A high stealth structure of an exhaust system with an adjustable radar shielding grid

Abstract

The application belongs to the field of stealth engine design and discloses a high-stealth structure of an exhaust system with an adjustable radar shielding grid, which comprises a round-to-square section, a converging section, an expanding section and a stealth adjusting mechanism; the stealth adjusting mechanism comprises a power component, a cylindrical connecting rod, an adjustable sliding block and a radar shielding grid; the radar shielding grid is detachably connected with a horizontally arranged grid connecting shaft; the adjustable sliding block and the grid connecting shaft are in sliding fit with the side wall; when it is necessary to weaken the radar scattering signals in the rear cavity of the engine, the number of the radar shielding grids can be adjusted so that part of the radar waves cannot enter the cavity of the engine; when it is necessary to adjust the refraction attenuation times of the radar waves in the complex cavity of the engine or the incident and reflection positions of the radar waves, the left-right adjustable function of the radar shielding grid can be started to control the refraction times of the radar waves of the engine and the incident and reflection positions of the refraction waves, so that the radar scattering signals of the airplane and the rear of the engine can be obviously reduced.

Description

Technical Field

[0001] This application belongs to the field of stealth engine design, and specifically relates to a high stealth structure for an exhaust system with an adjustable radar-shielding grille. Background Technology

[0002] With the increasing demands for radar stealth of aero engines from new-generation stealth aircraft, and given that radar scattering generated by the engine's rear cavity accounts for more than 95% of the total rearward radar scattering of the aircraft, the conventional stealth measures to improve the engine's rearward radar stealth capability are radar reshaping and radar absorbing materials.

[0003] When conventional radar stealth measures for engines cannot meet the operational requirements of aircraft to significantly reduce low-frequency radar scattering signals, the current stealth modification of engine internal cavity components is not sensitive to low-frequency radar scattering signals. At the same time, there is a lack of radar absorbing materials that are resistant to medium and high temperatures and have significant suppression effects on low-frequency signals. Therefore, the ability of conventional radar stealth measures to suppress radar stealth signals in the low-frequency band is limited.

[0004] To address the challenge of limited radar signal suppression measures in the L, S, and C low-frequency bands, a high-stealth structure with an adjustable radar shielding grille and a simple exhaust system is needed to reduce low-frequency radar stealth signals. Summary of the Invention

[0005] The purpose of this application is to provide a high stealth structure for an exhaust system with an adjustable radar-shielding grille, in order to solve the problem that the stealth modification of engine internal cavity components is not sensitive to low-frequency radar scattering signals in the prior art.

[0006] The technical solution of this application is: a high stealth structure for an exhaust system with an adjustable radar shielding grille, comprising a circular-to-square section, a converging section, an expanding section, and a stealth adjustment mechanism; the front end of the circular-to-square section is connected to the engine, and the converging section is connected between the circular-to-square section and the expanding section; the stealth adjustment mechanism includes a power component, a cylindrical connecting rod, an adjustable sliding block, and a radar shielding grille; the power component is disposed on the circular-to-square section, and one end of the cylindrical connecting rod is fixedly connected to the output end of the power component, and the other end is fixedly connected to the adjustable sliding block;

[0007] The expansion section includes a sidewall, an upper expansion adjustment piece, and a lower expansion adjustment piece. There are two sets of sidewalls, both of which are vertically arranged. The upper and lower expansion adjustment pieces are arranged vertically and are located between the two sets of sidewalls.

[0008] The sidewall has a horizontally arranged first sliding groove, and the adjustable sliding block slides horizontally within the first sliding groove. The radar shielding grid is vertically arranged between the upper expansion adjustment plate and the lower expansion adjustment plate. The radar shielding grid is detachably connected to a horizontally arranged grid connecting shaft. The sidewall has a horizontally arranged second sliding groove that communicates with the first sliding groove. The grid connecting shaft slides horizontally within the second sliding groove, and both ends of the grid connecting shaft are connected to the adjustable sliding block.

[0009] Preferably, the power component includes a fixed mounting base, an actuating cylinder, and a pull rod; the fixed mounting base is fixedly connected to the arc-shaped outer side wall of the round-to-square section, the actuating cylinder is hinged to the fixed mounting base, the piston rod of the actuating cylinder is hinged to the pull rod, and the end of the pull rod away from the actuating cylinder is fixedly connected to the cylindrical connecting rod.

[0010] Preferably, the grid connecting shaft is provided with a plurality of detachable connecting parts at intervals along its axial direction, each of the detachable connecting parts being detachably connected to the radar shielding grid, and the number of radar shielding grids is 4-30.

