A vectoring jet based on self-excited sweeping oscillatory jet

Abstract

The application provides a vector nozzle based on self-excited sweeping oscillation jet flow, which comprises an airflow pipeline, a gas source, a switch valve, an exciter, a first pipeline and a second pipeline; the gas source delivers gas to the first pipeline and the second pipeline through the switch valve, and the exciter sprays gas along the first side wall or the second side plate. The application controls the opening and closing of the exciter array on one side by controlling the switch valve, when the oscillator array on one side starts to work and generates oscillation jet flow, due to the Coanda effect, the main jet flow at the nozzle outlet is deflected at a certain angle towards the side, so as to adjust the deflection direction of the main jet flow. At the same time, since the exciter is a self-excited sweeping oscillator, only less than 1% of the flow of the engine is needed to effectively control the main airflow of the engine, which provides the possibility of practical application for the engine thrust vector control by using secondary flow.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of active flow control, and particularly relates to a vectoring nozzle based on self-excited sweeping oscillatory jet. BACKGROUND

[0002] Thrust vector control (TVC) is a technique that relies on the direct conversion of the thrust direction to provide more powerful control moments, which can greatly enhance the operational effectiveness and maneuverability of fighter aircraft. In short, the thrust vectoring technology is to obtain the lateral force to drive the aircraft to turn by directly changing the thrust direction. The emergence of thrust vectoring technology makes jet aircraft, mainly fighter aircraft, have unprecedented maneuverability, or higher agility, and also obtains the short take-off ability that can take off with a shorter running distance, and further reduces or even cancels the aerodynamic rudder of the aircraft, thereby reducing the aerodynamic resistance of the aircraft and reducing the mass of the aircraft. Therefore, there is no doubt that the thrust vectoring technology is an advanced control technology for jet fighters.

[0003] The vectoring nozzle mainly has two shapes, one of which is circular in cross section (axisymmetric type), and the jet flow thereof can be deflected at a certain angle with the axis in the circumferential direction of 360°, and the vector control flexibility is higher, but the mechanism is more complex; the other is square in cross section (two-dimensional type), and the jet flow thereof can only be deflected in the up and down directions within a certain angle with the axis, and therefore is also called two-dimensional vectoring nozzle. Compared with the axisymmetric nozzle, the structure and control method thereof are simpler, and the F119 engine of the F-22 fighter aircraft has been applied.

[0004] The traditional thrust vectoring technology is to use a complex mechanical structure to realize the rotation of the engine nozzle to change the angle of the nozzle to change the direction of the jet flow to obtain the control of the thrust vector. This control method has some obvious disadvantages, for example, the complex mechanical structure increases the weight of the aircraft and the difficulty of equipment maintenance and repair; the complexity of the control system is improved; the material of the nozzle has special requirements; the change of the nozzle shape has a hysteresis effect on the control of the thrust vector; and it is not conducive to the stealth of the aircraft. Therefore, in the past 20 years, aerodynamic vectoring propulsion technology has been widely concerned by researchers all over the world. Unlike the mechanical vectoring nozzle which uses actuating hardware to guide the jet flow of the engine nozzle, the aerodynamic thrust vectoring nozzle uses secondary flow injection or induction to control the main jet flow, so as to realize the effective vector deflection of the main jet flow of the engine nozzle. Compared with the mechanical vectoring nozzle, the most intuitive difference of the aerodynamic vectoring nozzle is that it has a fixed shape and no mechanical actuating components. This scheme is considered to have the potential to reduce the mass by 60% to 70%, and has very good reliability and life expectancy.

[0005] One important approach in the field of aerodynamic vector propulsion technology is the Coanda effect. The Coanda effect is a tendency of a fluid (liquid or gas) to follow a convex surface when flowing past it. The Coanda effect is used in a Coanda nozzle to inject a secondary flow in the direction of the main flow, thereby deflecting the main flow.

