A test system and test method for multi-dimensional wave impact test

Abstract

This invention discloses a test system and method for multi-dimensional wave impact testing, specifically relating to the field of hydrodynamic testing. It includes a test tank and a high-speed camera. The test tank is equipped with a wave generator. A front mounting panel and a rear mounting panel are rotatably connected within the test tank, linked by a hinge. Limiting components are provided on both the front and rear mounting panels. A test model is also placed within the test tank, with pressure sensors mounted on its surface. The high-speed camera is electrically connected to a computer, which in turn is electrically connected to a buzzer and a hydrophone. This invention solves the problems of existing wave impact pressure acquisition processes, which require numerous channels and take a long time, potentially leading to insufficient memory and data loss. Furthermore, writing large amounts of test data to hard drives reduces testing efficiency. This invention achieves efficient acquisition of coupled data such as load, sound, and flow field under extreme wave conditions.

Description

Technical Field

[0001] This invention relates to the field of hydrodynamic testing, and in particular to a test system and method for multi-dimensional wave impact testing. Background Technology

[0002] Wave impact on structures refers to the strong nonlinear interaction between ocean waves and marine structures, characterized by large peak loads and short durations. This phenomenon frequently occurs in extreme marine environments, causing severe damage to large-scale cross-river and cross-sea projects such as offshore platforms, wharf projects, and cross-sea bridges, threatening the lives and property of personnel. Therefore, the problem of wave impact on structures has received considerable attention from scholars and engineers and is a hot and challenging issue in the field of marine engineering.

[0003] For such complex slamming processes, theoretical analysis can only provide simplified analytical results of slamming loads and limited information on the slamming flow field. Numerical simulation has gradually become an effective means of studying the impact of waves on structures. Currently, scholars at home and abroad have conducted extensive numerical studies on the characteristics of wave slamming loads on marine structures, the slamming process, and its influencing factors, and have obtained many important research conclusions. Numerical simulation methods are mainly divided into mesh-based methods and meshless methods. Mesh-based methods, such as the finite element method, finite volume method, and finite difference method, require the establishment of a mesh to discretize the computational domain. They are suitable for handling simple flow problems, but when dealing with moving boundary problems with free surfaces, re-meshing is required and the calculation is more complex. At the same time, re-meshing is difficult when the topology changes greatly, making it difficult to accurately track rapidly changing free surfaces and fluid-structure interfaces. Meshless methods, such as smoothed particle hydrodynamics and moving particle semi-implicit methods, are not bound by meshes and use discretely distributed particle particles to simulate continuous medium fluids. They can handle problems with large deformations of free surfaces, but when dealing with high Reynolds number flows, artificial viscosity needs to be introduced, and the computational efficiency is relatively low.

[0004] Wave impacts on structures involve coupling effects between fluids and structures, resulting in structural deformation and complex free surface phenomena such as wave surface rolling and breaking. This requires enormous computational resources, and the accuracy and precision of capturing wave impact pressure still need improvement. Compared to the former two methods, physical model experiments typically yield more accurate and realistic results. Wave flume equipment, however, is a powerful experimental tool in marine engineering, widely used in the study of various structures (offshore wind turbines, breakwaters, subsea pipelines, oil platforms, etc.). Existing experimental schemes are often limited to acquiring impact pressure, lacking multi-dimensional data acquisition of the impact process. Furthermore, due to the large peak impact load and short impact time, high sampling frequencies are often required during experiments. However, the numerous channels and long acquisition times required for wave impact pressure can lead to memory shortages and data loss during acquisition, and writing large amounts of data to hard drives also reduces experimental efficiency. Based on these issues, there is an urgent need for an efficient experimental measurement system to improve data acquisition efficiency. Summary of the Invention

