A water landing test system and test method

Abstract

The present invention relates to a water landing test system and method. The test system includes a launch device for launching a scaled-down aircraft model, a water pool for the scaled-down aircraft model to undergo water landing testing, a first data acquisition module for collecting motion characteristic information of the scaled-down aircraft model during water landing, a second data acquisition module for collecting force characteristic information of the scaled-down aircraft model during water landing, and a data processing module for analyzing the changing relationship between the motion characteristic information and the force characteristic information. The launch device includes a launch rail, a launch trolley that slides with the launch rail, a locking and releasing mechanism, and a launch mechanism. The launch mechanism includes a drive assembly that applies different launch forces to the trolley to achieve different speeds, and an interception assembly that stops the trolley to eject the scaled-down aircraft model. The system can test and analyze the relationship between the motion characteristics, fluid dynamics characteristics, and strength characteristics of the aircraft during water landing.

Description

Technical Field

[0001] The present invention relates to the field of forced landing of aircraft on water, and in particular to a forced landing test system and test method. Background Art

[0002] Advanced air transportation, using unmanned low-altitude aircraft to transport people and cargo, is considered an emerging sector globally. In regions with well-developed water systems, unmanned low-altitude water-crossing aircraft present significant development opportunities. Furthermore, with the increasing frequency of global cross-ocean flights, water landing performance, as a key safety indicator, is gaining increasing attention. Therefore, it is crucial to conduct water landing airworthiness compliance testing on aircraft.

[0003] Issues that need to be focused on when studying forced landings include whether the aircraft's posture is optimal at the moment of entry into the water, whether the aircraft's integrity can be guaranteed at the moment of impact and after it stops gliding on the water, and whether the aircraft has enough time to float on the water to wait for rescue.

[0004] Civil aviation standards currently have clear provisions for forced ditching, but lack realistic research results on specific aspects such as water entry attitude, optimal control, and structural damage. Using real aircraft for actual flight tests is prohibitively expensive, and safety is difficult to guarantee. Current domestic CFD calculations and tank drag test distance simulations also fall far short of realistic simulations.

[0005] Therefore, the industry urgently needs to develop a test system that can test and analyze the relationship between the motion characteristics, fluid dynamic characteristics and strength characteristics of the aircraft during the water landing process, and provide a safe test flight verification environment for some water-related aircraft, so as to carry out water-related performance verification, extreme conditions testing, and fault simulation testing, and improve the safety and reliability of aircraft design. Summary of the Invention

[0006] The present invention solves the problem that the industry urgently needs to develop a test system that can test and analyze the relationship between the motion characteristics, fluid dynamics characteristics and strength characteristics of the aircraft during the water landing process, and provide a safe test flight verification environment for some water-related aircraft. It provides a water ditching test system and test method to solve this technical problem. It can test and analyze the relationship between the motion characteristics, fluid dynamics characteristics and strength characteristics of the aircraft during the water landing process, and provide a safe test flight verification environment for some water-related aircraft, so as to carry out water-related performance verification, extreme condition testing, and fault simulation testing, thereby improving the safety and reliability of aircraft design.

[0007] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0008] A forced landing test system includes a launching device for launching a scaled-down model of an aircraft, a water pool for testing the scaled-down model's landing on water, a first data acquisition module for collecting motion characteristic information of the scaled-down model during landing, a second data acquisition module for collecting force characteristic information of the scaled-down model during landing, and a data processing module for analyzing the changing relationship between the motion characteristic information and the force characteristic information. The motion characteristic information includes the scaled-down model's water entry attitude angle and water entry velocity.

[0009] The ejection device includes a mounting base with a horizontal reference surface, an ejection slide rail movably connected below the mounting base with one end facing the pool, an ejection trolley slidably engaged with the ejection slide rail for carrying the scaled model, a locking and releasing mechanism for locking the ejection trolley before the ejection operation and unlocking the ejection trolley at the start of the ejection operation, and an ejection action mechanism for driving the ejection trolley to perform the ejection operation. The ejection action mechanism includes a driving assembly for applying different ejection forces to the ejection trolley to give different speeds, and an intercepting assembly for stopping the ejection trolley to eject the scaled model away.

[0010] The ejection slide rail includes two hinge points directly or indirectly hinged to the mounting base, the hinge axis of each hinge point is a horizontal line perpendicular to the sliding track of the ejection trolley, and at least one hinge point is hinged to the mounting base through a telescopic module with controlled telescopic extension;

[0011] The ejection trolley includes a body that slides with the ejection slide rail and a bracket for supporting the scaled model. The bracket is rotatably connected to the body, and the rotation axis between the bracket and the body is parallel to the sliding trajectory of the body. The bracket and the body are configured so that when the bracket supporting the scaled model is not subjected to external force, the bracket and the body remain relatively stationary.