[0006] The aerodynamic vector propulsion technology consumes secondary flow, which has a negative impact on the overall propulsion efficiency. The smaller the secondary flow consumption, the higher the efficiency of the aerodynamic vector propulsion control. Numerous studies have shown that compared with steady-state jet flow, the use of non-steady-state disturbance can greatly improve the control efficiency of the flow. Currently, the traditional non-steady-state fluid exciter mainly includes a synthetic jet exciter and a plasma exciter. However, the working conditions in the exhaust nozzle of an aero-engine are harsh, and the reliability of all components is extremely high. The traditional non-steady-state exciter has defects such as poor safety, low reliability, insufficient excitation strength, and difficulty in electromagnetic protection, and thus is difficult to use in actual working conditions. For example, the traditional straight jet flow needs to use a gap to inject secondary fluid, which can deflect the main flow of the engine, but consumes at least 2% of the mass flow of the engine, or even more than 5%, resulting in a large loss of engine thrust and difficulty in practical application. SUMMARY

[0007] To solve at least one of the above technical problems, the present application provides a vector nozzle based on self-excited sweeping oscillatory jet flow. A new type of secondary flow exciter is used to generate high-frequency and high-speed sweeping oscillatory jet flow at the outlet under stable inlet conditions, greatly enhancing the mixing action of the secondary excitation flow and the main flow, thereby achieving the purpose of greatly reducing the consumption of secondary flow mass flow. The purpose of the present application is achieved by the following scheme:

[0008] A vector nozzle based on self-excited sweeping oscillatory jet flow, comprising an airflow pipeline, a gas source, a switch valve, an exciter, a first pipeline, and a second pipeline.

[0009] The airflow pipeline comprises a main flow channel having a first side wall and a second side wall opposite to the first side wall. A plurality of exciters are arranged on the first side wall and the second side wall, and the exciters are self-excited sweeping oscillators. The exciters on the first side wall are in communication with the first pipeline, and the exciters on the second side wall are in communication with the second pipeline.

[0010] The gas source supplies gas to the first pipeline and the second pipeline through the switch valve, and the switch valve is adapted to open the first pipeline and close the second pipeline, or open the second pipeline and close the first pipeline.

[0011] The exciter sprays gas along the first side wall or the second side wall.

[0012] Further, a pressure regulating valve is further connected between the gas source and the switch valve.

[0013] Further, the jet direction of the exciter is tangential to the first side wall or the second side wall, or is set at an angle with the jet or the first side wall or the second side wall, and the angle is preferably ±15°.

[0014] Further, the outlet of the gas flow pipeline is set in a trumpet shape.

[0015] Further, the switch valve is a stop valve or a two-position three-way electromagnetic valve.

[0016] Further, the exciter comprises an air inlet cavity, a contraction port, a first oscillation cavity and a first jet port.

[0017] The air inlet cavity is connected with the first pipeline or the second pipeline, gas enters the exciter from the air inlet cavity, and after passing through the contraction port, the gas is accelerated to enter the first oscillation cavity, the contraction port is connected with one end of the first oscillation cavity, and the first jet port is connected with the other end of the first oscillation cavity.

[0018] The first oscillation cavity has two partition bodies symmetrically arranged with the center line of the contraction port and the first jet port as the axis of symmetry, and the first oscillation cavity is partitioned into a gas oscillation part in the middle and two gas reflux parts distributed on both sides.

[0019] Further, the first jet port is connected with the first oscillation cavity through a throat hole.

[0020] Further, the outer end of the first jet port is larger than the connection end with the throat hole.

[0021] Further, the partition body is in an "L" shape, and two right-angled edges of the partition body form the gas reflux parts with two side walls of the first oscillation cavity.

[0022] Further, the exciter further comprises a first inlet, a second inlet, a second oscillation cavity and a second jet port.