[0005] The present invention aims to provide a test system and test method for multi-dimensional wave impact testing, which solves the problems in the existing test process, such as the need for multiple channels and long time for wave impact pressure acquisition, the possibility of insufficient memory and loss of test data, and the reduction of test efficiency due to writing a large amount of test data to the hard disk.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A test system for multi-dimensional wave impact testing includes a test tank and a high-speed camera located outside the test tank. An observation window is provided on the front side of the test tank, and a wave generator is provided on the left side of the test tank. A front mounting panel and a rear mounting panel located on the right side of the wave generator are rotatably connected inside the test tank. Both the front and rear mounting panels are rotatably and sealingly connected to the two inner walls of the test tank. The front and rear mounting panels are connected by hinges. Limiting components are provided on both the front and rear mounting panels to restrict their movement. A test model is also provided inside the test tank. Multiple pressure sensors are provided on the surface of the test model. The high-speed camera is used to capture the wave impact process and the flow field characteristics before and after it. The high-speed camera is electrically connected to a computer, and the computer is electrically connected to a buzzer and a hydrophone located on the top of the test tank. The hydrophone is located on the left side of the front mounting panel.

[0007] Furthermore, the limiting component includes two sliding plates respectively disposed on both sides of the front mounting panel or the rear mounting panel. Each sliding plate is slidably connected to the top of the test water tank. The top of the test water tank has multiple threaded holes, and the sliding plates are connected to the threaded holes by limiting bolts.

[0008] Furthermore, each of the two sliding plates has a wedge-shaped rubber pad on its opposite side.

[0009] Furthermore, a traction motor is provided on the sliding plate located on the left side, and a traction rope is wound on the traction motor. The traction rope is fixedly connected to the front mounting panel or the rear mounting panel, and an opening is provided on the sliding plate for the traction rope to pass through.

[0010] The above settings allow for adjustment of the test model's position or its suspension, simulating wave impact testing during the free vibration of a floating body. Furthermore, when the test model is not mounted on the front mounting panel, both the front and rear mounting panels can be placed flat at the bottom of the test tank or angled to simulate different underwater terrains.

[0011] Furthermore, the test model is detached and connected to the front mounting panel or limiting assembly.

[0012] Furthermore, reflective tracer particles are distributed inside the test tank, and a laser is also provided outside the test tank, with the laser guided by a light guide arm.

[0013] Furthermore, a high-powered lighting lamp is installed above the test tank.

[0014] With the above setup, tracer particles are illuminated on the measurement plane under the combined action of a single laser or weak illumination and a laser. A high-speed camera can capture a series of consecutive images based on different exposure positions. Using image correlation techniques, the distance traveled by the same tracer particle pattern in two images is calculated, and its velocity is simultaneously determined, thus describing the flow field characteristics within the tank. Furthermore, near the surface of the flow field, wave breaking and impact cause bright spots in the captured images under laser illumination. Under sufficient illumination, the high-speed camera can capture wave propagation patterns, including bubble formation and dissipation, wave curling, falling, and breaking. Bubbles, acting as "tracer particles" in the aerated region, are illuminated against the water behind the experimental tank, allowing the images to capture the shadows formed by the bubbles. A cross-correlation algorithm is then used to calculate the structural texture, yielding the bubble velocity as the velocity of the aerated region. This technique is used to analyze the flow field before and after the impact of breaking waves on structures.

[0015] Furthermore, the test water tank is also equipped with a wave height meter and a flow velocity meter located on the left side of the front mounting panel. The wave height meter and flow velocity meter are used to measure the flow field characteristics and velocity in the non-photographed area.

[0016] Furthermore, the test method includes the following steps:

[0017] S1. Fix the test model on the front mounting panel or limiting component of the test system. If the test model is not mounted on the front mounting panel, place one end of the front mounting panel flat on the bottom of the test water tank, and adjust the rear mounting panel to form a slope with a large tilt angle.

[0018] S2. The position or angle of the measurement model in the test tank is determined by the front mounting panel and the limiting components.

[0019] S3. By controlling the wave generator to generate a wave group, the wave group is focused at a designated location, and the waves break at the designated location and impact the test model.