[0012] Preferably, the first data acquisition module includes an underwater robot for capturing images of the scaled-down model's landing process from underwater and / or a camera unit for capturing images of the scaled-down model's landing process from outside the pool, and an analysis and processing unit for identifying motion characteristic information of the scaled-down model based on the images of the landing process.

[0013] When the camera unit is used to capture images of the scaled model's landing process, the camera unit is disposed on one side of the scaled model's landing trajectory or on both sides of the scaled model's landing trajectory, and the camera unit's lens is flush with the water surface in the pool. The pool wall and the water surface in the pool are both above the ground, and the pool wall is configured as follows:

[0014] The pool wall is a transparent wall panel, or

[0015] The pool wall is provided with a through hole for a camera to shoot an image of the scaled-down model during the water immersion process, and the through hole is provided with a transparent window.

[0016] Preferably, the camera unit includes at least two lenses for capturing images of the scaled model's immersion process in a binocular or multi-lens shooting manner. When binocular shooting is performed, the two lenses perform binocular shooting at an angle of 90°.

[0017] Preferably, the first data acquisition module further includes a light source for providing supplementary light to the water-impacting position of the scaled model.

[0018] Preferably, the first data acquisition module includes a gyroscope and an acceleration sensor built into the scaled model.

[0019] Preferably, the surface of the scaled model in contact with the water surface during landing is defined as a force-bearing surface, and the second data acquisition module includes a thin film sensor attached to the force-bearing surface to monitor pressure distribution information of the force-bearing surface.

[0020] Preferably, the load-bearing surface of the scaled model includes the regional surface corresponding to the belly of the aircraft to be tested, the lower surface of the wing and the position of the engine nacelle.

[0021] Preferably, the two ends of the ejection rail are defined as a near-water end and a far-water end, respectively, and the locking and releasing mechanism is provided at the far-water end of the ejection rail;

[0022] The driving component of the ejection action mechanism includes an elastic rope for pulling the ejection trolley to slide from the far water end to the near water end of the ejection slide rail, a servo winch for winding up the elastic rope, and a winding mechanism for driving the servo winch to rotate, and the servo winch rotates in coordination with the ejection slide rail; the intercepting component of the ejection action mechanism includes an arresting rope connected to the ejection slide rail, and the arresting rope is located on the sliding trajectory of the ejection trolley along the ejection slide rail.

[0023] Preferably, two first support blocks for supporting the two wings of the scaled model respectively and a second support block for supporting the tail are provided above the bracket, each of the support blocks is connected to a supporting rod parallel to the pitch axis of the scaled model, and a connecting block is provided below the scaled model, with the forward direction of the scaled model during ejection as the front side and the other side as the rear side, and a supporting groove adapted to the supporting rod is provided on the rear side of the connecting block.

[0024] Preferably, the connecting block is detachably connected to the scaled model.

[0025] Preferably, the support block is also provided with a spring pin assembly for preventing the scaled model from sliding off the support block, the spring pin assembly includes a pin structure that abuts against the scaled model to prevent the scaled model from sliding off the ejection trolley, and a spring that pushes the pin structure to maintain abutment with the scaled model, one end of the pin structure is a slope, and the pin structure abuts against the scaled model through the slope.

[0026] Preferably, when the bracket supports the scaled model, the rotation axis between the bracket and the vehicle body coincides with the roll axis of the scaled model.

[0027] Preferably, the water pool further comprises a wave-making mechanism for simulating the generation of waves.

[0028] A ditching test method based on the ditching test system comprises the following steps:

[0029] S1. Using the telescopic module to adjust the inclination angle of the ejection rail and the mounting base horizontal reference plane, and adjusting the ejection force by the drive assembly to adjust the attitude angle and / or ejection speed of the scaled model carried on the ejection vehicle;

[0030] S2. Release the locking release mechanism to lock the ejection trolley, so that the ejection trolley slides along the ejection rail until the ejection trolley is stopped by the interception assembly, and the scaled model flies into the pool from the ejection trolley;

[0031] S3. The two data acquisition modules respectively collect information on the motion characteristics and force characteristics of the scaled model during the water landing process and record the measured data of the scaled model;

[0032] S4. Repeat steps S1 to S3 until a predetermined amount of test data is obtained. After the predetermined amount of test data is obtained, the relationship between the motion characteristic information and the force characteristic information of the scaled model during the water landing is sorted and analyzed.

[0033] Preferably, the method further comprises the following steps:

[0034] S5. Perform fluid-structure interaction dynamics simulation of the scaled model's water impact process using XFlow software;

[0035] S6. The measured data of the scaled model and the simulation results obtained by XFlow software are mutually verified and integrated;

[0036] S7. Repeat steps S1 to S3, and iteratively modify the XFlow software simulation model and parameters based on the measured data of the scaled model collected again, until the XFlow software simulation model reaches the expected accuracy range, and then output the simulation model.

