all larger, and this has just increased the structural weight of himself, and the flutter characteristic of aircraft is produced to certain influence.
Therefore, people wish when keeping wingtip device aerodynamic characteristic, to reduce the weight of wingtip device, reduce the increase of moment of flexure weight and the impact on flutter characteristic that because wingtip device is installed, bring.
Summary of the invention
The object of the present invention is to provide a kind of wingtip device, it can, when keeping wingtip device aerodynamic characteristic, reduce the weight of wingtip device.
For achieving the above object, the invention provides a kind of airplane wingtip device, described airplane wingtip device comprises interconnecting gangway and wing tip portion, the medial end of described interconnecting gangway is connected with the far-end of aircraft wing, the outboard end of described interconnecting gangway is connected with described wing tip portion, wherein, described wing tip portion comprises a plurality of wing tip sections, each wing tip section comprises respectively wing tip and wing root, the wing root of described first wing tip section is connected with the outboard end of described interconnecting gangway, and it is arranged between the leading edge and trailing edge of described interconnecting gangway outboard end, the wing root of described n+1 wing tip section is positioned on the wing tip of n wing tip section, and the wing root chord length of described n+1 wing tip section is in the wing tip chord length of n wing tip section, wherein n > 0.
In the present invention, the top in each wing tip section of aircraft is referred to as to " wing tip ", the bottom of each wing tip section of aircraft is referred to as to " wing root ".
Especially, the thickness of described n+1 wing tip section is thinner than described n wing tip section.
Especially, the chord length of the wing tip of described each wing tip section is less than the chord length of its wing root.More particularly, the wing tip section of described each wing tip Duan Douwei chord length convergent.
Especially, the chord length of the wing root of described first wing tip section is less than or equal to the chord length of the outboard end of described interconnecting gangway.
Especially, the medial end chord length of described interconnecting gangway is greater than the outboard end chord length of described interconnecting gangway.
Especially, described interconnecting gangway is the interconnecting gangway of chord length convergent.
Especially, the top-surface camber of described interconnecting gangway and lower surface camber are smooth surface.
Especially, the far-end of described interconnecting gangway and described aircraft wing is smoothly connected.
Especially, described airplane wingtip device and described aircraft wing are one-body molded.
Especially, the trailing edge line of described wing tip portion and the alignment of the trailing edge line of described interconnecting gangway.
Especially, the initiating terminal of the interconnecting gangway of described wingtip device be positioned at described wing along exhibition to the 85%-100% of length.
Especially, the chord length of the first paragraph wing root of described wing tip portion is the 10%-100% of described interconnecting gangway outboard end chord length.
Especially, costa and the trailing edge line of each wing tip section of described wing tip portion are respectively conic section line segment, line transect, straight line or broken line.Especially, the costa of described each wing tip section is conic line segment, and described trailing edge line is straight line.More particularly, described conic section line segment is parabola, hyperbola or ellipse.
In addition, the present invention also provides a kind of airplane wingtip device, described airplane wingtip device comprises interconnecting gangway and wing tip portion, the medial end of described interconnecting gangway is connected with the far-end of aircraft wing, the outboard end of described interconnecting gangway is connected with described wing tip portion, it is characterized in that, described wing tip portion comprises wing root and wing tip, the wing root of described wing tip portion is connected with the outside end face of described interconnecting gangway, and it is arranged between the leading edge and trailing edge of described interconnecting gangway outboard end, the chord length of described wing root is less than the chord length of end face outside described interconnecting gangway.
Especially, the thickness of described wing tip portion is thinner than described interconnecting gangway.
Especially, the wing tip chord length of described wing tip portion is less than its wing root chord length.More particularly, described wing tip portion is the wing tip portion of chord length convergent.
Especially, the medial end chord length of described interconnecting gangway is greater than the outboard end chord length of described interconnecting gangway.More particularly, the interconnecting gangway that described interconnecting gangway is chord length convergent.
Special than ground, the top-surface camber of described interconnecting gangway and lower surface camber are smooth surface.
Especially, the far-end of described interconnecting gangway and described aircraft wing is smoothly connected.
Especially, described airplane wingtip device and described aircraft wing are one-body molded.
Especially, the trailing edge line of described wing tip portion and the alignment of the trailing edge line of described interconnecting gangway.
Especially, the initiating terminal of the interconnecting gangway of described wingtip device be positioned at described wing along exhibition to the 85%-100% of length.
Especially, the chord length of the wing root of described wing tip portion is the 10%-100% of described interconnecting gangway outboard end chord length.
Especially, costa and the trailing edge line of described wing tip portion are respectively conic section line segment, line transect, straight line or broken line.More particularly, the costa of described each wing tip portion is conic line segment, and described trailing edge line is straight line.More particularly, described conic section line segment is parabola, hyperbola or ellipse.
Due to the stepped setting of wingtip device of the present invention, so increased more than one discontinuity surface on its wing tip, thereby the wing tip whirlpool that wing tip induces is suppressed mutually, weakened turbulence rate, thereby reached drag-reduction effect, in addition, wing root moment of flexure increment of the present invention is less, thereby alleviated the structural weight of aircraft, also less on flutter characteristic impact.
Accompanying drawing explanation
Fig. 1 is the front view of the winglet embodiment of trailing edge alignment of the present invention;
Fig. 2 is the schematic diagram of another trailing edge alignment winglet of the present invention embodiment;
Fig. 3 is the front view of the winglet embodiment of leading edge alignment of the present invention;
Fig. 4 is the schematic diagram of the winglet embodiment of another leading edge alignment of the present invention;
Fig. 5 is the front view of another winglet of the present invention embodiment, in this embodiment, and in the middle of described stepped wing tip portion is arranged on;
Fig. 6 is the schematic diagram of winglet as shown in Figure 5;
Fig. 7 shows the embodiment of another trailing edge alignment winglet of the present invention, in this embodiment, and the wing root chord length of n+1 wing tip section and the tip chord appearance of n wing tip section etc.