[0020] S4. Simultaneously measure the peak pressure during wave impact, the image of wave propagation pattern, the flow field characteristics and velocity, and the sound of wave breaking and impact through pressure sensors, high-speed cameras, flow meters and hydrophones.

[0021] S5. Set the sampling position and sampling frequency of the pressure sensor according to the focused wave group characteristics in step S3.

[0022] S6. The pressure during wave impact is measured by the voltage signal of the pressure sensor, and the wave height is measured by the wave height meter. The sound signal and electrical signal when the buzzer is activated are simultaneously pre-recorded to achieve synchronization with the sound of wave breaking and impact. The synchronized measurement signal is obtained through program processing.

[0023] S7. Repeat steps S2 to S6, changing the preset angle and tilt angle between the test model and the vertical plane of the test tank to achieve tests of different wave impact modes.

[0024] S8. Analyze the experimental data and study the extreme wave impact process and impact characteristics under different wave parameters and structural positions.

[0025] Compared with existing technologies, the beneficial effects of this solution are:

[0026] 1. This invention provides a multi-dimensional wave impact testing system capable of fixing and adjusting the positions of test models of different shapes and sizes, as well as simulating different wave impact modes, thus expanding the applicability and flexibility of the test. Simultaneously, this invention also provides a testing method for the system, capable of simultaneously measuring multiple data such as pressure, sound, and flow field during wave impact, providing comprehensive experimental information for studying the impact of waves on ocean structures and facilitating the revelation of the physical mechanisms and laws of wave impact. Furthermore, this testing method calculates the pressure acquisition area based on the wave impact mode and focusing characteristics, improving the test acquisition efficiency by reducing the sampling frequency of pressure sensors outside the designated area.

[0027] 2. This invention also addresses the problems of existing experimental systems lacking multi-dimensional data acquisition of the impact process, having a single fixed structural form, and lacking observation of the complex wave morphology before and after the impact process. The test model of this invention has multiple fixing methods, can simulate different wave impact modes, and simultaneously measure various data such as pressure, sound, and flow field during wave impact, providing an effective experimental means for studying the impact of waves on marine structures. This experimental system can not only measure the wave impact load and local slamming pressure acting on the structure, but also consider the variation characteristics of impact pressure under different impact modes and different fixed structural modes. It also considers the influence of sound free on the surface foam of the broken liquid on the impact load, simulating the impact characteristics and patterns of marine structures under different sea conditions. Targeting the characteristics of impact pressure and focused wave groups, this experimental method dynamically sets the pressure sampling position and sampling frequency, reducing the memory and hard drive requirements of the acquisition equipment. Attached Figure Description

[0028] Figure 1 This is an axonometric view of the front mounting panel of a test system for a multi-dimensional wave impact test according to Example 1;

[0029] Figure 2 This is a front view of the test system for a multi-dimensional wave impact test according to Example 1;

[0030] Figure 3 This is a multidimensional data graph collected by the test system of a multidimensional wave impact test in Example 1;

[0031] Figure 4 This is an axonometric view of the front mounting panel of a test system for a multi-dimensional wave impact test, as described in Example 2. Detailed Implementation

[0032] The present invention will be further described in detail below through specific embodiments:

[0033] The reference numerals in the accompanying drawings include: 1. Test water tank; 2. High-speed camera; 3. Observation window; 4. Wave generator; 5. Front mounting panel; 6. Rear mounting panel; 7. Sliding plate; 8. Limit bolt; 9. Rubber pad; 10. Traction motor; 11. Traction rope; 12. Test model; 13. Pressure sensor; 14. Fixing plate; 15. Hydrophone; 16. Laser; 17. Light guide arm; 18. Illumination lamp.

