CN115848613A

CN115848613A - Distributed seamless active flexible wing

Info

Publication number: CN115848613A
Application number: CN202210402950.1A
Authority: CN
Inventors: 陈东和; 戴玉婷; 田博丞; 姚鑫彤
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2022-04-18
Filing date: 2022-04-18
Publication date: 2023-03-28

Abstract

The invention designs a distributed seamless active flexible wing. The wing is composed of multiple sections of independent wing sections, each wing section can independently change the camber in a distributed mode, and each independent variable camber wing section is composed of a steering engine, a sectional hinged wing rib and a sliding skin. And two adjacent wing sections are connected by a flexible film, so that the deformation between the distributed variable camber wing sections is continuous and smooth. Compared with the wings of the traditional passenger plane, the invention adopts a scheme of distributed active flexible deformation, realizes the functions of the traditional flaps and ailerons through the independent flexible deformation of each wing section, reduces the mechanism complexity of the wings and lightens the weight of the wings; on the other hand, the whole wing is seamless, so that a gap is not generated when the control surface acts, the airflow separation generated by the gap is avoided, the pneumatic efficiency is improved, the pneumatic noise is weakened, and the method is a very potential seamless control surface mode in the future.

Description

Distributed seamless active flexible wing

Technical Field

The invention belongs to the technical field of airplane design, and particularly relates to a distributed seamless active flexible trailing edge wing.

Background

The wings of a passenger plane are main components generating lift, and need to meet the requirements of high lift-drag ratio during cruising, high lift-drag ratio during takeoff, and high lift-drag ratio during landing. To meet these demands, components such as low-speed ailerons, high-speed ailerons, flaps, slats, speed reduction plates, and the like are arranged on the rigid wings. The components only work under specific working conditions, and under different flight conditions, some components can not work, so that dead weight is caused.

The deformation scheme of the active flexible wing mainly comprises four deformation modes, namely spanwise deformation, chordwise deformation, torsional deformation and plane shape deformation. The spanwise deformation can change the dihedral angle and the wingspan, and can change the stability and the lift-drag ratio of the airplane; the chord-direction deformation changes and controls the camber of the airfoil on the airfoil section, and the requirements under different working conditions when the airplane flies are met only by virtue of the chord-direction deformation; the torsional deformation changes the torsional angle of each airfoil section; the plane shape deformation changes the wing area, the sweep angle and the like.

Chordal deformation is one of the directions in which there is a great potential. Most of the chord-wise flexible wings nowadays have the following problems:

1. and the wing sections are not transited, and gaps are generated when the wing sections are deformed to different degrees, so that the lift-drag characteristic of the airplane is poor due to airflow separation.

2. Irregular deformation of the wing increases aerodynamic noise.

There is therefore a need for a chordwise deformed distributed seamless active flexible wing.

Disclosure of Invention

According to one aspect of the present invention, there is provided an airfoil having a distributed seamless trailing edge, comprising:

spar, rib, skin, steering mechanism, wing section transition structure.

The wing beam is a main force bearing part of the wing, and the two wing beams are made of wood laminates in total. The first spar is disposed at 30% chord length and the second spar is disposed at 50% chord length. In order to connect the wings at the left side and the right side, the invention uses a rectangular carbon tube to penetrate through the wing ribs of the wing sections at the inner sides of the left wing and the right wing.

The wing rib is divided into a front section and a rear section, the front section is a rigid wing rib, and a steering engine mounting hole is formed in the rigid wing rib; the rear section is a flexible wing rib, and the lower edge of the flexible wing rib is bonded with the rear wing beam. And a strut which is hinged with the upper edge and the lower edge of the flexible wing rib is arranged between the upper edge and the lower edge of the flexible wing rib, so that the flexible wing rib is not influenced to be bent, and the wing rib is prevented from collapsing. The flexible trailing edge of each panel comprises three of said flexible ribs. The middle flexible wing rib is driven by the steering engine to drive the left and right flexible wing ribs to change the bending degree. The three flexible wing ribs are respectively provided with two round holes at the front end and the rear end of the flexible rear edge, and the first connecting rod and the second connecting rod are respectively inserted into the round holes at the front end and the rear end of the wing ribs. Thus ensuring the deformation coordination of the whole wing panel.

The skin, which is used to maintain the aerodynamic profile, is supported by the ribs. The front half part of each wing covers a wooden mask and a thermal shrinkage skin, the rear half part of each wing section covers a PET flexible skin on the surface of the flexible trailing edge mechanism, the PET flexible skin on the lower surface is adhered to the bottom of the skin supporting device, and the front end of the PET flexible skin on the upper surface is fixed in the skin sliding groove and is allowed to slide along the chord direction.

The operating mechanism is used for driving the rear edge to change the camber. In some embodiments, the steering mechanism includes a steering engine and a linkage. A steering engine is arranged in each wing section, the steering engines are mounted on steering engine mounting holes of the middle wing ribs through bolts, and the driving force of the steering engines is transmitted to the middle connecting point of the flexible trailing edge mechanism through a connecting rod, so that the bending degree of the whole flexible trailing edge is changed.