[0023] The first inlet and the second inlet are connected with the first pipeline or the second pipeline; the oscillation cavity is in a semi-elliptical shape, and the second jet port is arranged at the end close to the minor axis of the oscillation cavity; and the first inlet and the second inlet are arranged at a distance from the end of the oscillation cavity in a circular arc shape.

[0024] Further, the first duct and the second duct each comprise a bleed cavity, the gas source is an engine, the main gas flow of the engine enters the gas flow duct, and the lateral gas flow of the engine enters the bleed cavity.

[0025] Further, an annular cavity is arranged, a plurality of gas holes are arranged on the outer wall surface of the engine, the annular cavity covers the gas holes, the lateral gas flow output from the gas holes of the engine is collected by the annular cavity, and the gas flow is output to the bleed cavity through a second interface on the annular cavity.

[0026] Further, sealing rings are arranged on the two outer walls of the annular cavity in contact with the outer wall of the engine.

[0027] Further, the annular cavity is provided with a fracture, two lugs are arranged at the fracture, a locking mechanism is locked through a locking hole on the lug, and the gap between the two lugs when locked is smaller than the gap when not locked.

[0028] Further, the main flow passage and the gas flow outlet form a throat at the connection, and the exciter is located at the throat; the exciter is processed on the outer wall surface at the end of the main flow passage or on the intermediate piece by milling, and the opening of the exciter being milled is closed by clamping the outer wall surface of the main flow passage and the inner wall surface of the gas flow outlet.

[0029] The advantages of the present application compared with the prior art are that the present application provides a vector nozzle based on self-excited sweeping oscillating jet, which comprises a gas flow duct, a gas source, a switch valve, an exciter, a first duct and a second duct; the gas source delivers gas to the first duct and the second duct through the switch valve, and the exciter sprays gas along the first side wall or the second side plate. The present application controls the opening and closing of the exciter array on one side by controlling the switch valve, and when the oscillator array on one side starts to work and generates an oscillating jet, the main jet at the outlet of the nozzle is deflected at a certain angle in the direction of that side due to the Coanda effect, so as to adjust the deflection direction of the main jet. The present application uses a self-excited sweeping oscillator to generate a secondary flow, which can greatly reduce the use of engine gas flow, and only needs to use less than 1% of the engine flow to effectively control the engine main gas flow, and there is no complex mechanical control structure, which increases the reliability. It provides the possibility of practical application for using secondary flow to implement engine thrust vector control. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings illustrate exemplary embodiments of the present application and together with the general description of the application given above and the detailed description of the application given below, serve to explain the principles of the present application. These drawings are included herewith and constitute a part of this specification.

[0031] Figure 1 is a schematic diagram of a vector nozzle structure based on self-excited sweeping oscillating jet flow of the present application;

[0032] Figure 2 is Figure 1 is a partial schematic diagram in A-A direction of the present application;

[0033] Figure 3 is Figure 1 is a partial schematic diagram in B-B direction of the present application;

[0034] Figure 4 is Figure 1 is a schematic diagram of the second embodiment of the exciter of the present application;

[0035] Figure 5 is Figure 1 is a schematic diagram of the specific implementation of the vector nozzle of the present application;

[0036] Figure 6 is Figure 5 is an axial section view of the vector nozzle of the present application;

[0037] Figure 7 is Figure 5 is an engine of the vector nozzle structure of the present application;

[0038] Figure 8 is a deflection effect diagram of the traditional straight jet flow and the oscillating jet flow to guide the main airflow.

[0039] Wherein: 1, air source; 2, on-off valve; 3, pressure regulating valve; 4, first pipeline; 5, second pipeline; 6, first side wall; 7, second side wall; 8, exciter; 81, air inlet cavity; 82, contraction port; 83, first oscillating cavity; 831, gas oscillation part; 832, gas backflow part; 84, partition body; 85, throat; 86, first nozzle; 9, exciter; 91, first inlet; 92, second inlet; 93, second oscillating cavity; 94, second nozzle; 100, main jet flow; 200, first jet flow; 300, second jet flow; 301, third jet flow; 401, airflow outlet; 402, bleed air cavity; 403, main flow passage; 404, first airflow interface; 405, exciter; 406, engine; 407, annular cavity; 408, second airflow interface; 409, lug; 410, air hole. DETAILED DESCRIPTION

[0040] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related content, and are not a limitation on the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings.

