A rear body retraction fluid thrust vectoring nozzle

Abstract

The application discloses a rear body contraction type fluid thrust vector nozzle, which comprises a contraction section, a static pressure cavity, a main jet outlet, a control valve, a contraction wall surface, a secondary flow inlet and a wall surface secondary flow hole. The contraction section is arranged above and below the static pressure cavity, the main jet outlet is arranged at the tail end of the contraction section, the contraction wall surface is arranged at the tail of the static pressure cavity, the secondary flow inlet is arranged on the side of the rear body contraction type fluid thrust vector nozzle, and the wall surface secondary flow hole is arranged on the contraction wall surface. The static pressure cavity is in communication with the secondary flow inlet and the wall surface secondary flow hole, and the secondary flow inlet is controlled by the control valve. The rear body contraction type fluid thrust vector nozzle can realize jet vector deflection control while reducing the thickness of the rear body, has a good application prospect in the integration design of the fluid thrust vector and an aircraft, and can further promote the practical application of the fluid thrust vector nozzle.

Description

Technical Field

[0001] This invention belongs to the field of aircraft control technology, specifically a rear-body contraction fluid thrust vectoring nozzle. Background Technology

[0002] Thrust vectoring technology is widely used in high-performance fighter jets both domestically and internationally. It can improve an aircraft's maneuverability, agility, stealth, and short takeoff and landing capabilities. Currently, mechanical thrust vectoring technology is widely used. It achieves the deflection of the engine exhaust stream through complex mechanical transmission components, thus suffering from disadvantages such as complex structure, heavy weight, and slow deflection response. Compared to mechanical thrust vectoring, the next-generation fluid thrust vectoring technology uses a fixed nozzle profile and employs flow control within the nozzle to alter the flow structure and further induce jet deflection. Compared to mechanical thrust vectoring, fluid thrust vectoring technology has advantages such as simple structure, light weight, fast deflection response, and high control efficiency, and is expected to become the next generation of practical thrust vectoring technology.

[0003] However, all existing fluid thrust vectoring nozzles have a large aft body thickness. Methods such as shock wave vectoring, co-current flow, and reverse flow all require an expanding inclined wall at the nozzle exit, making the aft body area several times the area of ​​the tail jet exit. This large aft body thickness increases aircraft drag and hinders the integrated design of the aircraft and its propulsion system. In practical applications, this drawback leads to a decrease in cruise performance, stealth capabilities, and range, hindering the practical application of fluid thrust vectoring technology. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a rear-body contraction fluid thrust vectoring nozzle, which has a contraction rear body shape, can realize continuous and controllable deflection of the tail jet, and effectively reduce the rear body drag of the aircraft and improve its stealth performance.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A rear-body contraction-type fluid thrust vectoring nozzle includes a contraction section, a static pressure chamber, a main jet outlet, a control valve, a contraction wall, a secondary flow inlet, and secondary flow orifices on the wall. The contraction section is located above and below the static pressure chamber; the main jet outlet is located at the end of the contraction section; the contraction wall is located at the tail end of the static pressure chamber; the secondary flow inlet is located on the side of the rear-body contraction-type fluid thrust vectoring nozzle; and the secondary flow orifices on the wall are arranged on the contraction wall. The static pressure chamber is connected to the secondary flow inlet and the secondary flow orifices on the wall. The secondary flow inlet is controlled by the control valve.

[0007] Furthermore, the contraction section includes an upper contraction section and a lower contraction section, and the main jet outlet includes an upper main jet outlet and a lower main jet outlet. The upper main jet outlet is located at the end of the upper contraction section, and the lower main jet outlet is located at the end of the lower contraction section.

[0008] Furthermore, the contraction wall is installed between the upper main jet outlet and the lower main jet outlet; the contraction wall includes an upper wall and a lower wall, and the contraction wall has a certain angle with the main jet outlet, and the upper wall and the lower wall contract into a wedge shape towards the center of the nozzle.

[0009] Furthermore, the upper and lower wall surfaces are curved surfaces or straight inclined surfaces.

[0010] Furthermore, the static pressure chamber is located between the upper contraction section, the lower contraction section, the upper wall surface, and the lower wall surface.

