Pneumatic thrust vectoring nozzle capable of deflecting at large vector angle and having quick thrust reversing function

Abstract

The invention discloses a pneumatic thrust vectoring nozzle capable of deflecting at a large vector angle and having a quick thrust reversion function, belongs to the field of aerospace craft engine exhaust systems, and can quickly realize main jet flow large vector angle deflection and thrust reversion control through injection and cutoff of passive secondary flow to achieve thrust multi-mode switching of a propulsion system of an aircraft. The runner comprises a main runner, a secondary runner, an expansion runner, a reverse thrust runner and an outlet runner. According to the jet pipe, deflection control is conducted on jet flow only through small disturbance of passive secondary flow in the secondary flow channel and Coanda wall faces on the two sides in the expansion flow channel, the jet flow quantity of the reverse thrust flow channel and the outlet flow channel is distributed, the large vector angle deflection and the reverse thrust function of the jet flow are achieved, reverse thrust control can be rapidly completed within 0.2 s, and the reverse thrust coefficient reaches 0.215. Complex mechanical moving parts and high-pressure air source control devices are not needed, jet flow vector rapid deflection, rapid thrust change and reverse thrust control can be achieved, and the jet flow vector control device has the advantages of being large in deflection vector angle, rapid in control response, capable of achieving rapid reverse thrust and the like.

Description

Technical Field

[0001] The present invention belongs to the field of aero-engines, and in particular to a novel control system applied to an aero-engine exhaust system, and specifically relates to an aerodynamic vector nozzle capable of large vector angle deflection and having a rapid reverse thrust function. Background Art

[0002] Modern warfare places higher and higher demands on aircraft performance indicators such as strong stealth, high maneuverability, and fast response. In order to improve the above-mentioned index requirements, advanced nozzles with reverse thrust and thrust vectoring functions provide a new measure to improve maneuverability. Aircraft using thrust vectoring nozzles with reverse thrust functions have 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. However, vector thrust can generate direct force and control torque, which can not only improve the maneuverability at high angles of attack and effectively expand the flight envelope, but also is the main control means during post-stall maneuvers and an important measure to achieve post-stall maneuvers. However, although the current traditional mechanical thrust vectoring technology meets the needs of current service, it also has some limitations, such as the increase in weight due to the large number of parts, poor sealing and maintainability, complex structure and high cooling difficulty. These problems not only reduce the aerodynamic performance and service life of the engine, but also increase the radar reflection area of ​​the nozzle, affecting the stealth performance. Therefore, people have been looking for a method to deflect the jet without a large number of active mechanical structures, and fluid thrust vectoring technology came into being. In principle, fluid thrust vectoring technology can well solve the problems raised in the application process of mechanical thrust vectoring, showing the characteristics of simple structure, fast response and excellent vector performance. Researchers from various countries have conducted extensive and in-depth research on it. Among them, the passive aerodynamic thrust vector nozzle is a new type of aerodynamic thrust vector nozzle. Since it does not need to draw air from the engine or the airborne air source, it only draws passive secondary flow from the environment, and can achieve rapid vector deflection of the jet through the injection and truncation of the passive secondary flow, showing extremely high engineering value. Despite the many advantages of various types of aerodynamic thrust vector nozzles, there are still key problems such as small vector deflection angle (no more than 30°), and there is an urgent need to find an aerodynamic vector nozzle with a large vector angle.