[0041] It should be noted that the embodiments and features in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0042] Referring to the drawings Figure 1 The present application provides a vector nozzle based on self-excited sweeping oscillation jet, comprising an airflow duct, a gas source 1, a switch valve 2, an exciter 8, a first duct 4 and a second duct 5.

[0043] The airflow duct is used to jet high-speed airflow to the outside to propel the aircraft. In order to achieve vector control, n (n≥1) sweeping fluid oscillation exciters 8 are symmetrically arranged on the Coanda surface configuration on both sides of the nozzle outlet of the airflow duct. The fluid oscillation exciters 8 on both sides can independently generate sweeping oscillation jets of a certain frequency. When the oscillation array on one side starts to work and generates oscillation jets, due to the Coanda effect, the main jet 100 at the nozzle outlet is deflected at a certain angle to that side, thereby adjusting the deflection direction of the main jet 100. The exciter used in the present application can change the direction of the main jet within a certain angle range at a certain frequency without changing the absolute value of the speed of the main jet at the outlet under the condition that the inlet flow is stable, i.e. the inlet flow does not change. The jet forms a sweeping jet.

[0044] Specifically, the airflow duct comprises a first side wall 6 and a second side wall 7 corresponding to the first side wall 6, and a plurality of exciters 8 are arranged on the first side wall 6 and the second side wall 7. The exciters 8 on the first side wall 6 are in communication with the first duct 4, and the exciters 8 on the second side wall 7 are in communication with the second duct 5. The gas source delivers gas to the first duct 4 and the second duct 5 through the switch valve 2. The switch valve 2 has at least two modes, one of which conducts the first duct 4 and closes the second duct 5, so that the exciters 8 on the first side wall 6 in communication with the first duct 4 jet high-speed airflow to deflect the main flow through the airflow duct to the direction of the first side wall 6. The other mode of the switch valve 2 is to conduct the second duct 5 and close the first duct 4, so as to realize the deflection of the main flow to the second side wall 7. Thus, the purpose of controlling the jet direction of the vector nozzle is achieved. Of course, the switch valve 2 can also have a third mode of neither conducting the first duct 4 nor conducting the second duct 5. The switch valve 2 is preferably a stop valve or a two-position three-way electromagnetic valve.

[0045] The control structure and method of the aerodynamic vector thrust nozzle provided by the present application adopt a flow control strategy, have simple structure, high reliability and strong adaptability, do not need to use complex mechanical structure to change the shape of the nozzle, and reduce the weight of the aircraft. The change of the shape of the nozzle does not increase the drag of the aircraft, and the stealth performance of the aircraft can be significantly improved.

[0046] In a preferred embodiment, a pressure regulating valve 3 is further connected between the gas source 1 and the on-off valve 2. By controlling the pressure regulating valve 3, the inlet pressure and flow rate of the exciter 8 are regulated, so as to control the deflection angle of the main jet 100. Increasing the inlet pressure and flow rate can increase the deflection angle γ of the main jet 100. When the flow rate and flow of the fluid output by the exciter 8 increase, the influence on the main jet 100 increases, so as to cause the deflection of the jet to increase.

[0047] In one embodiment, the direction of the nozzle 86 of the exciter 8 is tangent to the first side wall 6 or the second side wall 7. The deflection angle γ of the main jet can reach the maximum under the same excitation pressure and flow rate.

[0048] In another embodiment, the direction of the nozzle of the exciter is arranged at an angle α with the first side wall 6 or the second side wall 7. The angle α is preferably ±15 degrees. By the angle design, the response law between the deflection angle γ of the main jet and the inlet pressure and flow rate can be changed.