[0011] Preferably, the convergence section includes two sets of convergence adjustment plates arranged vertically, with the convergence adjustment plates abutting against the sidewall.

[0012] Preferably, the outlet ends of the sidewall, the upper expansion adjustment plate, and the lower expansion adjustment plate are all serrated. The height of the sidewall is greater than the height of the upper expansion adjustment plate, the lower expansion adjustment plate, and the convergence adjustment plate. The angle range of the outlet end of the sidewall is 40° to 70°, and the angle range of the outlet ends of the upper and lower expansion adjustment plates is 100° to 130°.

[0013] Preferably, the side wall is provided with a cooling channel, which is the same as the cooling channel in the round-to-square section, and the inner side of the side wall is provided with a cooling hole that communicates with the main gas passage.

[0014] This application discloses a high-stealth structure for an exhaust system with an adjustable radar-shielding grille, comprising a circular-to-square section, a converging section, an expanding section, and a stealth adjustment mechanism. The stealth adjustment mechanism includes a power component, a cylindrical connecting rod, an adjustable sliding block, and a radar-shielding grille. A horizontally arranged grille connecting shaft is detachably connected to the radar-shielding grille. The adjustable sliding block and the grille connecting shaft slide in cooperation with the side wall. When it is necessary to reduce the radar scattering signal in the engine's rearward cavity, the number of radar-shielding grilles can be adjusted so that the spacing between the radar-shielding grilles is smaller than the wavelength of the incident electromagnetic wave, preventing some radar waves from entering the engine cavity. When it is necessary to adjust the number of radar wave refractions or the position of radar wave incident and reflection in the complex engine cavity, the left-right adjustable function of the radar-shielding grille can be activated to control the number of radar wave refractions and the position of incident and reflected wave refractions, thereby significantly reducing the radar scattering signal in the rearward direction of the aircraft and engine. Attached Figure Description

[0015] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0016] Figure 1 This is an isometric drawing of the overall structure of this application;

[0017] Figure 2 This is a schematic diagram of the structure of the radar shielding grid of this application when it reaches the front end of its travel.

[0018] Figure 3 This is a schematic diagram of the structure of the radar shielding grid when it reaches the last end of its travel.

[0019] 1. Round to square section; 2. Fixed mounting base; 3. Actuating cylinder; 4. Tie rod; 5. Cylindrical connecting rod; 6. Adjustable sliding block; 7. Side wall; 8. Converging adjustment plate; 9. Upper expansion adjustment plate; 10. Lower expansion adjustment plate; 11. Grid connecting shaft; 12. Radar shielding grid. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0021] A high-stealth structure for an exhaust system with an adjustable radar-shielding grille, used on a vectoring nozzle, such as... Figure 1 As shown, it includes a circular-to-square section 1, a converging section, an expanding section, and a stealth adjustment mechanism. The front end of the circular-to-square section 1 is connected to the engine. The converging section connects the circular-to-square section 1 and the expanding section. The circular-to-square section 1, the converging section, and the expanding section form the main combustion passage for discharging combustion gases from inside the engine. The inlet end of the main combustion passage is the front end of the nozzle, and the outlet end is the rear end of the nozzle.

[0022] The stealth adjustment mechanism includes a power component, a cylindrical connecting rod 5, an adjustable sliding block 6, and a radar shielding grid 12. The power component, the cylindrical connecting rod 5, and the adjustable sliding block 6 are all symmetrically arranged in two sets through the middle of the main gas passage. The power component is located on the round-to-square section 1. One end of the cylindrical connecting rod 5 is fixedly connected to the output end of the power component, and the other end is fixedly connected to the adjustable sliding block 6.

[0023] The expansion section includes a side wall 7, an upper expansion adjustment piece 9, and a lower expansion adjustment piece 10. There are two sets of side walls 7, both of which are vertically arranged. The upper expansion adjustment piece 9 and the lower expansion adjustment piece 10 are arranged vertically and positioned between the two sets of side walls 7.

[0024] A first horizontally arranged sliding groove is provided on the outer side of the side wall 7. An adjustable sliding block 6 slides horizontally and fits into the first sliding groove. The radar shielding grid 12 is vertically arranged between the upper expansion adjustment plate 9 and the lower expansion adjustment plate 10. The shape of the radar shielding grid 12 can be fan-shaped, curved cone, etc. A horizontally arranged grid connecting shaft 11 is detachably connected to the radar shielding grid 12. A second horizontally arranged sliding groove is provided on the side wall 7 and communicates with the first sliding groove. The grid connecting shaft 11 slides horizontally and fits into the second sliding groove. Both ends of the grid connecting shaft 11 are connected to the adjustable sliding block 6.