[0037] Beneficial technical effects of the technical solution of the present invention:

[0038] (1) The ejection device is used to eject the scaled model into the water. The first and second data acquisition modules simultaneously collect information about the motion and force characteristics of the scaled model during its impact. The ejection device's ejection mechanism drives the ejection trolley to slide along the length of the rail at varying speeds. The interceptor assembly then intercepts the trolley, allowing the scaled model to be ejected into the water independently due to its own inertia.

[0039] The ejection rail of the ejection device is hinged to the mounting base at two hinge points, one of which is hinged to the mounting base via a controlled telescopic module. Controlling the telescopic module's extension and retraction can change the inclination of the ejection rail, thereby changing the pitch angle of the scaled model. The ejection trolley includes a rotatably connected body and a bracket. The axis of rotation between the bracket and the body is parallel to the body's sliding trajectory. By rotating the bracket, the roll angle of the scaled model can be changed. By varying the ejection trolley's sliding speed and the pitch and roll angles of the scaled model, various water entry speeds and postures of the aircraft can be simulated. This allows for a comprehensive analysis and understanding of the relationship between the motion and force characteristics of the scaled model during water entry. This enables smooth flight verification, water wading performance verification, extreme conditions testing, and fault simulation testing of the aircraft, providing guidance for aircraft structural design and improving the safety and reliability of aircraft design.

[0040] (2) The configuration of a glass pool wall above the ground is conducive to observers and camera equipment observing (shooting) the movement state of the scale model when it lands on the water from the side, and then accurately monitoring the longitudinal movement characteristics of the aircraft such as the pitch angle and glide angle.

[0041] (3) A measurement solution that combines a camera unit with sensors built into the scaled model. The camera unit is a non-contact measurement device. Compared to measurement solutions that use only onboard gyroscopes and accelerometers, it offers advantages such as high measurement accuracy, convenient data transmission, and the ability to record video information about the scaled model's motion. Furthermore, this combination of a camera unit and sensors built into the scaled model can support measurement data fusion analysis later on, further improving measurement accuracy and system reliability.

[0042] (4) The thin film sensor is installed on the stress-bearing surface of the scaled model, including the belly, lower part of the wing and lower part of the engine nacelle of the scaled model. These positions are mainly selected based on the main stress-bearing parts and vulnerable parts of the scaled model during the water entry process. The stress and damage conditions of the scaled model during the water entry process can be comprehensively analyzed.

[0043] (V) XFlow can calculate the dynamic pressure distribution of water on various parts of the scaled model. By simulating the moment when the scaled model contacts the water surface, the impact force of water on the scaled model fuselage can be analyzed, thereby evaluating the integrity and potential damage of the structure. This has guiding significance for the study of structural strength characteristics. Based on the measured indoor scaled model water entry data and the results of simulation software such as XFlow, the mutual verification and fusion of test and simulation data are carried out, and the simulation model and related parameters are iteratively modified. This can improve the accuracy and reliability of the simulation model, facilitating the subsequent use of the simulation model to provide guidance for the structural design of related models. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic structural diagram of a ditching test system according to an embodiment of the present invention is shown;

[0045] Figure 2 A schematic structural diagram of an ejection device according to an embodiment of the present invention is shown;

[0046] Figure 3 A schematic diagram showing the coordination between the ejection vehicle and the scaled model in an embodiment of the present invention is shown;

[0047] Figure 4 Shown Figure 3 Enlarged view of point A in the middle;

[0048] Figure 5 A cross-sectional view of the ejection vehicle and the scaled model in an embodiment of the present invention is shown.

[0049] In the accompanying drawings:

[0050] 1-mounting base; 11-telescopic module; 2-ejection slide rail; 2a-far water end; 2b-near water end; 21-servo winch; 22-elastic rope; 23-barrier rope; 24-locking release mechanism; 3-ejection trolley; 31-carriage body; 32-bracket; 321-support block; 322-support rod; 323-spring pin assembly; 4-scale model; 41-connecting block; 411-support groove; 5-pool; 51-pool wall; 511-window; 52-camera unit; 53-light source. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following is a further detailed description of a water ditching test system and test method proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention, so they have no technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0052] The following will be combined with the Figures 1 to 5 The technical solutions of a ditching test system and test method of the present invention are described in detail with specific embodiments.

