An aircraft with a fluid thrust vectoring nozzle integrated with its wings.

Abstract

This invention discloses an aircraft with an integrated fluid thrust vectoring nozzle and wing, comprising an integrated airfoil, an engine, an engine exhaust nozzle, and a fluid thrust vectoring nozzle; the engine is embedded within the integrated airfoil, and the engine exhaust nozzle is pre-deflected upwards. This aircraft with an integrated fluid thrust vectoring nozzle and wing effectively reduces the thickness of the wing's trailing edge, thereby reducing aft drag during flight; it is lightweight, has fewer moving parts, and exhibits fast deflection response, providing controllable pitching moment within the aircraft's cruise angle of attack; it improves the lift coefficient and control moment; and it enhances the aircraft's infrared stealth performance.

Description

Technical Field

[0001] This invention belongs to the field of aircraft vector control technology, specifically an aircraft with an integrated fluid thrust vector nozzle and wing. Background Technology

[0002] Thrust vectoring technology has been widely used to improve the maneuverability and agility of next-generation fighter jets. Based on their structural design and deflection mechanism, thrust vectoring is divided into two types: mechanical and fluid. Mechanical thrust vectoring changes the jet direction by deflecting the mechanical profile at the nozzle tail. Its design is mature and widely used in modern fighter jets; however, it suffers from drawbacks such as heavy structural weight, numerous moving parts, and slow deflection response. Fluid thrust vectoring nozzles, on the other hand, do not require changes to the nozzle shape. They rely on flow control methods such as jet injection to change the jet direction, resulting in a relatively simple structure and fewer moving parts.

[0003] Existing fluid thrust vectoring nozzles are primarily installed at the tail of aircraft to provide control torque, with limited consideration for integrated flight and engine design. Researchers such as Han Jiexing installed a rectangular passive fluid thrust vectoring nozzle on the trailing edge of an airfoil and verified the lift-enhancing and drag-reducing effects of the jet flow on the wing shape through wind tunnel tests. However, the rectangular passive fluid thrust vectoring nozzle has a relatively thick thickness h1 (e.g., Figure 1 As shown in the figure, it will cause significant rear drag on the aircraft, and it is still some distance from practical application.

[0004] Most ground experiments and numerical simulations of fluid vector nozzles show that free flow causes pressure changes near the nozzle exit, affecting the boundary layer on the nozzle's inner wall and further influencing the flow field within the nozzle. Circulation control, as a flow control method, modifies circulation by creating the Coanda effect through airflow at the wing's trailing edge, thereby increasing lift, reducing drag, and controlling attitude. It offers advantages such as simplicity, light weight, and ease of implementation. Circulation control technology has broad application prospects in enhancing aircraft performance, such as improving stall angle of attack, delaying flow separation, and increasing lift and reducing drag, and is increasingly valued in innovative flight control. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an aircraft that integrates a fluid thrust vectoring nozzle with an airfoil, which provides attitude control torque for the aircraft while reducing the thickness of the airfoil tail section and reducing the pressure drag of the aircraft.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] An aircraft with an integrated fluid thrust vectoring nozzle and wing includes an integrated airfoil, an engine, an engine exhaust nozzle, and a fluid thrust vectoring nozzle. The engine is embedded within the integrated airfoil, and the engine exhaust nozzle is pre-deflected upwards.

[0008] Furthermore, the engine exhaust nozzle includes a circular-to-square straightening section and a square bending deflection section connected in sequence.

[0009] Furthermore, the aspect ratio of the rectifying section depends on the number of engines, the jet outlet area, and the flow rate of the jet outlet at the operating point.

[0010] Furthermore, the fluid thrust vector nozzle includes multiple nozzle segments, each of which includes a deflection wall plate, a deflection control hole, a deflection control valve, and a deflection static pressure chamber.

[0011] Furthermore, the wall surface of the deflection plate is a planar rectangle, and the aspect ratio of the wall surface is determined by the jet expansion angle and the spatial position of the shear layer, which is obtained through experiments.

[0012] Furthermore, the sum of the areas of all deflection control holes on the same wall surface does not exceed 10% of the area of ​​the wall surface.

[0013] Furthermore, the deflection control hole is disposed at the front end of the deflection wall plate; the diameter and number of the deflection control hole depend on the required secondary flow rate.

[0014] Furthermore, the deflection static pressure chamber is used to connect the deflection control hole to the outside atmosphere.

[0015] Furthermore, the deflection control valve is used to change the degree of connection of the deflection static pressure chamber.