[0011] Furthermore, a horizontal baffle is installed in the static pressure chamber to divide it into an upper static pressure chamber and a lower static pressure chamber. The secondary flow inlet includes an upper secondary flow inlet and a lower secondary flow inlet, and the wall secondary flow orifice includes an upper wall secondary flow orifice and a lower wall secondary flow orifice. The upper static pressure chamber is connected to the upper secondary flow inlet and the upper wall secondary flow orifice, and the lower static pressure chamber is connected to the lower secondary flow inlet and the lower wall secondary flow orifice.

[0012] Furthermore, the secondary flow holes on the upper wall and the lower wall are respectively arranged on the upper wall and the lower wall.

[0013] Furthermore, the control valve includes an upper control valve and a lower control valve, which are used to control the upper secondary flow inlet and the lower secondary flow inlet, respectively.

[0014] Furthermore, the upper control valve and the lower control valve respectively control the closure degree of the upper secondary flow inlet and the lower secondary flow inlet, so as to control the vector deflection degree of the tail jet of the rear body contraction fluid thrust vector nozzle.

[0015] According to the above technical solution, the working principle of this rear-body contraction fluid thrust vectoring nozzle is as follows: In the non-vectoring state, the upper and lower control valves are completely closed, preventing external fluid from entering the secondary flow orifice on the wall from the secondary flow inlet. The jet flows out through the upper and lower contraction sections, respectively, via the upper main jet outlet and the lower main jet outlet. Due to the Coanda effect, the upper main jet adheres to the upper wall surface of the contraction wall, and the lower main jet adheres to the lower wall surface. The upper and lower main jets merge at the tail of the contraction wall and then leave the nozzle wall. At this time, the main jet is in a non-vectoring state, without deflection, and the thrust direction remains unchanged.

[0016] In vector mode, taking the upward deflection of the jet as an example, the upper control valve is open while the lower control valve remains closed. Ambient fluid can enter the nozzle through the upper secondary flow inlet, the upper static pressure chamber, and the secondary flow orifice on the upper wall. Due to the supplementation of the secondary flow, the upper main jet will leave the upper wall, forming a wall-detached flow. At this time, the lower main jet remains attached to the lower wall. Because the lower wall is deflected upwards, the lower main jet merges with the upper main jet after passing through the lower wall, resulting in an overall upward deflection of the jet, and the nozzle generates a downward thrust component.

[0017] The present invention discloses a rear-body contraction type fluid thrust vectoring nozzle, which has the following beneficial effects:

[0018] The nozzle's aft body shape is converging, which facilitates integration of the nozzle with the aircraft's aft body shape, reduces drag, and enhances stealth. Its converging wall simultaneously serves as both the vectoring nozzle wall and the aircraft's aft tip shape, resulting in a simple structure. Vector control exhibits high linearity, and the tail jet vector control is stable and reliable. This aft-body converging fluid thrust vectoring nozzle, while reducing aft body thickness, achieves vector deflection control of the jet, demonstrating promising application prospects in the integrated design of fluid thrust vectoring and aircraft flight-engine systems, and further advancing the practical application of fluid thrust vectoring nozzles. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a rear-body contraction fluid thrust vector nozzle structure in one embodiment of the present invention;

[0020] Figure 2 yes Figure 1 A side view of the rear-body contraction fluid thrust vectoring nozzle shown.

[0021] Figure 3 yes Figure 1 A top view of the rear-body contraction fluid thrust vectoring nozzle shown.

[0022] Figure 4 yes Figure 1 The rear view of the rear-body contraction fluid thrust vectoring nozzle shown.

[0023] Figure 5 yes Figure 3 The figure shows a cross-sectional view of the AA section of the rear-body contraction fluid thrust vector nozzle. The figure also shows the flow direction of the main jet through the upper and lower contraction sections.

[0024] Figure 6 This is a schematic diagram illustrating the principle of jet neutrality in one embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the upward deflection of the jet in one embodiment of the present invention;

[0026] Figure 8This is a schematic diagram of the jet deflection principle in one embodiment of the present invention;

[0027] Figure 9 This is a schematic diagram of the force vector angle control law obtained in a force measurement experiment of a rear-body contraction fluid thrust vector nozzle in one embodiment of the present invention.

