Triple-folding throat-adjustable aero-engine nozzle

Abstract

The invention belongs to the technical field of aero-engine structural design, and relates to a triple-folding throat-adjustable aero-engine nozzle. The spray pipe comprises a square section connected with a round outlet of the spray pipe through a round-to-square section, the square section comprises an upper outer cover, a lower outer cover and a side wall, an adjusting plate is arranged between the upper outer cover and the lower outer cover and comprises a first folding piece, a second folding piece, a sliding plate and a single-side expansion section, one end of the first folding piece is hinged to the round-to-square section, and the other end of the first folding piece is hinged to the side wall. The other end of the second folding piece is hinged to the sliding plate, the plate face of the sliding plate is attached to and slidably connected with the plate face of the single-side expansion section, the sliding plate is driven by the actuator cylinder to move, and the other end of the single-side expansion section is connected to the tail end of the lower outer cover. According to the three-folding spray pipe adjusting mechanism, low detection performance and high pneumatic performance are both considered through the reconfigurable flow channel.

Description

Technical Field

[0001] This application belongs to the field of aero-engine structural design technology, specifically relating to an aero-engine nozzle with a three-fold adjustable throat. Background Technology

[0002] With the continuous advancement of aerospace detection technology, the management of aircraft detectability in complex airspace environments has become a key area of ​​cutting-edge research. The nozzle system of an aero-engine, as a critical channel for the exhaust of high-temperature exhaust gases, generates significant electromagnetic wave scattering characteristics and infrared radiation features, which are among the main factors affecting the backward signal characteristics of an aircraft. Therefore, developing advanced nozzle technology to effectively manage these signal characteristics is of great significance for improving the overall performance of aircraft.

[0003] Currently, the design of aero-engine nozzles faces an inherent contradiction between the requirements for high-performance aerodynamics and low observability. High-performance aero-engines pursue high thrust-to-weight ratios and high efficiency, which requires nozzles to have unobstructed flow paths and optimized area adjustment capabilities at full power (afterburner) to maximize thrust output. However, from the perspective of low observability, it is necessary to optimize signal characteristics through methods such as "geometry shaping" and "thermal management," which often requires changing or even constraining the shape of the flow path, potentially interfering with airflow and causing performance losses. How to achieve low observability without sacrificing core aerodynamic performance is an extremely challenging design problem.

[0004] Existing technologies for achieving low detectability of nozzles have certain limitations. One is the traditional mechanically adjustable nozzle technology. The core design of this type of nozzle relies on the movement of movable adjusting vanes to change the throat area, adapting to the aerodynamic requirements of the engine under different operating conditions. However, its adjustment modes are entirely geared towards aerodynamic performance, and low detectability is not a design goal for its configuration variations. Therefore, its structure cannot effectively shield high-temperature components in front, and its potential for reducing electromagnetic wave and infrared signature is limited.

[0005] Secondly, there is the technology of fixed special-configuration nozzles, such as nozzles with curved flow channels or non-axisymmetric cross-sections. These designs, through their inherent geometry, can physically shield the internal high-temperature regions using the nozzle walls, thus optimizing signal characteristics to some extent. However, these nozzles are typically fixed in configuration and lack the ability to adjust the throat area. When an aircraft needs to engage the afterburner to obtain maximum thrust, the fixed, complex flow channel shape will restrict exhaust efficiency, leading to a significant loss of thrust performance and making it difficult to meet the stringent power response requirements of highly maneuverable flight platforms. Therefore, they are commonly found in applications where the thrust variation range is not critical. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a three-fold adjustable aero-engine nozzle, comprising a square section connected to the nozzle's circular outlet via a circular-to-square section. The square section includes an upper outer cover, a lower outer cover, and a sidewall. An adjustment plate is provided between the upper and lower outer covers. The adjustment plate includes a first folding piece, a second folding piece, a sliding plate, and a single-sided expansion section. One end of the first folding piece is hinged to the circular-to-square section, and the other end is hinged to the second folding piece. The other end of the second folding piece is hinged to the sliding plate. The surface of the sliding plate is in contact with and slidably connected to the surface of the single-sided expansion section. The sliding plate is driven to move by an actuator. The other end of the single-sided expansion section is connected to the end of the lower outer cover.

[0007] Preferably, the slide plate is provided with at least two tenons on the side that fits against the single-sided expansion section, and the single-sided expansion section is provided with corresponding mortises, so that the slide plate and the single-sided expansion section can be slidably connected by the tenon and mortise fit.

[0008] Preferably, the back of the slide plate is provided with at least two lugs, which are respectively connected to the end of the piston rod of an actuating cylinder mounted on each side wall.

[0009] Preferably, a sealing ear is provided on the side of the skateboard that is in contact with the single-sided expansion section. The sealing ear extends in a direction perpendicular to the direction of movement of the skateboard, and its cross-section is arc-shaped. One end is formed on the skateboard, and the other end is overhanging. The apex of the arc is pressed against the single-sided expansion section.

