Flow field measurement method and system for dam break flow flowing through vegetation

Abstract

The invention relates to a flow field measurement method and system for dam break flow flowing through vegetation, and the method comprises the following steps: S1, manufacturing a vegetation experiment model, and enabling the refractive index of a solid material for simulating vegetation to be the same as the refractive index of fluid; s2, a particle image velocity measurement device is arranged, the particle image velocity measurement device comprises a laser source and a camera, the laser source faces the vegetation experiment model, an area illuminated by laser is located behind the solid material, and the camera faces the front of the solid material; s3, dam break flow is generated by pulling out the baffle; and S4, taking a picture of the area illuminated by the laser through the camera, and processing data of the picture to obtain information of the flow field. Compared with the prior art, the method has the advantages that the vegetation is simulated by manufacturing the transparent solid material with the same refractive index as the fluid, and the aims that the solid does not block light rays and does not refract the light rays are achieved, so that the flow field in the vegetation can be effectively measured through the PIV technology.

Description

Technical Field

[0001] The invention relates to the technical field of flow field measurement, and in particular to a flow field measurement method and system for dam-break flow passing through vegetation. Background Art

[0002] In the field of flow field measurement, Acoustic Doppler velocimetry (ADV) and Particle Image Velocimetry (PIV) are two commonly used techniques.

[0003] An acoustic Doppler velocimeter (ADV) is an instrument that uses the Doppler effect of acoustic waves to measure the velocity of a fluid (5). It sends sound waves into the fluid and then calculates the velocity and flow rate distribution of the fluid based on the echo signals received by the sound waves.

[0004] The working principle of ADV includes the following steps:

[0005] Acoustic transmission: The instrument sends high-frequency acoustic signals into the fluid through the built-in acoustic transmitter.

[0006] Sound wave reflection: The transmitted sound wave signal will encounter particles or liquid interfaces in the fluid and reflect back to form an echo signal.

[0007] Doppler effect: The movement of particles or liquid in the fluid will cause the frequency of the echo signal to change, which is the Doppler effect.

[0008] Flow velocity calculation: By analyzing the frequency changes of the echo signal, ADV can calculate the velocity of the fluid, including the flow velocity size and direction.

[0009] ADV has the characteristics of high accuracy, real-time monitoring and strong adaptability, and is suitable for measurements in different scales and flow rate ranges.

[0010] Particle image velocimetry (PIV) is a transient, multi-point, non-contact fluid mechanics velocimetry method. It scatters some tracer particles with good tracking and reflective properties in the flow field, irradiates the section area of ​​the measured flow field with laser light, continuously captures two or more exposed particle images through the imaging recording system, and then uses the image correlation method to analyze the captured PIV images to obtain the average displacement of the particle image in each small area, thereby determining the two-dimensional fluid velocity distribution of the entire area on the flow field section.

[0011] The PIV system is mainly composed of a laser source, a flow field containing tracer particles, a high-speed camera and a computer. The laser source emits a sheet laser beam to illuminate a section of the flow field in the reactor. The tracer particles added to the flow field scatter the laser, so that the laser can be scattered to the side of the flow field. A high-speed camera is set in a direction perpendicular to the illuminated section, and the behavior of the illuminated flow field is continuously photographed at a set time interval, and the data is then transmitted to the computer. The computer then processes the data according to the set program and algorithm to obtain the velocity and concentration information of the flow field.

[0012] PIV technology breaks through the limitations of traditional single-point measurement and can simultaneously measure the two-dimensional velocity distribution or three-dimensional velocity field on a cross section of the flow field without contact, achieving interference-free measurement, and the PIV method has high measurement accuracy. After years of development, PIV technology has become increasingly mature in image acquisition and data processing algorithms, and has been widely recognized by people. As a powerful means to study various complex flow fields, it is widely used in various flow measurements.

[0013] Although ADV and PIV are widely used in the field of flow field measurement, they each have some shortcomings:

[0014] 1. Limitations of Acoustic Doppler Velocimeter (ADV):

[0015] Limited measurement range: ADV is a point measurement device inserted into the fluid. It can only measure the flow velocity around the sensor and cannot provide comprehensive data on a large flow field. This limitation makes ADV incapable of measuring the flow velocity distribution in a large area. Specifically, for the measurement of the flow field inside vegetation, ADV is an invasive measurement method that only measures a single point and is affected by nearby obstacles. Therefore, it is not suitable for measuring the flow field inside vegetation.

