CN118770602B

CN118770602B - Flexible wing structure based on passive inhibition flutter of multistable plate

Info

Publication number: CN118770602B
Application number: CN202411167517.XA
Authority: CN
Inventors: 沈路; 任建华; 熊晶鸿
Original assignee: Harbin Institute Of Technology shenzhen Shenzhen Institute Of Science And Technology Innovation Harbin Institute Of Technology
Current assignee: Harbin Institute Of Technology shenzhen Shenzhen Institute Of Science And Technology Innovation Harbin Institute Of Technology
Priority date: 2024-08-23
Filing date: 2024-08-23
Publication date: 2025-09-16
Anticipated expiration: 2044-08-23
Also published as: CN118770602A

Abstract

The invention discloses a flexible wing structure for passively inhibiting flutter based on a multistable plate, which relates to the field of high-altitude long-endurance aircrafts and comprises a first wing shell, a second wing shell, a multistable thin plate and an I-shaped beam, wherein the first wing shell is divided into a front part and a rear part, the I-shaped Liang Guanchuan is connected with the front part of the first wing shell and the second wing shell, the tail part of the multistable thin plate is connected with the rear part of the first wing shell through a bonding and fixing method, the other end of the multistable thin plate is fixed on one side of the I-shaped beam through a bolt, the surface of the circular area is provided with a circular area with bistable characteristic, and the surface of each circular area is connected with a sucker which is connected with an air source through an air source pipeline.

Description

Flexible wing structure based on passive inhibition flutter of multistable plate

Technical Field

The invention relates to the technical field of high-altitude long-endurance aircraft equipment, in particular to a flexible wing structure for passively inhibiting flutter based on a multistable plate.

Background

The emerging application of the unmanned aerial vehicle in the field of monitoring and reconnaissance at present makes the unmanned aerial vehicle become an important existence incomparable with the traditional light airplane and satellite. In pursuit of more excellent aerodynamic performance to improve voyage, such unmanned aerial vehicles are generally designed as lightweight, high aspect ratio structures.

However, although the flexibility characteristic of the blade is remarkably enhanced by the light-weight high-aspect ratio structure, the blade is more easily subjected to large-amplitude bending deformation under the influence of aerodynamic load, meanwhile, the problem of aeroelastic instability is more easily generated under extreme conditions such as strong wind, strong turbulence and the like, and large-scale vibration is induced to cause structural damage. Therefore, it is important to control the large scale vibrations of such high aspect ratio flexible wing structures due to aeroelastic instability.

At present, methods capable of effectively suppressing large-scale vibrations are mainly classified into two main categories. The first is realized by changing the wing structure, and the possibility and influence of large-scale vibration are reduced by designing and optimizing the wing structure to reduce deflection and improve rigidity. The second type is realized by controlling the flow field on the surface of the wing, the large-scale vibration of the wing is usually caused by periodical vortex shedding on the wing surface, and the vortex shedding can cause large-scale fluctuation of aerodynamic force to cause the wing to vibrate in large scale, the flow field on the surface of the wing can be changed by adjusting the shape of the front edge of the wing and the gesture of the trailing edge flap in real time, or the flow separation on the surface of the wing is controlled by the wing surface blowing and sucking device, so that the wing does not vibrate due to the periodical vortex shedding, and the stability of the structure is ensured.

Existing methods of damping large scale vibrations by changing the wing structure often require the introduction of additional complexities, such as design, manufacturing, and maintenance complexities, which can create system reliability and durability issues. Furthermore, to change the wing structure, new structures, materials, or mechanisms may need to be added, which may increase the overall weight of the aircraft, potentially reducing its performance and efficiency. Therefore, this method may cause a series of problems such as low reliability, high cost, inconvenience in use, and the like.

For suppressing large scale vibrations by controlling the flow field on the wing surface, one common approach is to actively adjust the shape of the wing leading edge or the attitude of the trailing edge flap in real time to suppress the large scale vibrations. However, this often requires the introduction of complex control systems and implementation mechanisms, wherein the control systems must be highly reliable and stable. Furthermore, additional energy consumption is unavoidable in order to drive the actuators and the control system. These factors increase the design, manufacturing, and maintenance costs of the aircraft, making the overall cost prohibitive.