[0053] Example

[0054] like Figures 1 to 5 As shown, a water landing test system of this embodiment includes a launching device for launching a scaled-down aircraft model 4, a water pool 5 for the scaled-down model 4 to undergo water landing testing, a first data acquisition module for collecting motion characteristic information of the scaled-down model 4 during the landing process, a second data acquisition module for collecting force characteristic information of the scaled-down model 4 during the landing process, and a data processing module for analyzing the changing relationship between the motion characteristic information and the force characteristic information. The above-mentioned motion characteristic information includes the water entry attitude angle and the water entry speed of the scaled-down model 4. By simulating various water entry attitudes and water entry speeds of the aircraft landing, the relationship between the motion characteristic information and the force characteristic information of the scaled-down model 4 during the landing process can be comprehensively analyzed and understood.

[0055] Specifically, the ejection device includes a mounting base 1 having a horizontal reference surface, an ejection rail 2 movably connected to the mounting base 1, an ejection trolley 3 that slides with the ejection rail 2 and is used to carry a scaled model 4, a locking release mechanism 24 for locking the ejection trolley 3 before the ejection operation and unlocking the ejection trolley 3 at the beginning of the ejection operation, and an ejection action mechanism that drives the ejection trolley 3 to perform the ejection operation. In this embodiment, the mounting base 1 is fastened to the ceiling of the test site, and the bottom surface of the mounting base 1 is a horizontal surface. The ejection rail 2 is movably connected to the mounting base 1, and can directly control the ejection rail 2 to swing relative to the mounting base 1, thereby adjusting the entry angle of the scaled model 4. The ejection action mechanism includes a drive assembly that can drive the ejection trolley 3 to slide along the length of the ejection rail 2 at different speeds, and an interception assembly that is used to stop the ejection trolley 3 to eject the scaled model 4.

[0056] The connection relationship between the ejection rail 2 and the mounting base 1 is described in detail as follows:

[0057] When the scaled model 4 is tested for ejection into water, the ejection trolley 3 slides along the ejection rail 2 toward the water surface. It is necessary to drive the scaled model 4 to be ejected obliquely toward the water surface. Therefore, one end of the ejection rail 2 is positioned lower and closer to the water surface, while the other end is positioned higher and farther away from the water surface. First, the end of the ejection rail 2 closer to the water surface is defined as the near-water end 2b, and the end of the ejection rail 2 farther away from the water surface is defined as the far-water end 2a. The ejection rail 2 is provided with two hinge points that are directly or indirectly hinged to the mounting seat 1. The two hinge points are arranged along the length direction of the ejection rail 2, and the hinge axis of each hinge point is a horizontal line perpendicular to the sliding trajectory of the ejection trolley 3. In this embodiment, the two hinge points of the ejection slide 2 are connected to the mounting base 1 by a telescopic module 11. The ends of the telescopic module 11 are connected to the ejection slide 2 and the mounting base 1 in a hinged manner. When the two telescopic modules 11 are not synchronized, the ejection slide 2 can be tilted by adjusting the hinge connection between the telescopic module 11 and the mounting base 1 through controlled telescopic adjustment at at least one of the hinge points. The telescopic module 11 in this embodiment is a pneumatic cylinder. The cylinder body of the pneumatic cylinder is connected to the mounting base 1, and the piston rod of the pneumatic cylinder is connected to the ejection slide 2. Controlling the extension and contraction of the pneumatic cylinder can change the inclination angle of the ejection slide 2. It should be noted that in this embodiment, a fixed rod is also connected between the pneumatic cylinder near the water-proximal end 2b of the ejection slide 2 and the mounting base 1. The ends of the fixed rod are respectively fixedly connected to the mounting base 1 and the cylinder body of the pneumatic cylinder, thereby locking the position of the pneumatic cylinder, preventing it from swinging and only allowing it to extend and retract. However, the two pneumatic cylinders in this embodiment can also drive the ejection slide 2 to swing.

[0058] It should be understood that in another embodiment, one hinge point of the ejection rail 2 can also be directly connected to the mounting base 1, and the other hinge point can be connected to the mounting base 1 through the telescopic module 11. Controlling the telescopic module 11 to extend and retract can also drive the ejection rail 2 to swing, thereby changing the pitch angle of the scaled model 4 and adjusting the water entry attitude angle of the scaled model 4.

[0059] The structure of the ejection car 3 is specifically described as follows:

[0060] The ejection trolley 3 includes a body 31 that slides with the ejection rail 2 and a bracket 32 ​​for supporting the scaled model 4. The body 31 is installed below the ejection rail 2. The bracket 32 ​​is rotatably connected to the body 31, and the rotation axis between the bracket 32 ​​and the body 31 is parallel to the sliding trajectory of the body 31. The bracket 32 ​​and the body 31 fit tightly against each other. When the bracket 32 ​​supporting the scaled model 4 is not subject to external force, the friction between the bracket 32 ​​and the body 31 can keep the two relatively stationary, that is, the bracket 32 ​​can only rotate when the tester adjusts it. After the tester completes the angle adjustment of the bracket 32, the bracket 32 ​​supporting the scaled model 4 can no longer shift relative to the body 31. When the bracket 32 ​​and the body 31 are controlled to rotate relative to each other, the roll angle of the scaled model 4 can be changed, thereby adjusting the entry attitude angle of the scaled model 4.