[0025] The radar shielding grille 12 has multiple sets and is evenly distributed along the length of the grille connecting axis 11. As the number of radar shielding grilles 12 increases, the spacing between the radar shielding grilles 12 becomes smaller. The spacing between adjacent radar shielding grilles 12 or between the radar shielding grille 12 and the side wall 7 determines the wavelength of the radar wave. When the spacing between the radar shielding grilles 12 is smaller than the wavelength of the incident electromagnetic wave, the radar wave cannot enter the engine cavity to form a strong scattering source. The comprehensive suppression effect of radar stealth signal can be achieved by controlling the adjustable position of the radar shielding grille 12.

[0026] When it is necessary to reduce the radar scattering signal into the engine cavity, the number of radar shielding grids 12 can be adjusted so that the spacing between the radar shielding grids 12 is smaller than the wavelength of the incident electromagnetic wave, so that some radar waves cannot enter the engine cavity.

[0027] When it is necessary to adjust the number of radar wave refractions or the position of radar wave incident and reflection within the complex cavity of the engine, the left and right adjustable function of the radar shielding grid 12 can be activated. Specifically, the cylindrical connecting rod 5 is moved along the axis of the main gas passage by two sets of power components in a synchronous manner. The cylindrical connecting rod 5 drives the grid connecting shaft 11 and the radar shielding grid 12 to move towards or away from the rear end of the nozzle, thereby controlling the number of radar wave refractions and the position of incident and reflected waves, so as to significantly reduce the radar scattering signal of the aircraft and engine.

[0028] The adjustable sliding block 6 is arranged along the axial direction of the main gas passage, and the grille connecting shaft 11 is arranged along the transverse direction of the nozzle. The adjustable sliding block 6 and the grille connecting shaft 11 have the same stroke. When the grille connecting shaft 11 is in the position... Figure 2 When in position, the radar shielding grille 12 is closest to the front end of the nozzle; when the grille connecting shaft 11 is in position... Figure 3 When positioned, the radar shielding grille 12 is closest to the rear end of the nozzle.

[0029] In summary, by controlling the spacing, number, and position of the radar shielding grilles 12, when the wavelength of the low-frequency radar wave is adjusted to be greater than the size of the incident engine cavity structure, the radar wave cannot enter the engine cavity. Furthermore, by adjusting the position of the radar shielding grilles 12, the incident position and direction of the radar wave can be changed, which greatly reduces the radar scattering signal behind the engine. This compensates for the shortcomings of conventional radar stealth measures and solves the problem of poor radar signal suppression capability in the L, S, and C low-frequency bands of conventional radar stealth measures behind the engine. At the same time, it has the advantages of simple structure and good stealth performance.

[0030] The radar shielding grille 12 and the grille connecting shaft 11 can be detachably connected by bolts, pins or other structures.

[0031] Preferably, the power component includes a fixed mounting base 2, an actuator cylinder 3, and a pull rod 4. The fixed mounting base 2 is fixedly connected to the arc-shaped outer wall 7 of the round-to-square section 1. The actuator cylinder 3 is hinged to the fixed mounting base 2, and the piston rod of the actuator cylinder 3 is hinged to the pull rod 4. The end of the pull rod 4 away from the actuator cylinder 3 is fixedly connected to the cylindrical connecting rod 5. When the piston rods of the two sets of actuator cylinders 3 extend synchronously, the pull rod 4 is pushed out, controlling the radar shielding grid 12 to move towards the rear end of the nozzle. When the piston rods of the two sets of actuator cylinders 3 retract simultaneously, the pull rod 4 is pulled back, controlling the radar shielding grid 12 to move towards the front end of the nozzle, thereby adjusting the position of the radar shielding grid 12. The number of actuator cylinders 3 can be symmetrically arranged from 2 to 6.

[0032] Preferably, the grid connecting shaft 11 is provided with a plurality of detachable connecting parts at intervals along its axial direction. These can be pre-set threaded holes or pin holes, etc. Each detachable connecting part can be detachably connected to the radar shielding grid 12. The number of radar shielding grids 12 is 4-30. By setting detachable connecting parts, the number of radar shielding grids 12 can be efficiently adjusted.

[0033] Preferably, the convergence section includes two sets of convergence adjustment plates 8 arranged vertically, with the convergence adjustment plates 8 abutting against the side wall 7. By adaptively modifying the structure of the convergence section, the stable operation of the stealth adjustment mechanism can be ensured.

