Aero-engine special-shaped nozzle structure deformation characteristic measurement test bed and test method

Abstract

The invention relates to an aero-engine special-shaped nozzle structure deformation characteristic measurement test bench and an experiment method, and belongs to the technical field of aero-engine test. Comprising a special-shaped spray pipe clamping module, an aerodynamic load simulation module and a measurement module, a special-shaped spray pipe is suspended on a test support frame through the special-shaped spray pipe clamping module, the aerodynamic load simulation module provides simulated airflow for the special-shaped spray pipe, and high-precision measurement of deformation of the special-shaped spray pipe is completed through the measurement module; the special-shaped spray pipe clamping module comprises a double-side self-adaptive adjusting mechanism installed at an outlet of a special-shaped spray pipe, and installation of spray pipes of different geometric configurations is achieved by adjusting the sliding position and the section of the lower end connecting end. The aerodynamic load simulation module is installed at an inlet of the special-shaped spray pipe through the flange connecting assembly, and simulative airflow is introduced into the special-shaped spray pipe, so that the special-shaped spray pipe generates accurate and controllable aerodynamic deformation. The problem of fracture caused by the fact that the outlet of the spray pipe is not supported is solved, and high-precision measurement and non-shielding shooting can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine testing, and in particular relates to a test bench and an experimental method for measuring deformation characteristics of an aero-engine special-shaped nozzle structure. Background Art

[0002] The aeroengine nozzle is a key component in generating thrust for fighter jets. Its aerodynamic performance and structural reliability have a decisive impact on the overall performance of the aircraft. With the increasing demand for stealth combat platforms and super-maneuverable flight, low-observable, shaped nozzles are gradually becoming a core configuration in the next-generation aerodynamic propulsion systems. Under sustained high-speed flight and complex airflow environments, nozzles are susceptible to asymmetric load excitation, leading to structural deformation, stress concentration, and unstable dynamic response. Therefore, the aerodynamic deformation behavior of shaped nozzle structures under typical operating conditions urgently needs to be studied through controlled and repeatable experimental observations.

[0003] Existing related research, such as the 2022 "Propulsion Technology" paper "Study on Fluid-Structure Coupling Characteristics of Double S-Bend Nozzles," points out that special-shaped nozzles deform violently in the second bend section and at the exit, and the nozzle exit is more prone to flutter, causing material fatigue and structural failure. Under the existing experimental platform, due to the complex shape and variable structure of special-shaped nozzles, the traditional rigid bracket clamping method has limitations such as difficult adaptation, slow adjustment, and cumbersome assembly and disassembly; especially when the nozzle outlet is not effectively constrained, it is easy to cause flutter or even breakage of the free end, causing damage to the experimental instrument or safety hazards. At the same time, traditional measurement methods are limited to a single shooting angle, making it difficult to achieve synchronous capture of the full-domain deformation characteristics of the nozzle.

[0004] Therefore, there is an urgent need for an experimental testing platform with strong adaptability, high stability and non-contact stereoscopic observation capabilities to support the precise structural response measurement of special-shaped nozzles under aerodynamic excitation and the safe and controllable experiment. Summary of the Invention

[0005] Technical issues to be solved: To overcome the shortcomings of existing technologies, the present invention provides a test bench and experimental method for measuring the deformation characteristics of aircraft engine special-shaped nozzle structures. This test bench utilizes a special-shaped nozzle clamping module to quickly locate and secure the nozzle outlet, addressing the problem of nozzle breakage caused by lack of support. The clamping module also accommodates nozzles of varying geometric configurations (such as S-bend, rectangular, and elliptical cross-sections), allowing replacement in less than 10 minutes and significantly improving efficiency. The combination of a binocular camera and the clamping module enables high-precision measurement and unobstructed photography.

[0006] The technical solution of the present invention is: a test bench for measuring the deformation characteristics of the structure of an aircraft engine special-shaped nozzle, comprising a special-shaped nozzle clamping module, an aerodynamic load simulation module, and a measurement module. The special-shaped nozzle is suspended on a test support frame by the special-shaped nozzle clamping module, the aerodynamic load simulation module provides simulated airflow to the special-shaped nozzle, and the measurement module completes high-precision measurement of the deformation of the special-shaped nozzle with a measurement accuracy of ±0.001mm. The special-shaped nozzle clamping module includes a double-sided adaptive adjustment mechanism installed at the special-shaped nozzle outlet. The upper end of the double-sided adaptive adjustment mechanism is slidably connected to the test support frame, and the lower end is detachably connected to the special-shaped nozzle outlet. By adjusting the sliding position and the cross-section of the lower end connection end, nozzles of different geometric configurations can be installed; The aerodynamic load simulation module is installed at the inlet of the special-shaped nozzle through a flange connection component, and a simulated airflow is introduced into the special-shaped nozzle to cause the special-shaped nozzle to produce aerodynamic deformation that is precisely controllable.