[0061] In addition, the ejection action mechanism can also be used to change the speed at which the scaled model 4 is ejected. Based on this test equipment, the sliding speed of the ejection trolley 3, the pitch angle and roll angle of the scaled model 4 can be changed, thereby simulating various entry postures and entry speeds of the aircraft into the water. The relationship between the motion characteristic information and the force characteristic information of the scaled model 4 during the landing process can be fully analyzed and understood, and the aircraft flight test verification, wading performance verification, extreme condition test, and fault simulation test can be smoothly carried out, providing guidance for the aircraft structural design and improving the safety and reliability of the aircraft design.

[0062] The locking and releasing mechanism 24 is mounted on the distal end 2a of the ejection rail 2. The locking and releasing mechanism 24 switches between locking and releasing the ejection trolley 3. Before the ejection operation begins, the locking and releasing mechanism 24 is used to lock the body 31 of the ejection trolley 3 at the distal end 2a of the ejection rail 2. After the ejection mechanism is ready for ejection, the locking and releasing mechanism 24 is controlled to release the body 31 of the ejection trolley 3, and ejection can begin. The locking and releasing mechanism 24 can use a controlled clamp to clamp or release the body 31 of the ejection trolley 3. Alternatively, the locking and releasing mechanism 24 can use an electromagnet, a vacuum suction cup, or other structure to absorb the body 31 of the ejection trolley 3, lock the position of the ejection trolley 3, and release the ejection trolley 3 after releasing the absorption of the ejection trolley 3.

[0063] In this embodiment, the driving assembly of the ejection action mechanism includes a servo winch 21 installed and rotatably connected to the ejection slide rail 2, a winding mechanism that drives the servo winch 21 to rotate, and an elastic rope 22 wound on the servo winch 21. One end of the elastic rope 22 is fixedly connected to the servo winch 21, and the other end is connected to the body 31 of the ejection cart 3. The servo winch 21 rotates under the control of the winding mechanism. By winding the elastic rope 22, the tension of the elastic rope 22 can be changed. When the locking release mechanism 24 releases the ejection cart 3, the elastic ropes 22 with different tensions pull the ejection cart 3 to slide, which can enable the ejection cart 3 to reach different sliding speeds. In addition, it should be understood that the driving component of the ejection action mechanism needs to pull the ejection trolley 3 from the far water end 2a of the ejection slide rail 2 to the near water end 2b. The driving component in this embodiment is installed at the far water end 2a of the ejection slide rail 2, and the near water end 2b of the ejection slide rail 2 is rotatably connected to a pulley. The elastic rope 22 of the driving component first passes around the pulley at the near water end 2b of the ejection slide rail 2, and then connects to the ejection trolley 3. When the ejection trolley 3 is released, the taut elastic rope 22 will inevitably slide from the far water end 2a of the ejection slide rail 2 to the near water end 2b. The intercepting component of the ejection action mechanism includes an arresting rope 23 on the sliding track of the vehicle body 31. Both ends of the arresting rope 23 are connected to the ejection slide rail 2. The arresting rope 23 is suspended below the ejection slide rail 2. When the ejection trolley 3 slides past the arresting rope 23, the ejection trolley 3 is blocked by the arresting rope 23 and cannot continue to slide. The scaled model 4 installed on the ejection trolley 3 will be ejected due to inertia and fly into the pool 5, completing the ejection operation.

[0064] Specifically, three support blocks 321 are mounted above the bracket 32 ​​of the ejection vehicle 3. These include two first support blocks and one second support block. The two first support blocks are used to support the wings of the scaled model 4, while the second support block is used to support the tail. Each support block 321 has a through slot extending along the roll axis of the scaled model 4 at the top. Each slot is connected to a support rod 322 parallel to the pitch axis of the scaled model 4. The scaled model 4 is also connected to three connecting blocks 41 corresponding to each supporting block 321. The connecting blocks 41 are detachably connected to the scaled model 4. Each connecting block 41 is provided with a supporting groove 411 engaged with the supporting rod 322 on the side facing the far water end 2a of the ejection slide rail 2. The supporting groove 411 passes through the connecting block 41 along the direction of the pitch axis of the scaled model 4. When the scaled model 4 is installed on the bracket 32, each connecting block 41 is embedded in the corresponding supporting block 321 through groove, and the supporting rod 322 connected to the supporting block 321 passes through the supporting groove 411 of the corresponding connecting block 41. In the process of the ejection trolley 3 driving the scaled model 4 to slide toward the water surface, the supporting rod 322 of each supporting block 321 abuts against the groove wall of the supporting groove 411 of the corresponding connecting block 41, ensuring that the pitch angle of the scaled model 4 remains stable.

