CN113104196B

CN113104196B - High-lift device and high-lift method for aircraft

Info

Publication number: CN113104196B
Application number: CN202110594514.4A
Authority: CN
Inventors: 尼早; 袁坚锋; 祁宇丹
Original assignee: Commercial Aircraft Corp of China Ltd
Current assignee: Commercial Aircraft Corp of China Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-05-24
Anticipated expiration: 2041-05-28
Also published as: CN113104196A

Abstract

A high lift device and a high lift method for an aircraft are disclosed. A high lift device (1) for an aircraft may comprise: a connection bracket (10) for connecting the high lift device to a wing (2) of the aircraft; a front panel (3) and a rear panel (5) secured to the connecting bracket, the front panel being spaced apart from the rear panel to form a slot between the front panel and the rear panel, the front panel having a first surface facing the slot and the rear panel having a second surface facing the slot; a first cover plate (4) located on the rear panel; and an actuator (7) capable of controlling the extension of the first cover plate into the slot between the front and rear wing sections. An aircraft comprising the wing and a high lift method for an aircraft are also disclosed.

Description

High-lift device and high-lift method for aircraft

Technical Field

The invention relates to the field of aircrafts, in particular to a high-lift device and a high-lift method for an aircraft.

Background

The trailing edge flap is an important high lift device of the airplane and has great influence on the safety of taking off and landing of the airplane and the economy of the airplane. The aircraft has larger lift coefficient, can reduce the takeoff and landing speed of the aircraft, thereby reducing the requirements on a flight runway and improving the airport adaptability of the aircraft. At the same time, the flap is required to have no reduction in lift and no additional drag during cruise to ensure economy of the aircraft.

In the prior art, the flap for increasing the lift force of the airplane during takeoff and landing of the airplane has a complex structure and does not have an active control function. For example, in the prior art, a high lift device with a seam is not obvious in high lift effect, complex in structural form and free of active control function, so that the high lift device cannot be adaptive to different flight states. Some high lift devices with variable forms can generate obvious adverse changes to basic wing profiles when changing forms, and the lift force, the resistance and the lift-drag ratio performance of the high lift devices are greatly reduced.

Accordingly, there is a need in the art for an improved high lift device for an aircraft.

Disclosure of Invention

The invention provides a high lift device for an aircraft, which has a simple structure and an obvious high lift effect, and can effectively improve lift force in the taking-off and landing stages of the aircraft. In a preferred embodiment, the high lift device of the present invention contains active control functions and does not affect the basic airfoil profile behavior after closing the slot.

In one embodiment of the invention, a high lift device (1) for an aircraft is provided, comprising: a connection bracket (10) for connecting the high lift device to a wing (2) of the aircraft; a front panel (3) and a rear panel (5) secured to the connecting bracket, the front panel being spaced apart from the rear panel to form a slot between the front panel and the rear panel, the front panel having a first surface facing the slot and the rear panel having a second surface facing the slot; a first cover plate (4) located on the rear panel; and an actuator (7) capable of controlling the first cover plate to extend into the slot between the front panel and the rear panel.

In one aspect, the first cover plate is movably connected to a connection point on the second surface of the rear wing such that the first cover plate is rotatable about the connection point in the slot, wherein a side of the first cover plate opposite the connection point is rotatable to a target location, the target location comprising a first location on the second surface of the rear wing, a second location on the first surface of the front wing, or a location in the slot between the first location and the second location.

In one aspect, one side of the first cover plate is connected to the connection point at an intersection edge of the second surface of the aft wing section and the lower surface of the aft wing section.

In one aspect, the side of the first cover plate opposite the connection point is rotated to the intersection edge of the first surface of the forward wing section and the lower surface of the forward wing section such that the lower surface of the forward wing section, the first cover plate, and the lower surface of the aft wing section form a coherent arcuate lower surface.

In one aspect, the first cover plate is positioned in a cavity within the rear panel, wherein the actuator is capable of controlling movement of the first cover plate into the slot.

In one aspect, the high lift device further comprises: a second cover plate (6) movably connected to the rear panel and above the first cover plate, the actuator being capable of controlling the extension of the second cover plate into the slot between the front panel and the rear panel.

In one aspect, one side of the second cover plate is movably connected to a second connection point on the upper surface of the rear wing section, and a movable side of the second cover plate opposite the second connection point is rotatable about the second connection point in the slot, wherein the movable side of the second cover plate is rotatable to a target position comprising a third position on the second surface of the rear wing section, a fourth position on the first surface of the front wing section, or a position in the slot between the third position and the fourth position.