[0007] A further technical solution of the present invention is: the measurement module is a binocular stereo vision precision measurement system, comprising two cameras, and the optical paths of the two cameras are arranged at an angle of 15-30 degrees.

[0008] A further technical solution of the present invention is: the bilateral adaptive adjustment mechanism includes two symmetrically arranged adjustment plates, the upper end of the adjustment plate is a strip plate with an oblong hole in the vertical direction, wherein the oblong hole serves as an adjustment guide groove for the installation position of the adjustment plate and the test support frame; the lower end of the adjustment plate is a positioning groove consistent with the outlet profile of the special-shaped nozzle to be tested, and the outlet of the special-shaped nozzle is positioned by the positioning grooves at the lower ends of the two symmetrical adjustment plates. After positioning, the outlet of the special-shaped nozzle is clamped and fixed by fasteners located on both sides of the positioning grooves.

[0009] A further technical solution of the present invention is: the test support frame is a rectangular frame structure, and outlet adjustment rods are slidably installed on two opposite sides of the top rectangular frame. By adjusting the installation position of the outlet adjustment rod, the displacement adjustment of the special-shaped nozzle along the direction perpendicular to its symmetrical cross-section is completed; T-shaped grooves are symmetrically opened on both sides of the outlet adjustment rod in the horizontal direction for installing the head of the positioning bolt, and the screw of the positioning bolt passes through the oblong hole of the adjustment plate and is fastened by a nut; by adjusting the penetration position of the positioning bolt on the oblong hole, the height adjustment of the positioning groove of the adjustment plate is achieved; by adjusting the horizontal position of the positioning bolt on the outlet adjustment rod, the displacement adjustment of the positioning groove of the adjustment plate along the center line direction of the outlet of the special-shaped nozzle is achieved.

[0010] A further technical solution of the present invention is that a transverse support stabilizing bar is installed in the middle of the height direction of the test support frame for installing the measurement module.

[0011] A further technical solution of the present invention is: the flange connection assembly is coaxially mounted on the outer edge of the special-shaped nozzle inlet, its outer diameter is consistent with the outer diameter of the aerodynamic load simulation module, and 8 through holes are opened circumferentially along the upper edge of the flange disk surface, and the 8 through holes are respectively connected to the aerodynamic load simulation module through fasteners.

[0012] A further technical solution of the present invention is: the pneumatic load simulation module is a pneumatic load simulation device, which adopts an electronically controlled proportional valve system to control the compressed air output, has a built-in PID feedback regulation loop, provides continuously adjustable stable air pressure between 0.1MPa and 10.0MPa, a maximum air flow rate of 500L / min, a flow error of no more than ±2%, and is sealedly connected to the inlet of the special-shaped nozzle.

[0013] An experimental method for measuring deformation characteristics of an aircraft engine special-shaped nozzle structure, the specific steps are as follows: Install the flange connection assembly on the outer edge of the nozzle inlet, and fix the aerodynamic load simulation module to the nozzle inlet through bolts arranged circumferentially on the flange connection assembly; Build a test support frame and install the outlet adjustment rod horizontally on the top of the test support frame. The initial position of the outlet adjustment rod is set in the middle of its installation edge; Connect the upper end of the bilateral adaptive adjustment mechanism to the outlet adjustment rod, and adjust the longitudinal position and horizontal position of the bilateral adaptive adjustment mechanism and the horizontal position of the outlet adjustment rod so that the positioning groove at the lower end of the bilateral adaptive adjustment mechanism is flush with the nozzle outlet, and clamp and secure with fasteners; Adjust the binocular stereo vision precision measurement system so that its two cameras are at an angle of 15–30° to ensure complete coverage of the nozzle deformation area; The aerodynamic load simulation module is controlled to introduce 0.1–10.0 MPa high-pressure gas into the nozzle. After the deformation stabilizes, the binocular stereo vision precision measurement system synchronously collects data. Change to a different nozzle configuration and repeat the above steps.

