A bypass dual-throat aerodynamic vectoring nozzle and a control method thereof

Abstract

The application discloses a bypass type double-throat aerodynamic vector nozzle and a control method thereof, and relates to the technical field of aero-engine. The application discloses a bypass type double-throat aerodynamic vector nozzle and a control method thereof, and relates to the technical field of aero-engine. The adjustable triangular block is designed by a triangular structure formed by a converging section before a throat of a binary bypass type aerodynamic vector nozzle, a front section of a bypass channel and an inner wall surface of a turning section, the minimum geometric cross-sectional area of the throat or the minimum aerodynamic flow cross-sectional area of the throat is adjusted through geometric adjustment or aerodynamic adjustment, so that the flow of the nozzle is changed, and the wide-range working requirements of an engine are matched. The adjustable triangular block can be divided into a geometric adjustment method and an aerodynamic adjustment method according to different mechanisms. The application solves the problem that the flow of the nozzle cannot be adjusted in a wide range without affecting the original vector performance of the bypass type aerodynamic vector nozzle, and further expands the application scenarios of the aerodynamic vector nozzle.

Description

Technical Field

[0001] This invention relates to the field of aircraft propulsion system design, and in particular to a bypass-type dual-throat aerodynamic vector nozzle and its control method. Background Technology

[0002] Thrust vectoring technology is one of the key technologies that advanced fighter jets must possess. This technology can provide additional thrust torque to the aircraft, increase the maximum stall angle of attack, and improve the aircraft's maneuverability and safety. However, the operating range of current engines and nozzles is relatively narrow. For advanced fighter jets, the need for flow regulation is increasing, especially during evasive maneuvers, interception, pursuit, and other maneuvering maneuvers, where afterburner is unavoidable. Moreover, these situations require increased thrust vectoring to enable the fighter jet to gain the upper hand. Therefore, thrust vectoring nozzles with efficient operation over a wider operating range are of great value to future aircraft.

[0003] Currently, most operational mechanical thrust vectoring nozzles rely on hydraulically actuated fish-scale mechanical structures to change the throat area. This not only presents significant design challenges but also results in complex, bulky, and unreliable mechanical structures with extremely high costs. Therefore, although they were the first to appear, many designs remain at the theoretical stage. Consequently, researchers have gradually shifted their focus to aerodynamic vectoring nozzle technologies. Compared to purely mechanical control, generating thrust vectors through secondary flow disturbances of the main stream offers a simpler structure, lighter weight, and higher reliability, making it a new solution for thrust vectoring technology.

[0004] Bypass-type passive dual-throat aerodynamic vector nozzle is a new type of aerodynamic thrust vectoring technology that has emerged in recent years. Gas flows sequentially through the front convergent section of the first throat, the first throat, and the front expansion convergent section of the second throat, and finally flows out from the second throat. A secondary flow is introduced through a specially designed bypass channel, which disturbs the mainstream at the first throat. The disturbance is then amplified by the downstream concave cavity structure, generating a significant thrust vector.

[0005] However, due to the special structure of the fixed geometry of the nozzle, it can only be designed according to a specific engine operating condition and cannot be adjusted over a wide range. Considering the wide range of operation of the current fighter jet engine and the requirements of afterburner, it is necessary to design a wide range of flow adjustment for the aerodynamic thrust vectoring nozzle. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a bypass-type dual-throat aerodynamic vectoring nozzle and its control method. This addresses the technical problem that traditional thrust vectoring nozzles with flow regulation functions are complex in design, bulky in structure, and unsuitable for engineering applications. This invention employs a special design with adjustable triangular blocks, resulting in a simple structure and efficient flow regulation. It enables wide-range flow regulation of this type of nozzle, meeting the broad-range operating requirements of current aero-engines.

[0007] To achieve the above technical objectives, the present invention will adopt the following technical solution:

[0008] A bypass-type dual-throat pneumatic vector nozzle includes a nozzle body, the nozzle body comprising a nozzle wall, a cavity expansion section, and a cavity convergence section.