In one aspect, the active side of the second cover plate is rotated to the intersection edge of the first surface of the forward wing section and the upper surface of the forward wing section such that the upper surface of the forward wing section, the second cover plate, and the upper surface of the aft wing section form a coherent arcuate upper surface.

In one aspect, when the aircraft takes off or lands, the first cover plate and the second cover plate are respectively attached to the surface of the rear wing section or are accommodated in a cavity in the rear wing section, so as to open a seam between the front wing section and the rear wing section.

In one aspect, the actuators are connected to the first and second cover plates by links, respectively, the actuators moving the first and/or second cover plates to respective target positions based on control commands.

In one aspect, the first surface of the forward wing section is a concave arc surface that is concave from the slot to the forward wing section, and the second surface of the aft wing section is a convex arc surface that is convex from the aft wing section to the slot.

In one aspect, the connecting bracket comprises a first end rib (10a) and a second end rib (10b), wherein the forward panel and the aft panel are secured between the first end rib and the second end rib; or the connecting bracket comprises a plurality of supporting rods, and the front wing panel and the rear wing panel are respectively fixed to the corresponding supporting rods.

In one aspect, the attachment bracket is rotatably connected to a wing of the aircraft such that the high lift device is rotatable relative to the wing of the aircraft.

In one aspect, during a cruise phase of the aircraft, the direction of the high lift device coincides with a wing direction of the aircraft; and in the takeoff or landing stage of the aircraft, the high lift device and the lower surface of the wing of the aircraft form a specified included angle.

In one embodiment of the invention, there is provided an aircraft comprising a wing, the aircraft comprising a high lift device as described above, the high lift device being connected to the wing.

In one embodiment of the invention, there is provided a high lift method for an aircraft comprising a high lift device connected to a wing of the aircraft, the high lift device comprising separate forward and aft wing sections with a slot therebetween, the forward wing section having a first surface facing the slot and the aft wing section having a second surface facing the slot, the method comprising: determining an angle of attack of the aircraft; attaching a first cover plate movably connected to the rear wing section to a second surface of the rear wing section or to be received into a cavity within the rear wing section when the angle of attack is greater than or equal to a threshold; and extending the first cover plate into a slot between the forward wing section and the aft wing section to reduce the slot when the angle of attack is less than the threshold.

In one aspect, the first cover plate reduces or closes the lower end of the slot between the forward wing section and the aft wing section.

In one aspect, the high lift method further comprises: reducing or closing an upper end of a slot between the forward wing section and the aft wing section using a second cover plate movably connected to the aft wing section when the angle of attack is less than the threshold.

In an aspect, when the angle of attack is less than the threshold, aligning the direction of the high lift device with the wing direction of the aircraft; and when the attack angle is larger than or equal to the threshold value, enabling the high lift device to form a specified included angle with the lower surface of the wing of the aircraft.

The invention provides a high lift device with an active control function, which is provided with an internal seam passage capable of being actively controlled. In one embodiment, the internal seam may be a double arc design. When the airplane takes off and lands, the high lift device can be actively controlled to form a seam between the front wing section and the rear wing section, momentum is effectively guided into the boundary layer, the separation of upper surface airflow is eliminated or delayed, the airfoil lift force is effectively improved, the taking-off and landing speed of the airplane is reduced, the requirement on a flight runway is reduced, and the airport adaptability of the airplane is improved. When the airplane is cruising, the seam in the high lift device can be closed, the basic airfoil shape is recovered, the airfoil surface is smooth, the basic airfoil lift force is not reduced, and the additional resistance is not generated.

Drawings

FIG. 1 is a schematic illustration of an aircraft wing and high lift device according to one embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a high lift device according to an embodiment of the present invention.

Fig. 3 is a schematic perspective view of a high lift device according to one embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view of a high lift device according to one embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view of a high lift device according to another embodiment of the present invention.

Fig. 6 is a CFD mesh schematic of a high lift device according to one embodiment of the invention.

Fig. 7 is a graph of different airfoil lift coefficients as a function of angle of attack for a high lift device according to an embodiment of the invention.

Fig. 8 is a graph of different airfoil drag coefficients versus angle of attack for a high lift device according to an embodiment of the present invention.

FIG. 9 is a comparison of flow field and streamlines for a base airfoil and an airfoil having internal slots according to one embodiment of the present invention.

Detailed Description

The present invention will be further described with reference to the following examples and drawings, but the scope of the invention should not be limited thereto.