[0034] Example 1

[0035] like Figures 1 to 3As shown, a test system for multi-dimensional wave impact testing includes a test tank 1 and a set of high-speed cameras 2 located outside the test tank 1. An observation window 3 is provided on the front side of the test tank 1, and a wave generator 4 is provided on the left side of the test tank 1. In this embodiment, the wave generator 4 consists of a cylinder and a push plate. The cylinder is fixed inside the test tank 1 by a support plate, and the push plate is slidably and sealingly connected inside the test tank 1. A front mounting panel 5 and a rear mounting panel 6 are rotatably connected to the right side of the wave generator 4 inside the test tank 1. Both the front mounting panel 5 and the rear mounting panel 6 are rotatably and sealingly connected to the front and rear inner walls of the test tank 1. The front mounting panel 5 and the rear mounting panel 6 are connected by hinges. When the front mounting panel 5 is placed flat in the test tank 1, it does not interfere with the wave generator 4, allowing the front mounting panel 5 to be placed at the bottom of the test tank 1 and forming a certain slope with the rear mounting panel 6 to simulate different underwater terrains. Both the front mounting panel 5 and the rear mounting panel 6 are equipped with limiting components, which can restrict the movement of the front mounting panel 5 or the rear mounting panel 6. The limiting components consist of two sliding plates 7 respectively located on both sides of the front mounting panel 5 or the rear mounting panel 6. Each sliding plate 7 is slidably connected to the top of the test water tank 1. The top of the test water tank 1 has multiple horizontally distributed threaded holes. The sliding plates 7 are connected to the threaded holes through limiting bolts 8. A wedge-shaped rubber pad 9 is also attached to the opposite side of the two sliding plates 7. A traction motor 10 is bolted to the sliding plate 7 on the left side of each limiting component. A traction rope 11 is wound on the traction motor 10. In this embodiment, the traction rope 11 is not elastic. In the figure, the traction rope 11 is freely wound on the output shaft of the traction motor 10. The traction rope 11 is fixedly connected to the end of the front mounting panel 5 or the rear mounting panel 6 by adhesive. The sliding plate 7 has an opening for the traction rope 11 to pass through. The limiting component, rubber pad 9, and traction rope 11 restrict the movement of the front mounting panel 5 or the rear mounting panel 6. While limiting the placement of the front mounting panel 5 or the rear mounting panel 6, the angle between the front mounting panel 5 or the rear mounting panel 6 and the horizontal plane can be adjusted, increasing the adjustment range. Simultaneously, the traction motor 10 and the traction rope 11 allow the test model 12 to be suspended in a floating state for wave impact testing simulating the free vibration process of a floating body. The rear mounting panel 6 is constructed of high-strength aluminum plate and rigid ribs, ensuring the strength and stability of the testing system and guaranteeing the smooth conduct of tests where the test model 12's attitude is changed to different tilt angles.

[0036] The test tank 1 also contains a test model 12, the surface of which is equipped with multiple pressure sensors 13. These pressure sensors 13 are used to measure the peak pressure and position during wave impact. A high-speed camera 2 is used to capture the wave impact process and the flow field characteristics before and after it. The high-speed camera 2 is electrically connected to a computer, which is electrically connected to a buzzer and a hydrophone 15 located on the top of the test tank 1. In this embodiment, the hydrophone 15 is a waterproof microphone. The hydrophone 15 is mounted on the left side of the front mounting panel 5 via a fixing plate 14. The hydrophone 15 is used to measure the sound during wave breaking and impact. The buzzer switches on and off after receiving the measurement signal, synchronizing the sound with other measurements.