[0028] Wherein: 1. Upper main jet outlet; 2. Lower main jet outlet; 3. Upper wall surface; 4. Lower wall surface; 5. Secondary flow orifice on upper wall surface; 6. Secondary flow orifice on lower wall surface; 7. Upper secondary flow inlet; 8. Lower secondary flow inlet; 9. Upper control valve; 10. Lower control valve; 11. Upper static pressure chamber; 12. Lower static pressure chamber; 13. Upper contraction section; 14. Lower contraction section. Detailed Implementation

[0029] The following detailed description, in conjunction with the accompanying drawings, provides a description of a rear-body contraction type fluid thrust vectoring nozzle proposed in this invention. In the description of this invention, it should be understood that terms such as "left side," "right side," "upper part," "lower part," and "bottom," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element 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 merely illustrative of the technical solution and do not limit the scope of protection of this invention.

[0030] In this embodiment, Figures 1 to 5 Taking a rear-body contraction fluid thrust vector nozzle as an example, it includes an upper main jet outlet 1, a lower main jet outlet 2, an upper wall surface 3, a lower wall surface 4, a secondary flow hole on the upper wall surface 5, a secondary flow hole on the lower wall surface 6, an upper secondary flow inlet 7, a lower secondary flow inlet 8, an upper control valve 9, a lower control valve 10, an upper static pressure chamber 11, a lower static pressure chamber 12, an upper contraction section 13, and a lower contraction section 14.

[0031] like Figure 1 As shown, the upper wall surface 3 is installed at the upper main jet outlet 1 and tilted downwards at a certain angle; the lower wall surface 4 is installed at the lower main jet outlet 2 and tilted upwards at a certain angle; the upper wall surface 3 and the lower wall surface 4 converge into a pointed wedge shape downstream of the nozzle. The upper wall surface 3 and the lower wall surface 4 can be straight surfaces as shown in the figure, or they can be curved surfaces, such as arc surfaces. The upper secondary flow inlet 7, the lower secondary flow inlet 8, the upper control valve 9, and the lower control valve 10 are installed on the side of the nozzle.

[0032] like Figure 5As shown, the upper secondary flow inlet 7 is connected to the upper static pressure chamber 11 and the secondary flow hole 5 on the upper wall; the lower secondary flow inlet 8 is connected to the lower static pressure chamber 12 and the secondary flow hole 6 on the lower wall; the closure degree of the upper secondary flow inlet 7 and the lower secondary flow inlet 8 can be controlled by the upper control valve 9 and the lower control valve 10, respectively. The main jet is divided into upper and lower streams through the upper contraction section 13 and the lower contraction section 14, and flows out through the upper main jet outlet 1 and the lower main jet outlet 2, respectively.

[0033] Based on the aforementioned rear-body contraction fluid thrust vectoring nozzle, its jet vector control method is as follows:

[0034] Jet non-vector state control such as Figure 6 As shown in the figure (0 indicates valve closed, 0 indicates valve open). Both upper control valve 9 and lower control valve 10 are closed. At this time, both upper static pressure chamber 11 and lower static pressure chamber 12 are isolated from the surrounding fluid of the nozzle, forming a sealed cavity. After the upper main jet flows out from the upper main jet outlet 1, it will be deflected downwards and adhere to the upper wall surface 3 due to the Coanda effect. After the lower main jet flows out from the lower main jet outlet 2, it will be deflected upwards and adhere to the lower wall surface 4 due to the Coanda effect. The upper and lower main jets merge at the tail of the contraction wall to form a single jet and leave the nozzle wall. At this time, the main jet is in a non-vector state and does not deflect, and the thrust direction remains unchanged.

[0035] Jet vector state control such as Figure 7 and 8 As shown, Figure 7 The upper control valve 9 is open, while the lower control valve 10 remains closed. At this time, the upper static pressure chamber 11 is in fluid communication with the surrounding environment of the nozzle. The secondary flow can flow into the upper side of the nozzle through the upper secondary flow inlet 7, the upper static pressure chamber 11, and the secondary flow hole 5 on the upper wall, causing the upper main jet to leave the upper wall 3. At this time, the lower main jet is still in an upward deflection state on the lower wall 4. Therefore, after the upper and lower main jets merge, the overall jet is in an upward deflection state, and the nozzle is subjected to a downward thrust component.

[0036] Figure 8 The upper control valve 9 is closed, and the lower control valve 10 is open. At this time, the lower static pressure chamber 12 is in fluid communication with the surrounding environment of the nozzle. The secondary flow can flow into the lower side of the nozzle through the lower secondary flow inlet 8, the lower static pressure chamber 12, and the secondary flow hole 6 on the lower wall, causing the lower main jet to leave the lower wall 4. At this time, the upper main jet is still deflected downwards on the upper wall 3. Therefore, after the upper and lower main jets merge, the overall jet is deflected downwards, and the nozzle is subjected to an upward thrust component.

[0037] By controlling the closure degree of the upper control valve 9 and the lower control valve 10, continuous control of the jet vector angle can be achieved.

[0038] Figure 9The force vector angle control law of a rear-body contraction fluid thrust vector nozzle in this embodiment is presented in a box balance force measurement experiment. The results show that this rear-body contraction fluid thrust vector nozzle can achieve continuous and reliable vector deflection of the jet, with a maximum force vector angle of 6°. The horizontal axis in the figure represents the control quantity δ of the control valve. v The vertical axis represents the force vector angle θ generated by the nozzle. T The definitions of the two variables mentioned above are as follows:

[0039]

[0040]

[0041] Where S0 is the area of ​​the secondary flow inlet that controls the valve to close, S max The total area of ​​the secondary flow inlet; when δ v A value greater than 0 indicates the control quantity of the upper control valve 9, while the lower control valve 10 remains fully closed; when δ... v A value less than 0 represents the opposite of the control quantity of the lower control valve 10, while the upper control valve 9 remains fully closed; F y The vector force T generated by the jet deflection z This refers to the axial thrust generated by the nozzle.

[0042] 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. A rear-body contraction type fluid thrust vectoring nozzle, characterized in that, It includes a contraction section, a static pressure chamber, a main jet outlet, a control valve, a contraction wall, a secondary flow inlet, and secondary flow orifices on the wall. The contraction section is located above and below the static pressure chamber, the main jet outlet is located at the end of the contraction section, the contraction wall is located at the tail of the static pressure chamber, the secondary flow inlet is located on the side of the rear-body contraction fluid thrust vector nozzle, and the secondary flow orifices on the wall are arranged on the contraction wall. The static pressure chamber is connected to the secondary flow inlet and the secondary flow orifices on the wall. The secondary flow inlet is controlled by the control valve.

2. The rear-body contraction fluid thrust vectoring nozzle according to claim 1, characterized in that, The contraction section includes an upper contraction section and a lower contraction section, and the main jet outlet includes an upper main jet outlet and a lower main jet outlet. The upper main jet outlet is located at the end of the upper contraction section, and the lower main jet outlet is located at the end of the lower contraction section.

3. The rear-body contraction type fluid thrust vectoring nozzle according to claim 2, characterized in that, The contraction wall is installed between the upper main jet outlet and the lower main jet outlet; the contraction wall includes an upper wall and a lower wall, and the contraction wall has a certain angle with the main jet outlet, and the upper wall and the lower wall contract into a wedge shape towards the center of the nozzle.

4. The rear-body contraction fluid thrust vectoring nozzle according to claim 3, characterized in that, The upper and lower walls are either curved or straight inclined surfaces.

5. The rear-body contraction fluid thrust vectoring nozzle according to claim 2, characterized in that, The static pressure chamber is located between the upper contraction section, the lower contraction section, the upper wall surface, and the lower wall surface.

6. The rear-body contraction fluid thrust vectoring nozzle according to claim 5, characterized in that, A horizontal baffle is installed in the static pressure chamber to divide it into an upper static pressure chamber and a lower static pressure chamber. The secondary flow inlet includes an upper secondary flow inlet and a lower secondary flow inlet. The secondary flow orifice on the wall includes an upper wall secondary flow orifice and a lower wall secondary flow orifice. The upper static pressure chamber is connected to the upper secondary flow inlet and the upper wall secondary flow orifice, and the lower static pressure chamber is connected to the lower secondary flow inlet and the lower wall secondary flow orifice.

7. The rear-body contraction fluid thrust vectoring nozzle according to claim 6, characterized in that, The secondary flow holes on the upper wall and the lower wall are respectively arranged on the upper wall and the lower wall.

8. The rear-body contraction fluid thrust vectoring nozzle according to claim 7, characterized in that, The control valve includes an upper control valve and a lower control valve, which are used to control the upper secondary flow inlet and the lower secondary flow inlet, respectively.

9. The rear-body contraction fluid thrust vectoring nozzle according to claim 8, characterized in that, The upper control valve and the lower control valve control the closure degree of the upper secondary flow inlet and the lower secondary flow inlet, respectively, so as to control the vector deflection degree of the tail jet of the rear body contraction fluid thrust vector nozzle.

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