[0065] In addition, when the scaled model 4 is mounted on the ejection trolley 3, since the water-proximal end 2b of the ejection rail 2 is generally lower, the scaled model 4 tends to slide downward and detach from the ejection trolley 3. In order to prevent the scaled model 4 from detaching from the ejection trolley 3 before the ejection operation begins, a spring pin assembly 323 is also installed on the support block 321 to prevent the scaled model 4 from sliding off the support block 321. The spring pin assembly 323 includes a pin structure that abuts against the connecting block 41 of the scaled model 4 to prevent the scaled model 4 from sliding off the ejection trolley 3, and a spring that pushes the pin structure to slide toward the connecting block 41 of the scaled model 4. After the scaled model 4 is installed on the ejection trolley 3, one end of the pin structure faces the connecting block 41, and the end face of the pin structure facing the connecting block 41 is an inclined surface. The spring pushes the pin structure to slide toward the connecting block 41 of the scaled model 4, so that the pin structure is offset against the connecting block 41 of the scaled model 4 through the above-mentioned inclined surface. Before the ejection operation begins, it is necessary to ensure that the force exerted by the pin structure on the scaled model 4 is sufficient to prevent the scaled model 4 from sliding downward; when the ejection trolley 3 is stopped by the interception assembly, the scaled model 4 will continue to move toward the pool 5 due to inertia, and at the same time, the connecting block 41 of the scaled model 4 pushes the pin structure of the spring pin assembly 323 to retract, and the spring pin assembly 323 removes the obstruction to the scaled model 4, and the scaled model 4 can be ejected into the water.

[0066] Furthermore, when the bracket 32 ​​supports the scaled model 4, the rotation axis between the bracket 32 ​​and the vehicle body 31 coincides with the roll axis of the scaled model 4, so that the rotation angle of the bracket 32 ​​corresponds to the roll angle of the scaled model 4. Therefore, by controlling the rotation of the bracket 32 ​​by a specified angle, the roll angle of the scaled model 4 can be accurately adjusted.

[0067] Specifically, when collecting motion characteristic information during the landing of the scaled model 4, since the actual entry angle and velocity of the scaled model 4 during the actual launch cannot be accurately determined, the first data acquisition module includes a camera unit 52 that captures images of the scaled model 4 during the landing process from outside the pool 5, and an analysis and processing unit that identifies the motion characteristic information of the scaled model 4 based on the landing process images. The camera unit 52 captures images of the scaled model 4 during the landing process, and the analysis and processing unit then uses video analysis and image analysis techniques to determine motion characteristic information such as the entry angle and velocity of the scaled model 4. The obtained motion characteristic information is highly accurate, facilitating precise analysis of the relationship between the motion characteristic information and the force characteristic information during the landing of the scaled model 4. Specifically, the camera unit 52 can be positioned on one side of the landing trajectory of the scaled model 4 or on both sides of the landing trajectory. The camera unit 52's lens is flush with the water surface in the pool 5, allowing it to capture images of the scaled model 4 during the landing process from a horizontal perspective, facilitating accurate determination of the entry angle.

[0068] Because the camera unit 52 needs to capture images from outside the pool 5, the pool wall 51 and the water surface within the pool 5 are both elevated above ground level to facilitate access and installation of the camera unit 52. In this embodiment, the pool wall 51 is constructed of concrete and includes a through-hole for capturing images of the scaled-down model 4 during its immersion in the water. A transparent window 511 is installed in the through-hole to facilitate image capture by the camera unit 52. While it is understood that the pool wall 51 could alternatively be constructed of transparent glass panels for improved light transmittance and easier filming, a concrete sidewall with a transparent observation window is more suitable and less prone to cracking.

[0069] The camera unit 52 is a high-speed camera including at least two lenses for capturing images of the scaled model 4 during the water immersion process in a binocular or multi-lens manner. When binocular photography is performed, the two lenses perform binocular photography at an angle of 90°.

[0070] In order to ensure that the camera unit 52 can capture clear images, the first data acquisition module further includes a light source 53 for supplementing light to the water position of the scaled model 4 . The light source 53 in this embodiment is fixedly mounted on the bottom surface of the mounting base 1 .

[0071] In addition, the first data acquisition module may also use an underwater robot for capturing images of the scaled model 4 during its entry into the water. The underwater robot may be used alone or in conjunction with the camera unit 52 to capture images from different angles.