A wing section transition structure. Two adjacent wing sections and the end plates are connected through a silica gel film. The silica gel film and the PET flexible skin are bonded by using special silica gel glue.

The mechanism that each wing section of the trailing edge can be independently deformed and the wing surface is smooth and continuous is as follows:

because every wing section respectively installs a steering wheel, this steering wheel can be controlled alone, and the silica gel film can bear and warp by a wide margin, so every wing section can warp independently and do not receive other wing section restrictions.

And the adjacent wing sections are connected with each other through a silica gel film. When the wing section deforms between the upper limit position and the lower limit position, the silica gel film correspondingly deforms to keep the surface of the wing smooth and continuous.

Drawings

FIG. 1 is an internal structure of a flexible wing according to one embodiment of the invention;

FIG. 2 is a compliant mechanism according to one embodiment of the invention;

FIG. 3 is a skin arrangement according to one embodiment of the invention;

FIG. 4 is an actuation range of a compliant mechanism according to one embodiment of the present invention.

Reference signs

Detailed Description

The internal structure of the flexible wing according to the embodiment of the invention is described in detail below with reference to the accompanying drawings.

FIG. 1 is an internal structure of a flexible wing according to one embodiment of the invention. The front wing beam (11) and the rear wing beam (12) are parts of the wing which mainly bear bending moment and are made of 2mm basswood laminates. The wing box (3) is the part of the wing which mainly bears the torque.

The carbon square tube (21) is inserted into the outer rigid wing rib square hole (4111), the middle rigid wing rib square hole (4121) and the side rigid wing rib square hole (4131) of the inner wing sections of the two wings and is locked by a first bolt (22) and a second bolt (23).

The outboard rib attachment region (4011), the mid-rib attachment region (4021), and the inboard rib attachment region (4031) are bonded to the rear spar (12) using glue.

Each panel has three flexible ribs, an outer flexible rib (401), a middle flexible rib (402), and an inner flexible rib (403); three rigid ribs, an outer rigid rib (411), a middle rigid rib (412), and an inner rigid rib (413). The three flexible wing ribs are provided with front connecting rods (51) to maintain the coordinated deformation of the front parts of the flexible wing ribs; a rear link (52) is also mounted to maintain the coordinated deformation of the rear of the flexible rib.

FIG. 2 is a compliant mechanism according to one embodiment of the present invention. The first support (711), the second support (712) and the third support (713) are respectively hinged to the first pair of lugs (701), the second pair of lugs (702) and the third pair of lugs (703) of the flexible wing rib by bolts. The middle rigid wing rib (412) is provided with a steering engine mounting hole (4122), and the steering engine (61) is mounted on the steering engine mounting hole (4122). The driving pull rod (63) is connected to the rudder arm (62) and the driving pull rod connecting hole (64).

A PET skin (42) covers the surface of the flexible trailing edge mechanism. PET skins (42) on the upper surface and the lower surface are respectively bonded to the top and the bottom of the outer flexible wing rib (401), the middle flexible wing rib (402), the inner flexible wing rib (403) and the second wing beam (12). The PET skin (42) with the unbonded upper surface is placed in the skin sliding groove (43) and can slide along the chord direction. When the middle flexible wing rib (402) is deformed under the driving of the driving connecting rod (63), the outer flexible wing rib (401) and the inner flexible wing rib (403) deform along with the middle flexible wing rib (402). The PET skin on the lower surface of the wing bends together with the flexible wing ribs, and the PET skin (42) on the upper surface of the wing slides along the skin sliding groove (43) while bending. The deformation of each wing segment is determined by an independently controlled steering engine.

FIG. 3 is a skin layout according to one embodiment of the invention. Each wing has three wing sections, namely an outer wing section (81), a middle wing section (82) and an inner wing section (83). The wing tip end plate (91) and the wing root end plate (92) are formed by cutting carbon plates.

The PET skin is cut from a 0.2mm thick PET film and bonded to the flexible ribs and rear spar (12) with white latex. The wing box (3) is covered with a heat-shrinkable skin.

And the silica gel skin with the thickness of 0.1mm is bonded among the adjacent wing sections, the wing sections and the end plates by using special silica gel glue. Because the silicone skin has good elasticity. In the experiment, the whole wing can be deformed coordinately as long as the deflection angle of the steering engine is within the range of +/-30 degrees.

FIG. 4 is an actuation range of a compliant mechanism according to one embodiment of the present invention. When the deflection angle of the steering engine (61) is 0 degrees, the wing profile of each wing section is NACA4412. When the deflection angle of the steering engine (61) is an upper limit angle, the flexible rear edge bends upwards to the maximum degree, namely an upper limit position; when the steering engine deflection angle (61) is a lower limit angle, the flexible rear edge bends downwards to the maximum degree, namely a lower limit position.

The mechanism by which each panel of the trailing edge can deform independently and the wing surface continues smoothly is as follows:

And the adjacent wing sections are connected with each other through a silica gel film. When the wing section deforms between the upper limit position and the lower limit position, the silica gel film generates corresponding deformation, and the surface of the wing is kept smooth and continuous all the time.