[0016] Higher cost: ADV equipment is relatively expensive, which limits its widespread use in research or applications with limited budgets.

[0017] The measurement accuracy of clear water is low: In clear water, the measurement accuracy of ADV will be reduced, and it is necessary to improve the measurement accuracy by mixing an appropriate amount of suspended particles.

[0018] 2. Limitations of PIV:

[0019] Applicable to pure fluids: PIV technology works best in pure fluids without interference from solid particles. When there are solid boundaries or fluid-solid coupling in the flow field, the measurement effect of PIV will be seriously affected.

[0020] Light blocked by solids: A major problem faced by PIV technology in fluid-structure interaction experiments is light blocked by solids, which leads to discontinuities in the measurement area and incomplete data. Transparent materials can partially solve this problem, but it increases the difficulty of maintaining thermal boundaries and may change the optical path, distorting the particle image.

[0021] Measurement area limitation: Due to insufficient laser intensity, low spatial resolution and limited light sheet expansion, commercial PIV systems have limited measurement areas. This is particularly restrictive for PIV applications on full-scale models, which require the construction of large optical systems and camera technology to overcome this limitation.

[0022] In summary, although ADV and PIV technologies have their own advantages in the field of flow field measurement, they also have obvious limitations. ADV's point measurement and high cost limit its scope of application, while PIV's light blocking problem and measurement area limitation in fluid-solid coupling scenarios also affect its measurement results. These limitations have prompted researchers to seek new measurement technologies in order to obtain more accurate and comprehensive flow field data. Summary of the invention

[0023] The purpose of the present invention is to provide a method and system for measuring the flow field of dam break flow passing through vegetation, combining the refractive index matching technology with particle image velocimetry (PIV) to address the shortcomings of the existing PIV technology in studying fluid-solid interaction, especially in the scenario of dam break flow and vegetation interaction. By making transparent solid materials with the same refractive index as the fluid to simulate vegetation, the goal of solids not blocking or refracting light is achieved, thereby enabling PIV technology to effectively measure the flow field inside vegetation.

[0024] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0025] The first object of the present invention is to provide a flow field measurement method of a dam-break flow passing through vegetation, comprising the following steps:

[0026] S1. Making a vegetation experimental model, wherein the vegetation experimental model is provided with a first cavity, a second cavity, a baffle and a fixing plate, wherein the baffle is used to separate the first cavity and the second cavity, wherein the first cavity contains a fluid, wherein the second cavity is provided with a solid material, wherein the solid material is used to simulate vegetation, wherein the refractive index of the solid material is the same as that of the fluid, wherein the fixing plate is connected to the solid material, and wherein the fixing plate is used to fix the solid material;

[0027] S2, deploying a particle image velocimetry measuring device, the particle image velocimetry measuring device comprising a laser source and a camera, the laser source facing the vegetation experimental model so that the area illuminated by the laser is behind the solid material, and the camera facing the front of the solid material;

[0028] S3, generating dam-break flow by pulling out the baffle;

[0029] S4. Take photos of the area illuminated by the laser through a camera, and obtain flow field information after processing the data of the photos.

[0030] Furthermore, the second cavity contains fluid.

[0031] Furthermore, the particle image velocimetry measuring device also includes a computer; the computer is connected to the camera.

[0032] Furthermore, the computer is connected to a laser source.

[0033] Furthermore, the computer is connected to the camera in communication, and the computer is connected to the laser source in communication. The communication connection may be a wired or wireless connection.

[0034] Furthermore, step S4 specifically includes the following process:

[0035] The camera continuously takes pictures of the area illuminated by the laser at preset time intervals and transmits them to the computer. After data processing, the velocity and distribution information of the flow field is obtained.

[0036] Furthermore, the section of the area illuminated by the laser is perpendicular to the direction in which the camera is facing.

[0037] Furthermore, the solid material is cylindrical; the fixing plate is provided with an opening, and the opening matches the shape and size of the solid material.

[0038] Furthermore, the fluid is water; the solid material is hydrogel. Water can be tap water, which is less expensive than salt solution. Based on the selected fluid water, hydrogel is selected as the solid material to simulate vegetation. The preparation method of hydrogel is simple. During the preparation process, the refractive index can be adjusted by adjusting the concentration to match the refractive index of the fluid. The size and shape of the mold can be adjusted to obtain hydrogels of different sizes and shapes to simulate vegetation in different states.