[0004] Secondly, when using conventional speed brakes or traditional mechanical reverse thrust, the aircraft generally needs to slow down the throttle or wait for the mechanical reverse thrust device to be activated. This not only results in poor deceleration performance and slow reverse thrust response, but also prolongs the precious time for the next maneuver. If reverse thrust can be used in the air, the engine can maintain a large power at this time, which not only improves the deceleration performance, but also allows rapid acceleration after deceleration, and improves the agility of the aircraft. When the aircraft is in a passive position due to tail pursuit, rapid deceleration and acceleration can turn the passive into active, and may turn defeat into victory. At sea level, the deceleration overload achieved by using reverse thrust is much higher than that achieved by using speed brakes. The larger the Mach number, the greater the improvement in deceleration performance. Reverse thrust can also achieve a very high deceleration overload at supersonic speed, which is not achievable by conventional speed brakes. According to research, the deceleration time of a certain aircraft using reverse thrust is about 38% shorter than that using speed brakes. From the above discussion, it can be seen that in order to further improve the stealth, agility and maneuverability of the aircraft, and to enable the aircraft to have the ability to maneuver over stall, it is necessary to use an aerodynamic vector nozzle with a fast reverse thrust function and a large vector angle. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes an aerodynamic vector nozzle with large vector angle deflection and fast reverse thrust function. The jet is deflected and controlled by the tiny disturbance of the passive secondary flow in the secondary flow channel and the Coanda walls on both sides in the expansion flow channel, thereby distributing the jet flow entering the reverse thrust flow channel and the outlet flow channel, realizing large vector angle deflection and reverse thrust of the jet, and can complete the reverse thrust control within 0.2s. The reverse thrust coefficient reaches more than 0.215. It has the advantages of large deflection vector angle, fast response and reverse thrust function, and can effectively improve the stealth, agility and maneuverability of the aircraft.

[0006] To achieve the above-mentioned invention objectives, the present invention adopts the following technical solutions: an aerodynamic vector nozzle with a fast reverse thrust function that can deflect at a large vector angle, comprising a main flow channel, a secondary flow channel, an expansion flow channel, a reverse thrust flow channel and an outlet flow channel; the nozzle of the main flow channel is a two-dimensional rectangular nozzle, the main flow channel inlet is used to connect to the power device of the aircraft, the main flow channel outlet is connected to the expansion flow channel inlet, the secondary flow channel is arranged on the outside of the main flow channel, the secondary flow channel inlet is connected to the static pressure chamber and leads to the local environment, a passive secondary flow control seam is arranged at the secondary flow channel outlet as an aerodynamic constraint, which is connected to the expansion flow channel inlet and leads to the jet boundary, a pair of rear bodies are arranged on the upper and lower sides behind the expansion flow channel outlet, and together with the expansion flow channel form a reverse thrust flow channel and an outlet 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 ducted fan or a high-pressure air source.

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

[0010] As a preferred technical solution, one end of the upper and lower passive secondary flow control slits of the secondary flow channel is connected to the throat of the mainstream nozzle outlet, and the other end is connected to the upper and lower expansion solid walls, which is 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 slits have an angle with the mainstream direction.

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

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

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

[0014] As a preferred technical solution, the nozzle configuration extends in parallel along the span direction 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, and the flow rate of the jet entering the reverse thrust flow channel and the outlet flow channel is controlled and distributed, so as to achieve the purpose of large vector angle deflection of the jet or jet reverse thrust.

[0016] Preferably, the present invention mainly controls the injection and cutoff of the passive secondary flow to distribute the flow of the jet into the outlet flow channel or the reverse thrust flow channel, thereby quickly achieving the control effect of large vector angle deflection and reverse thrust.