[0049] In a further optimization scheme, the outlet of the gas flow pipe is in the shape of a horn. Specifically, the outlet presents a gradually expanding shape from the direction of the gas flow. The horn-shaped outlet can further increase the swing angle of the vector nozzle tail flow. And the gas flow is attached by using the Coanda effect. Using the Coanda co-flow control, the angle deflection range of the main jet can also be increased, and the thrust vectorization is maximized. Preferably, the shapes of the first side wall and the second side wall are both circular arcs with a radius R (R>0.1m) and an arc angle b (5°<b<70°). The position of the nozzle of the exciter is the starting position of the circular arc.

[0050] The exciter includes various forms, such as the feedback self-excited oscillator shown in FIG. 8A or the non-feedback self-excited oscillator shown in FIG. 8B. The above exciters can all use the oscillating jet exciter as the excitation device of the Coanda co-flow control to generate a jet flow with a frequency of tens of hertz to tens of thousands of hertz. Since there is no moving part or electromagnetic mechanism, the problems of wear and aging caused by the moving mechanical parts of other non-steady-state excitation devices, and the electromagnetic protection problems caused by the plasma / electromagnetic components are avoided, and the service life, safety, reliability and robustness of the device are improved. Figures 2-3 Figure 4 Specifically, the feedback self-excited oscillator provided in FIG. 8A includes an inlet cavity 81, a contraction port 82, a first oscillation cavity 83 and a first nozzle 86.

[0051] Specifically, the feedback self-excited oscillator provided in FIG. 8A includes an inlet cavity 81, a contraction port 82, a first oscillation cavity 83 and a first nozzle 86. Figures 2-3

[0052] ​​The air inlet cavity 81 is communicated with the first pipe 4 or the second pipe 5. Thus, the air flow pressurized by the pressure regulating valve 3 is introduced into the feedback self-excited oscillator. The air inlet cavity 81 is connected with the contraction port 82 through a contracted pipe. The air flow is further accelerated to enter the first oscillation cavity 83. The cross-sectional area of the oscillation cavity is much larger than that of the contraction port 82, and the air flow is high-pressure air passing through the contraction port 82. The air flow enters the oscillation cavity in a jet state. In the large space of the oscillation cavity, part of the air flow diffuses along the direction of the oscillation cavity.

[0053] The first oscillation cavity 83 is symmetrically provided with two partition bodies 84 with the center line of the contraction port 82 and the first jet port 86 as the symmetry axis. The two partition bodies 84 divide the first oscillation cavity 83 into a gas oscillation part 831 in the middle and two gas return parts 832 distributed on both sides. The gas return parts 832 form feedback channels. The partition bodies 84 are in an "L" shape, and the two right-angle edges of the partition bodies 84 and the two side walls of the first oscillation cavity 83 form the gas return parts 832. The bottom edge of the "L" shape is close to the contraction port 82. When the air flow passes through the partition bodies 84, it diffuses to the vertical edges of the partition bodies 84 and forms eddies. The eddies on both sides are difficult to be completely equal, so there must be an eddy with stronger rotation, which promotes the main air flow to deflect to the side of the eddy with stronger rotation and further strengthens the intensity of the eddy on this side, while weakening the intensity of the eddy on the other side. At the same time, due to the close flow of the main air flow to one side, the pressure at the outlet of the gas return part 832 close to this side is lower. When the main air flow passes through the inlet of the gas return part 832, due to the pressure difference, more gas will flow from the gas return part 832 on this side to the outlet of the gas return part, and compensate the pressure at the outlet, and push the main flow away from the eddy on this side. When the main air flow deflects to the other side by a larger angle, the eddy on the other side will dominate in rotation intensity, so that the main air flow is quickly attracted to the other side. The above process is repeated to realize the output of the high-frequency oscillating first jet 200 at the first jet port 86.

