CN115556959A - Design method of airfoil shear variable sweep form, deformed wing, wing and aircraft - Google Patents

Abstract

The invention provides an airfoil shear variable-sweep form design method, a deformable wing, a wing and an aircraft. Among them, the design method includes: in the process of shearing and sweeping, design the slight chord length and root chord length in the direction of flow of the airfoil to keep constant; The coordinates are determined in the following way: determine the airfoil according to the coordinates of the leading edge point of the wing root, the leading edge rotation angle χ _n of the deformed airfoil corresponding to the n-th sweep change, and the coordinates of any point on the front airfoil of the n-th sweep change The new coordinates corresponding to any point after shearing the sweepback χ _n angle, wherein, the arbitrary point includes the leading edge point of the wing tip. After the airfoil is designed in the form of shear change and sweep, the flow direction of the ribs remains unchanged during the rotation process, maintaining a good aerodynamic shape, and making the structure have better stability during the deformation process.

Description

Design method of shear-variable-sweep form of airfoil, deformed wing, wing and aircraft

technical field

The invention belongs to the technical field of variant aircraft, and relates to a design method of an airfoil shear-variable-sweep form, a deformed wing, a wing and an aircraft.

Background technique

In recent years, the world's aircraft field is focusing on the development of variant aircraft that are adaptive to the flight environment (such as altitude, speed, climate, etc.) and can perform multiple tasks (such as cruising, circling, maneuvering, etc.). This type of aircraft can independently change its structure and aerodynamic layout according to the needs of the flight mission, and maintain good flight performance under complex flight environmental conditions. Through intelligent design and control, variant technology can adaptively change important parameters such as wing shape, thickness, and camber according to tasks and environments, so that the aircraft can obtain ideal aerodynamic characteristics under different flight conditions, taking into account the The use performance at different speeds and the resolution of the contradictions in the aerodynamic layout design of modern aircraft play a very important role in improving the overall performance of military aircraft. After entering this century, with the development of new advanced fighter jets and unmanned aerial vehicles, variant technology has become one of the epoch-making disruptive technologies that determine the performance of future aircraft.

Fixed-wing aircraft have always faced the contradiction between high-speed and low-speed flight performance requirements: large-swept wings can effectively reduce shock wave resistance, but the flight efficiency is low at subsonic speeds; straight wings have better flight performance at low speeds. However, in the transonic stage, the shock wave resistance experienced increases geometrically. In order to make the aircraft not only have better economy in supersonic cruise flight, but also obtain satisfactory low-speed flight performance, the variable-sweep angle wing came into being. Current variable-sweep wings cannot maintain a good aerodynamic shape during rotation.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art.

For this reason, the present invention provides a kind of airfoil shear variable sweep form design method, deformation wing, wing and aircraft.

Technical solution of the present invention is as follows:

According to the first aspect, there is provided a design method for the shear-variable-sweep form of the airfoil, the design method comprising:

In the process of shear and sweep, the slight chord length and root chord length of the design airfoil in the direction of flow remain unchanged;

After designing any nth sweep change, the coordinates of any point on the airfoil are determined by the following method:

According to the coordinates of the leading edge point of the wing root, the leading edge rotation angle χ _n of the deformed airfoil corresponding to the n-th sweep change, and the coordinates of any point on the airfoil before the n-th sweep change, determine the shear deformation of any point on the airfoil Corresponding new coordinates after grazing x _n angles, wherein, the arbitrary point includes the leading edge point of the wing tip.

Further, according to the coordinates of the leading edge point of the wing root, the leading edge rotation angle χ _n of the deformed airfoil corresponding to the n-th sweep change, and the coordinates of any point on the front airfoil face of the n-th sweep change, the shear of any point on the airfoil is determined. Corresponding new coordinates after shearing the sweepback χ _n angle, wherein, said arbitrary point comprises the leading edge point of the wing tip, including:

Calculate the position X of the leading edge corresponding to any point p (x, y) according to the coordinates of the leading edge point of the wing root and the coordinates of the leading edge point of the nth variable- _sweep front;

According to x _{front_n} , the coordinates of the leading edge point of the wing root, the rotation angle χ _n and the coordinates of any point on the airfoil before changing the sweep for the nth time, determine the corresponding new value of any point on the airfoil after shearing the angle of χ _n coordinate.