The specific embodiment
As depicted in figs. 1 and 2, in one embodiment of the invention, airplane wingtip device is multi-ladder shape, it comprises interconnecting gangway 1 and wing tip portion 2, the medial end of described interconnecting gangway 1 is connected with the far-end of aircraft wing 6, the outboard end of described interconnecting gangway 1 is connected with described wing tip portion 2, and wherein, described wing tip portion comprises a plurality of wing tip sections 3
n, each wing tip section comprises respectively wing tip 4
nwith wing root 5
n, described first wing tip section 3
1 wing root 5
1be connected with the outboard end of described interconnecting gangway 1, and align with the trailing edge of described interconnecting gangway 1 outboard end, described n+1 wing tip section 3
n+1 wing root 5
1be positioned at n wing tip section 3
nwing tip 4
nupper, and described n+1 wing tip section 3
n+1 wing root 5
1chord length is less than n wing tip section 3
nwing tip 4
nchord length, wherein n > 0.In addition, as shown in Figure 1, the trailing edge line of described wing tip portion 2 and the alignment of the trailing edge line of described interconnecting gangway 1.
In a preferred embodiment of the invention, described n+1 wing tip portion 3
n+1thickness be thinner than described n wing tip portion 3
n.The chord length of the wing tip 4 of described each wing tip section 3 is less than the chord length of its wing root 5, and forms the wing tip section 3 of chord length convergent.Described first wing tip section 3
1 wing root 5
1chord length be less than or equal to the chord length of the outboard end of described interconnecting gangway 1.The medial end chord length of described interconnecting gangway 1 is greater than the outboard end chord length of described interconnecting gangway 1, and forms the interconnecting gangway 1 of chord length convergent.The top-surface camber of described interconnecting gangway 1 and lower surface camber are smooth surface.Described interconnecting gangway 1 is smoothly connected with the far-end of described aircraft wing.Described airplane wingtip device and described aircraft wing are one-body molded.
In addition, in a preferred embodiment of the invention, the initiating terminal of the interconnecting gangway 1 of described wingtip device be positioned at described wing along exhibition to the 85%-100% of length, the first paragraph wing root 5 of described wing tip portion 2
1chord length be the 10%-100% of the outboard end chord length of described interconnecting gangway 1.
In another embodiment of the present invention, described wingtip device also can be single stair shape, comprise interconnecting gangway 1 and wing tip portion 2, the medial end of described interconnecting gangway 1 is connected with the far-end of aircraft wing 6, the outboard end of described interconnecting gangway 1 is connected with described wing tip portion, it is characterized in that, described wing tip portion 2 comprises wing root 5 and wing tip 4, the wing root 5 of described wing tip portion 2 is connected with the outside end face of described interconnecting gangway 1, and align with the trailing edge of described interconnecting gangway 1 outboard end, and the chord length of described wing root 5 is less than the chord length of described interconnecting gangway 1 outside end face.
In addition, the costa of each wing tip section 3 of described wing tip portion 2 is conic section line segment, line transect, straight line or broken line.More particularly, described conic section line segment is parabola, hyperbola or ellipse.As shown in Figure 1, the leading edge of described wing tip portion 2 each wing tip section 3 is conic section line segments in one embodiment of the invention.
As shown in Figure 3 and Figure 4, in another embodiment of the present invention, described first wing tip section 3
1 wing root 5
1can also align with the leading edge of described interconnecting gangway 1 outboard end.Now, the costa of described wing tip portion 2 and the alignment of the costa of described interconnecting gangway 1.
In addition, the trailing edge line of each wing tip section 3 of described wing tip portion 2 is conic section line segment, line transect, straight line or broken line.More particularly, described conic section line segment is parabola, hyperbola or ellipse.And as shown in Figure 3, in one embodiment of the invention, the trailing edge line of each wing tip section 3 of described wing tip portion 2 is straight lines.
In addition, as shown in Figure 5 and Figure 6, in another embodiment of the present invention, described wing tip portion 2 can be arranged on the centre of described interconnecting gangway 1 outboard end, i.e. described first wing tip section 3
1 wing root 5
1neither align with the leading edge of described interconnecting gangway 1 outboard end, also do not align with the trailing edge of described interconnecting gangway 1 outboard end.
Now, costa and the trailing edge line of each wing tip section of described wing tip portion 2 can be respectively conic section line segment, line transect, straight line or broken line, and more particularly, described conic section line segment is parabola, hyperbola or ellipse.Described costa and trailing edge line can adopt the line segment of same type, also can adopt dissimilar line segment.And as shown in Figure 5 and Figure 6, the trailing edge line of the wing tip section 3 of described wing tip portion 2 is straight lines in one embodiment of the invention, costa is conic line segment.
Above-mentioned set-up mode as described in Fig. 3-6 also can be for the winglet of single-order scalariform, and its method to set up and above-mentioned multistage scalariform winglet similar do not repeat them here.
In addition, as shown in Figure 7, in one embodiment, n+1 wing tip section 3
n+1 wing root 5
n+1chord length and n wing tip section 3
nwing tip 4
nchord length equates, in this case, in the junction of each wing tip section, chord length is cut, so it still can produce the shape of ladder.
Technology contents of the present invention and technical characterstic disclose as above, yet are appreciated that under creative ideas of the present invention, and those skilled in the art can make various changes and improve said structure, but all belongs to protection scope of the present invention.The description of above-described embodiment is exemplary rather than restrictive, and protection scope of the present invention is determined by claim.