[0014] A further technical solution of the present invention is: the initial pressure of the airflow entering the aerodynamic load simulation module is 0.1 MPa, and is gradually increased to 2.7 MPa at intervals of 0.2 MPa, and each pressure level is maintained for 30 seconds. After the nozzle structure deformation stabilizes, the binocular measurement system synchronously collects image data, sets the sampling frequency to 1 Hz, collects 300 frames of images and takes the average value.

[0015] A further technical solution of the present invention is: the camera resolution of the binocular stereo vision precision measurement system is 2048×2048 pixels, the frame rate is 30fps, the spatial resolution is not less than 0.05mm, and the tail end of the camera is connected to a power supply and a display device to ensure that the images of the two cameras are synchronized.

[0016] Beneficial effects The beneficial effects of the present invention are: through modular design, the present invention achieves precise control of nozzle positioning and installation, airflow simulation, and measurement. It can also prevent nozzle outlet breakage caused by the nozzle outlet being unfixed, and there is no obstruction to the stereoscopic vision precision measurement system. The specific effects are analyzed as follows: 1. This invention uses a binocular stereo vision system (camera angle 15–30°, resolution 2048×2048 pixels) to achieve non-contact full-field scanning, with a measurement accuracy of ±0.001mm and a spatial resolution ≥0.05mm. This far exceeds traditional strain gauges (±0.01mm) or single-view systems, and accurately captures subtle deformation features in key areas such as nozzle bends.

[0017] 2. This invention features a dedicated double-sided adaptive adjustment mechanism. The positioning groove fits the nozzle outlet contour and is tightened with 25 N·m bolts. This completely solves the problem of flutter and even breakage at the nozzle outlet free end in traditional clamping, ensuring experimental safety and data reliability.

[0018] 3. The modular design (flange connection assembly + adjustable mechanism) of this invention supports the rapid replacement of non-axisymmetric nozzles with S-bend, rectangular, or elliptical cross-sections in 10 minutes or less (compared to 30 minutes or more with traditional methods), improving efficiency by 67%. It also adapts to nozzle outlets of different sizes through horizontal and vertical displacement adjustment, eliminating the cost of customized chemical equipment.

[0019] 4. The pneumatic load device (PID adjustable from 0.1–10.0 MPa) simulates real engine operating conditions, achieving a flow rate error of ≤±2%. The step-by-step loading strategy (0.2 MPa interval / 30-second pressure hold) combined with a binocular system for synchronous data acquisition enables full-field data capture (averaging 300 frames) under stable deformation conditions, eliminating transient errors.

[0020] 5. The camera's 15-30° angle arrangement avoids obstruction of the field of view caused by the nozzle's curved structure; the 12,000 N / mm high-rigidity support frame (12 transverse rods + 4 longitudinal rods) suppresses vibration interference and ensures measurement repeatability.

[0021] 6. The flange connection assembly (standardized interface with 8 bolt holes) of the present invention ensures airtightness; the wide adjustable pressure range (0.1–10.0 MPa) covers all engine operating conditions, providing high-confidence experimental data for structural life prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of an optional test bench for measuring deformation characteristics of an aircraft engine special-shaped nozzle structure according to an embodiment of the present invention; Figure 2This is a schematic diagram of an optional special-shaped nozzle of an aircraft engine special-shaped nozzle structure deformation characteristic measurement test bench according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the installation of an adjustment plate and an outlet adjustment rod of an optional test bench for measuring deformation characteristics of an aircraft engine special-shaped nozzle structure in an embodiment of the present invention; Figure 4 This is a schematic diagram of the installation angle of a binocular stereo vision precision measurement system for an aircraft engine special-shaped nozzle structure deformation characteristic measurement test bench, which is optional in an embodiment of the present invention; Figure 5 This is a schematic diagram of structural deformation measurement results of a test bench for measuring structural deformation characteristics of an aircraft engine special-shaped nozzle, which is optional in an embodiment of the present invention; Explanation of the accompanying symbols: 1. Complex geometric configuration nozzle of aircraft engine, 1-1. First type of special-shaped nozzle, 1-2. Second type of special-shaped nozzle, 1-3. Third type of special-shaped nozzle; 2. Flange connection assembly; 3. Bilateral adaptive adjustment mechanism, 3-1. First adjustment plate, 3-2. Second adjustment plate; 4. Outlet adjustment rod; 5. Longitudinal support stabilizer bar; 6. Lateral support stabilizer bar; 7. Aerodynamic load simulation device; 8. Binocular stereo vision precision measurement system. DETAILED DESCRIPTION The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] Based on the existing experimental platform, due to the complex shape and variable structure of the special-shaped nozzle, the traditional rigid bracket clamping method has limitations such as difficult adaptation, slow adjustment, and cumbersome disassembly and assembly; especially when the nozzle outlet is not effectively constrained, it is easy to cause the free end to flutter or even break, causing damage to the experimental equipment or safety hazards. The present invention provides an aircraft engine special-shaped nozzle structure deformation characteristic measurement test bench, including a special-shaped nozzle clamping module, an aerodynamic load simulation module, and a measurement module. The special-shaped nozzle is suspended on the test support frame through the special-shaped nozzle clamping module, and the aerodynamic load simulation module provides simulated airflow to the special-shaped nozzle. The measurement module is used to complete high-precision measurement of the deformation of the special-shaped nozzle, with a measurement accuracy of ±0.001mm; the special-shaped nozzle clamping module includes a double-sided adaptive adjustment mechanism installed at the outlet of the special-shaped nozzle, the upper end of the double-sided adaptive adjustment mechanism is slidably connected to the test support frame, and the lower end is detachably connected to the outlet of the special-shaped nozzle. By adjusting the sliding position and the cross-section of the lower end connection, the installation of nozzles with different geometric configurations can be achieved; the aerodynamic load simulation module is installed at the inlet of the special-shaped nozzle through a flange connection assembly, and a simulated airflow is introduced into the special-shaped nozzle, so that the special-shaped nozzle produces precise and controllable aerodynamic deformation.