Further, the position x _{front_n} of the leading edge corresponding to any point p(x, y) is calculated according to the coordinates of the leading edge point of the wing root and the coordinates of the leading edge point of the nth variable-sweep front wing through the following formula:

x _{front_n} =kx+b

k＝(x ₁ -x _{2_n-1} )/(y ₁ -y _{2_n-1} )

b=(y ₁ x _{2_n-1} -y _{2_n-1} x ₁ )/(y ₁ -y _{2_n-1} )

Among them, p ₁ (x ₁ , y ₁ ) is the coordinates of the leading edge point of the root of the wing, and p ₂ (x _{2_n-1} , y _{2_n-1} ) is the coordinates of the leading edge point of the leading edge point of the nth variable-sweep front wing.

Further, according to x _{front_n} , the coordinates of the leading edge point of the wing root, the rotation angle χ _n and the coordinates of any point on the airfoil before the nth sweep change, determine the shear sweep of any point on the airfoil χ _n The corresponding new coordinates after the angle:

x _{new_n} ＝((x _{front_n} -x ₁ )*cos(χ ₁ )+(yy ₁ )*sin(χ _n )+x ₁ )+(xx _{front_n} )

y _{new_n} ＝(yy ₁ )*cos(χ _n )-(x _{front_n} -x ₁ )*sin(χ _n )+y ₁

Wherein, (x _{new_n} , y _{new_n} ) is the new coordinate corresponding to p(x, y) after the nth sweep change.

According to a second aspect, a deformable wing is provided, the deformable wing adopts a shear-swept form, and the shear-sweep form is designed by using the above-mentioned design method.

According to a third aspect, there is provided a wing, the wing includes a fixed wing and the above-mentioned deformable wing, the deformable wing is rotatably connected to the fixed wing, and the deformable wing deforms according to the shear deformation during the rotation process. Shear deformation occurs in the swept form.

According to a fourth aspect, there is provided an aircraft comprising the above-mentioned wing.

The above technical scheme designs a shear-sweep form, wherein in the process of shear-sweep, the slightly chord length and the root chord length of the designed airfoil in the direction of flow remain unchanged and according to the coordinates of the leading edge point of the wing root, Parameters such as the rotation angle of the leading edge of the deformed airfoil determine the position coordinates of any point on the airfoil after deformation. After the airfoil is designed in this shear-variable-sweep form, the flow direction of the ribs remains unchanged during the rotation process, maintaining a good aerodynamic shape. Make the structure have better stability in the deformation process.

Description of drawings

The accompanying drawings are included to provide further understanding of the embodiments of the invention, and constitute a part of the specification, are used to illustrate the embodiments of the invention, and together with the description, explain the principle of the invention. Apparently, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings according to these drawings without creative efforts.

Fig. 1 is the schematic diagram of the appearance of the shear variable swept airfoil of the embodiment of the present invention;

Fig. 2 is a schematic diagram illustrating parameters of a shear-swept airfoil according to an embodiment of the present invention.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. The following description of at least one exemplary embodiment is merely illustrative in nature and in no way taken as limiting the invention, its application or uses. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

The relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. At the same time, it should be understood that, for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered part of the Authorized Specification. In all examples shown and discussed herein, any specific values should be construed as illustrative only, and not as limiting. Therefore, other examples of the exemplary embodiment may have different values. It should be noted that like numerals and letters denote like items in the following figures, therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

As shown in Fig. 1 to Fig. 2, in one embodiment of the present invention, a kind of airfoil shear-sweep form design method is provided, and this design method comprises:

Step 1. In the process of shearing and sweeping, the slight chord length and the root chord length of the design airfoil in the direction of flow remain unchanged;

Step 2: After designing any nth sweepback change, the coordinates of any point on the airfoil are determined in the following way:

According to the coordinates of the leading edge point of the wing root, the leading edge rotation angle χ _n of the deformed airfoil corresponding to the n-th sweep change, and the coordinates of any point on the airfoil before the n-th sweep change, determine the shear deformation of any point on the airfoil Corresponding new coordinates after grazing x _n angles, wherein, the arbitrary point includes the leading edge point of the wing tip.

For example, the shape of a variable-sweep wing is shown in Figure 1, where L is the half-span length of the deformed airfoil, c ₂ is the length of the slight chord, and c ₁ is the length of the root chord. The directions c ₁ and c ₂ remain unchanged. For example, the deformed wing can perform multiple rotations and become swept back. Any point on the surface can be determined by the above method, and thus the relevant parameters of the deformed wing after the rotation and sweep can be obtained.