[0072] In addition, the camera unit 52 is a non-contact measurement device, and the first data acquisition module also includes a gyroscope and an accelerometer built into the scaled model 4. The gyroscope is used to measure the attitude angle of the scaled model 4, while the accelerometer can measure the acceleration and speed of the scaled model 4. The measurement solution using the camera unit 52 combined with the built-in sensors of the scaled model 4 has the characteristics of high measurement accuracy, while the camera unit 52 has the advantages of convenient measurement data transmission and the ability to record motion video information of the scaled model 4. The solution combining the camera unit 52 with the built-in sensors of the scaled model 4 can later support measurement data fusion analysis, further improving measurement accuracy and system reliability.

[0073] In this embodiment, the surface of the scaled model 4 that contacts the water during landing is defined as the force-bearing surface. The second data acquisition module includes a thin film sensor (not shown) attached to the force-bearing surface. When the scaled model 4 lands on the water, the thin film sensor can conveniently monitor the pressure distribution information on the force-bearing surface. In the scaled model 4, the force-bearing surface includes the surface corresponding to the belly of the aircraft under test, the underside of the wings, and the engine nacelles.

[0074] In addition, the water pool 5 also includes a wave-making mechanism for simulating the generation of waves, which can generate specified types of waves in the water pool 5, thereby simulating the landing process test under different sea conditions.

[0075] A ditching test method based on the ditching test system comprises the following steps:

[0076] S1. Using the telescopic module to adjust the inclination angle of the ejection rail 2 and the mounting base 1 on the horizontal reference plane, the ejection force is adjusted by the drive assembly to adjust the attitude angle and / or ejection speed of the scaled model 4 carried on the ejection vehicle 3;

[0077] S2. Unlock the release mechanism 24 to lock the ejection trolley 3, so that the ejection trolley 3 slides along the ejection rail 2 until the ejection trolley 3 is intercepted by the interception assembly, and the scaled model 4 is ejected from the trolley 3 and flies into the pool 5;

[0078] S3. Two data acquisition modules collect information about the motion characteristics and force characteristics of the scaled model 4 during the water landing process and record the measured data of the scaled model 4;

[0079] S4 repeats steps S1 to S3 until a predetermined amount of test data is obtained. After obtaining a predetermined amount of test data, the relationship between the motion characteristic information and the force characteristic information of the scaled model 4 during the water landing is analyzed;

[0080] S5. Perform fluid-structure interaction dynamics simulation of the water impaction process of scaled model 4 using XFlow software;

[0081] S6. The measured data of the scaled model 4 is mutually verified and integrated with the simulation results of the XFlow software;

[0082] S7. Repeat steps S1 to S3, and iteratively modify the XFlow software simulation model and parameters based on the measured data of the scaled model 4 collected again, until the XFlow software simulation model reaches the expected accuracy range, and then output the simulation model.

[0083] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A ditching test system, characterized in that: The device comprises a launching device for launching a scaled-down model of an aircraft, a water pool for testing the scaled-down model's landing in water, a first data acquisition module for collecting motion characteristic information of the scaled-down model during the landing process, a second data acquisition module for collecting force characteristic information of the scaled-down model during the landing process, and a data processing module for analyzing the changing relationship between the motion characteristic information and the force characteristic information, wherein the motion characteristic information includes the water entry attitude angle and water entry speed of the scaled-down model; The first data acquisition module includes an underwater robot for capturing images of the scaled model's landing process from underwater and / or a camera unit for capturing images of the scaled model's landing process from outside the pool, and an analysis and processing unit for identifying motion characteristic information of the scaled model based on the images of the landing process. The camera unit includes at least two lenses for capturing images of the scaled model's landing process in a binocular or multi-lens manner. When binocular photography is performed, the two lenses perform binocular photography at a 90° angle. When the camera unit is used to capture images of the scaled-down model's landing process, the camera unit is disposed on one side of the scaled-down model's landing trajectory or on both sides of the scaled-down model's landing trajectory, and a lens of the camera unit is flush with the water surface in the pool. The pool wall and the water surface in the pool are both above the ground. The pool wall is configured as follows: the pool wall is a transparent wall panel, or the pool wall is provided with a through hole for the lens to capture images of the scaled-down model's landing process, and the through hole is provided with a transparent window. The ejection device includes a mounting base with a horizontal reference surface, an ejection slide rail movably connected below the mounting base with one end facing the pool, an ejection trolley slidably engaged with the ejection slide rail for carrying the scaled model, a locking and releasing mechanism for locking the ejection trolley before the ejection operation and unlocking the ejection trolley at the start of the ejection operation, and an ejection action mechanism for driving the ejection trolley to perform the ejection operation. The ejection action mechanism includes a driving assembly for applying different ejection forces to the ejection trolley to give different speeds, and an intercepting assembly for stopping the ejection trolley to eject the scaled model away. The ejection slide rail includes two hinge points directly or indirectly hinged to the mounting base, the hinge axis of each hinge point is a horizontal line perpendicular to the sliding track of the ejection trolley, and at least one hinge point is hinged to the mounting base through a telescopic module with controlled telescopic extension; The ejection trolley includes a body that slides with the ejection slide rail and a bracket for supporting the scaled model. The bracket is rotatably connected to the body, and the rotation axis between the bracket and the body is parallel to the sliding trajectory of the body. The bracket and the body are configured so that when the bracket supporting the scaled model is not subjected to external force, the bracket and the body remain relatively stationary.