FIG. 1 is a schematic illustration of an aircraft wing and high lift device according to one embodiment of the present invention. The wing 2 may be a wing of various aircraft, such as an airplane, a drone, etc. The high lift device may comprise a connection bracket 10, which connection bracket 10 is used to support an airfoil part of the high lift device 1 and may connect the high lift device 1 to a wing 2 of an aircraft. The high lift device 1 may be connected to the wing 2 in various ways, for example by a fixed or movable connection to the trailing edge of the wing 2. In fig. 1 is shown that the attachment bracket 10 of the high lift device 1 is movably attached to the wing 2 by means of a hinge at

positions

2a, 2 b. In other embodiments, other means of attachment may be used, such as welding, a pivot connection, etc. Each aircraft may comprise one or more high lift devices 1 mounted to respective wings of the aircraft, and/or to one or more locations of each wing. The high lift device 1 can increase lift during takeoff and landing of an aircraft, thereby reducing flying speed.

As shown in state (i) in fig. 1, during the takeoff and landing phases of the aircraft, the high lift device 1 may deflect downward at an angle relative to the wing 2, and the lower surface of the high lift device 1 forms an included angle (for example, less than 180 degrees) with the lower surface (pressure surface) of the wing 2, thereby reducing the gas flow rate of the pressure surface of the wing and increasing the gas flow rate of the suction surface (upper surface), increasing the pressure difference between the pressure surface and the suction surface of the wing, and further increasing the wing lift.

As shown in state (ii) in fig. 1, during the cruising phase of the aircraft, the high lift device 1 may be in a direction consistent with the wing 2, for example, the lower surface of the high lift device 1 is 180 degrees from the lower surface of the wing 2, increasing the wing area, thereby maintaining stable lift force without generating additional drag.

Fig. 2 is a schematic structural diagram of a high lift device according to an embodiment of the present invention. The connection bracket 10 of the high lift device 1 may comprise a first end rib 10a and a second end rib 10b, the first end rib 10a and the second end rib 10b being used for connecting the high lift device 1 to a wing of an aircraft. As mentioned above, the high lift device 1 may be fixedly or movably connected to the wing at the

positions

2a, 2b of the first end rib 10a and the second end rib 10 b.

The high lift device 1 may further comprise a high lift wing secured between the first end rib 10a and the second end rib 10b, the high lift wing comprising a front panel 3 and a rear panel 5 separated to form a slot 20 between the front panel 3 and the rear panel 5, the slot allowing airflow therethrough. For convenience of description, the surface of the front panel 3 facing the slot may be referred to as a first surface, and the surface of the rear panel 5 facing the slot may be referred to as a second surface. Thereby, a seam is formed between the first surface of the front panel 3 and the second surface of the rear panel 5. Since the front panel 3 and the rear panel 5 are fixed between the first end rib 10a and the second end rib 10b, respectively, the front panel 3 and the rear panel 5 can maintain a fixed relative position with respect to each other, i.e., maintain a fixed seam way. When the high lift device 1 is mounted to a wing, the front panel 3 may be adjacent to the wing, while the rear panel 5 is remote from the wing. I.e. the front panel 3 is located between the wing and the rear panel 5. In other embodiments, the aft wing section 5 may be located between the wing and the forward wing section 3.

Although fig. 2 shows that the connecting bracket 10 comprises a first end rib 10a and a second end rib 10b, in other embodiments the connecting bracket 10 of the high lift device 1 may comprise a different structure, for example comprising a plurality of support bars to which the front panel 3 and the rear panel 5 may be respectively fixed and forming a slot 20 between the front panel 3 and the rear panel 5. For example, a plurality of support rods of the attachment bracket may support the lower surface of the front panel 3 and the lower surface of the rear panel 5, respectively. Alternatively, the plurality of support rods of the connecting bracket may support the upper surface of the front panel 3 and the upper surface of the rear panel 5, respectively.

In addition, the high lift device 1 may further include a first cover plate 4 (lower cover plate). The first cover plate 4 may have a shape, for example, a rectangular shape, conforming to the cross section (for example, the lower end surface) of the seam between the front wing section 3 and the rear wing section 5, so as to close the lower surface seam between the front wing section 3 and the rear wing section 5. According to one embodiment of the invention, the first cover plate 4 may be attached to a second surface of the rear panel 5 or extend into the slot between the front panel 3 and the rear panel 5 to increase or decrease the slot.

Optionally, the high lift device 1 may further comprise a second cover plate 6 (upper cover plate), and the second cover plate 6 may have a shape, such as a rectangle, conforming to the cross section (e.g., upper end surface) of the slot between the front panel 3 and the rear panel 5 to close the upper surface slot between the front panel 3 and the rear panel 5. According to one embodiment of the invention, the second cover plate 6 may be attached to the surface of the rear panel 5 or moved in a slot to increase or decrease the slot between the front panel 3 and the rear panel 5. Although fig. 2 illustrates the first and

second cover plates

4, 6 separate from the aft wing section 5, the first and

second cover plates

4, 6 may be mounted on the aft wing section 5. In another embodiment, the first and

second cover plates

4, 6 may be located in cavities within the aft wing panel 5.