In the embodiment of the present invention, the tip chord length, the root chord length, the wing root leading edge point and the wing tip leading edge point all have exact definitions in the art.

It can be seen that the embodiment of the present invention designs a shear-sweep form, wherein in the process of shear-sweep, the chord length and the root chord length of the design airfoil along the direction of flow remain unchanged and according to the leading edge of the wing root Point coordinates, the rotation angle of the leading edge of the deformed airfoil and other parameters determine the position coordinates of any point on the airfoil after deformation. After the airfoil is designed in this shear-variable-sweep form, the flow direction of the ribs remains unchanged during the rotation process, maintaining a good The aerodynamic shape makes the structure have better stability during deformation.

In the above-mentioned embodiment, in order to accurately deform the coordinates of any point on the rear airfoil surface, according to the coordinates of the leading edge point of the wing root, the leading edge rotation angle χ _n of the deformed airfoil corresponding to the nth sweep change, and the nth sweep sweep front wing The coordinates of any point on the surface determine the corresponding new coordinates of any point on the airfoil after shearing and changing the sweepback x _n angle, including:

Calculate the position X of the leading edge corresponding to any point p (x, y) according to the coordinates of the leading edge point of the wing root and the coordinates of the leading edge point of the nth variable- _sweep front;

According to x _{front_n} , the coordinates of the leading edge point of the wing root, the rotation angle χ _n and the coordinates of any point on the airfoil before changing the sweep for the nth time, determine the corresponding new value of any point on the airfoil after shearing the angle of χ _n coordinate.

It can be seen that in the embodiment of the present invention, the coordinates of the leading edge point of the wing root remain unchanged, and the coordinates of the leading edge point of the wing tip change with each deformation, and its initial value is a known value (the first time the swept back front wing The coordinates of the slightly leading edge point are the initial values), and the calculation method of the corresponding coordinates after deformation is the same as the calculation method of the coordinates after deformation corresponding to any point on the airfoil surface.

In the embodiment of the present invention, the position x of the leading edge corresponding to any point p(x, y) is calculated according to the coordinates of the leading edge point of the wing root and the coordinates of the leading edge point of the nth variable-sweep front wing through the following formula: _{front_n} :

x _{front_n} =kx+b

k＝(x ₁ -x _{2_n-1} )/(y ₁ -y _{2_n-1} )

b=(y ₁ x _{2_n-1} -y _{2_n-1} x ₁ )/(y ₁ -y _{2_n-1} )

Among them, p ₁ (x ₁ , y ₁ ) is the coordinates of the leading edge point of the root of the wing, and p ₂ (x _{2_n-1} , y _{2_n-1} ) is the coordinates of the leading edge point of the leading edge point of the nth variable-sweep front wing.

In the embodiment of the present invention, according to x _{front_n} , the coordinates of the leading edge point of the wing root, the rotation angle χ _n and the coordinates of any point on the airfoil before the nth sweep change, the post-shear transformation of any point on the airfoil is determined by the following formula: The corresponding new coordinates after grazing χ _n angle:

x _{new_n} ＝((x _{front_n} -x ₁ )*cos(χ ₁ )+(yy ₁ )*sin(χ _n )+x ₁ )+(xx _{front_n} )

y _{new_n} ＝(yy ₁ )*cos(χ _n )-(x _{front_n} -x ₁ )*sin(χ _n )+y ₁

Wherein, (x _{new_n} , y _{new_n} ) is the new coordinate corresponding to p(x, y) after the nth sweep change.

According to another embodiment, a deformable airfoil is provided, the deformable airfoil adopts a shear-swept form, and the shear-sweep form is designed by using the above-mentioned design method.

It can be seen that the shearing and sweeping form adopted by the deformed wing keeps the flow direction of the ribs unchanged during the sweeping process, which can well maintain the aerodynamic shape.

According to another embodiment, there is also provided a wing, which includes a fixed wing and the above-mentioned deformed wing, the deformed wing is rotatably connected to the fixed wing, and the deformed wing is sheared according to the Shear deformation occurs in the form of variable backsweep.

In the embodiment of the present invention, the specific connection mode of the fixed wing and the deformable wing can be designed using conventional technical means.

For example, the airfoil adopts the above-mentioned shear variable-sweep design, in which the spar rotates around the rotation axis at the root of the wing, while the rib keeps the flow direction unchanged during the rotation, maintaining a good aerodynamic shape. The structure has better stability during deformation.

According to another embodiment, there is also provided an aircraft, which includes the above-mentioned wing.