[0054] The first jet port 86 is connected with the first oscillation cavity 83 through the throat 85. Specifically, the fluid diffused in the first oscillation cavity is contracted through the throat 85. Since the main fluid has deflected in the oscillation cavity, the first jet 200 emitted from the throat 85 will continue the direction of the main fluid in the oscillation cavity. The outer end of the first jet port 86 is larger than the connection end with the throat 85, specifically forming a horn-shaped opening. The horn-shaped opening consistent with the jet port can increase the oscillation space of the air flow.

[0055] Attached Figure 4Another exciter 9 is provided, which is a self-excited oscillator without feedback. It comprises a first inlet 91, a second inlet 92, a second oscillation cavity 93 and a second nozzle 94.

[0056] The first inlet 91 and the second inlet 92 are connected with the first pipeline 4 or the second pipeline 5. Therefore, the flow of the second jet 300 of the first inlet 91 and the third jet 301 of the second inlet 92 is theoretically consistent.

[0057] The oscillation cavity is semi-elliptical, and the second nozzle 94 is arranged at the end of the short axis of the ellipse. The first inlet 91 and the second inlet 92 are arranged at the arc-shaped end of the oscillation cavity. Therefore, the second jet 300 flowing along the first inlet 91 and the third jet 301 flowing along the second inlet 92 will converge in the middle of the second oscillation cavity 93 and have kinetic energy moving towards the second nozzle 94. However, at this time, the arc-shaped end of the oscillation cavity forms a vacant area, and the second jet 300 or the third jet 301 will flow to the vacant area under the action of fluid pressure to form a vortex, and the third jet 301 or the second jet 300 will be sprayed out of the second nozzle 94 along its direction. When the second jet 300 or the third jet 301 forms a vortex, the third jet 301 or the second jet 300 will be affected by low pressure and deviate towards the vortex. The abundant fluid in the vortex of the second jet 300 or the third jet 301 will drive it to directly spray out of the nozzle when it returns to the second jet 300 or the third jet 301. A periodic self-excited oscillation is formed.

[0058] Referring to the drawings Figure 5 , a vector nozzle based on self-excited sweeping oscillation jet is disclosed. Referring to the drawings Figure 1 , a structural schematic diagram is disclosed, and Figure 5 , a structural schematic diagram is disclosed, and Figure 1 , a structural schematic diagram is disclosed, and Figure 5 , a structural schematic diagram is disclosed, and Figure 1 The structures of the embodiments described in the drawings can be equivalent or replaceable with each other.

[0059] Referring to the drawings Figures 5-6 , the vector nozzle comprises an air outlet 401, a bleed air cavity 402, a main flow channel 403, an air source, a switch valve, a first air flow interface 404, an exciter 405, an engine 406, an annular air cavity 407 and a second air flow interface 408. The air outlet 401 and the bleed air cavity 402 are integrally formed.

[0060] The front end of the main flow channel 403 is in the shape of a cone, and the rear end is in the shape of a regular rectangular flow channel or a cylindrical flow channel, so that the main air flow can be accelerated after passing through the front end flow channel into the rectangular or cylindrical flow channel.

[0061] The air outlet 401 in the shape of a horn is connected to the rectangular or cylindrical end of the main flow channel 403, and forms a throat at the connection. The exciter 405 is located at the throat, and by emitting oscillating air flow to the throat, the main air flow is deflected. In one embodiment, the exciter 405 is milled on the outer wall of the end of the main flow channel 403. The upper end surface of the exciter 405 is closed by abutting the end of the main flow channel 403 with the inner wall of the air outlet 401 and the air cavity 402. In another embodiment, the exciter 405 is milled in an intermediate piece, which is clamped between the inner wall of the main flow channel 403 or the air outlet 401 and the air cavity 402, and the milled opening of the exciter 405 is closed by the inner wall of the main flow channel 403 or the air outlet 401 and the air cavity 402.