The various components of the high lift device 1 may comprise the same or different materials, such as alloys, metals (e.g. aluminum or steel, etc.), composites, etc.

Fig. 3 is a schematic perspective view of a high lift device according to one embodiment of the present invention. The high lift device 1 comprises a front panel 3 and a rear panel 5 fixed between a first end rib 10a and a second end rib 10b, and a slot 20 is formed between the front panel 3 and the rear panel 5 to allow airflow from the lower surface of the high lift device 1 through the slot 20 to the upper surface of the high lift device 1. Fig. 3 also shows a first cover plate 4 and a second cover plate 6 on the surface of the rear panel 5. In another embodiment, the first and

second cover plates

4, 6 may be located in cavities within the aft wing panel 5.

Fig. 4 is a schematic cross-sectional view of a high lift device according to one embodiment of the present invention. The first cover plate 4 is movably connected to a connection point on the second surface 51 of the rear panel 5 such that the first cover plate 4 can be rotated about the connection point in the slot. For example, the first cover plate 4 may have a connecting side 41 and a moving side 42 opposite the connecting side, the connecting side 41 of the first cover plate 4 being movably connected to the second surface 51 of the rear panel 5, so that the first cover plate 4 can be rotated about the connecting side 41 in the slot 20. The connection side 41 of the first cover plate 4 may be connected to a connection point on the second surface 51, for example on the second surface 51 of the rear panel 5 or at the intersection edge of the second surface 51 and the lower surface of the rear panel 5.

The live side 42 of the first cover plate 4 can be rotated to a target position, including a first position on the second surface of the aft wing 5, a second position on the first surface 31 of the forward wing 3, or a position between the first and second positions (i.e., in the slot 20). In one embodiment, the connecting side 41 of the first cover plate 4 is connected to the intersection edge of the second surface 51 of the rear panel 5 and the lower surface of the rear panel 5. In other embodiments, the connecting side 41 of the first cover plate 4 may be connected to other locations on the second surface 51 of the rear panel 5.

The second cover plate 6 may have a connecting side 61 and a moving side 62 opposite the connecting side, the connecting side 61 of the second cover plate 6 being movably connected to the upper surface of the rear panel 5, and the moving side 62 of the second cover plate being located in the slot 20 such that the second cover plate can rotate in the slot about the connecting side 61 of the second cover plate. The active side 62 of the second cover 6 can be rotated to a target position, including a third position on the second surface of the rear panel 5, a fourth position on the first surface 31 of the forward panel 3, or a position between the third and fourth positions (i.e., in the slot 20).

For example, state (i) in fig. 4 shows that the first cover plate 4 and the second cover plate 6 are respectively attached to the surface of the rear panel 5. In one embodiment, the first and

second cover plates

4, 6 may have a curvature that conforms to the surface of the aft wing section in which they are located, such that the outer surfaces of the first and second cover plates 4, 6 (the surfaces distal from the aft wing section 5) form a coherent outer surface with the surface of the aft wing section 5, e.g., a flat surface, an arcuate surface, etc.

In addition, state (ii) in fig. 4 shows that the first cover plate 4 and the second cover plate 6 close the lower end and the upper end of the seam way, respectively. In one embodiment, the first cover plate 4 and the second cover plate 6 may have a curvature conforming to the lower surface and the upper surface of the high lift device 1, respectively, such that the outer surfaces (surfaces away from the slot way) of the first cover plate 4 and the second cover plate 6 form a coherent lower surface and upper surface with the high lift device 1, e.g. flat surfaces, curved surfaces, etc.

In another embodiment, the first cover plate 4 may be affixed to the lower surface of the aft panel 5 and slid into the slot 20 between the forward panel 3 and the aft panel 5 to increase or decrease the slot between the forward panel 3 and the aft panel 5. Similarly, a second cover plate 6 may be affixed to the upper surface of the aft wing 5 and slid into the slot 20 between the forward and

aft wings

3, 5 to increase or decrease the slot between the forward and

aft wings

3, 5. It should be appreciated that the first and/or

second coverplates

4, 6 may be located anywhere on the aft wing 5 and movable within the slot 20, such as at any suitable location above, in the middle of, or below the second surface 51 of the aft wing 5, and movable within the slot 20 to increase or decrease the slot between the forward and

aft wings

3, 5.