[0017] The beneficial benefits of the present invention are: Compared with the traditional mechanical thrust vector nozzle with reverse thrust function and the existing aerodynamic vector nozzle, the secondary flow channel and the expansion flow channel are arranged at the outlet of the main flow channel. Only by injecting and cutting off the passive secondary flow, the flow rate of the jet entering the outlet flow channel and the reverse thrust flow channel can be controlled and distributed. The reverse thrust control can be completed within 0.2s, and the reverse thrust coefficient reaches more than 0.215, realizing large vector angle rapid deflection and reverse thrust function. The nozzle has the advantages of simple structure, simple control, fast response, large vector deflection angle and reverse thrust function, which provides a new form for the design of future aircraft exhaust systems with strong stealth, high maneuverability, fast response and other performance indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the embodiments described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 is an isometric view of a nozzle provided by an embodiment of the present invention; Figure 2 is a front view of a nozzle provided by an embodiment of the present invention; Figure 3 This is a Schlieren diagram under a pressure ratio of 1.5 when the upper throttle valve is closed and the lower throttle valve is opened, provided by an embodiment of the present invention; Figure 4 This is a schlieren diagram under a pressure ratio of 2.0 when the upper throttle valve is closed and the lower throttle valve is opened, provided by an embodiment of the present invention; Figure 5 This is a Schlieren diagram under a pressure ratio of 2.5 when the upper throttle valve is closed and the lower throttle valve is opened, provided by an embodiment of the present invention; Figure 6 This is a schlieren diagram under a pressure ratio of 3.0 when the upper throttle valve is closed and the lower throttle valve is opened, provided by an embodiment of the present invention; Figure 7 It is a numerical simulation diagram when the upper throttle valve is closed and the lower throttle valve is opened provided by an embodiment of the present invention; 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 opened; Fig. 9 is a diagram showing 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; Fig.10 It is a diagram showing the change 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 reverse thrust effect diagram; Among them, 1-main 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 slit; 7-upper passive secondary flow control slit; 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 DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0021] The embodiment of the present invention provides a passive aerodynamic thrust vector nozzle with reverse thrust function, referring to Figure 1-9 The implementation object is a thrust nozzle, including a main flow channel 1, a secondary flow channel, an expansion flow channel, a reverse thrust flow channel 10, and an outlet flow channel 12.

[0022] In this embodiment, the main channel 1 is a rectangular convergent nozzle, and both the inlet and the outlet are rectangular, which is mainly used to obtain a stable rectangular jet flow field.

[0023] In this embodiment, the expansion flow channel and the secondary flow channel are the main control positions in the device. The expansion flow channel is mainly composed of the lower Coanda wall 8 and the upper Coanda wall 9. The secondary flow 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 seam 7, the lower passive secondary flow control seam 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.

[0024] In this embodiment, the upper reverse thrust flow channel 11 is mainly composed of the upper Coanda wall 7 and the curved wall of the upper rear body 21 , and the lower reverse thrust flow channel 10 is mainly composed of the lower Coanda wall 8 and the curved wall of the lower rear body 22 .

[0025] In this embodiment, the outlet flow channel 12 is composed of the wall surfaces of the upper rear body 21 and the lower rear body 22 close to the nozzle axis.

[0026] The working principle of the nozzle in this embodiment is: The large vector angle deflection method of the nozzle is a synthetic force vector angle deflection method. Specifically, the jet ejected from the outlet of the expansion channel can enter different channels through control, that is, the jet flow entering the reverse thrust channel and the outlet channel can be distributed, the jet ejected from the outlet of the reverse thrust channel forms a decomposition force vector angle, and the jet ejected from the outlet of the outlet channel forms another decomposition force vector angle, thereby jointly forming a synthetic force vector angle. Since the jet flow entering the reverse thrust channel can be changed from 0%-100%, the jet flow entering the outlet channel can also be changed from 0%-100%, so different decomposition force vector angles can be formed, thereby forming different synthetic force vector angles.

[0027] When the vector thrust is not required, 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 are fully opened to the local environment. The jet is ejected from the main flow channel 1, and the upper and lower static pressure chamber gases are ejected at the throat due to the jet ejection effect. Since the upper and lower throttle valves are both in the open state, the jet remains neutral, and the wall attachment deflection phenomenon does not occur. The jet is ejected from the outlet flow channel 12.

[0028] In the vector thrust condition, for this configuration, it is divided into upper deflection and lower deflection. The working principle of the upper deflection is that the upper left throttle valve 31 and the upper right throttle valve 33 are partially or completely closed, and the lower left throttle valve 32 and the lower right throttle valve 34 are fully opened to the local environment. The jet is ejected from the main channel 1. At the throat, due to the inconsistent passive secondary flow injection intensity, the jet is deflected upward, and the wall attachment deflection phenomenon occurs. Part of the jet is ejected from the upper reverse thrust channel 11, and the other part is ejected from the outlet channel 12, or all of it is ejected from the upper reverse thrust channel 11, forming vector thrust. The working principle of the lower deflection is that the upper left throttle valve 31 and the upper right throttle valve 33 are fully opened to the local environment, and the lower left throttle valve 32 and the 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 passive secondary flow injection intensity, the jet is deflected downward, and the wall attachment deflection phenomenon occurs. Part of the jet is ejected from the lower reverse thrust channel 10, and the other part is ejected from the outlet channel 12, or all of the jet is ejected from the lower reverse thrust channel 10, forming a vector thrust.