[0016] Furthermore, the deflection control valve includes a linear limiting groove, a valve plate, and a driving device. The linear limiting groove restricts the movement trajectory of the valve plate, ensuring it can only move in a straight line. The driving device controls the position of the valve plate on the linear limiting groove. By changing the valve plate's position on the linear limiting groove, the opening of the deflection control valve between the deflection static pressure chamber and the atmosphere can be altered, thereby adjusting the connectivity between the deflection static pressure chamber and the external atmosphere, as well as the flow rate. Ultimately, this changes the adhesion between the jet and the wall, allowing the jet to linearly and controllably change its direction.

[0017] The present invention discloses an aircraft with an integrated fluid thrust vectoring nozzle and wing, which has the following advantages:

[0018] Compared to the traditional design where the nozzle is located at the wingtip, the technical solution of this invention reduces the thickness of the trailing edge of the wing by placing the nozzle forward, thereby effectively reducing the thickness of the trailing edge of the wing and thus reducing the drag during flight.

[0019] The technical solution of this invention uses a fluid-type thrust vector as a control device for thrust vector deflection. It has a light structure, few moving parts, and fast deflection response, and can provide a controllable pitching moment within the aircraft's cruise angle of attack.

[0020] The technical solution of this invention can reduce the temperature of the engine jet by mixing the engine jet with the external flow, while the multi-section deflection wall blocks the jet from below, thereby enhancing the infrared stealth performance of the aircraft.

[0021] At angles of attack above 16°, the technical solution of this invention, through an integrated design of internal and external flow coupling, can simultaneously serve as a propulsion device and a flow control device while providing control torque in the normal component of the thrust vector force, generating a supercirculation effect and improving the lift coefficient and control torque; it has application prospects in fields such as short takeoff and landing aircraft and high-maneuverability fighter jets. Attached Figure Description

[0022] Figure 1 It is a traditional integrated design of fluid thrust vectoring tube and wing;

[0023] Figure 2 This is a schematic diagram of the thickness of the rear body of an aircraft in which a fluid thrust vectoring nozzle and wing are integrated, according to the present invention.

[0024] Figure 3 This is a schematic diagram of the overall structure of an aircraft that integrates a fluid thrust vectoring nozzle with a wing, according to the present invention.

[0025] Figure 4 This is a schematic diagram of the fluid thrust vector nozzle part of the present invention;

[0026] Figure 5 This is a schematic diagram of the opening of two deflection control valves in one embodiment of the present invention;

[0027] Figure 6 yes Figure 5 The diagram shows the aircraft's status when the deflection control valve is in its open or closed position.

[0028] Figure 7 This is a schematic diagram of one deflection control valve being open and the other deflection control valve being closed in one embodiment of the present invention;

[0029] Figure 8 yes Figure 7 The diagram shows the aircraft's status when the deflection control valve is open or closed.

[0030] Figure 9 This is a schematic diagram showing that both deflection control valves are closed in one embodiment of the present invention;

[0031] Figure 10 yes Figure 9 The diagram shows the aircraft's status when the deflection control valve is open or closed.

[0032] Figure 11 This is a schematic diagram of the pitch test results of an aircraft wing with an angle of attack in the range of -4 to 12° in one embodiment of the present invention;

[0033] Figure 12 This is a schematic diagram of the experimental results of delayed stall of an aircraft at a high angle of attack of the aircraft wing in one embodiment of the present invention. Implementation

[0034] The following detailed description, in conjunction with the accompanying drawings, provides a multi-input multi-output non-stationary random vibration test system and test algorithm proposed in this invention. In the description of this invention, it should be understood that the terms "left side," "right side," "upper part," "lower part," "bottom," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Terms such as "first" and "second" do not indicate the importance of components and therefore should not be construed as limiting the invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of this invention.

[0035] This embodiment provides an aircraft with a fluid thrust vectoring nozzle integrated with a wing, such as... Figure 1 As shown, it includes an integrated airfoil 0, an engine 1, an engine exhaust nozzle, and a fluid thrust vectoring nozzle. The engine 1 is embedded within the integrated airfoil 0, and the engine exhaust nozzle is pre-deflected upwards.

[0036] like Figure 2 As shown, compared to the traditional design where the nozzle is located at the wingtip, this embodiment effectively reduces the thickness h2 of the wing tail, thereby reducing pressure drag during flight.

[0037] The pre-positioned upward-deflecting engine exhaust nozzle includes a circular-to-square straightening section 21 and a square bending deflection section 22 connected in sequence. The circular-to-square straightening section 21 is designed to transform the circular exhaust outlet of the engine into a rectangular nozzle, thereby matching the tangential velocity profile of the exhaust flow with the nozzle. Its aspect ratio depends on the number of engines, the exhaust outlet area, and the flow rate at the operating point of the exhaust outlet.