[0025] Specifically, the measurement module is a binocular stereo vision precision measurement system, which includes two cameras, and the optical paths of the two cameras are arranged at an angle of 15-30 degrees.

[0026] Specifically, the bilateral adaptive adjustment mechanism includes two symmetrically arranged adjustment plates, the upper end of the adjustment plate is a strip plate with an oblong hole in the vertical direction, wherein the oblong hole serves as an adjustment guide groove for the installation position of the adjustment plate and the test support frame; the lower end of the adjustment plate is a positioning groove consistent with the outlet profile of the special-shaped nozzle to be tested, and the outlet of the special-shaped nozzle is positioned by the positioning grooves at the lower ends of the two symmetrical adjustment plates. After positioning, the outlet of the special-shaped nozzle is clamped and fixed by fasteners located on both sides of the positioning grooves.

[0027] Specifically, the test support frame is a rectangular frame structure, and outlet adjustment rods are slidably installed on two opposite sides of the top rectangular frame. By adjusting the installation position of the outlet adjustment rod, the displacement adjustment of the special-shaped nozzle along the direction perpendicular to its symmetrical cross-section is completed; T-shaped grooves are symmetrically opened on both sides of the outlet adjustment rod in the horizontal direction for installing the head of the positioning bolt, and the screw of the positioning bolt passes through the oblong hole of the adjustment plate and is fastened by a nut; by adjusting the penetration position of the positioning bolt on the oblong hole, the height adjustment of the positioning groove of the adjustment plate is achieved; by adjusting the horizontal position of the positioning bolt on the outlet adjustment rod, the displacement adjustment of the positioning groove of the adjustment plate along the center line direction of the outlet of the special-shaped nozzle is achieved.

[0028] Specifically, a transverse support stabilizing bar is installed in the middle of the test support frame in the height direction for installing the measurement module.

[0029] Specifically, the flange connection assembly is coaxially mounted on the outer edge of the special-shaped nozzle inlet, and its outer diameter is consistent with the outer diameter of the aerodynamic load simulation device. Eight through holes are circumferentially opened on the upper edge of the flange disk, and the eight through holes are respectively connected to the aerodynamic load simulation device through fasteners.

[0030] Specifically, the pneumatic load simulation device uses an electronically controlled proportional valve system to control the compressed air output, and has a built-in PID feedback regulation loop to provide continuously adjustable stable air pressure between 0.1MPa and 10.0MPa. The maximum air flow rate is 500L / min, the flow error does not exceed ±2%, and it is sealed with the inlet of the special-shaped nozzle.