[0039] Further preferably, the solid material is 12% polyacrylamide hydrogel.

[0040] Furthermore, the baffle is a transparent plate.

[0041] Furthermore, the fixing plate is a transparent plate.

[0042] Optionally, different vegetation substrate conditions may be subsequently simulated by adjusting the settings of the fixing plate.

[0043] Further preferably, the baffle is a glass plate, and the fixing plate is an acrylic plate.

[0044] The second object of the present invention is to provide a flow field measurement system for dam-break flow passing through vegetation, wherein the flow field measurement system includes a vegetation experimental model and a particle image velocimetry measurement device.

[0045] Furthermore, the vegetation experimental model also includes a dam-break flow generating device body; the cavity of the dam-break flow generating device body is divided into a first cavity and a second cavity by a baffle; and the baffle is connected to the dam-break flow generating device body.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) The present invention provides a new flow field measurement scheme by combining refractive index matching technology and PIV, which can effectively solve the shortcomings of PIV in the study of fluid-solid interaction, especially in the scenario of interaction between dam break flow and vegetation, and provides an innovative solution for flow field measurement. The present invention aims to overcome the limitations of PIV technology in fluid-solid coupling scenarios through innovative measurement methods, especially the measurement difficulties of the flow field inside vegetation when dam break flow interacts with vegetation. Through this new method, the flow field distribution inside the interaction between dam break flow and vegetation can be accurately observed.

[0048] (2) The present invention uses a solid model made of refractive index matching material, which can significantly reduce the light loss caused by solid particles or vegetation obstruction in PIV measurement. In this way, the PIV system can more accurately capture the image of particles flowing through the solid boundary, thereby obtaining more accurate flow velocity data. Due to the use of refractive index matching materials, the reflection and refraction of light on the surface of the solid model can be reduced, thereby reducing noise and artifacts in the PIV image. This helps to improve the accuracy and reliability of flow field measurements, especially in complex fluid-solid coupling environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic top view of a solid material of a flow field measurement system for dam-break flow passing through vegetation according to an embodiment of the present invention;

[0050] Figure 2 A front view schematic diagram of a solid material of a flow field measurement system for dam-break flow passing through vegetation according to an embodiment of the present invention;

[0051] Figure 3 It is a structural schematic diagram of a vegetation experimental model of a flow field measurement system of a dam-break flow passing through vegetation according to an embodiment of the present invention;

[0052] Figure 4 This is a schematic diagram of a solid material hydrogel in a fluid water achieving refractive index matching according to an embodiment of the present invention;

[0053] Figure 5It is a structural schematic diagram of a flow field measurement system of a dam-break flow passing through vegetation according to an embodiment of the present invention;

[0054] Figure 6 Schematic diagram of a PIV image sequence obtained by a flow field measurement method of a dam-break flow passing through vegetation according to an embodiment of the present invention and a CFD numerical model of a comparative example, wherein (a) the flow field velocity obtained by the PIV experiment, and (b) the CFD numerical model result;

[0055] Figure 7 Schematic diagram of the solid material hydrogel prepared under different concentration conditions of the present invention;

[0056] The numbers in the figure show:

[0057] 1. First cavity, 2. Second cavity, 3. Baffle, 4. Fixed plate, 5. Fluid, 6. Solid material, 7. Laser source, 8. Camera, 9. Computer, 10. Area illuminated by laser, 11. Main body of dam-break flow generating device. DETAILED DESCRIPTION

[0058] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments. The features such as component models, material names, connection structures, control methods, etc. that are not clearly described in this technical solution are regarded as common technical features disclosed in the prior art.

[0059] The technical concept of the present invention is as follows:

[0060] The core purpose of the present invention is to solve the shortcomings of existing PIV technology in studying fluid-solid interactions, especially in the scenario of dam break flow and vegetation interaction. Although PIV technology is widely used in the field of fluid mechanics and can provide full-field contactless flow velocity measurement, it faces a series of challenges in complex flow fields involving fluid-solid coupling, especially when the fluid flows through solid boundaries such as vegetation. PIV technology has a good measurement effect in pure fluids, but in fluid-solid coupling experiments, especially when there are solid boundaries in the flow field, PIV technology is difficult to accurately measure the flow velocity in the near-wall area. This is because the presence of solid boundaries blocks light, making it difficult for PIV technology to capture the particle image behind the solid boundary, resulting in discontinuity in flow velocity measurement and incomplete data. In the study of the interaction between dam break flow and vegetation, the presence of vegetation will significantly affect the distribution and structure of the flow field. Existing PIV technology cannot effectively penetrate vegetation and measure the flow velocity distribution inside the vegetation, which limits the in-depth understanding of the interaction mechanism between dam break flow and vegetation.

