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

Abstract

The invention discloses a test system and a test method for a multi-dimensional wave impact test, and particularly relates to the field of hydrodynamic tests. Comprising a test water tank and a high-speed camera, the test water tank is provided with a wave maker, a front mounting panel and a rear mounting panel are rotatably connected in the test water tank, the front mounting panel and the rear mounting panel are connected through a hinge, limiting assemblies are arranged on the front mounting panel and the rear mounting panel, a test model is further arranged in the test water tank, and the high-speed camera is arranged in the test model. A pressure sensor is arranged on the surface of the test model, the high-speed camera is electrically connected with a computer, and the computer is electrically connected with a buzzer and a hydrophone. According to the technical scheme, the problems that in the existing test process, multiple channels are needed for wave impact pressure collection, time is long, test data are possibly lost due to insufficient memory, meanwhile, a large amount of test data are written into a hard disk, and the test efficiency is reduced are solved. And efficient acquisition of load, sound, flow field and other coupling data under the extreme wave condition is realized.

Description

Technical Field

[0001] The present invention relates to the field of hydrodynamic tests, and in particular to a test system and a test method for a multi-dimensional wave impact test. Background Art

[0002] Wave impact on structures refers to the strong nonlinear interaction between ocean waves and marine structures. The load is usually characterized by a large peak value and a short action time. This phenomenon often occurs in extreme marine environments and can cause serious damage to large-scale cross-river and cross-sea projects such as offshore platforms, dock projects, and cross-sea bridges, threatening the safety of life and property. Therefore, the problem of wave impact on structures has attracted much attention from scholars and engineers, and is a hot and difficult issue in the field of marine engineering.

[0003] For this complex slamming process, theoretical analysis can only provide a simplified analysis of the slamming load and limited slamming flow field information. Numerical simulation has gradually become an effective means to study the impact of waves on structures. At present, domestic and foreign scholars have conducted a large number of 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 grid-based methods and gridless methods. Grid-based methods such as finite element method, finite volume method, finite difference method, etc. require the establishment of grids to discretize the calculation domain, which is suitable for dealing with simple flow problems, but when dealing with moving boundary problems with free surfaces, it is necessary to re-grid and the calculation is more complicated. At the same time, it is more difficult to re-grid when the topological structure changes greatly, and it is difficult to accurately track the rapidly changing free surface and fluid-structure interface. Meshless methods such as smooth particle hydrodynamics method and moving particle semi-implicit method are not bound by grids and use discretely distributed particle points to simulate continuous medium fluids. They can deal with problems with large deformation of free surfaces, but when dealing with high Reynolds number flows, artificial viscosity needs to be introduced, and the calculation efficiency is low.

[0004] The impact of waves on structures involves the coupling effect of fluids and structures, resulting in complex free surface phenomena such as structural deformation and the rolling and breaking of wave surfaces. The amount of calculation required is huge, and the accuracy and precision of capturing wave impact pressure still needs to be improved; compared with the first two, physical model experimental research can usually obtain more accurate and more realistic results. Wave flume equipment is a powerful test tool in the field of marine engineering, which is widely used to study various structures (offshore wind turbines, breakwaters, submarine pipelines, oil platforms, etc.). Existing test schemes are often limited to the acquisition of impact pressure and lack multi-dimensional data collection of the impact process. In addition, due to the large peak value of the impact load and the short impact time, it is often necessary to set a higher sampling frequency during the test. However, the acquisition of wave impact pressure requires many channels and a long time, which may cause insufficient memory and loss of test data during the acquisition process. Writing a large amount of test data to the hard disk also reduces the test efficiency. Based on the above problems, there is an urgent need for an efficient test measurement system to improve the efficiency of data acquisition. Summary of the invention

[0005] The present invention aims to provide a test system and test method for a multi-dimensional wave impact test, which solves the problem that in the existing test process, the wave impact pressure collection requires many channels and a long time, and there may be insufficient memory and loss of test data. At the same time, writing a large amount of test data to the hard disk also reduces the test efficiency.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a test system for a multi-dimensional wave impact test, comprising a test water tank and a high-speed camera located outside the test water tank, an observation window is provided on the front side of the test water tank, a wave maker is provided on the left side of the test water tank, a front mounting panel and a rear mounting panel located on the right side of the wave maker are rotatably connected in the test water tank, the front mounting panel and the rear mounting panel are both rotatably sealed and connected to the two inner walls of the test water tank, the front mounting panel and the rear mounting panel are connected by a hinge, a limit assembly is provided on the front mounting panel and the rear mounting panel, the limit assembly can limit the movement of the front mounting panel or the rear mounting panel, a test model is also provided in the test water tank, a plurality of pressure sensors are provided on the surface of the test model, the high-speed camera is used to shoot the wave impact process and the flow field characteristics before and after, the high-speed camera is electrically connected to a computer, the computer is electrically connected to a buzzer and a hydrophone located at the top of the test water tank, and the hydrophone is located on the left side of the front mounting panel.