The other type of the air suction and blowing device can effectively control the flow separation of the surface of the wing through the front edge of the wing, so that large-scale vibration is restrained. However, the suction and blowing device requires additional energy to generate a high momentum airflow and release it to the wing surface to control flow separation. The convergence time of the control flow field is generally long, and the energy provided by the blowing and its range of action are limited, which results in a limited ability to control flow separation, and therefore, such leading edge blowing devices have a limited control.

Disclosure of Invention

The invention aims to provide a flexible wing structure based on a multistable plate for passively inhibiting flutter, which does not need additional sensors and controllers, has high response speed and simple and convenient operation, can effectively ensure the stability of the wing structure in a complex airflow environment, and ensures the flight safety of a solar aircraft in high altitude and long endurance.

The invention provides a flexible wing structure for passively inhibiting flutter based on a multistable plate, which comprises a first wing shell and a second wing shell and is characterized by further comprising an I-beam, wherein the I-beam is used for penetrating and connecting the first wing shell and the second wing shell, and the multistable plate is arranged on the I-beam and is positioned in the first wing shell.

Preferably, one side of the multistable sheet is provided with a threaded hole correspondingly connected with the I-beam, and the surface of the other side is provided with a plurality of circular bistable regions.

Preferably, the surfaces of the circular bistable regions are provided with sucking discs, and the sucking discs are connected with an air source through an air source pipeline.

Preferably, the first shell includes a first shell front portion and a first shell rear portion.

Preferably, a rectangular through groove in which the I-beam is embedded is formed in the middle of the front part of the first wing shell, and a gap for fixing the multistable thin plate is formed in the middle of the rear part of the first wing shell.

Preferably, the multistable sheet is fixed to the inner side of the rear portion of the first wing shell by means of adhesion, and is correspondingly connected with the i-beam.

Preferably, the i-beam and the multistable sheet are connected by bolts.

Preferably, the second wing shell is of an integrated structure, and a through groove corresponding to the I-beam is formed in the second wing shell.

Preferably, the I-beam is made of No. 45 steel, and the multistable sheet is made of 304 stainless steel.

The invention also provides a preparation method of the bistable region, which comprises the following steps:

s1, carrying out nano mechanical abrasion processing on the surface of a thin plate to form a plurality of circular areas;

S2, accelerating a plurality of stainless steel balls through an ultrasonic transducer to impact the circular area obtained in the step S1 at a high speed, so as to form a circular bistable area.

Therefore, the flexible wing structure based on the multistable plate passive vibration suppression adopts the structure, and has the following beneficial effects:

(1) When the wing is subjected to large-scale vibration, the multistable thin plate can be passively switched to another stable geometric structure, so that the shape of the tail edge part of the wing is changed, and the aerodynamic load fluctuation of the wing surface is reduced;

(2) The mass of the wing structure is not required to be changed, and additional sensors and controllers are not required to be added, so that the high-speed flexible wing structure has the advantages of being high in response speed, simple and convenient to operate and the like, and the problem of large-scale vibration of the high-aspect-ratio flexible wing structure caused by pneumatic elastic instability is solved.

The technical scheme of the invention is further described in detail through the drawings and the embodiments.

Drawings

FIG. 1 is a schematic overall profile of a flexible wing structure based on passive flutter suppression by multi-steady-state plates;

FIG. 2 is a cross-sectional view of a flexible wing structure based on passive flutter suppression by a multi-steady-state plate;

FIG. 3 is a schematic illustration of a multi-stable sheet and I-beam connection of a flexible wing structure based on passive flutter suppression of the multi-stable sheet;

FIG. 4 is a schematic view of a first shell structure of a flexible wing structure based on passive flutter suppression of the multi-stable panel, wherein (a) is a front view, (b) is a side view, (c) is a front view of the first shell and beam, multi-stable panel (with suction cup) connection, and (d) is a side view of the first shell and beam, multi-stable panel connection;

FIG. 5 is a second shell structure schematic of a flexible wing structure based on passive flutter suppression by a multi-stable plate;