[0010] Preferably, the inner side of the upper outer cover is also provided with an upper converging plate that shrinks the vertical spacing of the square segment and an upper expanding plate that expands the vertical spacing of the square segment. The upper converging plate and the upper expanding plate are connected at the end of the single-sided expansion segment that is connected to the slide plate.

[0011] Preferably, the second folding plate, the slide plate, the upper expansion plate, the single-sided expansion section, and the side wall are all provided with air film holes for guiding the external bypass gas or the gas inside the engine compartment to the surface of each structure.

[0012] The three-fold nozzle adjustment mechanism of this application achieves a balance between low detectability and high aerodynamic performance through a reconfigurable flow channel. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the nozzle in a fully obstructed state according to a preferred embodiment of the three-fold adjustable throat nozzle of the aircraft engine of this application.

[0014] Figure 2 This application Figure 1 A schematic diagram of the nozzle in full afterburner and high thrust state in the embodiment shown.

[0015] Figure 3 This application Figure 1Rear view of the nozzle in the fully obscured state of the embodiment shown.

[0016] Figure 4 This is a top view of the single-sided expansion segment structure.

[0017] Figure 5 This is a schematic diagram of the connections between the various structures of the adjustment plate.

[0018] Figure 6 This is a schematic diagram of the first folded piece structure.

[0019] Figure 7 This is a schematic diagram of the second folded piece structure.

[0020] Figure 8 This is a schematic diagram of a skateboard structure.

[0021] Figure 9 This is a schematic diagram of a unilateral expansion segment structure.

[0022] Among them, 1-round to square section, 2-first folding piece, 3-second folding piece, 4-actuating cylinder, 5-slide plate, 6-upper converging piece, 7-upper expanding piece, 8-single-sided expansion section, 9-side wall, 10-upper outer cover, 11-lower outer cover. Detailed Implementation

[0023] 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. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0024] This application provides a three-fold adjustable throat nozzle for an aircraft engine, such as... Figures 1-9As shown, the device includes a square section connected to the circular outlet of the nozzle via a circular-to-square section 1. The square section includes an upper outer cover 10, a lower outer cover 11, and a side wall 9. An adjustment plate is provided between the upper outer cover 10 and the lower outer cover 11. The adjustment plate includes a first folding piece 2, a second folding piece 3, a sliding plate 5, and a single-sided expansion section 8. One end of the first folding piece 2 is hinged to the circular-to-square section 1, and the other end is hinged to the second folding piece 3. The other end of the second folding piece 3 is hinged to the sliding plate 5. The surface of the sliding plate 5 is in contact with and slidably connected to the surface of the single-sided expansion section 8. The sliding plate 5 is driven to move by the actuating cylinder 4. The other end of the single-sided expansion section 8 is connected to the end of the lower outer cover 11.

[0025] like Figure 4 As shown, the unilateral expansion section 8 of this application is fixed to the side wall on both sides, as follows: Figure 5 As shown, the first folding piece 2 is hinged to the rear mounting edge of the round-to-square section 1 and can rotate around it. The second folding piece 3 is hinged to the first folding piece 2, which can form different folding angle states. The slide plate 5 can slide linearly against the single-sided expansion section 8. The actuating cylinder 4 can drive the slide plate 5 to move, realizing the linear extension and retraction of the slide plate 5 on the single-sided expansion section 8, thereby folding the first folding piece 2 and the second folding piece 3. Figure 1 As shown, when the actuator 4 is in its shortest extension / retraction state, the first folding plate 2 and the second folding plate 3 fold together to form a maximum convex state. At this time, the throat area is at its minimum, achieving a complete obstruction of the nozzle from the rear. Figure 3 As shown, the rear view only shows the second folding piece 3, and it is impossible to further explore the internal structure, thus improving the aircraft's survivability against infrared threats. Figure 2 As shown, when the aircraft is flying at high speed with afterburner engaged, the actuator 4 is in its longest extension state, extending the slide plate 5. The first folding plate 2 and the second folding plate 3 are hinged to form a straight state. At this time, the throat area is at its maximum, and the full afterburner high thrust mode is activated.

[0026] The single-sided expansion nozzle provided in this application shields the detection area below the nozzle based on the single-sided expansion section. Simultaneously, the folded flaps physically shield the hot-end components at the nozzle's upper tip, reducing contributions from solid-state infrared radiation and electromagnetic scattering signals. Furthermore, the nozzle exit design of this application features serrations. These serrations enhance the mixing of the high-temperature mainstream with ambient air, lowering the core flow temperature and reducing infrared signal contribution. The diffraction effect at the serrated edges also reduces electromagnetic wave reflection intensity, decreasing radar detectability.

[0027] In some alternative embodiments, at least two tenons are provided on the side of the slide plate 5 that is in contact with the single-sided expansion section 8, and a corresponding mortise is provided on the single-sided expansion section 8. The sliding connection between the slide plate 5 and the single-sided expansion section 8 is achieved by the tenon and mortise engagement.