Fig. 4 shows that the high lift device comprises an actuator 7 on the rear wing panel 5, the actuator 7 being connectable to the first and

second flaps

4, 6 via links (8a, 8b, 8c) and hinges (9a, 9b, 9c), respectively, the actuator 7 being extendable and retractable on the basis of a control command, e.g. the link 8a being extendable or retractable, such that the first and/or

second flap

4, 6 is moved to the respective target position. Although one actuator 7 is shown in FIG. 4, in other embodiments, each cover may be controlled using a separate actuator, or one or more covers may share an actuator, as the present invention is not limited in this respect.

In one embodiment, the actuator 7 may be connected to an aircraft operating system to receive an operating command, based on which the actuator 7 moves the first and/or

second cover plates

4, 6 to the respective target positions. For example, the actuator 7 may be connected to the aircraft operating system by a cable which may be routed from the rear panel 5 along the connection bracket (e.g. the first end rib 10a or the second end rib 10b) and the wing 2 to connect to the aircraft operating system. The cable can supply power to the actuator 7 and effect control of the actuator 7. In another embodiment, the actuator 7 may be powered by a separate power source (e.g., a battery). In addition, the actuators 7 may also communicate wirelessly with the aircraft operating system to receive operating commands wirelessly from the aircraft operating system. Thus, the high lift device of the present invention has an active control function in which the actuator 7 can control the extension into the interior slot or the retraction into the rear panel 5 of the first flap 4 and/or the second flap 6 in accordance with an operation command of the aircraft operation system, thereby actively controlling the open or closed state of the interior slot.

In fig. 4, state (i) shows that in the takeoff and landing phases of the aircraft, the first cover plate 4 and the second cover plate 6 are retracted (for example, attached to the surface of the rear wing section 5, respectively) to open the slot 20 between the front wing section 3 and the rear wing section 6, so that the airflow passes through the slot 20 from the lower surface of the high lift device 1 to the upper surface of the high lift device 1, thereby effectively guiding momentum to the boundary layer, eliminating or delaying the separation of the airflow on the upper surface, effectively improving the airfoil lift force, reducing the takeoff and landing speeds of the aircraft, reducing the requirements on the flight runway, and improving the airport adaptability of the aircraft. In conjunction with the state (i) in fig. 1, the high lift device 1 may form an included angle (for example, less than 180 degrees) with the lower surface (pressure surface) of the wing 2, thereby reducing the gas flow rate of the pressure surface of the wing and increasing the gas flow rate of the suction surface (upper surface), increasing the pressure difference between the upper and lower wing surfaces, and further increasing the wing lift.

In fig. 4, state (ii) shows that during the cruise phase of the aircraft, the active side of the first flap 4 is rotated into engagement with the forward wing section 3 (e.g. extending to the edge where the first surface of the forward wing section 3 meets the lower surface of the forward wing section 3), thereby closing the lower end of the slot 20 and preventing airflow from the lower surface of the high lift device 1 through the slot 20 to the upper surface of the high lift device 1. Optionally, the active side of the second cover plate 6 may be rotated into engagement with the forward wing section 3 (e.g. extending to the edge of the intersection of the first surface of the forward wing section 3 and the upper surface of the forward wing section 3) thereby closing the end of the slot 20. Closing the upper end of the slot 20 prevents air flow from entering the slot 20 from the upper surface of the high lift device 1 and causing turbulence.

In one embodiment, the upper and lower surfaces of the front panel 3 and the upper and lower surfaces of the rear panel 5 may each be cambered. In other embodiments, the upper and lower surfaces of the front and

rear panels

3, 5, respectively, may have other suitable streamlined surfaces.

In one embodiment, the first surface 31 of the front panel 3 may be a flat surface and the second surface 51 of the rear panel 5 may also be a flat surface. The width of the lower end of the slot way 20 can be larger than, equal to, or smaller than the width of the upper end of the slot way 20. In one embodiment, the first surface 31 of the front panel 3 and the second surface 51 of the rear panel 5 may each be a cambered surface, the curvatures of which may be the same or different. For example, the first surface 31 of the front panel 3 may be a concave arc (concave from the slot to the front panel 3) and the second surface 51 of the rear panel 5 may be a convex arc (convex from the rear panel 5 to the slot).

In a preferred embodiment, the internal seam channel based on the double-cambered surface design can ensure that two cambered surfaces of the internal seam channel are tangent to the suction surface (upper surface) of the high lift device, an effective drainage channel is formed, and a jet effect is formed at the outlet of the seam channel. The high-pressure fluid momentum of the pressure surface (lower surface) of the high-lift device can be fully introduced into the boundary layer at the middle rear part of the suction surface, so that the adverse pressure gradient is effectively resisted, and a remarkable high-lift effect is brought.

