CN115123517A - A ground-level controllable wing structure with large stall angle of attack - Google Patents

Abstract

The invention discloses a ground-level controllable wing structure with a large stall angle of attack, comprising: a controller, a drive motor and a wing; wherein, a mounting slot is provided on the upper part of the front end of the wing; the controller and the drive motor are both arranged in the installation slot; the controller is connected with the drive motor. The present invention greatly increases the stall angle of attack.

Description

A ground-level controllable wing structure with a large stall angle of attack

technical field

The invention belongs to the technical field of airfoils, and in particular relates to a ground-level controllable airfoil structure with a large stall angle of attack.

Background technique

In the flow around the airfoil, the lift and drag of the wing increase with the increase of the angle of attack. When a critical angle of attack is reached, a stall phenomenon occurs, the lift suddenly decreases, and the drag increases greatly. Accompanied by severe flow separation. This phenomenon is widely found in airfoils, blade-type hydraulic machinery, wind turbines, centrifugal compressors and other components. The occurrence of stall leads to a decrease in the performance and efficiency of the airfoil, which affects the safe and stable operation of related components. In recent years, the stall problem has become a hot issue, attracting extensive attention from scholars and engineers. How to effectively suppress the stall has become a key research direction at present.

The traditional method of increasing the critical angle of attack for stall is to add passive devices (vortex generators, Gurney flaps, etc.) on the outer surface of the wing, but this device will bring additional resistance in the case of a small angle of attack, which is not worth the gain. In addition, active flow control methods such as synthetic jet, plasma excitation, and suction control mainly control the local flow of the flow field near the airfoil to delay flow separation and improve aerodynamic performance. However, this method not only requires additional equipment such as air circuit, controller, actuator and power supply, but also requires external energy input, which increases the weight and energy loss of the aircraft.

SUMMARY OF THE INVENTION

The technical problem solved by the invention is: to overcome the deficiencies of the prior art, to provide a wing structure with a large stall angle of attack based on the controllable ground layer, and to greatly increase the stall angle of attack by controlling the boundary layer.

The object of the present invention is achieved through the following technical solutions: a controllable high-stall-angle-of-attack wing structure based on the ground layer, comprising: a controller, a drive motor and a wing; wherein, the upper part of the front end of the wing is provided with an installation The controller and the drive motor are both arranged in the installation slot; the controller is connected with the drive motor.

In the above-mentioned ground-based controllable large stall angle of attack wing structure, the controller includes a rotating shaft and several blades; wherein, several blades are connected with the circumferential end of the rotating shaft; several blades are along the rotating shaft. Evenly distributed in the circumferential direction.

In the above-mentioned ground-based controllable wing structure with a large stall angle of attack, the controller further includes a drive shaft; wherein, one end of the drive shaft is connected to the rotating shaft, and the other end of the drive shaft is connected to the The drive motor is connected.

The above-mentioned wing structure with a large stall angle of attack that is controllable based on the ground layer further includes: a drive motor mounting seat; wherein, the drive motor is arranged in the mounting groove through the drive motor mounting seat.

In the above-mentioned wing structure with a large stall angle of attack that is controllable based on the ground layer, the ratio of the length L2 of the wing to the width L7 of the controller is 3-5.

In the above-mentioned wing structure with high stall angle of attack controllable based on the ground layer, the ratio of the distance L4 between the center of the controller and the leading edge and the chord length L5 of the wing is 0.15-0.32.

In the above-mentioned ground-level controllable wing structure with a large stall angle of attack, the ratio of the radius L3 of the controller to the distance L6 from the center of the rotating shaft to the surface of the wing is 1.05-1.10.

In the above-mentioned wing structure with large stall angle of attack that is controllable based on the ground layer, the ratio of the width L7 of the controller to the width L1 of the installation groove is 0.98-0.99.

In the above-mentioned wing structure with a large stall angle of attack that is controllable based on the ground layer, the height Δ of the controller protruding from the upper wall of the wing is 0.5-0.7 times the thickness of the local boundary layer; wherein,

The local boundary layer thickness is obtained by the following formula:

Among them, δ is the thickness of the local boundary layer, Re is the local Reynolds number, ρ is the air density, U is the air speed, Δ is the height of the controller protruding from the wall, L4 is the distance between the center of the controller and the leading edge, and μ is the bond coefficient.