[0061] The solution of the present invention is to combine the refractive index matching technology with particle image velocimetry (PIV) to solve the shortcomings of PIV in studying fluid-solid interaction, especially in the scene of dam break flow and vegetation interaction. By making a transparent solid material with the same refractive index as the fluid to simulate vegetation, the goal of solid not blocking light and not refracting light is achieved, so that PIV technology can effectively measure the flow field inside vegetation.

[0062] Refractive index matching technology is a commonly used technology in the field of optics. Its core idea is to reduce or eliminate the reflection and refraction of light at the interface of different media by using refractive index matching materials, thereby improving the transmission efficiency and imaging quality of the optical system. In the present invention, the application of refractive index matching technology is mainly reflected in the following aspects:

[0063] Production of transparent solid materials: By selecting or synthesizing a transparent solid material with a refractive index similar to that of a fluid (such as water), a solid model simulating vegetation can be produced. This material needs to have good optical transparency and a refractive index similar to that of the fluid to ensure that light can pass through the solid model smoothly without obstruction.

[0064] Reduce light obstruction and refraction: Using solid models made of refractive index matching materials can significantly reduce light loss caused by solid particles or vegetation obstruction during PIV measurement. In this way, the PIV system can more accurately capture the image of particles flowing through solid boundaries, thereby obtaining more accurate flow velocity data.

[0065] Improve the accuracy of flow field measurement: Due to the use of refractive index matching materials, the reflection and refraction of light on the surface of solid models can be reduced, thereby reducing noise and artifacts in PIV images. This helps to improve the accuracy and reliability of flow field measurements, especially in complex fluid-solid coupling environments.

[0066] Expanding the application scope of PIV technology: By combining refractive index matching technology and PIV, the present invention not only improves the measurement capability of PIV in fluid-solid coupling scenarios, but also expands the application scope of PIV technology, enabling it to be better applied to the study of complex flow field problems such as the interaction between dam break flow and vegetation.

[0067] In summary, the present invention provides a new flow field measurement scheme by combining refractive index matching technology and PIV, which can effectively solve the shortcomings of PIV in the study of fluid-solid interaction, especially in the scenario of dam break flow and vegetation interaction, and provides an innovative solution for flow field measurement.

[0068] The present invention uses water as a fluid, which can be tap water. Compared with salt solutions, the cost is lower. Based on the selected fluid water, hydrogel is selected as a solid material to simulate vegetation. The preparation method of the hydrogel is simple. During the preparation process, the refractive index can be adjusted by adjusting the concentration, such as Figure 7 As shown, the refractive index of the fluid can be matched, and by adjusting the size and shape of the mold, hydrogels of different sizes and shapes can be obtained to simulate vegetation in different states.

[0069] Example

[0070] This embodiment provides a flow field measurement method for dam-break flow passing through vegetation, comprising the following steps:

[0071] Step 1, making a vegetation experimental model, the vegetation experimental model comprises a dam-break flow generating device body 11, the dam-break flow generating device body 11 is provided with a first cavity 1 and a second cavity 2, the cavity of the dam-break flow generating device body 11 is divided into the first cavity 1 and the second cavity 2 by a baffle 3, the baffle 3 is detachably connected to the side wall of the dam-break flow generating device body 11, the first cavity 1 contains a fluid 5, the second cavity 2 is provided with a solid material 6 and the fluid 5, the solid material 6 is used to simulate vegetation, the refractive index of the solid material 6 is the same as the refractive index of the fluid 5, the dam-break flow generating device body 11 comprises side walls and a bottom plate, the four side walls are connected in sequence, the side walls and the bottom plate are connected, the side walls and the bottom plate are transparent plates, the side walls and the bottom plate can be glass plates or acrylic plates, and the baffle 3 is a glass plate;

[0072] Key features: (1) Solid material 6 is 12% polyacrylamide hydrogel; (2) The refractive index of solid material 6 is the same as that of water; (3) Solid material 6 is cylindrical.