Features described and/or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and/or be combined with or replace features in other embodiments Features in .

It should be emphasized that the term "comprising/comprising" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof .

The above method of the present invention can be realized by hardware, and can also be realized by combining hardware and software. The present invention relates to such a computer-readable program that, when the program is executed by a logic component, enables the logic component to realize the above-mentioned device or constituent component, or enables the logic component to realize the above-mentioned various methods or steps. The present invention also relates to a storage medium for storing the above program, such as hard disk, magnetic disk, optical disk, DVD, flash memory and the like.

The many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Moreover, since many modifications and changes will readily occur to those skilled in the art, it is not intended to limit the embodiments of the present invention to the precise structures and operations illustrated and described, but to cover all suitable modifications and equivalents falling within the scope thereof. thing.

Parts not described in detail in the present invention are well-known technologies for those skilled in the art.

Claims (7)

1. a kind of airfoil shear change sweep form design method, it is characterized in that, described design method comprises: In the process of shear and sweep, the slight chord length and root chord length of the design airfoil in the direction of flow remain unchanged; After designing any nth sweep change, the coordinates of any point on the airfoil are determined by the following method: According to the coordinates of the leading edge point of the wing root, the leading edge rotation angle χ _n of the deformed airfoil corresponding to the n-th sweep change, and the coordinates of any point on the airfoil before the n-th sweep change, determine the shear deformation of any point on the airfoil Corresponding new coordinates after grazing x _n angles, wherein, the arbitrary point includes the leading edge point of the wing tip. 2. a kind of airfoil shear variable sweep form design method according to claim 1, is characterized in that, according to wing root leading edge point coordinates, the deformed airfoil leading edge rotation angle χ _n that changes sweep correspondingly for the nth time , the coordinates of any point on the airfoil before changing the sweep for the nth time determine the corresponding new coordinates of any point on the airfoil after shearing and changing the sweep x _n angle, wherein the arbitrary point includes the leading edge point of the wing tip, include: Calculate the position X of the leading edge corresponding to any point p (x, y) according to the coordinates of the leading edge point of the wing root and the coordinates of the leading edge point of the nth variable- _sweep front; According to x _{front_n} , the coordinates of the leading edge point of the wing root, the rotation angle χ _n and the coordinates of any point on the airfoil before changing the sweep for the nth time, determine the corresponding new value of any point on the airfoil after shearing the angle of χ _n coordinate. 3. a kind of airfoil shear variable sweep form design method according to claim 2, is characterized in that, by following formula, according to wing root leading edge point coordinates and the nth variable backswept front wing slightly leading edge point coordinates Calculate the position of the leading edge corresponding to any point p(x,y) in the X direction x _{front_n} : x _{front_n} =kx+b k＝(x ₁ -x _{2_n-1} )/(y ₁ -y _{2_n-1} ) b=(y ₁ x _{2_n-1} -y _{2_n-1} x ₁ )/(y ₁ -y _{2_n-1} ) Among them, p ₁ (x ₁ , y ₁ ) is the coordinates of the leading edge point of the root of the wing, and p ₂ (x _{2_n-1} , y _{2_n-1} ) is the coordinates of the leading edge point of the leading edge point of the nth variable-sweep front wing. 4. a kind of airfoil shear change sweep form design method according to claim 3, is characterized in that, by following formula according to x _{front_n} , wing root leading edge point coordinates, angle of rotation χ _n and the nth after changing The coordinates of any point on the airfoil before sweeping determine the corresponding new coordinates of any point on the airfoil after shearing and changing the sweepback x _n angle: x _{new_n} ＝((x _{front_n} -x ₁ )*cos(χ ₁ )+(yy ₁ )*sin(χ _n )+x ₁ )+(xx _{front_n} ) y _{new_n} ＝(yy ₁ )*cos(χ _n )-(x _{front_n} -x ₁ )*sin(χ _n )+y ₁ Wherein, (x _{new_n} , y _{new_n} ) is the new coordinate corresponding to p(x, y) after the nth sweep change. 5. A deformed airfoil, characterized in that the deformed airfoil adopts a shear-sweep form, and the shear-sweep form is designed by the design method described in any of claims 1-4. 6. A wing, characterized in that the wing comprises a fixed wing and the deformed wing according to claim 5, the deformed wing is rotatably connected to the fixed wing, and the deformed wing is rotated according to the specified Shear deformation occurs in the form of shear deformation and sweep described above. 7. An aircraft, characterized in that the aircraft comprises the wing according to claim 6.

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