In the above-mentioned wing structure with high stall angle of attack based on the controllable ground layer, the relationship between the rotational speed of the controller and the energy injected into the local boundary layer is as follows:

E=ρ·V ² ;

V=2π·r·n;

Among them, E is the energy injected into the local boundary layer, V is the gas velocity, r is the radius of the controller, and n is the rotational speed of the controller.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention greatly increases the stall angle of attack by controlling the boundary layer.

(2) The present invention can change the way of injecting energy into the boundary layer, so as to adapt to the requirements of the wing performance under different working conditions.

(3) The control method of the present invention is simple, and the additional resistance is small.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating preferred embodiments only and are not to be considered limiting of the invention. Also, the same components are denoted by the same reference numerals throughout the drawings. In the attached image:

1 is a top view of a wing structure with a controllable high stall angle of attack based on a ground layer provided by an embodiment of the present invention;

2 is a cross-sectional view of a wing structure with a controllable large stall angle of attack based on a ground layer provided by an embodiment of the present invention;

3 is a cross-sectional view of a wing structure with a controllable high stall angle of attack based on a ground layer provided by an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be more thoroughly understood, and will fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other under the condition of no conflict. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

1 is a top view of a ground layer-based controllable high-stall angle-of-attack wing structure provided by an embodiment of the present invention; FIG. 2 is a cross-sectional view of a ground-layer-based controllable high-stall angle-of-attack wing structure provided by an embodiment of the present invention 3 is a cross-sectional view of a wing structure with a controllable large stall angle of attack based on the ground layer provided by an embodiment of the present invention. As shown in Fig. 1 to Fig. 3, the wing structure with large stall angle of attack controllable based on the ground layer includes: a controller 1, a drive motor 7 and a wing 2; wherein, the upper part of the front end of the wing 2 is provided with a mounting groove 5; the controller 1 and the drive motor 7 are both arranged in the installation slot 5; the controller 1 is connected with the drive motor 7.

The speed of the drive motor is controlled, so that the controller injects energy into the boundary layer of the wing at different frequencies to increase the ability of the boundary layer to resist back pressure, thereby delaying the occurrence of separation and increasing the stall angle of attack of the wing.

The relationship between the rotational speed of controller 1 and the energy injected into the local boundary layer is as follows:

E=ρ·V ² ;

V=2π·r·n;

Among them, E is the injection energy, V is the gas velocity, r is the radius, and n is the rotational speed. The magnitude of the injected energy in the boundary layer is positively related to the rotational speed.

As shown in FIG. 2 , the controller 1 includes a rotating shaft 4 and several blades 3 ; wherein, several blades 3 are connected with the circumferential end of the rotating shaft 4 ; Specifically, the number of blades 3 is four. Through the rotation of the controller 1, the boundary layer of the wing is controlled, thereby delaying the occurrence of separation and increasing the stall angle of attack of the wing.

As shown in FIG. 2 , the controller 1 further includes a drive shaft 8 ; one end of the drive shaft 8 is connected to the rotating shaft 4 , and the other end of the drive shaft 8 is connected to the drive motor 7 .

As shown in FIG. 3 , the wing structure with large stall angle of attack controllable based on the ground layer further includes: a drive motor mount 6 ; wherein, the drive motor 7 is arranged in the mount slot 5 through the drive motor mount 6 .

Controller 1 is installed at the leading edge of and wing 2. The incoming Mach number ranges from 0.1 to 2.0, within which the controller 1 can effectively control the boundary layer.

The ratio between the distance L4 from the center of the controller 1 to the leading edge and the chord length L5 of the wing 2 is 0.15-0.32, and this installation position can make the controller 1 have the best control effect.

The ratio of the radius L3 of the controller 1 to the distance L6 from the center of the rotating shaft 4 to the surface of the wing is 1.05 to 1.10. This range makes the distance between the blade 3 protruding from the surface of the wing 2 appropriate and ensures that the controller 1 has a good control effect at the same time. , to minimize additional resistance.