[0007] Furthermore, the limiting assembly includes two sliding plates respectively arranged on both sides of the front mounting panel or the rear mounting panel, each of the sliding plates is slidably connected to the top of the test water tank, a plurality of threaded holes are provided on the top of the test water tank, and the sliding plates are connected to the threaded holes through limiting bolts.

[0008] Furthermore, wedge-shaped rubber pads are provided on opposite sides of the two sliding plates.

[0009] Furthermore, a traction motor is provided on the sliding plate 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, and an opening is provided on the sliding plate for the traction rope to pass through.

[0010] Through the above settings, the position of the test model can be adjusted or the test model can be placed in a suspended state to simulate the wave impact test of the free vibration process of the floating body. At the same time, since the front mounting panel is not installed with the test model, the front mounting panel and the front mounting panel can be placed flat on the bottom of the test tank or sloped at a certain angle to simulate different underwater terrains.

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

[0012] Furthermore, reflective tracer particles are distributed in the test water tank, and a laser is also arranged outside the test water tank, and the laser guides the laser through a light guide arm.

[0013] Furthermore, a high-power lighting lamp is provided above the test water tank.

[0014] Through the above settings, the tracer particles on the measurement plane are illuminated by a single laser or weak illumination and laser, and the high-speed camera can capture a set of continuous images according to different exposure positions. Through the image correlation technology, the distance moved by the same tracer particle pattern in the two images is obtained, and the moving speed is obtained at the same time, so the flow field characteristics in the flume are described. 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 irradiation, and when there is sufficient light, the high-speed camera can capture the wave propagation form, including the generation and dissipation of bubbles, the curling, falling, and breaking of waves. Bubbles are used as "tracer particles" in the aerated area. The water body is illuminated from the back of the test flume, so that the image can be formed by the shadow of bubbles, and then the structural texture is calculated by the cross-correlation algorithm, and the bubble speed is obtained as the speed of the aerated area. This technology is used to analyze the impact process of breaking waves and structures and the flow field before and after.

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

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

[0017] S1. Fix the test model on the front mounting panel or the limit assembly of the test system. If the test model is not mounted on the front mounting panel, a larger inclination angle can be formed to form a slope;

[0018] S2, measuring the position or angle of the model in the test water tank by means of the front mounting panel and the limit assembly;

[0019] S3, generating a wave group by controlling the wave maker, the wave group is focused at a specified position, and the wave is broken at the specified position and impacts the test model;

[0020] S4, synchronously measure the peak pressure during wave impact, images of wave propagation patterns, flow field characteristics and speed, and the sound of wave breaking and impact through pressure sensors, high-speed cameras, current meters and hydrophones;

[0021] S5, setting the sampling position and sampling frequency of the pressure sensor according to the focused wave group characteristics of step S3;

[0022] S6. Directly measure the pressure and wave height when the wave hits through the voltage signal, synchronize with the sound when the wave breaks and hits by pre-recording the sound signal and electrical signal when the buzzer is started, and obtain the synchronized measurement signal through program processing;

[0023] S7, repeating steps S2 to S6, changing the preset angle and inclination angle formed between the test model and the vertical plane of the test tank, to implement tests of different wave impact modes;

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

[0025] Compared with the prior art, this solution has the following beneficial effects:

[0026] 1. The present invention provides a test system for multi-dimensional wave impact test, which can realize the fixation and adjustment of the position of test models of different shapes and sizes, as well as the simulation of different wave impact modes, thereby expanding the scope of application and flexibility of the test. At the same time, the present invention also provides a test method for the test system, which can synchronously measure various data such as pressure, sound, flow field, etc. during wave impact, and provides comprehensive experimental information for studying the impact of waves on marine structures, which is conducive to revealing the physical mechanism and law of wave impact. In addition, this test method calculates the pressure acquisition area according to the wave impact mode and focusing characteristics, and improves the test acquisition efficiency by reducing the sampling frequency of the pressure sensor outside the specified area.