[0031] The present invention proposes an experimental method for measuring the deformation characteristics of an aircraft engine special-shaped nozzle structure, and the specific steps are as follows: Install the flange connection assembly on the outer edge of the nozzle inlet, and fix the aerodynamic load simulation device to the nozzle inlet through bolts arranged circumferentially on the flange connection assembly; Build a test support frame and install the outlet adjustment rod horizontally on the top of the test support frame. The initial position of the outlet adjustment rod is set in the middle of its installation edge; Connect the upper end of the bilateral adaptive adjustment mechanism to the outlet adjustment rod, and adjust the longitudinal position and horizontal position of the bilateral adaptive adjustment mechanism and the horizontal position of the outlet adjustment rod so that the positioning groove at the lower end of the bilateral adaptive adjustment mechanism is flush with the nozzle outlet, and clamp and secure with fasteners; Adjust the binocular stereo vision precision measurement system so that its two cameras are at an angle of 15–30° to ensure complete coverage of the nozzle deformation area; The aerodynamic load simulation device is controlled to introduce 0.1–10.0 MPa high-pressure gas into the nozzle. After the deformation stabilizes, the binocular stereo vision precision measurement system synchronously collects data. Change to a different nozzle configuration and repeat the above steps.

[0032] Specifically, the initial pressure of the airflow introduced into the aerodynamic load simulation device is 0.1 MPa, and is gradually increased to 2.7 MPa at intervals of 0.2 MPa, and maintained at each pressure level for 30 seconds. After the nozzle structure deformation stabilizes, the binocular measurement system synchronously collects image data, sets the sampling frequency to 1 Hz, collects 300 frames of images, and takes the average value.

[0033] Specifically, the camera resolution of the binocular stereo vision precision measurement system is 2048×2048 pixels, the frame rate is 30fps, the spatial resolution is not less than 0.05mm, and the rear end of the camera is connected to a power supply and a display device to ensure synchronization of the images of the two cameras.

[0034] The above technical solution is further described below with reference to examples and drawings: In one embodiment, referring to Figure 1 As shown in the figure, a stereoscopic vision test bench for measuring the deformation characteristics of a complex-geometry nozzle structure of an aircraft engine comprises: a complex-geometry nozzle 1, a flange connection assembly 2, a bilateral adaptive adjustment mechanism 3, an outlet adjustment rod 4, a longitudinal support stabilizer 5, a transverse support stabilizer 6, an aerodynamic load simulation device 7, and a binocular stereoscopic vision precision measurement system 8. The inlet of the complex-geometry nozzle 1 is connected to the flange connection assembly 2, which is connected to the aerodynamic load simulation device 7. The outlet of the nozzle 1 is connected to the bilateral adaptive adjustment mechanism 3. The aerodynamic load simulation device 7 is used to simulate the airflow within the engine, which flows through the nozzle 1 and causes precise and controllable aerodynamic deformation. The bilateral adaptive adjustment mechanism 3 is connected to the outlet adjustment rod 4, which is connected to the top transverse support stabilizer 6 of the test support frame. The binocular stereoscopic vision precision measurement system 8 is connected to the middle transverse support stabilizer 6 of the test support frame. The cameras are arranged at an angle of 15-30 degrees. The twelve transverse support stabilizers 6 and the four longitudinal support stabilizers 5 are interconnected to form a stable support frame.

[0035] The stereoscopic vision measurement test bench for deformation characteristics of complex geometric configuration nozzles of aircraft engines of this embodiment is used to carry out deformation characteristics measurement tests of special-shaped nozzles of aircraft engines. The experimental fixation of the nozzle 1 of the complex geometric configuration of the aircraft engine is completed by the bilateral adaptive adjustment mechanism 3 and the outlet adjustment rod 4, thereby preventing the nozzle outlet from breaking due to the lack of fixation of the nozzle outlet, and there is no obstruction to the binocular stereoscopic vision precision measurement system 8. In addition, by changing the position and size of the bilateral adaptive adjustment mechanism 3, the outlet adjustment rod 4, the longitudinal support stabilizer bar 5, and the transverse support stabilizer bar 6, it is possible to quickly replace and fix the measurement of different special-shaped nozzles 1 of aircraft engines. In one embodiment, Figure 1 、 2 As shown, the complex geometric configuration of the aircraft engine nozzle 1-1 / 1-2 / 1-3 is a non-axisymmetric structure with typical complex geometric characteristics. The inlet of nozzle 1 is connected to the aerodynamic load simulation device 7 via a flange connection assembly 2, and the outlet is fixedly connected via a bilateral adaptive adjustment mechanism 3 to prevent deflection or loosening caused by deformation. The aerodynamic load simulation device 7 is used to simulate the flow conditions inside the real engine, generating a high-pressure airflow within a controllable range. It acts on the interior of the nozzle 1 to induce its actual structural deformation under operating conditions.