[0037] Reflective tracer particles are distributed within the test tank 1. A laser 16 is installed outside the test tank 1, and the laser 16 is guided by a light guide arm 17 to generate a surface laser, allowing the laser surface to be perpendicular or parallel to the test tank 1. A high-powered illumination lamp 18 is installed above the test tank 1. Under the condition of laser alone, or under the combined effect of weak illumination and laser, the tracer particles on the measurement plane are illuminated, and the high-speed camera 2 can capture a series of continuous images according to different exposure positions. By using cross-correlation technology, the movement speed is obtained by measuring the distance the same particle pattern moves in two images, thus describing the flow field characteristics within the tank. In addition, near the surface of the flow field, wave breaking and impact will cause the captured image to appear as a bright spot under laser illumination. When the illumination is sufficient, the high-speed camera 2 can capture the wave propagation pattern, including the generation and dissipation of bubbles, and the curling, falling, and breaking of waves. Bubbles, acting as "tracer particles" in the aeration region, are illuminated against the water behind the experimental tank 1, allowing the image to capture the shadows cast by the bubbles. A cross-correlation algorithm is then used to calculate the structural texture, yielding the bubble velocity as the velocity of the aeration region. This technique is employed to analyze the flow field before and after the impact of the breaking wave on the structure. The experimental tank 1 is also equipped with a wave height meter and a flow meter, used to measure the flow field characteristics and velocities in areas not being photographed.

[0038] According to the principle of linear superposition, the wavefront at any point can be represented as the result of the superposition of regular waves of different frequencies and directions. The structure is placed at a distance from the wave-pushing plate. At this point, the control signal of wave generator 4 causes the wave group to focus near the structure, that is... ,in and Set according to experimental requirements. Water depth ,Depend on The frequency is (circular frequency) ,in It is a period), with an amplitude of wave number is The wavefronts formed are:

[0039]

[0040] Initial phase is Satisfy the following formula:

[0041]

[0042] The focusing time of each component wave is Focus position The frequencies and wavenumbers of the constituent waves satisfy the dispersion relation:

[0043]

[0044] The height of the pressure sensor from the bottom of the water tank is Select Pressure sensors within a certain range, enabling them to measure pressure over time. Within this range, the sampling frequency is dynamically adjusted to 10kHz. Outside this range, the pressure sampling frequency is adjusted to 100Hz.

[0045] Example 2

[0046] As attached Figure 4 As shown, the only difference between this embodiment and Embodiment 1 is that this embodiment does not include the traction motor 10 and the traction rope 11, and the test model 12 is bolted to the left side of the front mounting panel 5. The front mounting panel 5 has multiple bolt holes pre-drilled to fix test models 12 of different shapes and sizes, such as cylindrical, square, and spherical. Simultaneously, by utilizing the arbitrary angle formed between the test model 12 and the vertical plane of the test tank 1, different wave impact modes can be simulated, such as frontal impact and inclined plane impact.

[0047] Example 3

[0048] This embodiment uses the test system of Embodiment 1 or 2, and its test method includes the following steps:

[0049] S1. Fix the test model 12 on the front mounting panel 5 or the limiting component in the test system. If the test model 12 is not mounted on the front mounting panel 5, place one end of the front mounting panel 5 flat at the bottom of the test water tank 1, and adjust the rear mounting panel 6 to form a slope with a large tilt angle.

[0050] S2. The position or angle of the measurement model in the test water tank 1 is determined by the front mounting panel 5 and the limiting component. If the test model 12 is set in the test water tank 1 by the limiting component, its position is adjusted by sliding the test model 12.

[0051] S3. By controlling the wave generator 4, a wave group is generated. The wave group is focused at a designated location, and the waves break at the designated location and impact the test model 12.

[0052] S4. Simultaneously measure the peak pressure during wave impact, the image of wave propagation morphology, the flow field characteristics and velocity, and the sound of wave breaking and impact through pressure sensor 13, high-speed camera, flow meter and hydrophone 15.

[0053] S5. Set the sampling position and sampling frequency of the pressure sensor 13 according to the focused wave group characteristics in step S3.

[0054] S6. The pressure during wave impact is measured by the voltage signal of the pressure sensor, and the wave height is measured by the wave height meter. The sound signal and electrical signal when the buzzer is activated are simultaneously pre-recorded to achieve synchronization with the sound of wave breaking and impact. The synchronized measurement signal is obtained through program processing.

[0055] S7. Repeat steps S2 to S6 to change the preset angle and tilt angle between the test model 12 and the vertical plane of the test tank 1 to achieve tests of different wave impact modes.