[0027] 2. The present invention also solves the problems that the existing test system lacks multi-dimensional data collection of the impact process, the fixed form of the structure is single, and there is a lack of observation of the impact process and the complex wave forms before and after the process. The test model of the present invention has multiple fixing methods, can simulate different wave impact modes, and synchronously measure pressure, sound, flow field and other data during wave impact, providing an effective test method for studying the impact of waves on marine structures. This test system can not only measure the wave impact load and local slamming pressure acting on the structure, but also consider the changing characteristics of the impact pressure of waves under different impact forms and different fixed modes of the structure, while considering the influence of the sound free liquid surface foam on the impact load under the breaking, simulating the impact characteristics and laws of offshore structures under different sea conditions. In view of the characteristics of the impact pressure and the focused wave group, this test method dynamically sets the pressure sampling position and sampling frequency to reduce the memory and hard disk requirements of the acquisition equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is an isometric view of a front mounting panel in a test system for a multi-dimensional wave impact test in Example 1;

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

[0030] Figure 3 It is a multi-dimensional data graph collected by a test system of a multi-dimensional wave impact test in Example 1;

[0031] Figure 4 It is an axial side view of the front mounting panel in the test system of a multi-dimensional wave impact test in Example 2. DETAILED DESCRIPTION

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

[0033] The figure marks in the drawings of the specification include: test water tank 1, high-speed camera 2, observation window 3, wave maker 4, front mounting panel 5, rear mounting panel 6, sliding plate 7, limit bolt 8, rubber pad 9, traction motor 10, traction rope 11, test model 12, pressure sensor 13, fixing plate 14, hydrophone 15, laser 16, light guide arm 17, and lighting lamp 18.

[0034] Example 1

[0035] like Figures 1 to 3As shown, a test system for a multi-dimensional wave impact test includes a test water tank 1 and a group of high-speed cameras 2 located outside the test water tank 1. An observation window 3 is provided on the front side of the test water tank 1, and a wave maker 4 is provided on the left side of the test water tank 1. In this embodiment, the wave maker 4 is composed of a cylinder and a push plate. The cylinder is fixed in the test water tank 1 through a support plate, and the push plate is slidably and sealedly connected in the test water tank 1. A front mounting panel 5 and a rear mounting panel 6 located on the right side of the wave maker 4 are rotatably connected in the test water tank 1. The front mounting panel 5 and the rear mounting panel 6 are both rotatably and sealedly connected to the front and rear inner walls of the test water tank 1. The front mounting panel 5 and the rear mounting panel 6 are connected by a hinge. When the front mounting panel 5 is placed flat in the test water tank 1, it does not interfere with the wave maker 4, so that the front mounting panel 5 can be placed at the bottom of the test water tank 1 and form a certain slope with the rear mounting panel 6 to simulate different underwater terrains. A limit assembly is provided on the front mounting panel 5 and the rear mounting panel 6, and the limit assembly can limit the movement of the front mounting panel 5 or the rear mounting panel 6. The limit assembly consists of two sliding plates 7 arranged on both sides of the front mounting panel 5 or the rear mounting panel 6, and each sliding plate 7 is slidably connected to the top of the test water tank 1. The top of the test water tank 1 is provided with a plurality of laterally distributed threaded holes, and the sliding plates 7 are connected to the threaded holes through limit bolts 8. A wedge-shaped rubber pad 9 is also adhered 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 limit assembly, and 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, and the traction rope 11 is fixedly connected to the end of the front mounting panel 5 or the rear mounting panel 6 by adhesion. An opening is provided on the sliding plate 7 for the traction rope 11 to pass through. The position limiting assembly, rubber pad 9 and traction rope 11 can limit the placement and movement of the front mounting panel 5 or the rear mounting panel 6. While limiting the placement of the mounting panel or the rear mounting panel 6, the angle between the mounting panel or the rear mounting panel 6 and the horizontal plane can be adjusted, thereby increasing the range of adjustment. At the same time, the test model 12 can be placed in a suspended state by the traction motor 10 and the traction rope 11, which is used to simulate the wave impact test of the free vibration process of the floating body. The rear mounting panel 6 is composed of high-strength aluminum plates and rigid ribs, which can ensure the strength and stability of the test system and ensure that the posture of the test model 12 is changed so that the test process of the test model 12 with different tilt angles is carried out smoothly.