Fig. 4 also shows in state (ii) that the second surface 51 may have a recess to accommodate the first and

second cover plates

4, 6 such that when the first and

second cover plates

4, 6 are affixed to the second surface 51 of the rear panel 5, the second surface 51 is a continuous flat (or arcuate) surface without impeding the movement of the airflow in the slot 20, as shown in state (i).

By way of example and not limitation, the upper and lower surfaces of the forward and

aft wing segments

3, 5, respectively, may be cambered, and in state (ii), the lower surface of the forward wing segment 3, the (outer surface of the) first cover plate 4, and the lower surface of the aft wing segment 5 form a coherent cambered lower surface, while the upper surface of the forward wing segment 3, the (outer surface of the) second cover plate 6, and the upper surface of the aft wing segment 5 may form a coherent cambered upper surface. The airfoil illustrated in state (ii) may be referred to as the basic airfoil of the high lift device 1. In connection with state (ii) in fig. 1, the high lift device 1 can be in a consistent orientation with the wing 2, increasing the wing area and maintaining stable lift without creating additional drag.

Fig. 5 is a schematic cross-sectional view of a high lift device according to another embodiment of the present invention. The high lift device shown in fig. 5 may be similar to the high lift device shown in fig. 4, except that the first and

second coverplates

4, 6 may be located in cavities within the aft panel 5. For example, the first cover plate 4 may be located in a cavity near the lower surface of the aft wing section 5 and the second cover plate 6 may be located in a cavity near the upper surface of the aft wing section 5.

The actuator 7 may be connected to the first and

second coverplates

4, 6 by links (8a, 8b, 8c) and hinges (9a, 9b, 9c), respectively, and the actuator 7 may be retractable based on control commands such that the first and/or

second coverplates

4, 6 extend (e.g., move, slide) from a cavity within the rear panel 5 into the slot. For example, the first cover plate 4 may extend partially into the slot to reduce the slot between the leading panel 3 and the trailing panel 5. Alternatively, the first cover plate 4 may extend to the surface of the forward panel 3 to close the gap between the forward panel 3 and the aft panel 5. Similarly, the second cover plate 6 may extend partially into the slot to reduce the slot between the leading panel 3 and the trailing panel 5. Alternatively, the second cover 6 may extend to the surface of the forward panel 3 to close the gap between the forward panel 3 and the aft panel 5.

In fig. 5, state (i) shows that during the takeoff and landing phases of the aircraft, the first cover plate 4 and the second cover plate 6 are retracted (e.g., located in a cavity within the rear panel 5) to open the slot 20 between the front panel 3 and the rear panel 6, so that the airflow passes through the slot 20 from the lower surface of the high lift device 1 to the upper surface of the high lift device 1, thereby effectively introducing momentum into the boundary layer, eliminating or delaying separation of the upper surface airflow, and effectively increasing the airfoil lift.

In fig. 5, state (ii) shows that during the cruise phase of the aircraft, the first cover plate 4 extends to the surface of the forward panel 3 to close the lower end of the slot between the forward panel 3 and the aft panel 5, preventing airflow from the lower surface of the high lift device 1 through the slot 20 to the upper surface of the high lift device 1. Optionally, a second cover plate 6 extends to the surface of the forward panel 3 to close the upper end of the slot between the forward panel 3 and the aft panel 5. Closing the upper end of the slot 20 prevents air flow from entering the slot 20 from the upper surface of the high lift device 1 and causing turbulence.

According to the present invention, there is also provided a high lift method for an aircraft which may comprise a high lift device connected to a wing of the aircraft, such as the high lift device 1 described above. The high lift device 1 comprises separate front and rear panels with a slot between them, the front panel having a first surface facing the slot and the rear panel having a second surface facing the slot.

In step 1, the angle of attack of the aircraft may be determined. For example, sensors on the aircraft may determine the angle of attack of the aircraft.

In step 2, when the angle of attack is greater than or equal to the set threshold, a first cover plate movably connected to the aft wing is attached to a second surface of the aft wing or received into a cavity within the aft wing. Additionally, the high lift device may be angled at a specified angle to the lower surface of the wing of the aircraft. For example, during a takeoff or landing phase of an aircraft, this step may be performed in response to the angle of attack exceeding a threshold.

In step 3, when the angle of attack is less than the threshold, the first cover plate is extended into the slot between the forward wing panel and the aft wing panel to reduce the slot. For example, the first cover plate may reduce or close the lower end of the slot between the forward and aft panels. Additionally, a second cover plate movably connected to the aft wing may be used to reduce or close the upper end of the slot between the forward and aft wings. Furthermore, the direction of the high lift device can be aligned with the wing direction of the aircraft. For example, during a cruise phase of the aircraft, this step may be performed in response to the angle of attack being less than a threshold value.