2. A ditching test system according to claim 1, characterized in that: The first data acquisition module also includes a light source for supplementing light to the water-impacting position of the scaled model.

3. A ditching test system according to claim 1, characterized in that: The first data acquisition module includes a gyroscope and an acceleration sensor built into a scaled model.

4. A ditching test system according to claim 1, characterized in that: The surface of the scaled model in contact with the water surface during the landing process is defined as the force-bearing surface, and the second data acquisition module includes a thin film sensor attached to the force-bearing surface to monitor the pressure distribution information of the force-bearing surface.

5. A ditching test system according to claim 4, characterized in that: The force-bearing surfaces of the scaled model include regional surfaces corresponding to the belly, lower surfaces of the wings, and engine nacelle positions of the aircraft to be tested.

6. A ditching test system according to claim 1, characterized in that: The two ends of the ejection rail are defined as a near-water end and a far-water end, respectively, and the locking and releasing mechanism is provided at the far-water end of the ejection rail; The driving component of the ejection action mechanism includes an elastic rope for pulling the ejection trolley to slide from the far water end to the near water end of the ejection slide rail, a servo winch for winding up the elastic rope, and a winding mechanism for driving the servo winch to rotate, and the servo winch rotates in coordination with the ejection slide rail; the intercepting component of the ejection action mechanism includes an arresting rope connected to the ejection slide rail, and the arresting rope is located on the sliding trajectory of the ejection trolley along the ejection slide rail.

7. The ditching test system according to claim 1, characterized in that: Two first support blocks for supporting the two wings of the scaled model and a second support block for supporting the tail are provided above the bracket. Each of the support blocks is connected to a supporting rod parallel to the pitch axis of the scaled model. A connecting block is provided below the scaled model, with the forward direction of the scaled model during ejection as the front side and the other side as the rear side. A supporting groove adapted to the supporting rod is provided on the rear side of the connecting block.

8. A ditching test system according to claim 7, characterized in that: The connecting block is detachably connected to the scaled model.

9. A ditching test system according to claim 7, characterized in that: The support block is also provided with a spring pin assembly for preventing the scaled model from sliding off the support block. The spring pin assembly includes a pin structure that abuts against the scaled model to prevent the scaled model from sliding off the ejection vehicle, and a spring that pushes the pin structure to maintain abutment with the scaled model. One end of the pin structure is a slope, and the pin structure abuts against the scaled model through the slope.

10. The ditching test system according to claim 1, characterized in that: When the bracket supports the scaled model, the rotation axis between the bracket and the vehicle body coincides with the roll axis of the scaled model.

11. The ditching test system according to claim 1, characterized in that: The water pool also includes a wave-making mechanism for simulating the generation of waves.

12. A ditching test method based on the ditching test system according to any one of claims 1 to 11, characterized in that: The following steps are involved: S1. Using the telescopic module to adjust the inclination angle of the ejection rail and the mounting base horizontal reference plane, and adjusting the ejection force by the drive assembly to adjust the attitude angle and / or ejection speed of the scaled model carried on the ejection vehicle; S2. Release the locking release mechanism to lock the ejection trolley, so that the ejection trolley slides along the ejection rail until the ejection trolley is stopped by the interception assembly, and the scaled model flies into the pool from the ejection trolley; S3. The two data acquisition modules respectively collect information on the motion characteristics and force characteristics of the scaled model during the water landing process and record the measured data of the scaled model; S4. Repeat steps S1 to S3 until a predetermined amount of test data is obtained. After the predetermined amount of test data is obtained, the relationship between the motion characteristic information and the force characteristic information of the scaled model during the water landing is sorted and analyzed.

13. A ditching test method according to claim 12, characterized in that: The following steps are also included: S5. Perform fluid-structure interaction dynamics simulation of the scaled model's water impact process using XFlow software; S6. The measured data of the scaled model and the simulation results obtained by XFlow software are mutually verified and integrated; S7. Repeat steps S1 to S3, and iteratively modify the XFlow software simulation model and parameters based on the measured data of the scaled model collected again, until the XFlow software simulation model reaches the expected accuracy range, and then output the simulation model.

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