[0073] Step 2: Fix the vegetation experimental model. Place a fixing plate 4 into the second cavity 2. The fixing plate 4 is an acrylic plate. The solid material 6 is inserted into the opening of the fixing plate 4 having the same shape and size as the solid material 6. Figure 1 , 2 , as shown in 3;

[0074] Key Features: A cylindrical solid material 6 is inserted into a fixing plate 4 having an opening of the same shape and size as the solid material 6 .

[0075] Step 3: Arrange a particle image velocimetry device (PIV measurement device), which includes a laser source 7 and a camera 8. The laser source 7 is directed toward the vegetation experimental model so that the area 10 illuminated by the laser is behind the solid material 6, and the section of the area 10 illuminated by the laser is perpendicular to the direction of the camera 8, and the camera 8 is directed toward the front of the solid material 6. Figure 5 As shown;

[0076] Key features: (1) The area illuminated by the laser focus (laser illuminated area 10) is located behind the cylindrical solid material 6; (2) The position of the distance correction is located behind the cylindrical solid material 6.

[0077] Step 4: Generate dam break flow by pulling out the baffle 3.

[0078] Step 5: Use the camera 8 to take photos of the area 10 illuminated by the laser. Use the camera 8 to continuously take photos of the area 10 illuminated by the laser at preset time intervals.

[0079] Step 6, data processing and analysis, the photo of the area 10 illuminated by the laser is transmitted to the computer, and the image is processed by an image processing program based on the cross-correlation principle, such as Pivlab in Matlab, etc., to obtain the position change vector of the tracer particles in the image at each moment, and the velocity vector at each moment is calculated according to the spatial scale and time interval of the physical model, and the velocity magnitude and distribution data are obtained, see Figure 6 (a).

[0080] In this embodiment, the key point is to successfully produce a transparent solid material with the same refractive index as the experimental fluid to simulate vegetation, thereby solving the problem of solid blocking and refracting light in the dam-break flow-vegetation interaction flow field experiment. This innovation enables PIV technology to accurately measure the flow field flowing through vegetation, especially the flow velocity distribution inside the vegetation, which is of great practical significance for understanding and predicting the impact of dam-break flow on vegetation and formulating corresponding flood control measures.

[0081] Refractive index matching of transparent solid materials: In order to achieve smooth passage of light through the solid model without deflection, the present invention adopts refractive index matching technology. By carefully selecting and matching materials, a transparent solid material is produced, whose refractive index matches that of the fluid (such as water) in the experiment. The preparation of this material involves complex chemical and physical processes, and requires precise control of the material composition and processing conditions to ensure the consistency of the refractive index.

[0082] Preparation of transparent solid materials:

[0083] The refractive index matching solid material used in the experiment of this embodiment is 12% polyacrylamide hydrogel, such as Figure 4 shown.

[0084]

[0085]

[0086] Equipment: scale, beaker, glass rod, mold, ultrasonic cleaner, ice bath.

[0087] The prepared transparent solid material 6 not only matches the refractive index of the fluid 5, but also has good optical transparency and sufficient mechanical strength to simulate vegetation in the natural environment.

[0088] In this embodiment, the study area is set inside the vegetation or behind the stems of the vegetation, such as Figure 5 As shown, the area 10 illuminated by the laser is located behind a cylinder (solid material 6) simulating a plant stem, and light can pass through the cylinder without being refracted, so that the camera 8 can capture the flow field distribution in the rear or inner area of ​​the vegetation.

[0089] By realizing the above key points, the present invention successfully overcomes the limitations of traditional PIV technology in fluid-solid coupling experiments and provides an effective experimental measurement technology for the study of the interaction between dam break flow and vegetation.

[0090] The present invention has successfully conducted experiments and obtained data by innovatively applying refractive index matching technology and PIV technology. In the experiment of the embodiment, a transparent solid material 6 with the same refractive index as the experimental fluid 5 is made to simulate vegetation, which effectively solves the problem of solid blocking and refracting light, thereby successfully obtaining the flow field when the dam break flow passes through the vegetation. The specific effects are as follows:

[0091] 1. Innovative application of refractive index matching technology: The produced hydrogel material successfully matches the experimental fluid.

[0092] 2. Acquisition of experimental data: Using PIV technology based on refractive index matching materials, the precise measurement of the velocity field of two-dimensional flow field measurement is achieved, which improves the quantitative measurement capability of PIV technology for complex two-dimensional flow fields. In the experiment, the flow field distribution behind the vegetation material was accurately obtained.