The ratio of the length L2 of the airfoil 2 to the width L7 of the controller 1 is 3 to 5, and this range ensures the uniformity of the flow field in the spanwise direction of the airfoil 2 .

The ratio of the width L7 of the controller 1 to the width L1 of the installation groove 5 is 0.98-0.99, so as to minimize the airflow entering the installation groove 5 .

In order to ensure the introduction of less resistance, the height Δ of the protruding wall of the controller should be 0.5 to 0.7 times the thickness of the local boundary layer.

The local boundary layer thickness is obtained by the following formula:

Δ=L3-L6;

Among them, δ is the thickness of the local boundary layer, Re is the local Reynolds number, ρ is the air density, U is the air velocity, Δ is the height of the controller protruding from the wall, L4 is the distance between the center of the controller and the leading edge, and μ is the bond coefficient.

The invention greatly increases the stall angle of attack by controlling the boundary layer; the invention can change the way of injecting energy into the boundary layer to meet the requirements of different working conditions on the performance of the wing; the control method of the invention is simple, and the additional resistance smaller.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can use the methods and technical contents disclosed above to improve the present invention without departing from the spirit and scope of the present invention. The technical solutions are subject to possible changes and modifications. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention belong to the technical solutions of the present invention. protected range.

Claims (10)

1. A controllable big stall angle of attack wing structure based on ground floor, its characterized in that includes: the device comprises a controller (1), a driving motor (7) and a wing (2); wherein,

the upper part of the front end of the wing (2) is provided with a mounting groove (5);

the controller (1) and the driving motor (7) are arranged in the mounting groove (5);

the controller (1) is connected with the driving motor (7).

2. The ground-based layer controllable large stall angle of attack wing structure of claim 1, wherein: the controller (1) comprises a rotating shaft (4) and a plurality of blades (3); wherein,

the blades (3) are connected with the circumferential end of the rotating shaft (4);

the blades (3) are uniformly distributed along the circumferential direction of the rotating shaft (4).

3. The ground floor based controllable large stall angle of attack wing structure of claim 2, wherein: the controller (1) further comprises a drive shaft (8); one end of the driving shaft (8) is connected with the rotating shaft (4), and the other end of the driving shaft (8) is connected with the driving motor (7).

4. The ground-based layer controllable large stall angle of attack wing structure of claim 1, further comprising: a driving motor mounting base (6); the driving motor (7) is arranged in the mounting groove (5) through the driving motor mounting seat (6).

5. The ground floor based controllable large stall angle of attack wing structure of claim 1, wherein: the ratio of the span length L2 of the wing (2) to the width L7 of the controller (1) is 3-5.

6. The ground-based layer controllable large stall angle of attack wing structure of claim 1, wherein: the ratio of the distance L4 between the center of the controller (1) and the leading edge to the chord length L5 of the wing (2) is 0.15-0.32.

7. The ground-based layer controllable large stall angle of attack wing structure of claim 1, wherein: the ratio of the radius L3 of the controller (1) to the distance L6 from the center of the rotating shaft (4) to the surface of the wing is 1.05-1.10.

8. The ground-based layer controllable large stall angle of attack wing structure of claim 1, wherein: the ratio of the width L7 of the controller (1) to the width L1 of the mounting groove (5) is 0.98-0.99.

9. The ground-based layer controllable large stall angle of attack wing structure of claim 1, wherein: the height delta of the controller (1) protruding out of the upper wall surface of the wing (2) is 0.5-0.7 times the thickness of the local boundary layer; wherein,

the local boundary layer thickness is obtained by the following formula:

wherein δ is the local boundary layer thickness, Re is the local reynolds number, ρ is the air density, U is the air velocity, Δ is the height of the controller's convex wall, L4 is the distance between the center of the controller and the leading edge, and μ is the sticking coefficient.

10. The ground floor based controllable large stall angle of attack wing structure of claim 1, wherein: the relation formula of the rotating speed of the controller (1) and the energy injected to the local boundary layer is as follows:

E＝ρ·V ² ；

V＝2π·r·n；

wherein E is the energy injected into the local boundary layer, V is the gas velocity, r is the radius of the controller, and n is the rotating speed of the controller (1).

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