FIG. 6 is a schematic diagram of a multi-stable sheet structure of a flexible wing structure based on passive flutter-suppression of the multi-stable sheet, wherein (a) is a front view and a side view of the multi-stable sheet, (b) is a front view and a side view (with suction cups) of the multi-stable sheet, (c) is a schematic diagram of an initial steady state of the multi-stable sheet, and (d) is a schematic diagram of a steady state of the multi-stable sheet after deformation;

FIG. 7 is a schematic view of a wing structure of a flexible wing structure based on passive suppression of flutter by a multi-stable plate, wherein (a) is a schematic view of an initial stable state and a schematic view of a bistable region of the multi-stable thin plate wing structure, and (b) is a schematic view of a stable state and a schematic view of a deformed multi-stable thin plate wing structure and a schematic view of a stable state of a deformed bistable region;

FIG. 8 is a schematic illustration of a multi-stable sheet-to-wing control process for a flexible wing structure based on passive flutter suppression of the multi-stable sheet.

Reference numerals

1. The multi-stable wing comprises a first wing shell, a second wing shell, an I-beam, a threaded hole, a multi-stable thin plate, a front part of the first wing shell, a rear part of the first wing shell, a bistable region, a sucker and a bistable region, wherein the I-beam, the threaded hole, the multistable thin plate, the front part of the first wing shell, the rear part of the first wing shell, the bistable region and the sucker are arranged in sequence.

Detailed Description

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The terms "first," "second," and the like, as used herein, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

As shown in fig. 1 to 3, a flexible wing structure based on passive vibration suppression of a multistable plate adopts a NACA0012 wing type design in the initial appearance, and comprises a first wing shell 1, a second wing shell 2, an i-beam 3 and a multistable thin plate 5, wherein the i-beam 3 is made of 45 # steel, the strength of the whole structure of the wing is ensured, one end of the i-beam is provided with a threaded hole 4, the whole is in penetrating connection with the first wing shell 1 and the second wing shell 2, and the multistable thin plate 5 is arranged on the i-beam 3 through the threaded hole 4 by bolts and is positioned in the first wing shell.

As shown in fig. 4 to 6, the first shell 1 is divided into a first shell front portion 6 and a first shell rear portion 7, and overall exhibits an asymmetric thickness structure.

The front part 6 of the first wing shell is internally provided with a through groove corresponding to the I-beam, the through groove is directly embedded into the I-beam 3, one side of the plane is provided with a gap, the rear part 7 of the first wing shell is wedge-shaped, and the middle is provided with a gap connected with the multistable thin plate 5.

The second wing shell 2 is of an integrated structure and is of an asymmetric thickness structure, a through groove corresponding to the I-beam is formed in the second wing shell, the second wing shell is directly embedded into the I-beam 3, and the position of the second wing shell 2 on the beam is ensured and fixed.

The multistable thin plate 5 is made of 304 stainless steel, the cross section of the multistable thin plate is T-shaped, one end of the T-shaped thin plate is provided with a threaded hole 4, the threaded hole 4 corresponds to the threaded hole 4 on one end of the I-beam 3, the multistable thin plate is fixedly connected through a bolt, and the other end of the multistable thin plate 5 is fixedly arranged in the rear part 7 of the first wing shell through an adhesive fixing method;

The surface of the multistable sheet 5 is subjected to nano-mechanical abrasion processing to form a circular area arranged in a 1x3 manner, the circular area is impacted at high speed by an ultrasonic transducer through accelerating a plurality of stainless steel balls with diameters of 2mm, the circular processing area is stretched under the constraint of an unprocessed area by plastic deformation caused by severe impact to form compressive stress, and when the compressive stress from accumulated plastic deformation reaches a certain degree, the circular area shows bistable characteristics to form a bistable area 8.

The bistable region 8 has two states and no additional energy is required to maintain the two states, as shown in fig. 6 (c), with "+" representing a first initial stable state of the bistable region 8, as shown in fig. 6 (d), and "-" representing a second deformed stable state of the bistable region 8. When the wing undergoes large-scale vibrations, i.e. is subjected to a large external load, the three bistable regions 8 of the multistable sheet 5 will be transformed directly from the "+" first stable state to the "-" second stable state. Thus, the multistable sheet 5 transitions from the steady state shown in fig. 6 (c) to the steady state shown in fig. 6 (d) and eventually causes the wing structure to passively transition from the steady state shown in fig. 7 (a) to the steady state shown in fig. 7 (b).