[0029] In reverse thrust conditions, the upper left throttle valve 31 is fully opened, 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 opened, and the jet is ejected from the main channel 1. At the throat, due to the inconsistent injection intensity of the left and right passive secondary flows, the left jet is deflected downward into the lower reverse thrust channel 10, and the right jet is deflected upward into the upper reverse thrust channel 11, forming reverse thrust.

[0030] This embodiment specifically includes the following working modes: 1. Pushing state Reference Figure 8 When the upper and lower side flow valves are fully opened, the upper and lower static pressure chambers 2, 3, 4, 5 are completely open to the local environment. The jets eject the gas in the upper and lower static pressure chambers 2, 3, 4, 5, and the gas can be fully replenished. The jets do not interact with the solid wall boundary to produce wall attachment or deflection, and the jets remain neutral, and all the jets are ejected from the outlet flow channel 12.

[0031] 2. Vector state Reference Figure 3 , Figure 4 , Figure 5 , Figure 6The flow in the nozzle is all supersonic, with pressure ratios of 1.5, 2.0, 2.5, and 3.0, respectively. The working conditions are that the upper left throttle valve 31 and the upper right throttle valve 33 are partially or completely closed, and the lower left throttle valve 32 and the lower right throttle valve 34 are fully opened, leading to the local environment. The jet is ejected from the main channel 1. At the throat, due to the inconsistent passive secondary flow injection intensity, the jet is deflected upward, and interacts with the solid wall boundary to produce wall attachment. Part of the jet is ejected from the upper reverse thrust channel 11, and the other part is ejected from the outlet channel 12, or all of it is ejected from the upper reverse thrust channel 11, forming an upward vector thrust, refer to Fig. 9 The upper throttle valve of the nozzle is completely closed, and the lower throttle valve is fully opened. The vector angle increases from about 0° to above 69.31°. The maximum vector angle is 75.5°, and the stable time is 0.2s.

[0032] The upper left throttle valve 31 and the upper right throttle valve 33 are fully opened to the local environment, and the lower left throttle valve 32 and the lower right throttle valve 34 are partially or completely closed. The jet is ejected from the main channel 1. At the throat, due to the inconsistent passive secondary flow injection intensity, the jet is deflected downward and interacts with the solid wall boundary to produce a wall attachment phenomenon. A part of the jet is ejected from the lower reverse thrust channel 10, and the other part is ejected from the outlet channel 12, or all of the jet is ejected from the lower reverse thrust channel 10, forming a downward vector thrust.

[0033] 3. Reverse push state The upper left throttle valve 31 is fully opened, 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 opened. The jet is ejected from the main channel 1. At the throat, due to the inconsistent passive secondary flow injection intensity, the jet interacts with the solid wall boundary to produce a wall attachment phenomenon. The left jet is deflected downward into the lower reverse thrust channel 10, and the right jet is deflected upward into the upper reverse thrust channel 11 to form a reverse thrust; or the upper left throttle valve 31 is closed, the lower left throttle valve 32 is fully opened, and the upper right throttle valve 33 is fully opened. The valve 33 is fully opened and the lower right throttle valve 34 is fully closed. Similarly, the left jet is deflected upward into the upper reverse thrust channel 11, and the right jet is deflected downward into the lower reverse thrust channel 10, forming reverse thrust; or the upper throttle valves 31 and 33 are fully closed, the lower throttle valves 32 and 34 are fully opened, and the jets are all ejected from the upper reverse thrust channel 11, forming reverse thrust; or the upper throttle valves 31 and 33 are fully opened, the lower throttle valves 32 and 34 are fully closed, and the jets are all ejected from the lower reverse thrust channel 10, forming reverse thrust. Fig.10 The upper throttle valve of the nozzle is completely closed, and the lower throttle valve is fully open. The average horizontal thrust changes rapidly from 100% thrust to -21.5% thrust. The stable reversing time is 0.2s, and the reverse thrust coefficient reaches or exceeds 0.215.