[0093] 3. Verification of experimental results: Passed Figure 6 , compared with the processing results of the PIV experiment at the same time ( Figure 6 (a)) and the dam break numerical model based on OpenFOAM and its interFoam solver ( Figure 6 The velocity distribution obtained by (b)) verifies that the present invention can well observe the flow field distribution near the hydrogel cylinder, and the experimental results are consistent with the actual situation. This result further confirms the effectiveness of the present invention.

[0094] In summary, the present invention not only improves the accuracy and comprehensiveness of flow field measurements, but also has important practical significance for understanding and predicting the impact of dam break flows on vegetation. The present invention overcomes the limitations of PIV technology in fluid-solid coupling scenarios through innovative measurement methods, especially the measurement difficulties of the flow field inside vegetation when dam break flows interact with vegetation. Through this new method, the flow field distribution inside the interaction between dam break flows and vegetation can be accurately observed, thereby providing more comprehensive and accurate data for the study of dam break flow dynamics, which is of great practical significance for understanding the impact of dam break flows on vegetation, evaluating the energy dissipation effect of vegetation, and formulating corresponding flood control measures.

[0095] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning, or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for measuring the flow field of dam-break flow passing through vegetation, characterized in that: The following steps are involved: S1. A vegetation experimental model is prepared, wherein the vegetation experimental model is provided with a first cavity (1), a second cavity (2), a baffle (3) and a fixing plate (4), wherein the baffle (3) is used to separate the first cavity (1) and the second cavity (2), wherein the first cavity (1) contains a fluid (5), wherein the second cavity (2) contains a solid material (6), wherein the solid material (6) is used to simulate vegetation, wherein the refractive index of the solid material (6) is the same as the refractive index of the fluid (5), wherein the fixing plate (4) is connected to the solid material (6), and wherein the fixing plate (4) is used to fix the solid material (6); S2, deploying a particle image velocimetry measuring device, the particle image velocimetry measuring device comprising a laser source (7) and a camera (8), the laser source (7) facing the vegetation experimental model so that the area (10) illuminated by the laser is behind the solid material (6), and the camera (8) faces the front of the solid material (6); S3, generating dam-break flow by pulling out the baffle (3); S4. Using a camera (8) to take a picture of the area (10) illuminated by the laser, and after processing the data of the picture, the flow field information is obtained.

2. The method for measuring the flow field of dam-break flow passing through vegetation according to claim 1, characterized in that: The particle image velocimetry measuring device further comprises a computer (9); The computer (9) is connected to the camera (8).

3. The method for measuring the flow field of dam-break flow passing through vegetation according to claim 2, characterized in that: Step S4 specifically includes the following process: The camera (8) continuously takes pictures of the area (10) illuminated by the laser at preset time intervals and transmits the pictures to a computer (9). After data processing, the velocity magnitude and distribution information of the flow field are obtained.

4. The method for measuring the flow field of dam-break flow passing through vegetation according to claim 1, characterized in that: The section of the area (10) illuminated by the laser is perpendicular to the direction of the camera (8).

5. The method for measuring the flow field of dam-break flow passing through vegetation according to claim 1, characterized in that: The solid material (6) is cylindrical; The fixing plate (4) is provided with an opening, and the opening matches the solid material (6).

6. The method for measuring the flow field of dam-break flow passing through vegetation according to claim 1, characterized in that: The fluid (5) is water; The solid material (6) is a hydrogel.

7. The method for measuring the flow field of dam-break flow passing through vegetation according to claim 6, characterized in that: The solid material (6) is 12% polyacrylamide hydrogel.

8. The method for measuring the flow field of dam-break flow passing through vegetation according to claim 1, characterized in that: The baffle plate (3) and the fixing plate (4) are both transparent plates.

9. A flow field measurement system for dam-break flow passing through vegetation according to any one of claims 1 to 8, characterized in that: The flow field measurement system comprises a vegetation experimental model and a particle image velocimetry measurement device.

10. The flow field measurement system of dam-break flow passing through vegetation according to claim 1, characterized in that: The vegetation experimental model also includes a dam-break flow generating device body (11); The cavity of the dam-break flow generating device body (11) is divided into a first cavity (1) and a second cavity (2) by a baffle (3); The baffle (3) is connected to the dam-break flow generating device body (11).

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