[0038] A fluid thrust vectoring nozzle consists of multiple nozzle segments, each including a deflection wall, deflection control orifices, deflection control valves, and a deflection static pressure chamber. The number of segments depends on the thickness and deflection angle requirements of the aircraft's wing aft fuselage. For example... Figure 3 As shown, in this embodiment, the fluid thrust vector nozzle includes two sections, specifically including a first deflection wall plate 31, a first deflection control hole 33, a first deflection control valve 35, a first deflection static pressure chamber 37, a second deflection wall plate 32, a second deflection control hole 34, a second deflection control valve 36, and a second deflection static pressure chamber 38.

[0039] The deflection plate has a rectangular planar surface, and its aspect ratio is determined by the jet expansion angle and the spatial position of the shear layer, primarily obtained through experiments. The sum of the areas of all deflection control holes on the same wall surface does not exceed 10% of the total wall surface area.

[0040] like Figure 3 and 4 As shown, a first-stage deflection control hole 33 and a second-stage deflection control hole 34 are respectively disposed at the front ends of a first-stage deflection wall plate 31 and a second-stage deflection wall plate 32; the diameter and number of deflection control holes depend on the required secondary flow rate. The distance between the centers of two adjacent deflection control holes does not exceed three times the radius of the deflection control hole. The aircraft control method of the present invention is not limited to passive fluid thrust vectoring, that is, deflection can be based on control holes or secondary flow injection.

[0041] The deflection static pressure chamber is used to connect the deflection control port to the outside atmosphere. The deflection control valve is used to change the degree of connection of the deflection static pressure chamber.

[0042] The deflection control valve includes a linear limiting groove, a valve plate, and a drive device. The linear limiting groove restricts the movement of the valve plate, ensuring it can only move in a straight line. The drive device controls the position of the valve plate on the linear limiting groove. By changing the valve plate's position on the linear limiting groove, the opening of the deflection control valve between the deflection static pressure chamber and the atmosphere can be altered. This adjusts the connectivity between the deflection static pressure chamber and the external atmosphere, as well as the flow rate, ultimately changing the adhesion between the jet and the wall, allowing the jet to linearly and controllably change its direction.

[0043] The cross-sectional shape of the square bend deflection section 22 is consistent with the shape of the pre-set upper deflection end position of the square bend deflection section 22 (i.e., the middle part from the square bend deflection section 22 to the deflection control hole 33). Its bending angle depends on the deflection angle of the first section of the fluid thrust vector nozzle and the maximum deflection angle during double-stage deflection. The determination method is as follows: 1. Determine the mapping relationship between the deflection wall length and deflection wall angle of each section of the fluid thrust vector nozzle and the jet deflection capability through ground wind tunnel experiments or numerical simulation; 2. Determine the optimal deflection combination by comprehensively considering the maximum jet deflection angle during double-stage deflection and the single-stage deflection angle; 3. Align the thrust line during the first deflection with the thrust line of the entire machine. At this time, the exit angle of the exit position of the square bend deflection section 22 is equal to the jet deflection angle of the first deflection.

[0044] The control method for an aircraft integrating a fluid thrust vectoring nozzle and a wing, as described in this invention, is described in [reference needed]. Figures 5 to 10 .like Figure 5 and 6 As shown, when both the first-stage deflection control valve 35 and the second-stage deflection control valve 36 are open, the engine jet will deflect upward along the square bend deflection section 22. A preset deflection angle exists between the engine jet and the first-stage jet wall plate. At this time, because the jet thrust line is located behind the center of gravity, it provides pitching torque and thrust. Figure 7 and 8 As shown, when the first-stage deflection control valve 35 is closed and the second-stage deflection control valve 36 is open, the jet will form a section attached to the wall. At this time, the jet will be ejected along the aircraft axis, and the engine thrust will be parallel to the aircraft axis, providing the thrust required by the aircraft, but not providing control torque. Figure 9 and 10 As shown, when both the first-stage deflection control valve 35 and the second-stage deflection control valve 36 are closed, the jet will adhere to the wall twice and be ejected downwards along the second wall. Since the jet's point of action is behind the center of gravity, it will generate a nose-down torque, providing nose-down control torque and thrust. Between the three states, there is a good linear relationship between the deflection control valve opening and the provided force and torque, thus providing continuous and effective control torque for the aircraft. The aircraft's attitude control torque originates from both the direct force from the nozzle and the circulation control effect generated by the jet's entrainment of the external flow.