The following describes simulation and experimental analysis of the high lift device of the present invention. Firstly, basic wing type (namely, seam channel closing) CFD (fluid mechanics) grids (figure 6) and wing type CFD grids (figure 7) containing internal seam channels of the high-lift device are established, then, simulation analysis is carried out on lift coefficients and drag coefficients under different attack angles, and the simulation analysis is compared with a test result of a pool model. Fig. 8 is a graph of different airfoil drag coefficients versus angle of attack for a high lift device according to an embodiment of the present invention. FIG. 9 is a comparison of flow field and streamlines for a base airfoil and an airfoil with internal slots of a high lift device according to one embodiment of the present invention.

It can be found that:

1) the test result is matched with the simulation result, and the effectiveness of simulation analysis is proved;

2) when the angle of attack is greater than a certain angle, the performance of the wing profile with the inner slot channel is obviously better than that of the basic wing profile (the lift coefficient is large and the drag coefficient is small), but when the angle of attack is smaller than the angle, the wing profile with the inner slot channel is not as good as that of the basic wing profile;

3) the airfoil profile containing the internal seam channel can effectively improve the maximum lift coefficient CLmax, and the test result shows that the maximum lift coefficient CLmax of the invention is improved by 58 percent compared with the basic airfoil profile;

4) when the attack angle is larger than or equal to 9 degrees, the first cover plate 4 and the second cover plate 6 are opened and form a seam channel in the high lift device, and the dotted line in fig. 8 and 9 is the wing type result with the active control function, so that the lift force can be obviously increased when the attack angle is larger than or equal to 9 degrees, additional resistance is not generated when the attack angle is smaller than 9 degrees, and the advantages of a basic wing type and a wing type with an internal seam channel are considered.

By comparing the flow velocity field and the flow line (figure 9) of the basic airfoil profile and the airfoil profile with the internal slot channel under the attack angle of 18 degrees, the invention can be further proved to be capable of effectively guiding the flow, eliminating the separation and greatly increasing the lift force. Compared with a seam formed by a plane, the internal seam designed based on the double cambered surfaces can enable two cambered surfaces of the internal seam to be tangent to a suction surface (upper surface) of the high lift device, an effective drainage channel is formed, and a jet effect is formed at the outlet of the seam. The high-pressure fluid momentum of the pressure surface (lower surface) of the high-lift device can be fully introduced into the boundary layer at the middle rear part of the suction surface, so that the adverse pressure gradient is effectively resisted, and a remarkable high-lift effect is brought.

The invention provides a high lift device with an active control function, which is provided with an internal seam passage capable of being actively controlled. In one embodiment, the internal slot may be of a double arcuate design. When the airplane takes off and lands, the high lift device is actively controlled to form a seam between the front wing section and the rear wing section, momentum is effectively guided into the boundary layer, the separation of upper surface airflow is eliminated or delayed, the airfoil lift force is effectively improved, the taking-off and landing speed of the airplane is reduced, the requirement on a flight runway is reduced, and the airport adaptability of the airplane is improved. When the airplane is cruising, the seam in the high lift device is closed, the basic airfoil shape is recovered, the airfoil surface is smooth, the basic airfoil lift force is not reduced, and the additional resistance is not generated.

The numerical values given in the embodiments are only examples and do not limit the scope of the present invention. In addition, other components or steps not recited in the claims or specification of the invention may be present as a whole. Moreover, the singular reference of a component does not exclude the plural reference of such components.

It is also noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged.

The disclosed methods, apparatus, and systems should not be limited in any way. Rather, the present disclosure encompasses all novel and non-obvious features and aspects of the various disclosed embodiments, both individually and in various combinations and sub-combinations with each other. The disclosed methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do any of the disclosed embodiments require that any one or more specific advantages be present or that a particular or all technical problem be solved.

The present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many modifications without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A high lift device (1) for an aircraft, characterized in that it comprises:

a connection bracket (10) for connecting the high lift device to a wing (2) of the aircraft;

a forward wing (3) and a rearward wing (5) secured to the attachment bracket, the forward wing being spaced apart from the rearward wing to form a slot between the forward and rearward wings, the forward wing having a first surface facing the slot and the rearward wing having a second surface facing the slot;

a first cover plate (4) on the rear panel, the first cover plate being attached to a second surface of the rear panel facing the slot in one state or received into a cavity within the rear panel; and

an actuator (7) on the rear panel, the actuator being capable of controlling the first cover plate to extend into the slot between the front panel and the rear panel.