[0036] A test model 12 is also provided in the test tank 1. A plurality of pressure sensors 13 are provided on the surface of the test model 12. The pressure peak and position when the wave hits are measured by means of the pressure sensors 13. The high-speed camera 2 is used to photograph the wave impact process and the flow field characteristics before and after. The high-speed camera 2 is electrically connected to a computer. The computer is electrically connected to a buzzer and a hydrophone 15 located at the top of the test tank 1. The hydrophone 15 of this embodiment adopts a waterproof microphone. The hydrophone 15 is arranged on the left side of the front mounting panel 5 through a fixing plate 14. The hydrophone 15 is used to measure the sound when the wave breaks and hits. The buzzer is turned on and off after receiving the measurement signal, so as to synchronize the sound with other measurement contents.

[0037] Reflective tracer particles are distributed in the test water tank 1. A laser 16 is also provided outside the test water tank 1. The laser 16 guides the laser through a light guide arm 17 to generate a surface laser, so that the laser surface can be perpendicular or parallel to the test water tank 1. A high-power lighting lamp 18 is provided above the test water tank 1. Under the condition of a single laser, or under the combined effect of weak lighting and laser, the tracer particles on the measurement plane are illuminated, and the high-speed camera 2 can capture a set of continuous images according to different exposure positions. The moving speed is obtained by using the cross-correlation technology with the help of the distance moved by the same particle pattern in two pictures, so that the flow field characteristics in the water tank are described. 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 irradiation, and when there is sufficient light, the high-speed camera 2 can capture the wave propagation morphology, including the generation and dissipation of bubbles, and the curling, falling, and breaking of waves. The bubbles are used as "tracer particles" in the aerated area. The water body is illuminated from behind the test water tank 1, so that the image can be formed by the shadow of the bubbles. The cross-correlation algorithm is then used to calculate the structural texture, and the bubble velocity is obtained as the velocity of the aerated area. This technology is used to analyze the impact process of the breaking wave and the structure and the flow field before and after. The test water tank 1 is also equipped with a wave height meter and a current meter, which are used to measure the flow field characteristics and velocity of the non-shooting area.

[0038] According to the linear superposition principle, the wave surface at any point can be expressed as the result of the superposition of regular waves of different frequencies and directions. s The signal of the wave generator 4 is controlled to make the wave group focus near the structure, that is, x f ∈(x s -x1,x s -x1), where x1 and x2 are set according to the experimental requirements. The water depth h is determined by N f The frequency is f i (Circular frequency ω i =2π / T i =2πf i , where T iis the period), and the amplitude is a i , wave number is k i , the wave surface is:

[0039]

[0040] The initial phase is ε i Satisfy the following formula:

[0041] ε i =k i x b -2πf i t f +2mπ; m=0,±1,±2 … …

[0042] The focusing time of each component wave is t f , focus position x f , the frequency and wave number of the constituent waves satisfy the dispersion relation:

[0043]

[0044] The height of the pressure sensor from the bottom of the tank is z s , select The pressure sensor within the range of f -T N1 ,t f +T N1 ), 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 difference between this embodiment and embodiment 1 is that: in this embodiment, the traction motor 10 and the traction rope 11 are not included, and the test model 12 is bolted to the left side of the front mounting panel 5. A plurality of bolt holes are reserved on the front mounting panel 5, and test models 12 of different shapes and sizes can be fixed, such as cylindrical, square column, spherical, etc. At the same time, the test model 12 is used to form an arbitrary angle with the vertical plane of the test flume 1 to simulate different wave impact modes, such as frontal impact, oblique impact, etc.

[0047] Example 3

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

[0049] S1, fixing the test model 12 on the front mounting panel 5 or the limit assembly of the test system. If the test model 12 is not mounted on the front mounting panel 5, a larger inclination angle can be formed to form a slope;

[0050] S2, the position or angle of the measuring model in the test tank 1 is adjusted by the front mounting panel 5 and the limit assembly. If the test model 12 is set in the test tank 1 by the limit assembly, the set position of the test model 12 is adjusted by sliding the test model 12;

[0051] S3, generating a wave group by controlling the wave generator 4, the wave group is focused at a designated position, and the wave is broken at the designated position and impacts the test model 12;

[0052] S4, synchronously measuring the peak pressure during wave impact, the image of wave propagation morphology, flow field characteristics and speed, and the sound of wave breaking and impact through the pressure sensor 13, high-speed camera, current meter and hydrophone 15;