[0036] The flange connection assembly 2 is a high-precision coaxial interface component, its outer circumference precisely matching the outlet port of the aerodynamic load simulator 7. Eight 12mm diameter bolt holes are evenly distributed on its flange surface, secured with eight M12 high-strength bolts. This flange structure is connected to the nozzle 1 using girth welding, ensuring sufficient connection rigidity and sealing even under load.

[0037] In one embodiment, Figure 1 、 3 As shown, the bilateral adaptive adjustment mechanism 3 comprises a first adjustment plate 3-1 and a second adjustment plate 3-2, symmetrically arranged on either side of the nozzle outlet 1. Each adjustment plate has two oblong holes perpendicular to the horizontal at its upper end, serving as vertical guideways. Adjusting the position of the positioning bolts within the oblong holes allows the adjustment plate to move along the longitudinal support stabilizer bar 5 (upward and downward in the figure). Adjusting the adjustment plate's mounting position relative to the outlet adjustment bar 4 allows the adjustment plate to move along the transverse support stabilizer bar 6 (forward and backward in the figure). The oblong holes are 100 mm and 80 mm long, respectively, and, combined with the precision guide rail structure and fastening bolts, ensure reliable positioning after adjustment. The bottom of the adjustment plate features a positioning groove precisely shaped to the nozzle outlet contour, providing close contact with the end face of the nozzle 1, forming a closed, constrained support. The adjustment mechanism on both sides is secured by two M10 hexagonal bolts, tightened to a torque of 25 N·m to prevent relative slippage caused by load.

[0038] In one embodiment, Figure 1 、 4 As shown, the binocular camera shooting system 7 is installed on the lateral support stabilizer bar 6; the two cameras of the binocular stereo vision precision measurement system 8 are kept in the same horizontal position, with a longitudinal angle of 15°-30°, and the tail ends are connected to the power supply device and the display device to keep the screen sizes of the two cameras in the display device the same and the screen clear.

[0039] In one embodiment, Figure 1 As shown, the outlet adjustment rod 4 uses a screw-nut drive structure to control its linear movement, enabling bidirectional adjustment within a ±500mm range with an adjustment accuracy better than 1mm. The system is fixed by a clamping bracket and the middle section of the transverse support stabilizer bar 6, which bears the entire mass and positioning of the nozzle end adjustment system.

[0040] In one embodiment, Figure 1 As shown, the test support frame is equipped with 12 transverse support stabilizers 6 and four longitudinal support stabilizers 5. Each bar is made of high-strength aluminum alloy with a 50mm x 50mm square cross-section. The two types of support bars are connected by L- and T-shaped connectors (support frame connectors) to form a closed spatial truss structure, ensuring the overall system structure has a spatial stiffness of at least 12,000 N / mm under loading conditions.

[0041] In one embodiment, Figure 1 As shown, the binocular stereo vision precision measurement system 8 utilizes two high-resolution CCD industrial cameras with a resolution of 2048×2048 pixels and a frame rate of 30 fps, paired with high-transparency fixed-focus lenses. The two cameras are mounted on a mounting bracket with a three-dimensional adjustment mechanism and fixed to the surface of a lateral support stabilizer bar 6. The angle between the two cameras is set to 20°, and the mounting distance is 300 mm. The camera images are transmitted to the back-end processing system via Gigabit Ethernet. The accompanying measurement software supports automatic calibration, stereo reconstruction, dedistortion correction, 3D coordinate extraction, and surface fitting. The measurement system achieves a spatial resolution of 0.05 mm, with a measurement error of no more than ±0.001 mm.

[0042] In one embodiment, Figure 1 As shown, pneumatic load simulation device 7 uses an electronically controlled proportional valve system to control the compressed air output. A built-in PID feedback control loop provides a continuously adjustable, stable air pressure between 0.1 MPa and 10.0 MPa, with a maximum air flow rate of 500 L / min and a flow rate error of no more than ±2%. This device maintains a stable connection to nozzle 1, preventing air leakage and ensuring aerodynamic equivalence during structural response testing.

[0043] In one embodiment, Figures 1 to 4 As shown, the nozzle 1's inlet is connected to an aerodynamic load simulation device 7 via a flange connection assembly 2. The nozzle's outlet is positioned and clamped by a bilaterally adaptive adjustment mechanism 3, which is connected to a top lateral support stabilizer bar 6 via an outlet adjustment rod 4, forming a multi-dimensional adjustment channel. The lateral support stabilizer bar 6 and the longitudinal support stabilizer bar 5 are connected by high-rigidity connectors to form a closed, stable frame, ensuring the stability and repeatability of the entire system. A binocular stereoscopic precision measurement system 8 is positioned on both sides of the front of the measurement test area, enabling unobstructed, synchronous 3D data acquisition throughout the nozzle's deformation process.