[0034] Preferably, the exit ends of the sidewall 7, the upper expansion adjustment plate 9, and the lower expansion adjustment plate 10 are all serrated. The height of the sidewall 7 is greater than the heights of the upper expansion adjustment plate 9, the lower expansion adjustment plate 10, and the convergence adjustment plate 8. The angle range of the exit end of the sidewall 7 is 40° to 70°, and the angle range of the exit ends of the upper expansion adjustment plate 9 and the lower expansion adjustment plate 10 is 100° to 130°. By serrifying and angulating the sidewall 7, the upper expansion adjustment plate 9, and the lower expansion adjustment plate 10, the radar stealth performance of the vector nozzle is effectively improved.

[0035] Preferably, a cooling channel is provided inside the side wall 7, which is the same as the cooling channel inside the round-to-square section 1. A cooling hole communicating with the main gas passage is opened on the inner side of the side wall 7. The side wall 7 and the main gas passage are cooled by the cooling channel and the cooling hole respectively, so as to ensure the cooling performance and radar stealth capability of the vector nozzle.

[0036] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-stealth structure for an exhaust system with an adjustable radar-shielding grille, characterized in that: It includes a circular-to-square section (1), a convergent section, an expansion section, and a stealth adjustment mechanism; the front end of the circular-to-square section (1) is connected to the engine, and the convergent section is connected between the circular-to-square section (1) and the expansion section; the stealth adjustment mechanism includes a power component, a cylindrical connecting rod (5), an adjustable sliding block (6), and a radar shielding grid (12); the power component is located on the circular-to-square section (1), and one end of the cylindrical connecting rod (5) is fixedly connected to the output end of the power component, and the other end is fixedly connected to the adjustable sliding block (6); The expansion section includes a side wall (7), an upper expansion adjustment piece (9) and a lower expansion adjustment piece (10). There are two sets of side walls (7) and they are both vertically arranged. The upper expansion adjustment piece (9) and the lower expansion adjustment piece (10) are arranged vertically and are located between the two sets of side walls (7). The sidewall (7) has a horizontally set first sliding groove on its outer side. The adjustable sliding block (6) slides horizontally and fits into the first sliding groove. The radar shielding grid (12) is vertically set between the upper expansion adjustment plate (9) and the lower expansion adjustment plate (10). The radar shielding grid (12) is detachably connected to a horizontally set grid connecting shaft (11). The sidewall (7) has a horizontally set second sliding groove that communicates with the first sliding groove. The grid connecting shaft (11) slides horizontally and fits into the second sliding groove. The two ends of the grid connecting shaft (11) are connected to the adjustable sliding block (6). The grid connecting shaft (11) is provided with a plurality of detachable connecting parts at intervals along its axial direction. Each of the detachable connecting parts can be detachably connected to the radar shielding grid (12). The number of radar shielding grids (12) is 4-30.

2. The high stealth structure of the exhaust system with adjustable radar shielding grille as described in claim 1, characterized in that: The power component includes a fixed mounting base (2), an actuating cylinder (3), and a pull rod (4); the fixed mounting base (2) is fixedly connected to the arc-shaped outer wall (7) of the round-to-square section (1), the actuating cylinder (3) is hinged to the fixed mounting base (2), the piston rod of the actuating cylinder (3) is hinged to the pull rod (4), and the end of the pull rod (4) away from the actuating cylinder (3) is fixedly connected to the cylindrical connecting rod (5).

3. The high stealth structure of the exhaust system with adjustable radar shielding grille as described in claim 1, characterized in that: The convergence section includes two sets of convergence adjustment plates (8) arranged vertically, and the convergence adjustment plates (8) abut against the side wall (7).

4. The high stealth structure of the exhaust system with adjustable radar shielding grille as described in claim 3, characterized in that: The outlet ends of the sidewall (7), the upper expansion adjustment plate (9), and the lower expansion adjustment plate (10) are all serrated. The height of the sidewall (7) is greater than the height of the upper expansion adjustment plate (9), the lower expansion adjustment plate (10), and the convergence adjustment plate (8). The angle range of the outlet end of the sidewall (7) is 40° to 70°, and the angle range of the outlet ends of the upper expansion adjustment plate (9) and the lower expansion adjustment plate (10) is 100° to 130°.

5. The high stealth structure of the exhaust system with adjustable radar shielding grille as described in claim 1, characterized in that: The side wall (7) is provided with a cooling channel, which is the same as the cooling channel in the round-to-square section (1). The inner side of the side wall (7) is provided with a cooling hole that communicates with the main gas passage.

Images