[0034] The above is only a specific implementation measure of the present invention, but the protection scope of the present invention is not limited thereto. Any changes, replacements or isomerizations that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An aerodynamic vector nozzle capable of large vector angle deflection and having a rapid reverse thrust function, characterized in that: It comprises a main flow channel, a secondary flow channel, an expansion flow channel, a reverse thrust flow channel and an outlet flow channel; the main flow channel inlet is used to connect to the power device of the aircraft, the main flow channel outlet is connected to the expansion flow channel inlet, the secondary flow channel is arranged on the outside of the main flow channel, the secondary flow channel inlet is connected to the static pressure chamber and leads to the local environment, a passive secondary flow control seam is arranged at the secondary flow channel outlet as an aerodynamic constraint, connected to the expansion flow channel inlet, and leads to the jet boundary, a pair of rear bodies are arranged on the upper and lower sides behind the expansion flow channel outlet, and together with the expansion flow channel form the reverse thrust flow channel and the outlet flow channel.

2. The aerodynamic vector nozzle capable of large vector angle deflection and having rapid reverse thrust function according to claim 1, characterized in that: The nozzle has a fixed geometric surface, and the large vector angle deflection method of the nozzle of the main channel is a synthetic force vector angle deflection method. By controlling the jet flow rate entering the reverse thrust channel and the outlet channel, different decomposed force vector angles are achieved, thereby forming different large-angle synthetic force vector angles.

3. The aerodynamic vector nozzle capable of large vector angle deflection and having rapid reverse thrust function according to claim 1, characterized in that: The nozzle has a fixed geometrical surface, and the jet deflection angle is adjusted by controlling the injection and cutoff of the passive secondary flow, and the flow rate of the jet entering the reverse thrust flow channel and the outlet flow channel is controlled and distributed, so as to achieve the purpose of rapid jet reverse thrust.

4. The aerodynamic vector nozzle capable of large vector angle deflection and having rapid reverse thrust function according to claim 1, characterized in that: The power device connected to the main flow channel is one or more of an electric ducted fan, a high-pressure air source, an aviation engine such as a turbojet engine, a turbofan engine, or a rocket engine.

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

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

7. The aerodynamic vector nozzle capable of large vector angle deflection and having rapid reverse thrust function according to claim 3, characterized in that: One end of the upper and lower passive secondary flow control slits of the secondary flow channel is connected to the throat of the mainstream 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 slits are parallel to or at an angle to the mainstream direction.

8. The aerodynamic vector nozzle capable of large vector angle deflection and having rapid reverse thrust function according to claim 3, characterized in that: One end of the passive secondary flow static pressure chamber in the secondary flow channel is connected to the throttle valve, and the other end is connected to the passive secondary flow control seam, so as to provide a stable and controllable environmental back pressure for the nozzle.

9. The aerodynamic vector nozzle capable of large vector angle deflection and having rapid reverse thrust function according to claim 1, characterized in that: The expansion channel has an expansion-type Coanda wall from the inlet to the outlet, and the Coanda wall is a plurality of sections of curved walls with different curvatures or inclined straight walls or a combination thereof.

10. The aerodynamic vector nozzle capable of large vector angle deflection and having rapid reverse thrust function according to claim 1, characterized in that: The expansion flow channel and the rear upper and lower rear bodies form a reverse thrust flow channel and an outlet flow channel. The tangent angle of the reverse thrust flow channel outlet forms different angles with the nozzle axis, and the value range is 0°~180°. The wall surface of the outlet flow channel close to the nozzle axis is one or a combination of expansion, contraction, and parallel.

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