[0045] like Figure 11 As shown, wind tunnel test results prove that the control method described in this embodiment can provide pitch control torque for nose-down and nose-up within the aircraft's cruise angle of attack.

[0046] like Figure 12 As shown, wind tunnel test results demonstrate that at angles of attack above 16°, the control method described in this embodiment effectively improves the wing's stall angle of attack through internal and external flow coupling, thereby increasing lift.

[0047] Stealth performance is a crucial indicator for evaluating current weaponry and a significant characteristic of new weapon systems. Stealth performance encompasses technologies such as radar stealth, infrared stealth, visible light stealth (formerly known as camouflage), laser stealth, and acoustic stealth. With the development of infrared sensor and computer technologies, the ability of infrared detection systems to detect various targets has greatly improved. Therefore, in the overall design of aircraft, it is essential to effectively reduce infrared radiation signatures while minimizing radar cross-section, based on the principle of balanced detectability, to achieve infrared stealth design. The exhaust system is the primary source of infrared radiation for an aircraft. The infrared radiation from the hot cavity of its tail nozzle and the exhaust stream is mainly concentrated in the 3–5 μm mid-wave band. This band falls within the primary operating range of military infrared detection systems and represents a primary challenge in achieving infrared stealth for aircraft. Reducing the infrared radiation intensity of the exhaust system is a crucial technical approach to suppressing its infrared radiation characteristics. Therefore, the main measures for infrared stealth of the exhaust system include the following three aspects: shielding high-temperature components of the exhaust system to reduce their projected area in the detector direction; reducing the temperature of the hot cavity and exhaust flow of the tailpipe to decrease spectral radiance; and using low-emissivity materials to reduce the surface emissivity of the hot cavity wall of the tailpipe. Shielding technology reduces the infrared radiation intensity of the exhaust system by shielding its high-temperature components.

[0048] In this embodiment, the first and second deflection panels block the jet stream from below, with a very obvious blocking effect. At the same time, by mixing the engine with the external flow, the temperature of the engine jet stream is reduced, thereby enhancing the aircraft's infrared stealth capability.

[0049] Based on the description of preferred embodiments of the present invention, it should be clear that the present invention as defined by the appended claims is not limited to the specific details set forth in the above description, and many obvious modifications to the present invention without departing from its spirit or scope may also achieve the purpose of the present invention.

Claims

1. An aircraft with a fluid thrust vectoring nozzle integrated with a wing, characterized in that, It includes an integrated airfoil, an engine, an engine exhaust nozzle, and a fluid thrust vectoring nozzle; the engine is embedded in the integrated airfoil, and the engine exhaust nozzle is located in front of the tail of the wing and is pre-deflected upwards; The engine exhaust nozzle includes a circular-to-square straightening section and a square bending deflection section connected in sequence. The fluid thrust vector nozzle includes multiple nozzle segments, each of which includes a deflection wall plate, a deflection control hole, a deflection control valve, and a deflection static pressure chamber. The deflection control hole is located at the front end of the deflection wall plate; the diameter and number of the deflection control hole depend on the required secondary flow rate. The deflection static pressure chamber is used to connect the deflection control hole to the outside atmosphere; The deflection control valve is used to change the degree of connection of the deflection static pressure chamber; The fluid thrust vector nozzle comprises two sections, specifically including a deflection wall plate, a deflection control hole, a deflection control valve, a deflection static pressure chamber, a second deflection wall plate, a second deflection control hole, a second deflection control valve, and a second deflection static pressure chamber. The first deflection control hole and the second deflection control hole are respectively located at the front end of the first deflection wall plate and the second deflection wall plate.

2. The aircraft with an integrated fluid thrust vectoring nozzle and wing according to claim 1, characterized in that, The aspect ratio of the rectifier section depends on the number of engines, the jet outlet area, and the flow rate of the jet outlet at the operating point.

3. The aircraft with an integrated fluid thrust vectoring nozzle and wing as described in claim 1, characterized in that, The deflection wall panel has a planar rectangular surface, and the aspect ratio of the surface is determined by the jet expansion angle and the spatial position of the shear layer, which is obtained through experiments.

4. The aircraft with an integrated fluid thrust vectoring nozzle and wing according to claim 3, characterized in that, The sum of the areas of all deflection control holes on the same wall surface shall not exceed 10% of the area of ​​the wall surface.

5. The aircraft with an integrated fluid thrust vectoring nozzle and wing according to claim 1, characterized in that, The deflection control valve includes a linear limiting groove, a valve plate, and a drive device; the linear limiting groove is used to restrict the running trajectory of the valve plate, so that the valve plate can only run in a straight line; the drive device is used to control the position of the valve plate on the linear limiting groove.

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