[0062] The exciter generally has a total length of 8-30 mm and a height of 2-15 mm. The air cavities are distributed on both sides of the main flow channel 403, and have a large front end, and the end of the air cavity gradually narrows to the height of the exciter. The first air flow interface 404 is connected to the air cavity 402 for introducing a high-pressure air source. The air flow is further accelerated after passing through the contraction.

[0063] More than 98% of the air flow provided by the engine 406 is output through the main flow channel 403, and 0.5-2% of the air flow enters the annular cavity 407 through the air hole 410 provided on the engine, and the annular cavity 407 is provided with a second air flow interface 408, which is connected to the first air flow interface 404 through a switch valve. By controlling the on-off of the switch valve, the upper or lower exciter 405 can be selectively output to control the deflection of the main flow.

[0064] Sealing rings 411 are provided on the two outer walls of the annular cavity 407 that are in contact with the outer wall of the engine 406. The annular cavity 407 is provided with a break, and the break is provided with two lugs 409, and a gap of 0.5-5 mm is left between the two lugs 409. In a preferred embodiment, a gap of 2 mm can allow the engine to smoothly enter the annular cavity 407 and be locked relatively quickly and stably, facilitating the clamping of the engine 406 by the annular cavity 407. The two lugs 409 are locked by a locking piece, reducing the space around the annular cavity, and the sealing ring 411 is pressed against the wall of the engine 406, thereby achieving sealing. See the attached drawings. Figure 7The surface of the engine is provided with a plurality of air holes 410. The air holes are located in each compressor stator guide channel, in order to ensure that the influence of the bleed air on the engine can be ignored, it is assumed that there are n guide vane channels, each guide channel has a spacing of m, the bleed air hole has a diameter of D, and the sum of the cross-sectional areas of all the exciters in the single-sided nozzle is A. The following two relationships need to be met: 1: D < m; 2: πnD 2 / 4>10A.

[0065] Referring to the drawings Figure 8 By comparing the deflection state of the engine main jet flow when the engine adopts traditional straight jet flow and self-excited sweep type oscillating jet flow, it can be seen that when reaching 60L / min, the self-excited sweep type oscillating jet flow can already make the main jet flow of the engine produce a large deflection, and when adopting straight jet flow, even if reaching 100L / min, it cannot make the main jet flow produce a deflection angle that meets the use requirements.

[0066] In summary, the use of self-excited sweep type oscillating jet flow can make the excitation slit become a discrete excitation hole, and due to the action of the high-frequency oscillating jet flow generated by each hole, it is similar to a fan surface, so it can reduce the secondary excitation flow under the condition of similar excitation slit effect, and improve the vector efficiency.

[0067] The use of non-steady flow control strategy can effectively improve the control efficiency and reduce the consumption of secondary flow. The use of a new type of sweep type fluid oscillation exciter 9 generates tens to tens of thousands of hertz of oscillating jet flow, and the range affected by the same outlet area is larger, thereby reducing the air source consumption. The opening or closing of the single-sided exciter 9 array can be independently realized, and the inlet flow can be adjusted to realize flexible control of the deflection angle of the main jet flow 100. Moreover, since it does not have any moving parts or electromagnetic mechanisms, it avoids the problems of wear and aging caused by moving mechanical parts of other non-steady excitation devices, and the electromagnetic protection problems caused by plasma / electromagnetic components, thereby improving the service life, safety, reliability and robustness of the device.

[0068] In the description of the present specification, the description of the terms "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the present specification, the illustrative description of the above terms is not necessarily directed to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments / ways or examples. Furthermore, the skilled person in the art can combine and combine the different embodiments / ways or examples described in the present specification and the features of the different embodiments / ways or examples without contradiction.

[0069] Furthermore, the terms "first", "second", etc. are used herein for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined with "first", "second" etc. can explicitly or implicitly include at least one of such features. In the description of the application, the meaning of "plurality" is at least two, for example two, three, etc., unless explicitly and specifically defined otherwise.