[0044] In one embodiment, Figure 1 As shown in FIG, an experimental method for a stereoscopic vision measurement test bench for deformation characteristics of a nozzle structure with complex geometric configuration of an aircraft engine is described. The specific experimental steps are as follows: Step 1: Build the test apparatus. After securing the nozzle 1 to the flange connection assembly 2, connect it to the aerodynamic load simulator 7 using eight M12 bolts. Install the twelve transverse stabilizer bars 6 and four longitudinal stabilizer bars 5 according to the standard design drawings and secure them with support connectors to form a closed truss structure. Install the outlet adjustment rod 4 and connect it to the adjustment mechanism 3, ensuring that the nozzle outlet centerline is coaxial with the adjustment plate centerline. Step 2: Measurement System Installation. Mount the binocular stereo vision precision measurement system 8 in front of the lateral support stabilizer bar 6 using a bracket. Adjust the camera angle to 20° with the horizontal line to ensure that the imaging field of view covers the nozzle outlet area. Power on and connect to the data acquisition host. Use the calibration target plate to complete binocular calibration and record the camera intrinsic and extrinsic parameter matrices for subsequent 3D reconstruction. Step 3: Loading deformation test. Set the initial pressure of the pneumatic load simulation device 7 to 0.1MPa, and gradually increase it to 2.7MPa at 0.2MPa intervals. Maintain each pressure level for 30 seconds. After the nozzle structure deformation stabilizes, the binocular measurement system 8 synchronously collects image data, and performs feature point matching and three-dimensional coordinate calculation through the supporting algorithm. Set the sampling frequency to 1Hz, collect 300 frames of images and take the average value. The collected images are processed as follows: Figure 5 As shown; Step 4: Nozzle Replacement Experiment. Remove the original nozzle 1 and replace it with a different nozzle configuration. Repeat Steps 1 through 3, recording its deformation response at each pressure level. Thanks to the rapid adjustment capabilities of the dual-side adaptive adjustment mechanism 3 and the outlet adjustment lever 4, the total nozzle replacement time is no more than 10 minutes.

[0045] While ensuring structural rigidity and measurement accuracy, the present invention achieves high versatility, high repeatability and high adaptability. It is suitable for fluid-solid coupling deformation measurement research of various types of complex geometric nozzles, and provides accurate experimental support for nozzle structure design and life prediction.

[0046] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A test bench for measuring deformation characteristics of aircraft engine special-shaped nozzle structures, characterized by: It includes a special-shaped nozzle clamping module, an aerodynamic load simulation module, and a measurement module. The special-shaped nozzle is suspended on the test support frame through the special-shaped nozzle clamping module. The aerodynamic load simulation module provides simulated airflow to the special-shaped nozzle. The measurement module completes high-precision measurement of the special-shaped nozzle deformation with a measurement accuracy of ±0.001mm. The special-shaped nozzle clamping module includes a double-sided adaptive adjustment mechanism installed at the special-shaped nozzle outlet. The upper end of the double-sided adaptive adjustment mechanism is slidably connected to the test support frame, and the lower end is detachably connected to the special-shaped nozzle outlet. By adjusting the sliding position and the cross-section of the lower end connection end, nozzles of different geometric configurations can be installed; The aerodynamic load simulation module is installed at the inlet of the special-shaped nozzle through a flange connection component, and a simulated airflow is introduced into the special-shaped nozzle to cause the special-shaped nozzle to produce aerodynamic deformation that is precisely controllable.

2. The test bench for measuring deformation characteristics of aircraft engine special-shaped nozzle structures according to claim 1, characterized in that: The measurement module is a binocular stereo vision precision measurement system, which includes two cameras, and the optical paths of the two cameras are arranged at an angle of 15-30 degrees.

3. The test bench for measuring deformation characteristics of aircraft engine special-shaped nozzle structures according to claim 1, characterized in that: The bilateral adaptive adjustment mechanism includes two symmetrically arranged adjustment plates, the upper end of which is a strip plate with an oblong hole in the vertical direction, wherein the oblong hole serves as an adjustment guide groove for the installation position of the adjustment plate and the test support frame; the lower end of the adjustment plate is a positioning groove consistent with the outlet profile of the special-shaped nozzle to be tested, and the outlet of the special-shaped nozzle is positioned by the positioning grooves at the lower ends of the two symmetrical adjustment plates. After positioning, the outlet of the special-shaped nozzle is clamped and fixed by fasteners located on both sides of the positioning grooves.