[0028] like Figure 8 and Figure 9As shown, the tenon B on the single-sided expansion section 8 is a T-shaped groove, and the corresponding tenon A on the slide plate 5 is a T-shaped slide rail. Both extend along the front and rear direction of the nozzle.

[0029] In some alternative embodiments, the back of the slide plate 5 is provided with at least two lugs, which are respectively connected to the end of the piston rod of an actuating cylinder 4 mounted on each side wall.

[0030] refer to Figure 8 Lug D is a pin structure to be adapted to connect the piston rod of the actuator cylinder 4, which has one or two lugs.

[0031] In some alternative embodiments, a sealing ear is provided on the side of the slide plate 5 that is in contact with the single-sided expansion section 8. The sealing ear extends in a direction perpendicular to the direction of movement of the slide plate 5, and its cross-section is arc-shaped. One end is formed on the slide plate 5, and the other end is overhanging. The apex of the arc is pressed against the single-sided expansion section 8.

[0032] like Figure 8 As shown, during the movement of the folded piece 5, the sealing ear C always rests against the wall of the single-sided expansion section 8 to ensure sealing.

[0033] In some alternative embodiments, the inner side of the upper outer cover 10 is further provided with an upper converging plate 6 that shrinks the vertical spacing of the square segment and an upper expanding plate 7 that expands the vertical spacing of the square segment. The upper converging plate 6 and the upper expanding plate 7 are connected at the end opposite to the end of the single-sided expansion segment 8 that is connected to the slide plate.

[0034] like Figure 1 As shown, the upper converging plate 6 and the upper expanding plate 7 on the inner side of the upper outer cover 10 constitute the profile of the upper wall of the nozzle. This profile, together with the adjustable regulating plate, forms a complete flow channel. This structural design ensures a smooth transition of the flow channel profile, which is beneficial for maintaining aerodynamic performance.

[0035] In some alternative embodiments, the second folding piece 3, the sliding plate 5, the upper expansion piece 7, the single-sided expansion section 8, and the side wall 9 are all provided with air film holes for guiding the external bypass gas of the engine or the gas inside the engine compartment to the surface of each structure.

[0036] In this embodiment, reference Figures 6-9 The film cooling vents are usually oblique film cooling vents, which utilize external bypass gas or gas inside the engine compartment for cooling along the path.

[0037] The above description is merely a specific embodiment 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 three-fold adjustable throat aero-engine nozzle, comprising a square section connected to the circular nozzle outlet via a circular-to-square section (1), the square section comprising an upper outer cover (10), a lower outer cover (11), and a sidewall (9), characterized in that, An adjustment plate is provided between the upper outer cover (10) and the lower outer cover (11). The adjustment plate includes a first folding piece (2), a second folding piece (3), a sliding plate (5), and a single-sided expansion section (8). One end of the first folding piece (2) is hinged to the round-to-square section (1), and the other end is hinged to the second folding piece (3). The other end of the second folding piece (3) is hinged to the sliding plate (5). The surface of the sliding plate (5) is attached to and slidably connected to the surface of the single-sided expansion section (8). The sliding plate (5) is driven to move by the actuating cylinder (4). The other end of the single-sided expansion section (8) is connected to the end of the lower outer cover (11).

2. The three-fold adjustable throat aero-engine nozzle according to claim 1, characterized in that, At least two tenons are provided on the side of the slide plate (5) that is in contact with the single-sided expansion section (8), and a corresponding mortise is provided on the single-sided expansion section (8). The slide plate (5) and the single-sided expansion section (8) are slidably connected by the tenon and mortise.

3. The three-fold adjustable throat aero-engine nozzle according to claim 2, characterized in that, The back of the slide plate (5) is provided with at least two lugs, which are respectively connected to the end of the piston rod of an actuating cylinder (4) installed on each side wall.

4. The three-fold adjustable throat aero-engine nozzle according to claim 2, characterized in that, A sealing ear is provided on the side of the slide plate (5) that is in contact with the single-sided expansion section (8). The sealing ear extends in a direction perpendicular to the direction of movement of the slide plate (5), and its cross-section is arc-shaped. One end is formed on the slide plate (5), and the other end is suspended. The apex of the arc is pressed against the single-sided expansion section (8).

5. The three-fold adjustable throat aero-engine nozzle according to claim 1, characterized in that, The inner side of the upper outer cover (10) is also provided with an upper converging plate (6) that shrinks the vertical spacing of the square segment and an upper expanding plate (7) that expands the vertical spacing of the square segment. The upper converging plate (6) and the upper expanding plate (7) are connected at the end of the single-sided expansion segment (8) that is connected to the slide plate.

6. The three-fold adjustable throat aero-engine nozzle according to claim 3, characterized in that, The second folding piece (3), the sliding plate (5), the upper expansion piece (7), the single-sided expansion section (8) and the side wall (9) are all provided with air film holes, which are used to guide the external bypass gas of the engine or the gas inside the engine compartment to the surface of each structure.

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