[0009] The nozzle body has three guide rails on both sides: an adjustable triangular block pneumatic adjustment guide rail, an adjustable triangular block geometric rapid adjustment guide rail, and an adjustable triangular block geometric vector compensation adjustment guide rail.

[0010] The nozzle wall is symmetrically provided with adjustable triangular blocks, and the adjustable triangular blocks are provided with rotating shafts on both sides. The rotating shafts are slidably connected to the three guide rails. The bottom of the adjustable triangular blocks is provided with a bypass channel switch, and the bypass channel switch is slidably connected to the nozzle body.

[0011] The surface formed by connecting the vertices of the two adjustable triangular blocks is the cross-section of the first throat of the nozzle, and the surface on one side of the concave cavity convergence section is the cross-section of the second throat of the nozzle.

[0012] One side of the adjustable triangular block forms a converging segment at the front of the throat.

[0013] A bypass channel is formed between the adjustable triangular block and the nozzle body. The bypass channel includes a bypass channel front section, a bypass channel switch, and a bypass channel turning section.

[0014] The central section of the nozzle wall in the horizontal direction is defined as the nozzle symmetry plane.

[0015] Preferably, the dual-throat pneumatic vector nozzle has a binary configuration of rectangle, square, trapezoid, or parallelogram.

[0016] Preferably, the adjustable triangular block is rotated and translated via an actuation mechanism.

[0017] Preferably, the size of the adjustable triangular block is variable.

[0018] Preferably, the adjustable triangular block is slidably connected to the adjustable triangular block geometric quick adjustment guide rail: when the adjustable triangular block moves toward the nozzle symmetry plane, the cross-sectional area of ​​the nozzle throat decreases, and the dual-throat aerodynamic vector nozzle operates in a low-flow condition; when the adjustable triangular block moves away from the nozzle symmetry plane, the cross-sectional area of ​​the nozzle throat increases, and the dual-throat aerodynamic vector nozzle operates in a high-flow condition.

[0019] Preferably, when adjusting the bypass channel switch, vector fine-tuning is performed by adjusting an adjustable triangular block: the adjustable triangular block is slidably connected to the adjustable triangular block geometric vector compensation adjustment rail; when the adjustable triangular block moves away from the cross-section of the nozzle's second throat, the cross-sectional area of ​​the nozzle's first throat increases, compensating for flow rate changes or relatively high flow rate conditions caused by the vector adjustment of the bypass channel switch; when the adjustable triangular block moves towards the cross-section of the nozzle's second throat, the cross-sectional area of ​​the nozzle's first throat decreases, compensating for flow rate changes or relatively low flow rate conditions caused by the vector adjustment of the bypass channel switch.

[0020] Preferably, the adjustable triangular block is slidably connected to the adjustable triangular block pneumatic adjustment guide rail for horizontal sliding: when the adjustable triangular block moves away from the cross-section of the second throat of the nozzle, the outlet area of ​​the bypass channel turning section increases, the aerodynamic flow cross-sectional area of ​​the first throat of the nozzle increases, and the dual-throat aerodynamic vector nozzle operates in a high pressure ratio condition; when the adjustable triangular block moves toward the cross-section of the second throat of the nozzle, the outlet area of ​​the bypass channel turning section decreases, the aerodynamic flow cross-sectional area of ​​the first throat of the nozzle decreases, and the dual-throat aerodynamic vector nozzle operates in a low pressure ratio condition.

[0021] Preferably, the adjustable triangular block is slidably connected to the adjustable triangular block geometric quick adjustment guide rail, and the distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat pneumatic vector nozzle satisfy 0.1914≤L1 / H≤0.4886;

[0022] Under the premise of ensuring effective vector effect, L1 and H satisfy 0.2783≤L1 / H≤0.4283.

[0023] Preferably, the adjustable triangular block is slidably connected to the adjustable triangular block geometric vector compensation adjustment guide rail, and the distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat pneumatic vector nozzle satisfy 0.2783≤L1 / H≤0.3842.