The 3 bistable regions 8 on the multistable sheet 5 are respectively provided with a sucker 9, the sucker 9 is connected with an air source pipeline, and the air source pipeline penetrates through the second wing shell 2 and is connected with an air source at the root of the wing along the I-beam 3.

The suction disc 9 can actively adjust the state of the bistable region 8, after the wing changes into a large-scale vibration state, the suction disc 9 is controlled to suck air, the internal air pressure of the wing is reduced under the action of the suction air, and the deformed multistable thin plate is actively converted from the stable state shown in (d) of fig. 6 to the stable state shown in (c) of fig. 6, so that the state of the bistable region 8 is adjusted, and finally, the wing structure is passively converted from the stable state shown in (b) of fig. 7 to the stable state shown in (a) of fig. 7, so that the flight stability of the aircraft is ensured.

The specific principle of operation of the present invention is that the multistable sheet is in an initial steady state a when no chatter occurs, as shown in fig. 8. When the wing vibrates due to the severe environment, the sudden external load causes the wing to vibrate in a large scale, and when the load caused by vibration is larger than the threshold value of the deformation of the multistable thin plate, the multistable thin plate can be rapidly deformed so that the wing is changed from the state A to the state B. Meanwhile, the deformation of the tail edge of the wing can control flow separation, large-scale vortex shedding caused by a dynamic stall phenomenon is prevented, so that the flow above the wing surface tends to be stable, the aerodynamic load fluctuation of the wing surface is reduced, the wing is helped to change a large-scale vibration state, and the stability is recovered. Finally, after the flight is stabilized, the multistable sheet can be adjusted back to the initial stable state A by actively adjusting the suction cup.

Therefore, the invention provides the flexible wing structure based on the multistable plate for passively inhibiting flutter, which can passively deform when the wing vibrates in a large scale, change the aerodynamic shape of a local wing, reduce the aerodynamic load fluctuation of the wing, and further inhibit the large scale vibration problem of the wing.

It should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted by the same, and the modified or substituted technical solution may not deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A flexible wing structure based on passive suppression flutter of multistable board, includes first wing shell, second wing shell, its characterized in that still includes:

the I-beam is used for penetrating and connecting the first wing shell and the second wing shell;

A multistable sheet disposed on the i-beam and within the first wing shell;

One side of the multistable thin plate is provided with a threaded hole correspondingly connected with the I-beam, and the surface of the other side is provided with a plurality of circular bistable regions;

The surface of the circular bistable region is provided with sucking discs, and the sucking discs are connected with an air source through an air source pipeline.

2. A flexible wing structure passively damping flutter based on multi-stable panels of claim 1, wherein the first wing skin includes a first wing skin forward portion and a first wing skin aft portion.

3. The flexible wing structure based on the multistable plate for passively suppressing flutter according to claim 2, wherein the rectangular through groove in which the I-beam is embedded is formed in the middle of the front portion of the first wing shell, and a gap for fixing the multistable plate is formed in the middle of the rear portion of the first wing shell.

4. A flexible wing structure passively damping flutter based on multi-stable panels according to claim 3 wherein the multi-stable sheets are secured to the inside of the rear portion of the first shell by means of adhesive bonding and are correspondingly attached to the I-beams.

5. A flexible wing structure based on passive damping of flutter of a multi-stable panel as defined in claim 4 wherein said I-beam and said multi-stable sheet are bolted.

6. The flexible wing structure based on the multistable plate for passively suppressing flutter according to claim 1, wherein the second wing shell is an integrated structure, and a through groove corresponding to the I-beam is formed in the second wing shell.

7. The flexible wing structure of claim 5, wherein the I-beam is made of 45 # steel and the multistable sheet is made of 304 stainless steel.

8. A method of manufacturing a flexible wing structure based on passive flutter suppression of a multistable panel according to any of claims 1 to 7, characterized in that the bistable region is manufactured by the steps of: