A pneumatic vectoring nozzle with large vector angle deflection and rapid thrust reversal function

Abstract

This invention discloses an aerodynamic vector nozzle capable of large vector angle deflection and rapid thrust reverser function, belonging to the field of aerospace vehicle engine exhaust systems. It can rapidly achieve large vector angle deflection of the main jet and thrust reverser control through the injection and cutoff of passive secondary flow, enabling multi-mode thrust switching in the aircraft propulsion system. The invention includes a main jet channel, a secondary flow channel, an expansion channel, a thrust reverser channel, and an exit channel. This nozzle controls the jet deflection solely through minor disturbances in the passive secondary flow within the secondary channel and the double-sided Coanda walls in the expansion channel, distributing the jet flow to the thrust reverser channel and the exit channel to achieve large vector angle deflection and thrust reverser function. Thrust reverser control can be completed rapidly within 0.2 seconds, with a thrust reverser coefficient reaching 0.215. This invention eliminates the need for complex mechanical moving parts and high-pressure gas source control devices, enabling rapid jet vector deflection, rapid thrust variation, and thrust reverser control. It boasts advantages such as a large deflection vector angle, fast control response, and rapid thrust reverser capability.

Description

Technical Field

[0001] This invention belongs to the field of aero-engines, and in particular to a novel control system for aero-engine exhaust systems. Specifically, it relates to an aerodynamic vector nozzle with a large vector angle deflection and rapid thrust reversal function. Background Technology

[0002] Modern warfare places increasingly higher demands on aircraft performance indicators such as strong stealth, high maneuverability, and rapid response. To improve these performance requirements, advanced nozzles with thrust reverser and thrust vectoring capabilities offer a new measure to enhance maneuverability. Aircraft employing thrust vectoring nozzles with thrust reverser functionality possess greater air combat effectiveness.

[0003] First, at high angles of attack and after stall, the efficiency of aerodynamic control surfaces is very low, or even lost. Thrust vectoring, however, can generate direct force and control torque, not only improving maneuverability at high angles of attack and effectively expanding the flight envelope, but also serving as the primary control method during post-stall maneuvers and a crucial measure for achieving them. However, while current traditional mechanical thrust vectoring technology meets operational requirements, it also has limitations, such as increased weight due to numerous components, poor sealing and maintainability, complex structure, and high cooling difficulty. These problems not only reduce engine aerodynamic performance and service life but also increase the radar cross-section of the nozzle, affecting stealth performance. Therefore, researchers have been searching for a method to deflect the jet without a large number of moving mechanical structures, and fluid thrust vectoring technology emerged as a solution. Fluid thrust vectoring technology, in principle, effectively solves the problems encountered in the application of mechanical thrust vectoring, exhibiting characteristics of simple structure, fast response, and excellent vectoring performance. Researchers worldwide have conducted extensive and in-depth research on it. Among them, the passive aerodynamic thrust vectoring nozzle, as an emerging type of aerodynamic thrust vectoring nozzle, does not require drawing air from the engine or airborne air source. Instead, it draws passive secondary flow from the environment, and rapid vector deflection of the jet stream can be achieved through the injection and cutoff of the passive secondary flow, demonstrating extremely high engineering value. Nevertheless, despite the many advantages of various aerodynamic thrust vectoring nozzles, key issues such as small vector deflection angles (not exceeding 30°) still exist, urgently requiring the search for an aerodynamic vectoring nozzle with a large vector angle.

[0004] Secondly, aircraft using conventional speed brakes or traditional mechanical thrust reversers typically need to reduce throttle to idle or wait for the mechanical thrust reversers to activate, resulting in poor deceleration performance, slow thrust reverser response, and extended valuable time for the next maneuver. If thrust reversers can be used in the air, the engine can maintain higher power, improving deceleration performance and allowing for rapid acceleration after deceleration, thus enhancing the aircraft's agility. When an aircraft is being tailed and is in a passive position, rapid deceleration and acceleration can turn the tide, potentially turning defeat into victory. At sea level, the deceleration overload achieved using thrust reversers is much higher than that achieved using speed brakes. The higher the Mach number, the greater the improvement in deceleration performance. Thrust reversers can achieve very high deceleration overloads even at supersonic speeds, which is unattainable with conventional speed brakes. Studies have shown that the deceleration time of a certain aircraft using thrust reversers is approximately 38% shorter than that using speed brakes. From the above discussion, it is clear that to further improve the stealth, agility, and maneuverability of aircraft, as well as to enable post-stall maneuvers, it is necessary to adopt aerodynamic vectoring nozzles with rapid thrust reversers and large vector angles. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes an aerodynamic vector nozzle capable of large vector angle deflection and rapid thrust reverser function. By utilizing the subtle disturbances in the passive secondary flow within the secondary channel and the deflection control of the jet stream by the double-sided Coanda walls in the expansion channel, the jet flow rate entering the thrust reverser channel and exiting the channel is allocated. This achieves large vector angle deflection and thrust reverser function, completing thrust reverser control within 0.2 seconds with a thrust reverser coefficient exceeding 0.215. It boasts advantages such as a large deflection vector angle, rapid response, and thrust reverser function, effectively improving the stealth, agility, and maneuverability of aircraft.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: an aerodynamic vector nozzle capable of large vector angle deflection and rapid thrust reversal, comprising a main flow channel, a secondary flow channel, an expansion flow channel, a thrust reversal flow channel, and an exit flow channel; the nozzle of the main flow channel is a binary rectangular nozzle, the inlet of the main flow channel is used to connect to the aircraft's power unit, the outlet of the main flow channel is connected to the inlet of the expansion flow channel, the secondary flow channel is located outside the main flow channel, the inlet of the secondary flow channel is connected to the static pressure chamber leading to the local environment, the outlet of the secondary flow channel is provided with a passive secondary flow control slot as aerodynamic constraint, connected to the inlet of the expansion flow channel, leading to the jet boundary, and a pair of rear bodies are arranged on the upper and lower sides behind the outlet of the expansion flow channel, which together with the expansion flow channel form the thrust reversal flow channel and the exit flow channel.

[0007] As a preferred technical solution, the nozzle of the main channel is a convergent two-dimensional nozzle.

[0008] As a preferred technical solution, the power device connected to the main channel is an electric duct fan or a high-pressure air source.

[0009] As a preferred technical solution, the secondary flow channels are configured in two groups along the spanwise direction outside the main flow channel and in one group along the flow direction.

[0010] As a preferred technical solution, one end of the upper and lower passive secondary flow control slots of the secondary flow channel is connected to the throat of the main flow nozzle outlet, and the other end is connected to the upper and lower expansion-type solid walls, which are used to control the back pressure on both sides of the main jet at the throat. At the same time, the upper and lower passive secondary flow control slots are at an angle to the main flow direction.

[0011] As a preferred technical solution, the expansion channel has an expanding Coanda wall in the direction from the inlet to the outlet.

[0012] As a preferred technical solution, the expansion channel forms a reverse flow channel and an outlet flow channel with the upper and lower rear bodies.

[0013] As a preferred technical solution, one end wall of the reverse flow channel is the Coanda wall of the expansion flow channel, and the other end wall is the curved wall of the rear body.

[0014] As a preferred technical solution, the nozzle configuration extends parallel along the span to form a rectangular nozzle with a large aspect ratio.

[0015] As a preferred technical solution, the nozzle has a fixed throat geometry, and the jet deflection angle is adjusted by controlling the injection and cutoff of the passive secondary flow. The flow rate of the jet entering the reverse thrust channel and the outlet channel is controlled and distributed to achieve the purpose of large vector angle deflection of the jet or jet reverse thrust.

[0016] Preferably, the present invention mainly achieves the control effect of large vector angle deflection and reverse thrust by controlling the injection and cut-off of passive secondary flow and distributing the flow rate of the jet into the outlet flow channel or the reverse thrust flow channel.

[0017] The beneficial gains of this invention are:

[0018] Compared to traditional mechanical thrust vectoring nozzles with thrust reverser capabilities and existing aerodynamic thrust vectoring nozzles, this nozzle features a secondary flow channel and an expansion flow channel at the main flow outlet. The flow rate into the outlet and thrust reverser channels can be controlled and distributed solely through the injection and cutoff of the passive secondary flow. Thrust reverser control can be completed within 0.2 seconds, achieving a thrust reverser coefficient exceeding 0.215, enabling rapid deflection at large vector angles and thrust reverser functionality. This nozzle boasts advantages such as simplified structure, easy control, rapid response, large vector deflection angle, and thrust reverser capability, providing a new approach for the design of exhaust systems for future aircraft requiring strong stealth, high maneuverability, and rapid response. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an isometric view of a nozzle provided in an embodiment of the present invention;

[0021] Figure 2 This is a front view of a nozzle provided in an embodiment of the present invention;

[0022] Figure 3 This is a schlieren image provided by an embodiment of the present invention under a pressure ratio of 1.5 when the upper throttle valve is closed and the lower throttle valve is open;

[0023] Figure 4 This is a schlieren image of the upper throttle valve closed and the lower throttle valve open under a pressure ratio of 2.0, provided by an embodiment of the present invention.

[0024] Figure 5 This is a schlieren image provided by an embodiment of the present invention under a pressure ratio of 2.5 when the upper throttle valve is closed and the lower throttle valve is open;

[0025] Figure 6 This is a schlieren image of the pressure ratio 3.0 under the condition that the upper throttle valve is closed and the lower throttle valve is open, according to an embodiment of the present invention.

[0026] Figure 7 This is a numerical simulation diagram of the upper throttle valve being closed and the lower throttle valve being open, provided in an embodiment of the present invention;

[0027] Figure 8 This is a smoke flow display diagram provided by an embodiment of the present invention when the upper throttle valve is closed and the lower throttle valve is open;

[0028] Figure 9 This is a diagram illustrating the variation of the vector angle with the opening and closing of the upper and lower throttle valves, provided by an embodiment of the present invention.

[0029] Figure 10 This is a diagram showing the variation of horizontal thrust with the opening and closing of the upper and lower throttle valves, provided by an embodiment of the present invention; that is, a diagram showing the reverse thrust effect.

[0030] Among them, 1-main flow channel; 2-lower left passive secondary flow static pressure chamber; 3-upper left passive secondary flow static pressure chamber; 6-lower passive secondary flow control seam; 7-upper passive secondary flow control seam; 8-lower expansion type solid wall; 9-upper expansion type solid wall; 10-lower reverse thrust flow channel; 11-upper reverse thrust flow channel; 12-outlet flow channel; 21-upper rear body; 22-lower rear body; 31-upper left throttle valve; 32-lower left throttle valve; 33-upper right throttle valve; 34-lower right throttle valve; 42-lower static pressure chamber partition. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0032] This invention provides a passive aerodynamic thrust vectoring nozzle with reverse thrust function, referring to... Figure 1-9 The implementation target is the thrust nozzle, including the main flow channel 1, secondary flow channel, expansion flow channel, reverse thrust flow channel 10, and outlet flow channel 12.

[0033] In this embodiment, the main channel 1 is a rectangular converging nozzle with both the inlet and outlet being rectangular, mainly used to obtain a stable rectangular jet flow field.

[0034] In this embodiment, the expansion channel and the secondary channel are the main control positions in the device. The expansion channel is mainly composed of the lower Coanda wall 8 and the upper Coanda wall 9. The secondary channel is mainly composed of the upper left passive secondary flow static pressure chamber 3, the upper right passive secondary flow static pressure chamber 5, the lower left passive secondary flow static pressure chamber 2, the lower right passive secondary flow static pressure chamber 4, the upper passive secondary flow control slot 7, the lower passive secondary flow control slot 8, the upper static pressure chamber partition 41, the lower static pressure chamber partition 42, the upper left throttle valve 31, the upper right throttle valve 33, the lower left throttle valve 32, and the lower right throttle valve 34.

[0035] In this embodiment, the upper reverse thrust channel 11 is mainly composed of the upper Coanda wall 7 and the upper rear body 21 curved wall, and the lower reverse thrust channel 10 is mainly composed of the lower Coanda wall 8 and the lower rear body 22 curved wall.

[0036] In this embodiment, the outlet flow channel 12 is composed of the upper rear body 21 and the lower rear body 22, with the wall surfaces close to the nozzle axis.

[0037] The working principle of the nozzle in this embodiment is as follows:

[0038] The large vector angle deflection method of this nozzle is the resultant force vector angle deflection method. Specifically, the jet ejected from the expansion channel outlet can be controlled to enter different channels, that is, the jet flow rate entering the reverse thrust channel and the outlet channel can be distributed. The jet ejected from the reverse thrust channel outlet forms one decomposed force vector angle, and the jet ejected from the outlet channel outlet forms another decomposed force vector angle, thus forming a resultant force vector angle. Since the jet flow rate entering the reverse thrust channel can vary from 0% to 100%, and the jet flow rate entering the outlet channel can also vary from 0% to 100%, different decomposed force vector angles can be formed, thus forming different resultant force vector angles.

[0039] When thrust vectoring is not required, the upper left throttle valve 31, upper right throttle valve 33, lower left throttle valve 32, and lower right throttle valve 34 are fully open, venting to the local environment. The jet exits from the main flow channel 1, and at the throat, the jet ejects the gas in the upper and lower static pressure chambers. Since both the upper and lower throttle valves are open, the jet remains neutral and does not deflect off the wall; the entire jet exits from the outlet flow channel 12.

[0040] In vector thrust operation, for this configuration, there are two types of deflection: upward and downward. The upward deflection works by partially or completely closing the upper left throttle valve 31 and upper right throttle valve 33, while fully opening the lower left throttle valve 32 and lower right throttle valve 34, allowing flow to the local environment. The jet exits from the main flow channel 1. At the throat, due to inconsistent passive secondary flow induction intensity, the jet deflects upward, resulting in wall-attached deflection. Part of the jet exits from the upper reverse thrust channel 11, and another part exits from the outlet channel 12, or all of it exits from the upper reverse thrust channel 11, forming vector thrust. The downward deflection works by fully opening the upper left throttle valve 31 and upper right throttle valve 33, allowing flow to the local environment, while partially or completely closing the lower left throttle valve 32 and lower right throttle valve 34. The jet is ejected from the main channel 1. At the throat, due to the inconsistent intensity of the passive secondary flow, the jet deflects downward, resulting in a wall-attached deflection phenomenon. Part of the jet is ejected from the lower reverse thrust channel 10, and another part is ejected from the outlet channel 12, or all of it is ejected from the lower reverse thrust channel 10, forming a vector thrust.

[0041] During reverse thrust operation, the upper left throttle valve 31 is fully open, the lower left throttle valve 32 is fully closed, the upper right throttle valve 33 is fully closed, and the lower right throttle valve 34 is fully open. The jet is ejected from the main flow channel 1. At the throat, due to the inconsistent ejection intensity of the left and right passive secondary flows, the left jet deflects downward and enters the lower reverse thrust channel 10, while the right jet deflects upward and enters the upper reverse thrust channel 11, thus forming reverse thrust.

[0042] This embodiment specifically includes the following working methods:

[0043] 1. Flat push state

[0044] Reference Figure 8 When the upper and lower side flow valves are fully open, the upper and lower static pressure chambers 2, 3, 4, and 5 are fully open to the local environment. The jet guides the gas in the upper and lower static pressure chambers 2, 3, 4, and 5, ensuring sufficient gas replenishment. The jet does not interact with the solid wall boundary to cause adhesion or deflection; the jet remains neutral and exits entirely from the outlet flow channel 12.

[0045] 2. Vector State

[0046] Reference Figure 3 , Figure 4 , Figure 5 , Figure 6 The internal flow of the nozzle is entirely supersonic, with pressure ratios of 1.5, 2.0, 2.5, and 3.0. Under operating conditions, the upper left throttle valve 31 and upper right throttle valve 33 are partially or completely closed, while the lower left throttle valve 32 and lower right throttle valve 34 are fully open, venting to the local environment. The jet exits from the main flow channel 1. At the throat, due to inconsistent passive secondary flow induction intensity, the jet deflects upwards, interacting with the solid wall boundary to produce a wall adhesion phenomenon. Part of the jet exits from the upper reverse thrust channel 11, and another part exits from the outlet channel 12, or all of it exits from the upper reverse thrust channel 11, forming an upward vector thrust. (Refer to...) Figure 9 The nozzle is in a state where the upper throttle valve is completely closed and the lower throttle valve is fully open. The vector angle increases from about 0° to more than 69.31°, with a maximum vector angle of 75.5° and a stabilization time of 0.2s.

[0047] The upper left throttle valve 31 and upper right throttle valve 33 are fully open, opening to the local environment, while the lower left throttle valve 32 and lower right throttle valve 34 are partially or completely closed. The jet is ejected from the main flow channel 1. At the throat, due to the inconsistent intensity of the passive secondary flow injection, the jet deflects downward and interacts with the solid wall boundary to produce a wall adhesion phenomenon. Part of the jet is ejected from the lower reverse thrust channel 10, and another part is ejected from the outlet channel 12, or all of it is ejected from the lower reverse thrust channel 10, forming a downward vector thrust.

[0048] 3. Reverse Deduction State

[0049] With the upper left throttle valve 31 fully open, the lower left throttle valve 32 fully closed, the upper right throttle valve 33 fully closed, and the lower right throttle valve 34 fully open, the jet stream exits from the main flow channel 1. At the throat, due to the inconsistent intensity of the passive secondary flow injection, it interacts with the solid wall boundary, resulting in wall adhesion. The left jet stream deflects downwards into the lower reverse thrust channel 10, and the right jet stream deflects upwards into the upper reverse thrust channel 11, forming reverse thrust; or the upper left throttle valve 31 is closed, the lower left throttle valve 32 is fully open, and the upper right throttle valve 34 is fully open. With valve 33 fully open and lower right throttle valve 34 fully closed, similarly, the left jet deflects upward into the upper reverse thrust channel 11, and the right jet deflects downward into the lower reverse thrust channel 10, forming reverse thrust; or the upper throttle valves 31 and 33 are fully closed, and the lower throttle valves 32 and 34 are fully open, with all jets exiting from the upper reverse thrust channel 11, forming reverse thrust; or the upper throttle valves 31 and 33 are fully open, and the lower throttle valves 32 and 34 are fully closed, with all jets exiting from the lower reverse thrust channel 10, forming reverse thrust. (Refer to...) Figure 10 With the upper throttle valve fully closed and the lower throttle valve fully open, the average thrust changes rapidly from 100% to -21.5% in 0.2s, and the reverse thrust coefficient reaches or exceeds 0.215.

[0050] The above description is merely a specific implementation measure of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations, substitutions, or heterogeneities that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A pneumatic vector nozzle capable of large vector angle deflection and possessing rapid thrust reversal function, characterized in that: It includes a main flow channel, a secondary flow channel, an expansion flow channel, a thrust reverser flow channel, and an outlet flow channel. The main flow channel inlet is used to connect to the aircraft's power unit, and the main flow channel outlet is connected to the expansion flow channel inlet. The secondary flow channel is located outside the main flow channel, and the secondary flow channel inlet is connected to the static pressure chamber and leads to the local environment. The secondary flow channel outlet is provided with a passive secondary flow control slot as an aerodynamic constraint, and is connected to the expansion flow channel inlet, leading to the jet boundary. A pair of rear bodies are arranged on the upper and lower sides behind the expansion flow channel outlet, which together with the expansion flow channel form the thrust reverser flow channel and the outlet flow channel.

2. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 1, characterized in that, The geometry of the nozzle is fixed. The large vector angle deflection method of the nozzle in the main flow channel is the resultant force vector angle deflection method. By controlling the flow rate of the jet entering the reverse thrust channel and the outlet channel, different decomposed force vector angles are achieved, thereby forming different large-angle resultant force vector angles.

3. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 1, characterized in that, The nozzle has a fixed geometry. The jet deflection angle is adjusted by controlling the injection and cutoff of the passive secondary flow. The flow rate of the distributed jet into the reverse thrust channel and the outlet channel is controlled to achieve the purpose of rapid jet reverse thrust.

4. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 1, characterized in that: The power unit connected to the main channel is an electric ducted fan, a high-pressure air source, a turbojet engine, a turbofan engine, or a rocket engine.

5. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 1, characterized in that: The nozzle of the main channel is a convergent nozzle, a convergent-divergent nozzle, a binary nozzle, an axisymmetric nozzle, or a heterogeneous nozzle.

6. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 1, characterized in that: The secondary flow channels are configured as one or more groups along the spanwise direction outside the main flow channel, and as one or more groups along the flow direction.

7. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 3, characterized in that: The passive secondary flow control slots on the upper and lower sides of the secondary flow channel are connected at one end to the throat of the main flow nozzle outlet and at the other end to the upper and lower expansion-type solid walls. They are used to control the back pressure on both sides of the main jet at the throat. At the same time, the passive secondary flow control slots on the upper and lower sides are parallel to or at an angle to the main flow direction.

8. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 3, characterized in that: The passive secondary flow static pressure chamber in the secondary flow channel is connected to a throttle valve at one end and a passive secondary flow control slit at the other end, which is used to provide a stable and controllable environmental back pressure for the nozzle.

9. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 1, characterized in that: The expansion channel has an expanding Coanda wall in the direction from the inlet to the outlet. The Coanda wall is a combination of multiple curved walls or inclined straight walls with different curvatures.

10. A pneumatic vector nozzle with rapid reverse thrust function capable of large vector angle deflection according to claim 1, characterized in that: The expansion channel, together with the upper and lower rear bodies, forms a reverse thrust channel and an outlet channel. The tangent angle of the outlet of the reverse thrust channel forms different included angles with the nozzle axis, ranging from 0° to 180°. The wall surface of the outlet channel near the nozzle axis is one or a combination of expansion, contraction, and parallel.

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