[0053] S5, setting the sampling position and sampling frequency of the pressure sensor 13 according to the focused wave group characteristics of step S3;

[0054] S6. Directly measure the pressure and wave height when the wave hits through the voltage signal, synchronize with the sound when the wave breaks and hits by pre-recording the sound signal and electrical signal when the buzzer is started, and obtain the synchronized measurement signal through program processing;

[0055] S7, repeating steps S2 to S6, changing the preset angle and inclination angle formed between the test model 12 and the vertical plane of the test water tank 1, to implement tests of different wave impact modes;

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

[0057] The above are only embodiments of the present invention, and the common knowledge such as the known specific structures and / or characteristics in the scheme are not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A test system for multi-dimensional wave impact test, characterized in that: The invention comprises a test water tank and a high-speed camera located outside the test water tank, wherein an observation window is arranged on the front side of the test water tank, a wave maker is arranged on the left side of the test water tank, a front mounting panel and a rear mounting panel located on the right side of the wave maker are rotatably connected in the test water tank, the front mounting panel and the rear mounting panel are both rotatably sealed and connected with two inner walls of the test water tank, the front mounting panel and the rear mounting panel are connected by hinges, the front mounting panel and the rear mounting panel are both provided with limit assemblies, the limit assemblies can limit the movement of the front mounting panel or the rear mounting panel, a test model is also arranged in the test water tank, a plurality of pressure sensors are arranged on the surface of the test model, the high-speed camera is used to shoot the wave impact process and the flow field characteristics before and after, the high-speed camera is electrically connected to a computer, the computer is electrically connected to a buzzer and a hydrophone located on the top of the test water tank, and the hydrophone is located on the left side of the front mounting panel.

2. A test system for multi-dimensional wave impact test according to claim 1, characterized in that: The limit assembly includes two sliding plates arranged on both sides of the front installation panel or the rear installation panel, each of the sliding plates is slidably connected to the top of the test water tank, and a plurality of threaded holes are opened on the top of the test water tank, and the sliding plates are connected to the threaded holes through limit bolts.

3. A test system for multi-dimensional wave impact test according to claim 2, characterized in that: The opposite sides of the two sliding plates are both provided with wedge-shaped rubber pads.

4. A test system for multi-dimensional wave impact test according to claim 2, characterized in that: A traction motor is arranged on the sliding plate 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.

5. A test system for multi-dimensional wave impact test according to claim 1, characterized in that: The test model is detachably connected to the front mounting panel or the limiting assembly.

6. A test system for multi-dimensional wave impact test according to claim 1, characterized in that: Reflective tracer particles are distributed in the test water tank, and a laser is also arranged outside the test water tank, and the laser guides the laser through a light guide arm.

7. A test system for multi-dimensional wave impact test according to claim 6, characterized in that: A high-power lighting lamp is arranged above the test water tank.

8. A test system for multi-dimensional wave impact test according to claim 7, characterized in that: The test water tank is also provided with a wave height meter and a flow rate meter located on the left side of the front installation panel, and the wave height meter and the flow rate meter are used to measure the flow field characteristics and velocity in the non-shooting area.

9. A test system for a multi-dimensional wave impact test according to any one of claims 1 to 8, characterized in that: The test method comprises the following steps: S1. Fix the test model on the front mounting panel or the limit assembly of the test system. If the test model is not mounted on the front mounting panel, a larger inclination angle can be formed to form a slope; S2, measuring the position or angle of the model in the test water tank by means of the front mounting panel and the limit assembly; S3, generating a wave group by controlling the wave maker, the wave group is focused at a specified position, and the wave is broken at the specified position and impacts the test model; S4, synchronously measure the peak pressure during wave impact, images of wave propagation patterns, flow field characteristics and speed, and the sound of wave breaking and impact through pressure sensors, high-speed cameras, current meters and hydrophones; S5, setting the sampling position and sampling frequency of the pressure sensor according to the focused wave group characteristics of step S3; S6. Directly measure the pressure and wave height when the wave hits through the voltage signal, synchronize with the sound when the wave breaks and hits by pre-recording the sound signal and electrical signal when the buzzer is started, and obtain the synchronized measurement signal through program processing; S7, repeating steps S2 to S6, changing the preset angle and inclination angle formed between the test model and the vertical plane of the test tank, to implement tests of different wave impact modes; S8. Analyze the test data and study the extreme wave impact process and impact characteristics under different wave parameters and structural positions.

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