[0070] Those skilled in the art will understand that the above described embodiments are merely intended to clarify the present application, and are not intended to limit the scope of the present application. Other changes or modifications can be made by those skilled in the art based on the above disclosure, and such changes or modifications are still within the scope of the present application.

Claims

1. A vector nozzle based on a self-excited swept oscillating jet, comprising an airflow duct, characterized in that: It also includes an air source, a switch valve, an actuator, a first pipeline and a second pipeline; The airflow duct includes a main channel, the main channel having a first side wall and a second side wall corresponding to the first side wall, the first side wall and the second side wall are both provided with a plurality of exciters, the exciters being self-excited swept oscillators; the exciters on the first side wall are in communication with the first channel, and the exciters on the second side wall are in communication with the second channel; The gas source delivers gas to the first pipeline and the second pipeline through the switch valve, and the switch valve is suitable for opening the first pipeline and closing the second pipeline, or opening the second pipeline and closing the first pipeline; The exciter sprays gas along the first side wall or the second side wall; The exciter is a self-excited oscillator without feedback, comprising a first inlet, a second inlet, a second oscillation cavity, and a second nozzle; the first inlet and the second inlet are both connected to the first pipe or the second pipe; the oscillation cavity is semi-elliptical, and the second nozzle is provided at the end of the oscillation cavity close to the minor axis of the ellipse; the first inlet and the second inlet are set at a distance from the arc-shaped end of the oscillation cavity; The air source is an engine, and a plurality of air holes are provided on the surface of the engine; the air holes are located in each compressor stator guide channel. Assuming there are n guide vane channels, the spacing between each guide channel is m, the diameter of the air bleed hole is D, and the sum of the cross-sectional areas of all the exciter throats in a single nozzle is A. The following two relationships need to be satisfied: 1: D <m; 2: πnD 2 / 4>10A; More than 98% of the airflow provided by the engine is output through the main channel, and 0.5%-2% of the airflow will enter the annular cavity from the air hole set on the engine. The annular cavity is provided with a second airflow interface, which is connected to the first airflow interface through a switch valve; by controlling the on and off of the switch valve, the upper or lower exciter selectively outputs airflow, thereby controlling the deflection of the main flow.

2. A vector nozzle based on a self-excited swept oscillating jet according to claim 1, characterized in that: The nozzle direction of the exciter is tangent to or at an angle to the first side wall or the second side wall.

3. The vector nozzle based on self-excited swept oscillating jet according to claim 1, characterized in that: The outlet of the air flow duct is arranged in a trumpet shape, and both sides of the outlet are arcs with a radius of R, where R>0.1m, and an arc angle b, where 5° <b< 70°。 4. The vector nozzle based on self-excited swept oscillating jet according to claim 1, characterized in that: The switch valve is a stop valve or a two-position three-way solenoid valve.

5. A vector nozzle based on a self-excited swept oscillating jet according to any one of claims 1 to 4, characterized in that: The first duct and the second duct both include an air bleed cavity, the main airflow of the engine enters the airflow duct, and the lateral airflow of the engine enters the air bleed cavity.

6. The vector nozzle based on self-excited swept oscillating jet according to claim 5, characterized in that: It comprises an annular cavity which covers the air hole, collects the lateral airflow outputted from the engine through the air hole, and outputs the airflow to the air inlet cavity through a second interface on the annular cavity.

7. The vector nozzle based on self-excited swept oscillating jet according to claim 6, characterized in that: Sealing rings are provided on the two outer walls of the annular cavity that are in contact with the outer wall of the engine.

8. The vector nozzle based on self-excited swept oscillating jet according to claim 7, characterized in that: The annular cavity is provided with a fracture, and two lugs are provided at the fracture. The locking mechanism is locked through the locking holes on the lugs. When locked, the gap between the two lugs is smaller than the gap when unlocked.

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