2. The high lift device of claim 1, wherein:

the first cover plate is movably connected to a connection point on the second surface of the rear panel such that the first cover plate can rotate about the connection point in the slot,

wherein a side of the first cover plate opposite the connection point is rotatable to a target position, the target position comprising a first position on the second surface of the aft wing, a second position on the first surface of the forward wing, or a position in the slot between the first position and the second position.

3. The high lift device of claim 2, wherein:

one side of the first cover plate is connected to the connection point, which is located at the intersection edge of the second surface of the aft wing and the lower surface of the aft wing.

4. A high lift device according to claim 3, wherein:

the side of the first cover plate opposite the connection point is rotated to the intersection edge of the first surface of the forward wing section and the lower surface of the forward wing section, so that the lower surface of the forward wing section, the first cover plate and the lower surface of the aft wing section form a coherent arc-shaped lower surface.

5. The high lift device of claim 1, wherein:

the first cover plate is positioned in a cavity within the rear panel, wherein the actuator is capable of controlling movement of the first cover plate into the slot.

6. The high lift device of any one of claims 1 to 5, further comprising:

a second cover plate (6) movably connected to the rear panel and above the first cover plate, the actuator being capable of controlling the extension of the second cover plate into the slot between the front panel and the rear panel.

7. The high lift device of claim 6, wherein:

one side of the second cover plate is movably connected to a second connection point on the upper surface of the rear wing section, and the movable side of the second cover plate opposite to the second connection point can rotate around the second connection point in the seam way,

wherein the active side of the second cover plate is rotatable to a target position, the target position comprising a third position on the second surface of the aft wing, a fourth position on the first surface of the forward wing, or a position in the slot between the third position and the fourth position.

8. The high lift device of claim 7, wherein:

the movable side of the second cover plate rotates to the intersection edge of the first surface of the front wing section and the upper surface of the front wing section, so that the upper surface of the front wing section, the upper surfaces of the second cover plate and the upper surface of the rear wing section form a coherent arc-shaped upper surface.

9. The high lift device of claim 6, wherein:

when the aircraft takes off or lands, the first cover plate and the second cover plate are respectively attached to the surface of the rear wing section or are stored in a cavity in the rear wing section so as to open a seam between the front wing section and the rear wing section.

10. The high lift device of claim 6, wherein:

the actuators are connected to the first and second cover plates by links, respectively, and the actuators move the first and/or second cover plates to respective target positions based on control commands.

11. The high lift device of claim 1, wherein:

the first surface of the forward wing section is a concave arc surface that is concave from the slot to the forward wing section, and the second surface of the aft wing section is a convex arc surface that is convex from the aft wing section to the slot.

12. The high lift device of claim 1, wherein:

the connecting bracket comprises a first end rib (10a) and a second end rib (10b), wherein the front panel and the rear panel are secured between the first end rib and the second end rib; or

The linking bridge includes a plurality of bracing pieces, preceding wing panel with the back wing panel is fixed respectively to corresponding bracing piece.

13. The high lift device of claim 1, wherein:

the connecting bracket is rotatably connected to a wing of the aircraft such that the high lift device is rotatable relative to the wing of the aircraft.

14. The high lift device of claim 13, wherein:

during the cruising stage of the aircraft, the direction of the high lift device is consistent with the wing direction of the aircraft; and

and in the takeoff or landing stage of the aircraft, the high lift device and the lower surface of the wing of the aircraft form a specified included angle.

15. An aircraft comprising a wing, characterized in that the aircraft comprises a high lift device according to any one of claims 1 to 14, which is connected to the wing.

16. A high lift method for an aircraft, the aircraft comprising a high lift device connected to a wing of the aircraft, the high lift device comprising separate forward and aft wing segments with a slot therebetween, the forward wing segment having a first surface facing the slot and the aft wing segment having a second surface facing the slot, the method comprising:

determining an angle of attack of the aircraft;

attaching a first cover plate movably connected to the rear wing section to a second surface of the rear wing section facing the slot or to be received into a cavity within the rear wing section when the angle of attack is greater than or equal to a threshold; and

extending the first cover plate into a slot between the forward wing section and the aft wing section to reduce the slot when the angle of attack is less than the threshold.

17. The high lift method of claim 16, wherein:

the first cover plate reduces or closes the lower end of a seam between the front wing panel and the rear wing panel.

18. The high lift method of claim 17, further comprising:

reducing or closing an upper end of a slot between the forward wing section and the aft wing section using a second cover plate movably connected to the aft wing section when the angle of attack is less than the threshold.

19. The high lift method of claim 16, further comprising:

when the attack angle is smaller than the threshold value, enabling the direction of the high lift device to be consistent with the wing direction of the aircraft; and

and when the attack angle is larger than or equal to the threshold value, enabling the high lift device to form a specified included angle with the lower surface of the wing of the aircraft.