The invention has the following beneficial effects:

compared with the mainstream rigid wing, the flexible wing provided by the invention has no mechanisms such as ailerons and flaps, and therefore has smaller mechanism complexity.

And each wing section keeps smooth and continuous surface in the deformation process, and the adjacent wing sections, the silica gel skin between the wing sections and the end plate also keep smooth and continuous. Compared with the mainstream rigid wing, the flexible wing is less prone to airflow separation and has smaller aerodynamic noise.

The maximum lift-drag ratio under different flight speeds and heights can be achieved by adjusting the camber of the flexible trailing edge of each wing section, so that the flexible wing can enable the flight envelope range of the airplane to be larger.

Claims

1. An airfoil having a distributed seamless compliant trailing edge, the improvement comprising:

the front wing beam (11) and the rear wing beam (12) are the main parts bearing bending moment of the wing and are made of 2mm basswood laminates. The leading edge wing box (3) is the part of the wing which mainly bears the torque.

The first support (711), the second support (712) and the third support (713) are hinged to the first pair of lugs (701), the second pair of lugs (702) and the third pair of lugs (703) of the flexible wing rib respectively through bolts. The middle rigid wing rib (412) is provided with a steering engine mounting hole (4122) on which a steering engine (61) is mounted. The driving pull rod (63) is connected to the rudder arm (62) and the driving pull rod connecting hole (64).

A PET skin (42) covers the surface of the flexible trailing edge mechanism. PET skins (42) on the upper surface and the lower surface are respectively bonded to the top and the bottom of the outer flexible wing rib (401), the middle flexible wing rib (402), the inner flexible wing rib (403) and the second wing beam (12). The PET skin (42) with the unbonded upper surface is placed in a skin sliding groove (43), and can slide along the chord direction. When the middle flexible wing rib (402) is deformed under the driving of the driving connecting rod (63), the outer flexible wing rib (401) and the inner flexible wing rib (403) deform along with the middle flexible wing rib (402). The PET skin on the lower surface of the wing bends together with the flexible wing ribs, and the PET skin (42) on the upper surface of the wing slides along the skin sliding groove (43) while bending. The deformation of each wing segment is determined by an independently controlled steering engine, which provides six degrees of freedom to the controller.

Each wing has three wing sections, namely an outer wing section (81), a middle wing section (82) and an inner wing section (83). The wing tip end plate (91) and the wing root end plate (92) are formed by cutting carbon plates.

The PET covering is formed by cutting a PET film with the thickness of 0.2 mm. It is bonded to the flexible ribs and rear spar (12) with white latex. The wing box (3) is covered with a heat-shrinkable skin.

The silica gel skin is bonded among the adjacent wing sections, the wing sections and the end plates by using special silica gel glue. Because the silicone skin has good elasticity. In the experiment, the whole wing can be deformed coordinately as long as the deflection angle of the steering engine is within the range of +/-30 degrees.

2. The wing of claim 1, wherein:

each wing section is not limited by the deformation of other wing sections when deforming, and the deformation range is shown in figure 4. Each wing section is provided with three flexible wing ribs, and the steering engine drives the flexible wing ribs in the middle. To achieve the same deformation of the three flexible ribs, two carbon round tubes were used to connect the three flexible ribs.

The wing has a half-span length of 933mm, the width of the silica gel skin between the outer end plate and the outer side wing section and between the inner end plate and the inner side wing section is 48.5mm, the width of the silica gel skin between the wing sections is 93mm, and the width of the PET skin at the rear edge of the wing section is 216mm. The thickness of the PET skin is 0.2mm, and the thickness of the silica gel skin is 0.1mm. Through tests, the arrangement of the silica gel skin and the PET skin just enables the wings under various deformation conditions to keep smooth surfaces, and the area ratio of the silica gel skin is minimum.

The flexible bonding of the silica gel skin and the PET skin is realized by using special silica gel glue, and proper pretightening force is applied to the silica gel skin during bonding. Therefore, the out-of-plane rigidity of the silica gel skin is improved, and the surface of the silica gel skin is kept flat.

3. The wing of claim 1, wherein:

pneumatic torsion: by changing the camber of the wing to distribute the lift force on different wing sections, elliptical lift force distribution is approximately obtained, and the induced resistance is reduced.

Expanding a flight envelope: and selecting proper bending degree at certain flying height and speed to improve lift-drag ratio.

Replacement of high-lift devices: when taking off and landing, the camber of each wing section is increased to achieve the effect of increasing lift. Wherein the camber of the inboard wing section is greater than that of the outboard wing section, thus reducing the root bending moment.

Replacement of high and low speed ailerons: when flying at high speed, the airplane adjusts the roll angle by depending on the deformation of the inside wing section; and at low speed, the rolling angle is adjusted depending on the deformation of the outer wing section.

The method for realizing the functions comprises the following steps: the airplane is matched with the airplane under the working conditions of takeoff, landing, cruising, maneuvering and the like in advance, and is switched according to the flight working conditions in flight.

(a is the rudder amount of the aileron, v is the airspeed, is the roll angle and is the deflection angle of the steering engine).