[0024] Preferably, the horizontal distance L2 between the vertex of the adjustable triangular block and the downstream tip of the nozzle throat and the nozzle inlet height H satisfy 0.08753≤L2 / H≤0.3501.

[0025] The advantages of this invention are:

[0026] (1) This invention can achieve wide-range flow regulation of the nozzle, which can meet the future engine requirements for efficient thrust vectoring and wide-range flow regulation. It improves the performance of aircraft equipped with this nozzle in high-altitude, high-speed, afterburning and maneuvering flight, and expands the working range of the aircraft.

[0027] (2) The present invention uses two actuation methods, adjustable triangular block geometry and pneumatic adjustment, to adjust the nozzle according to different working conditions and requirements, and adopt different principle adjustment methods, thereby further increasing the versatility of the method.

[0028] (3) The adjustable triangular block designed in this invention is adjusted by translation and rotation, and the actuation mechanism is relatively simple.

[0029] (4) The present invention directly adjusts the minimum flow cross-sectional area of ​​the nozzle, and can meet the large flow adjustment requirements with a small range of operation.

[0030] (5) The present invention only adjusts the adjustable triangular block in front of the first throat of the nozzle, without changing the concave cavity structure behind the first throat, and does not affect the original nozzle vector adjustment law, which is convenient for engineering practice. Attached Figure Description

[0031] Figure 1 This is a symmetrical cross-sectional side view of the inner side of the nozzle of the present invention;

[0032] Figure 2 This is a side view of the outer structure of the nozzle of the present invention;

[0033] Figure 3 This is a side view of a symmetrical cross-section of the nozzle of the present invention;

[0034] Figure 4 This is a side view of the outer structure of the nozzle of the present invention;

[0035] Figure 5 This is a cross-sectional view of the inner symmetrical plane of the nozzle of the present invention. The dotted and dashed lines represent the upper and lower limits of the adjustable triangular block movement under the rapid flow regulation mode of the geometric adjustment method.

[0036] Figure 6 This is a cross-sectional view of the inner symmetrical plane of the nozzle of the present invention. The dotted and dashed lines represent the upper and lower limits of the adjustable triangular block movement under the vector compensation adjustment mode of the geometric adjustment method.

[0037] Figure 7 This is a cross-sectional view of the inner symmetrical plane of the nozzle of the present invention. The dotted and dashed lines represent the upper and lower limits of the movement of the adjustable triangular block under the pneumatic adjustment method.

[0038] Figure 8 This is a two-dimensional numerical simulation Mach number cloud diagram of the maximum opening state of the adjustable triangular block under the rapid flow adjustment method of the two-dimensional nozzle of the present invention.

[0039] Figure 9 This invention provides a two-dimensional numerical simulation of the Mach number cloud map of the minimum opening state of the adjustable triangular block under the rapid flow adjustment method of the two-dimensional nozzle.

[0040] Figure 10As an improvement to the adjustable triangular block described in this invention, the geometric dimensions of the triangular block can be adjusted, including but not limited to sleeve and connecting rod structures. The dotted line shows the triangular block after the geometric dimensions have been changed.

[0041] 1- Nozzle wall, 2- Nozzle symmetry plane, 3- First throat convergent section, 4- Adjustable triangular block, 5- Nozzle first throat, 6- Bypass channel front section, 7- Bypass channel switch, 8- Bypass channel turning section, 9- Cavity expansion section, 10- Nozzle second throat, 11- Cavity convergent section, 12- Adjustable triangular block pneumatic adjustment guide rail, 13- Adjustable triangular block geometric rapid adjustment guide rail, 14- Adjustable triangular block axis, 15- Adjustable triangular block geometric vector compensation adjustment guide rail. Detailed Implementation

[0042] The technical solutions of embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0043] A bypass-type dual-throat aerodynamic vector nozzle improves the triangular structure formed by the inner wall of the converging section, the front section of the bypass channel, and the turning section inside the nozzle into an adjustable design, namely an adjustable triangular block. The adjustable triangular block can be translated in a certain direction inside the nozzle to adjust the opening.

[0044] Furthermore, for ease of adjustment, the adjustable triangular block's mechanism is set to stepless adjustment, and guide rails of different angles can be set, allowing for adjustment of the opening by moving along guide rails at different angles. The adjustable triangular block employs two different adjustment mechanisms: a geometric adjustment method and a pneumatic adjustment method. Both methods can change the flow area of ​​the nozzle's throat, thereby altering the flow.

[0045] Furthermore, the geometric adjustment method has two adjustment modes: a rapid flow adjustment mode and a vector compensation mode.

[0046] The rapid flow regulation mode of the described geometric adjustment method is as follows: the adjustable triangular block moves vertically, and the minimum flow cross-section of the nozzle is located between the inner cusps of the upper and lower adjustable triangular blocks. Vertical movement of the adjustable triangular block allows for the most rapid adjustment of the nozzle flow rate, thus matching the engine's requirement for rapid flow regulation. Specifically, when the triangular block moves vertically towards the nozzle's binary symmetry plane, the geometric flow area of ​​the nozzle's throat decreases, and the nozzle flow rate decreases rapidly, corresponding to a low pressure ratio state for the engine; when it moves away from the nozzle's binary symmetry plane, the geometric flow area of ​​the nozzle's throat increases, and the nozzle flow rate increases rapidly, corresponding to a high pressure ratio state for the engine.

[0047] Furthermore, in the rapid flow adjustment mode, the maximum vertical movement range of the adjustable triangular block, the distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat pneumatic vector nozzle satisfy 0.1914≤L1 / H≤0.4886.

[0048] Furthermore, in the rapid flow adjustment mode, under the premise of ensuring effective vector effect, the distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat pneumatic vector nozzle satisfy 0.2783≤L1 / H≤0.4283.

[0049] The vector compensation mode of the geometric adjustment method involves the triangular block moving along the bisector of the angle between the front section and the turning section of the bypass channel. In this adjustment mode, during the adjustment of the nozzle's minimum flow cross-sectional area, each cross-sectional area in the nozzle bypass simultaneously increases or decreases, thereby reducing the impact on the basic configuration bypass. Specifically, when the vector nozzle opens a bypass on one side for flow adjustment, the secondary flow generated in the bypass compresses the mainstream flow area, altering the operating state of the nozzle and even the engine. The vector fine-tuning mode allows for flow matching of the reduced secondary flow based on geometric area conditions during vector adjustment. Furthermore, this adjustment mode has a smaller impact on the secondary flow, ensuring the nozzle's vector performance.

[0050] Furthermore, the adjustable triangular block moves along the bisector of the angle between the front section and the turning section of the bypass channel. When it moves away from the binary symmetry plane of the nozzle, the geometric flow area of ​​the nozzle throat increases, and the nozzle flow rate increases, corresponding to the nozzle vector open state or high flow rate condition. When it moves closer to the binary symmetry plane of the nozzle, the geometric flow area of ​​the nozzle throat decreases, and the nozzle flow rate decreases rapidly, corresponding to the nozzle vector closed state or low flow rate condition.

[0051] Furthermore, taking the baseline configuration as an example, the angle between the direction of movement and the horizontal direction is 22.5°.

[0052] Furthermore, in the vector compensation mode, the maximum range of movement of the adjustable triangular block along the tilt direction, and the distance L1 between the inner apex of the adjustable triangular block and the symmetrical plane of the nozzle and the nozzle inlet height H satisfy 0.2783≤L1 / H≤0.3842.

[0053] Furthermore, the aerodynamic adjustment method involves moving an adjustable triangular block horizontally while maintaining the same geometric area of ​​the nozzle throat. This horizontal movement alters the flow area of ​​the bypass turning section, changing the degree of expansion or compression of the bypass airflow, thereby changing the aerodynamic flow cross-sectional area of ​​the throat. Specifically, when the triangular block moves horizontally towards the nozzle outlet, the bypass channel transforms into a contraction channel, where the secondary flow accelerates and expands, increasing its impact on the main flow at the throat, reducing the main flow aerodynamic flow, and decreasing the nozzle flow rate. Conversely, when it moves horizontally towards the nozzle inlet, the bypass channel transforms into an expansion channel, where the secondary flow decelerates and compresses, weakening its impact on the main flow at the throat, increasing the main flow aerodynamic flow cross-sectional area, and increasing the nozzle flow rate.

[0054] Furthermore, the aerodynamic adjustment method operates in the nozzle vector state, which is when the nozzle bypass on one side is open, a secondary flow is generated in the bypass, the secondary flow disturbs the main flow, and the main flow in the nozzle is deflected.

[0055] Furthermore, under the aforementioned pneumatic adjustment method, as the adjustable triangular block moves horizontally towards the nozzle outlet / inlet direction, the degree of acceleration expansion / deceleration compression of the secondary flow in the bypass channel becomes more intense, and the nozzle aerodynamic throat area decreases / increases accordingly.

[0056] Furthermore, in the pneumatic adjustment method, the maximum horizontal movement range of the adjustable triangular block, and the horizontal distance L2 between the inner apex of the adjustable triangular block and the downstream apex of the nozzle throat, and the nozzle inlet height H satisfy 0.08753≤L2 / H≤0.3501.

[0057] As a further improvement to the adjustable triangular block pneumatic vector nozzle of the present invention, the adjustable triangular block itself is improved: the geometrically fixed adjustable triangular block is improved to be composed of adjustable connecting rods, which can adjust its shape and size; the actuation adjustment method of the adjustable triangular block is improved: the translational actuation of the triangular block is improved to rotational actuation; the adjustment method of the adjustable triangular block is improved: the independent geometric and pneumatic adjustment method is improved to a coupled adjustment method.

[0058] The following is a further explanation of the adjustable triangle block.

[0059] The triangular block structure formed by the wall of the converging section at the front of the nozzle throat, the front section of the bypass channel, and the inner wall of the turning section in this invention is the adjustable triangular block specially designed in this invention. Different adjustment methods of the adjustable triangular block can adjust the minimum flow cross section of the nozzle geometrically or pneumatically, thereby producing a throttling effect on the entire engine and achieving the effect of controlling the flow rate.

[0060] The nozzle's outer wall is designed with three guide rails corresponding to three different adjustment methods: the vertical and inclined guide rails operate using a geometric adjustment method, while the horizontal guide rails operate using a pneumatic adjustment method.

[0061] According to the actual needs of the aircraft and engine, the nozzle flow rate adjustment is divided into the following three situations: (1) Non-vector state, which is a rapid switch between a higher and lower pressure ratio, corresponding to the engine start-up, rapid climb and afterburner process; (2) Switching between vector state and non-vector state, which corresponds to the engine opening and closing vector to help the aircraft perform maneuvering under a certain working condition; (3) Vector state, which corresponds to the working condition when the engine needs to adjust the flow rate over a large range during maneuvering.

[0062] (1) In non-vector state, when the engine undergoes a large change in pressure ratio, the nozzle needs to adjust the flow rate over a wide range. In this case, the adjustable triangular block adjustment scheme is the rapid flow rate adjustment method in the geometric adjustment method. That is, the adjustable triangular block moves along the vertical slide rail, and the area between the inner tips of the two adjustable triangular blocks is the minimum flow cross-sectional area of ​​the nozzle. The adjustable triangular block moves in the vertical direction, directly changing the minimum geometric flow area of ​​the nozzle. The vertical movement control method can quickly match the engine flow rate requirement in non-appropriate state.

[0063] When the engine is at idle, the engine pressure ratio and flow rate are at their minimum, corresponding to the position where the adjustable triangular blocks are closest to the nozzle's symmetry plane, resulting in the strongest throttling effect. As the engine gradually transitions to its maximum operating state or afterburner is activated, the engine flow rate increases. At this time, the adjustable triangular blocks on both sides move away from the nozzle's symmetry plane along the vertical guide rail, increasing the nozzle's minimum flow cross-sectional area to meet the engine's high flow rate requirements. Conversely, when the engine transitions from its maximum operating state to a lower state or afterburner is deactivated, the adjustable triangular blocks on both sides move closer to the nozzle's symmetry plane along the vertical guide rail, decreasing the nozzle's minimum flow cross-sectional area to meet the engine's gradually decreasing flow rate requirements.

[0064] The adjustable triangular block moves vertically in this adjustment mode. The maximum geometrical range of movement of the adjustable triangular block is such that the distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat aerodynamic vector nozzle satisfy 0.1914 ≤ L1 / H ≤ 0.4886. Figure 5 As shown; under the premise of ensuring effective vector effect, the distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat aerodynamic vector nozzle satisfy 0.2783≤L1 / H≤0.4283. In order to ensure the secondary flow rate of the bypass channel, this range is reduced compared to the maximum geometric range.

[0065] like Figure 8 , Figure 9The figure shows the Mach number contour plot of the two-dimensional numerical simulation results of the nozzle under the conditions of engine pressure ratio 4 and rapid flow adjustment method at the maximum and minimum opening of the adjustable triangle block. In both modes, the nozzle throat has reached the speed of sound. Specifically, at the minimum opening of the adjustable triangle block, the nozzle mass flow rate is 9.03 kg / s, and at the maximum opening of the adjustable triangle block, the nozzle mass flow rate is 18.51 kg / s, which is 105% higher.

[0066] (2) When switching between non-vectoring and vectoring states, the secondary flow in the bypass channel of the bypass dual-throat aerodynamic thrust vectoring nozzle will affect the aerodynamic flow cross-sectional area of ​​the first throat, thus affecting the overall engine operating conditions. At this time, the adjustable triangular block adjustment scheme is the vector fine-tuning method in the geometric adjustment method, that is, the adjustable triangular block moves along the inclined slide rail. At this time, the bypass channel remains a straight channel. At the same time, the throat flow area occupied by the secondary flow when the vector is opened / closed can be compensated by adjusting the geometry of the first throat, thereby mitigating the change in the overall engine operating conditions caused by the opening / closing of the vector.

[0067] Taking the transition from a non-vectoring to a vectoring state of the nozzle as an example, in the non-vectoring state, both bypasses on both sides of the nozzle are closed, and the main flow is ejected in a straight line. In the vectoring state, one bypass channel is opened, and the secondary flow in the bypass channel impacts the main flow at the throat. At this time, the adjustable triangular blocks on both sides move along the inclined guide rail away from the nozzle's symmetry plane, increasing the minimum flow cross-sectional area of ​​the nozzle. This compensates for the secondary flow occupying the flow area of ​​the throat, preventing excessive changes in engine operating conditions. The flow regulation method during the transition from a vectoring to a non-vectoring state is similar to the above. The adjustable triangular blocks on both sides move along the inclined guide rail closer to the nozzle's symmetry plane, reducing the minimum flow cross-sectional area of ​​the nozzle, thereby reducing flow changes within the nozzle and ensuring overall engine operating conditions.

[0068] The adjustable triangular block moves along the tilt direction in this adjustment mode. The tilt direction is the bisector of the angle between the front section and the turning section of the bypass channel. Taking the reference configuration of the bypass dual-throat aerodynamic thrust vector nozzle as an example, the angle between the tilt movement direction and the horizontal direction is 22.5°. In the vector compensation mode, the maximum movement range of the adjustable triangular block along the tilt direction, the distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat aerodynamic vector nozzle satisfy 0.2783≤L1 / H≤0.3842.

[0069] The vector compensation method is mainly used to compensate for the secondary flow occupying the cross-sectional area of ​​the main aerodynamic flow when the nozzle switches between vector and non-vector states. Its flow rate change adjustment is smaller than that of the rapid flow rate adjustment method, so it can meet the flow rate adjustment requirements in this application scenario.

[0070] (3) When flow rate adjustment is required in the nozzle vector state, the flow area of ​​the nozzle throat can be controlled by the strength of the secondary flow. In this case, the adjustable triangular block adjustment scheme is a pneumatic adjustment method, that is, the adjustable triangular block moves along the horizontal slide rail. At this time, the flow area of ​​the front section of the bypass channel remains unchanged, while the flow area of ​​the turning section will increase / decrease with the movement, thereby forming a gradually widening / reducing flow channel. The secondary flow in the channel decelerates and compresses / accelerates and expands, thereby changing the aerodynamic flow cross-sectional area of ​​the main flow in the throat. Compared with the two geometric adjustment methods mentioned above, this adjustment uses the secondary flow aerodynamic method, and in the vector state, it can change the nozzle flow rate without the requirement of a minimum geometric flow cross-sectional area.

[0071] With the nozzle in a vectoring state, as the engine's operating pressure ratio increases, the adjustable triangular block moves along the horizontal slide rail towards the nozzle inlet. The bypass channel becomes an expanding channel, and the channel expansion ratio increases with the movement towards the inlet. This causes the secondary flow within the channel to decelerate and compress, reducing the impact on the main flow at the throat. Consequently, the aerodynamic cross-sectional area of ​​the main flow is reduced, increasing the nozzle flow rate to match the increased engine operating pressure ratio. Similarly, as the engine's operating pressure ratio decreases, the adjustable triangular block moves along the horizontal slide rail towards the nozzle outlet. The bypass channel becomes a contracting channel, and the secondary flow within the channel accelerates and expands. This reduces the aerodynamic cross-sectional area of ​​the main flow at the throat, decreasing the nozzle flow rate to match the decreased engine operating pressure ratio.

[0072] The adjustable triangular block moves horizontally, and the maximum horizontal movement range of the adjustable triangular block is such that the horizontal distance L2 between the inner tip of the adjustable triangular block and the downstream tip of the nozzle throat and the nozzle inlet height H satisfy 0.08753≤L2 / H≤0.3501.

[0073] The pneumatic adjustment method is mainly used in scenarios where the engine does not undergo large-scale operating condition adjustments. Therefore, the flow rate adjustment range is also lower than that of the rapid flow rate adjustment method. Thus, the pneumatic adjustment method can meet the flow rate adjustment requirements under these operating conditions.

[0074] As a further improvement of the present invention, the adjustable triangular block itself is improved. The adjustable triangular block is geometrically fixed and is improved to be composed of adjustable connecting rods. It is not limited to adjusting the position of the adjustable triangular block, but can also adjust its shape and size, thereby allowing for more precise adjustment of the nozzle convergence section and bypass structure.

[0075] As a further improvement of the present invention, the actuation mode of the adjustable triangular block is improved. The translational actuation of the adjustable triangular block is improved to rotational actuation, thereby changing the transmission structure and adapting to the engine installation method of different aircraft, thus expanding its application range.

[0076] As a further improvement of the present invention, the adjustment method of the adjustable triangular block is improved, and the independent geometric and aerodynamic adjustment method is improved into a coupled adjustment method to adapt to the complex flight commands and control methods during actual flight.

[0077] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bypass-type dual-throat pneumatic vector nozzle, characterized in that, Includes a nozzle body, which includes a nozzle wall (1), a cavity expansion section (9), and a cavity convergence section (11): Three guide rails are provided on both sides of the nozzle body: adjustable triangular block pneumatic adjustment guide rail (12), adjustable triangular block geometric rapid adjustment guide rail (13), and adjustable triangular block geometric vector compensation adjustment guide rail (15). The nozzle wall (1) is symmetrically provided with adjustable triangular blocks (4), and the adjustable triangular blocks (4) are provided with rotating shafts (14) on both sides. The rotating shafts (14) are slidably connected to the three guide rails. The bottom of the adjustable triangular blocks (4) is provided with a bypass channel switch (7), and the bypass channel switch (7) is slidably connected to the nozzle body. The surface formed by the line connecting the vertices of the two adjustable triangular blocks (4) is the cross section of the nozzle throat (5), and the surface on one side of the concave cavity convergence section (11) is the cross section of the nozzle throat (10). One side of the adjustable triangular block (4) forms a converging segment (3) at the front of the throat. A bypass channel is formed between the adjustable triangular block (4) and the nozzle body. The bypass channel includes a bypass channel front section (6), a bypass channel switch (7), and a bypass channel turning section (8). The central section in the horizontal direction of the nozzle wall (1) is defined as the nozzle symmetry plane (2).

2. The bypass-type dual-throat pneumatic vector nozzle according to claim 1, characterized in that, The dual-throat aerodynamic vector nozzle has a binary configuration of rectangle, square, trapezoid, or parallelogram.

3. A bypass-type dual-throat pneumatic vector nozzle according to claim 1, characterized in that, The adjustable triangular block (4) is rotated and translated by an actuation mechanism.

4. A bypass-type dual-throat pneumatic vector nozzle according to claim 1, characterized in that, The size of the adjustable triangular block (4) can be varied.

5. The control method for a bypass-type dual-throat pneumatic vector nozzle according to claim 1, characterized in that, The adjustable triangular block (4) is slidably connected to the adjustable triangular block geometric quick adjustment guide rail (13): when the adjustable triangular block (4) moves toward the nozzle symmetry plane (2), the cross-sectional area of ​​the nozzle throat (5) decreases, and the nozzle is in low flow condition; when the adjustable triangular block (4) moves away from the nozzle symmetry plane (2), the cross-sectional area of ​​the nozzle throat (5) increases, and the nozzle is in high flow condition.

6. The control method for a bypass-type dual-throat pneumatic vector nozzle according to claim 1, characterized in that, When adjusting the bypass channel switch (7), vector fine-tuning is performed by adjusting the adjustable triangular block (4): the adjustable triangular block (4) is slidably connected to the adjustable triangular block geometric vector compensation adjustment guide rail (15). When the adjustable triangular block (4) moves away from the cross section of the nozzle second throat (10), the cross section area of ​​the nozzle first throat (5) increases, compensating for the flow rate change or relatively large flow rate condition caused by the vector adjustment of the bypass channel switch (7); when the adjustable triangular block (4) moves towards the cross section of the nozzle second throat (10), the cross section area of ​​the nozzle first throat (5) decreases, compensating for the flow rate change or relatively small flow rate condition caused by the vector adjustment of the bypass channel switch (7).

7. The control method for a bypass-type dual-throat pneumatic vector nozzle according to claim 1, characterized in that, The adjustable triangular block (4) is slidably connected to the adjustable triangular block pneumatic adjustment guide rail (12) for horizontal sliding: when the adjustable triangular block (4) moves away from the cross section of the nozzle second throat (10), the outlet area of ​​the bypass channel turning section (8) increases, the secondary flow velocity in the bypass decreases, the impact on the main flow weakens, the cross section of the nozzle first throat (5) increases, and the double throat pneumatic vector nozzle is in high flow condition; when the adjustable triangular block (4) moves toward the cross section of the nozzle second throat (10), the outlet area of ​​the bypass channel turning section (8) decreases, the secondary flow velocity in the bypass increases, the impact on the main flow strengthens, the cross section of the nozzle first throat (5) decreases, and the double throat pneumatic vector nozzle is in low flow condition.

8. The control method for a bypass-type dual-throat pneumatic vector nozzle according to claim 5, characterized in that, The distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat pneumatic vector nozzle satisfy 0.1914≤L1 / H≤0.4886; Under the premise of ensuring effective vector effect, L1 and H satisfy 0.2783≤L1 / H≤0.4283.

9. The control method for a bypass-type dual-throat pneumatic vector nozzle according to claim 6, characterized in that, The adjustable triangular block (4) is slidably connected to the adjustable triangular block geometric vector compensation adjustment guide rail (15). The distance L1 between the inner cusps of the adjustable triangular block and the inlet height H of the dual-throat aerodynamic vector nozzle satisfy 0.2783≤L1 / H≤0.3842.

10. The control method for a bypass-type dual-throat pneumatic vector nozzle according to claim 7, characterized in that, The horizontal distance L2 between the vertex of the adjustable triangular block (4) and the downstream tip of the nozzle throat (5) satisfies 0.08753≤L2 / H≤0.3501 with respect to the nozzle inlet height H.

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