4. The test bench for measuring deformation characteristics of aircraft engine special-shaped nozzle structures according to claim 3, characterized in that: The test support frame is a rectangular frame structure, and outlet adjustment rods are slidably installed on two opposite sides of the top rectangular frame. By adjusting the installation position of the outlet adjustment rod, the displacement adjustment of the special-shaped nozzle along the direction perpendicular to its symmetrical cross-section is completed; T-shaped grooves are symmetrically opened on both sides of the outlet adjustment rod in the horizontal direction for installing the head of the positioning bolt, and the screw of the positioning bolt passes through the oblong hole of the adjustment plate and is fastened by a nut; by adjusting the penetration position of the positioning bolt on the oblong hole, the height adjustment of the positioning groove of the adjustment plate is achieved; by adjusting the horizontal position of the positioning bolt on the outlet adjustment rod, the displacement adjustment of the positioning groove of the adjustment plate along the center line direction of the outlet of the special-shaped nozzle is achieved.

5. The test bench for measuring deformation characteristics of aircraft engine special-shaped nozzle structures according to claim 4, characterized in that: The test support frame is provided with a transverse support stabilizing bar in the middle of the height direction for installing the measurement module.

6. The test bench for measuring deformation characteristics of aircraft engine special-shaped nozzle structures according to claim 1, characterized in that: The flange connection assembly is coaxially mounted on the outer edge of the special-shaped nozzle inlet, and its outer diameter is consistent with the outer diameter of the aerodynamic load simulation module. Eight through holes are opened circumferentially along the upper edge of the flange disk, and the eight through holes are respectively connected to the aerodynamic load simulation module through fasteners.

7. The test bench for measuring deformation characteristics of aircraft engine special-shaped nozzle structures according to claim 1, characterized in that: The pneumatic load simulation module is a pneumatic load simulation device that uses an electronically controlled proportional valve system to control the compressed air output. It has a built-in PID feedback regulation loop and provides continuously adjustable stable air pressure between 0.1MPa and 10.0MPa. The maximum air flow rate is 500L / min, the flow error does not exceed ±2%, and it is sealed with the inlet of the special-shaped nozzle.

8. A method for measuring deformation characteristics of an aircraft engine's special-shaped nozzle structure, implemented by the test bench for measuring deformation characteristics of an aircraft engine's special-shaped nozzle structure according to any one of claims 1 to 7; characterized in that The specific steps are as follows: Install the flange connection assembly on the outer edge of the nozzle inlet, and fix the aerodynamic load simulation module to the nozzle inlet through bolts arranged circumferentially on the flange connection assembly; Build a test support frame and install the outlet adjustment rod horizontally on the top of the test support frame. The initial position of the outlet adjustment rod is set in the middle of its installation edge; Connect the upper end of the bilateral adaptive adjustment mechanism to the outlet adjustment rod, and adjust the longitudinal position and horizontal position of the bilateral adaptive adjustment mechanism and the horizontal position of the outlet adjustment rod so that the positioning groove at the lower end of the bilateral adaptive adjustment mechanism is flush with the nozzle outlet, and clamp and secure with fasteners; Adjust the binocular stereo vision precision measurement system so that its two cameras are at an angle of 15–30° to ensure complete coverage of the nozzle deformation area; The aerodynamic load simulation module is controlled to introduce 0.1–10.0 MPa high-pressure gas into the nozzle. After the deformation stabilizes, the binocular stereo vision precision measurement system synchronously collects data. Change to a different nozzle configuration and repeat the above steps.

9. The method for measuring deformation characteristics of an aircraft engine special-shaped nozzle structure according to claim 8, characterized in that: The initial pressure of the airflow introduced into the aerodynamic load simulation module is 0.1 MPa, and is gradually increased to 2.7 MPa at intervals of 0.2 MPa. Each pressure level is maintained for 30 seconds. After the nozzle structure deformation stabilizes, the binocular measurement system synchronously collects image data, sets the sampling frequency to 1 Hz, collects 300 frames of images, and takes the average value.

10. The method for measuring deformation characteristics of an aircraft engine special-shaped nozzle structure according to claim 8, characterized in that: The binocular stereo vision precision measurement system has a camera resolution of 2048×2048 pixels, a frame rate of 30fps, a spatial resolution of not less than 0.05mm, and the rear end of the camera is connected to a power supply and a display device to ensure synchronization of the images of the two cameras.

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