[0056] S8. Analyze the experimental data and study the extreme wave impact process and impact characteristics under different wave parameters and structural positions.

[0057] The above are merely embodiments of the present invention, and common knowledge such as specific structures and / or characteristics in the solutions are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A test system for multi-dimensional wave impact testing, characterized in that: The device includes a test tank and a high-speed camera located outside the test tank. An observation window is provided on the front side of the test tank, and a wave generator is located on the left side of the test tank. A front mounting panel and a rear mounting panel located on the right side of the wave generator are rotatably connected inside the test tank. Both the front and rear mounting panels are rotatably and sealingly connected to the two inner walls of the test tank and are connected by hinges. Each of the front and rear mounting panels is equipped with a limiting component to restrict its movement. A test model is also provided inside the test tank, and multiple pressure sensors are provided on the surface of the test model. The high-speed camera is used to capture the wave impact process and the flow field characteristics before and after it. The high-speed camera is electrically connected to a computer, and the computer is electrically connected to a buzzer and a hydrophone located on the top of the test tank, on the left side of the front mounting panel. The limiting assembly includes two sliding plates respectively disposed on both sides of the front mounting panel or the rear mounting panel. Each sliding plate is slidably connected to the top of the test water tank. The top of the test water tank has multiple threaded holes, and the sliding plates are connected to the threaded holes by limiting bolts. The test model is detached and connected to the front mounting panel or limiting component; A traction motor is provided on the sliding plate located on the left side. A traction rope is wound on the traction motor. The traction rope is fixedly connected to the front mounting panel or the rear mounting panel. An opening is provided on the sliding plate for the traction rope to pass through. When the test model is connected to the limit assembly, the traction motor and traction rope can keep the test model in a suspended state.

2. The test system for a multi-dimensional wave impact test according to claim 1, characterized in that: Both sliding plates have wedge-shaped rubber pads on opposite sides.

3. The test system for a multi-dimensional wave impact test according to claim 1, characterized in that: The test tank contains reflective tracer particles, and a laser is installed outside the test tank. The laser is guided by a light guide arm.

4. The test system for a multi-dimensional wave impact test according to claim 3, characterized in that: A high-powered light is installed above the test tank.

5. The test system for a multi-dimensional wave impact test according to claim 4, characterized in that: The test tank is also equipped with a wave height meter and a flow velocity meter located on the left side of the front mounting panel. The wave height meter and flow velocity meter are used to measure the flow field characteristics and velocity in the non-photographed area.

6. A test method based on the test system for a multi-dimensional wave impact test according to any one of claims 1-5, characterized in that: The experimental method includes the following steps: S1. Fix the test model on the front mounting panel or limiting component of the test system. If the test model is not mounted on the front mounting panel, place one end of the front mounting panel flat at the bottom of the test tank, and adjust the rear mounting panel to form a slope with a large tilt angle. S2. Adjust the position or angle of the measurement model in the test tank using the front mounting panel and limiting components; S3. By controlling the wave generator to generate a wave group, the wave group is focused at a designated location, and the waves break at the designated location and impact the test model. S4. Simultaneously measure the peak pressure during wave impact, the image of wave propagation pattern, flow field characteristics and velocity, and the sound of wave breaking and impact through pressure sensors, high-speed cameras, flow meters and hydrophones. S5. Set the sampling position and sampling frequency of the pressure sensor according to the focused wave group characteristics in step S3. S6. The pressure during wave impact is measured by the voltage signal of the pressure sensor, and the wave height is measured by the wave height meter. The sound signal and electrical signal when the buzzer is activated are simultaneously pre-recorded to achieve synchronization with the sound of wave breaking and impact. The synchronized measurement signal is obtained through program processing. S7. Repeat steps S2 to S6, changing the preset angle and tilt angle between the test model and the vertical plane of the test tank to achieve tests of different wave impact modes. S8. Analyze the experimental data and study the extreme wave impact process and impact characteristics under different wave parameters and structural positions.

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