Device for testing relevance between liquid bubble void ratio and slamming load of ocean structure

Abstract

The invention provides a liquid bubble void ratio and ocean structure slamming load relevance testing device which comprises two supporting frames. The device further comprises a gas-liquid two-phase environment simulation mechanism located between the two supporting frames and a liquid bubble void ratio measurement subsystem arranged corresponding to the gas-liquid two-phase environment simulation mechanism. The high-speed vertical motion simulation mechanism is arranged between the two supporting frames and is positioned above the gas-liquid two-phase environment simulation mechanism; the slamming load test subsystem is arranged corresponding to the high-speed vertical motion simulation mechanism; the invention has the following beneficial effects: the bubble generation system can adjust the flow and concentration of bubbles according to experimental requirements, realizes accurate control of the void ratio of the bubbles, and is suitable for simulating complex marine environments with different bubble contents; and through the high-precision combination of the silk screen sensor and the pressure sensor, the real-time monitoring of the bubble void ratio and the precise measurement of the slamming load on the structure when the structure enters water can be realized.

Description

Technical Field

[0001] The invention relates to the field of fluid dynamics and marine engineering technology, and in particular to a device for testing the correlation between liquid bubble void ratio and marine structure slamming load. Background Art

[0002] When marine structures interact with water at high speed, they are often subjected to significant instantaneous slamming loads. This type of slamming phenomenon is widely present in engineering applications, such as water landing of spacecraft, re-entry of ships, entry of missiles into the water, and deck slamming of offshore platforms. In these events, the rapid interaction between the structure and the water will generate huge slamming forces in a very short time, affecting the safety and stability of the structure. In addition, in the marine environment, the water often contains a large number of bubbles, which may come from biological activities, wind and wave breaking or snowmelt. The bubbles in the water play an important role in the slamming load, affecting the structure. The instantaneous pressure distribution and peak load on the structure are measured; studies have shown that bubbles in water can significantly reduce the impact force, but current research is mostly focused on the impact force test in a pure water environment. The research on the impact load in an aerated water environment is relatively limited, especially the lack of equipment that can quantitatively test the effect of the bubble porosity in water on the impact load of the structure; in addition, although numerical simulation provides a theoretical basis for studying fluid interactions in aerated water, it cannot fully meet the needs of actual engineering applications due to the complexity and nonlinearity of gas-liquid interactions. Therefore, conducting actual model experiments is still a reliable means to study the aerated impact load.

[0003] The existing experimental equipment is mainly used for water entry experiments in a single scenario, which is difficult to meet the test requirements under complex working conditions. In particular, when it comes to experiments involving high-speed water entry and different bubble porosity conditions, the existing equipment lacks a system for bubble generation and accurate measurement, and cannot fully reflect the impact of the bubble field on the impact force of the structure; Accurately measuring the porosity of bubbles in water is crucial to studying the impact of bubbles on the impact load; the porosity reflects the proportion of gas in the liquid, which directly affects the dynamic characteristics of the water body during the impact process. Traditional porosity measurement methods (resistance probes, optical fiber probes, capacitance sensors, ray methods, etc.) are not effective in complex water dynamics. There are certain limitations in the mechanical environment, and the wire mesh sensor, as a multiphase flow measurement technology based on electrical signals, has high spatial and temporal resolution, can accurately capture the characteristics of gas-liquid two-phase flow, and is particularly suitable for the study of multiphase flow and bubble flow; compared with traditional methods, the wire mesh sensor has higher accuracy and real-time performance in measuring porosity, which makes it an ideal tool for studying the slamming load problem in a gas-containing water environment, but the wire mesh sensor has not been applied to the field of gas-containing slamming. Therefore, there is an urgent need for a test device that can apply the wire mesh sensor to the field of gas-containing slamming in marine engineering and the correlation between the liquid bubble porosity and the marine structure slamming load. Summary of the invention

[0004] In view of the shortcomings of the prior art mentioned above, the purpose of the present invention is to provide a testing device for the correlation between liquid bubble porosity and marine structure slamming load, which is used to solve the problem that current research is mostly focused on slamming force testing in pure water environments, while research on slamming loads in aerated water environments is relatively limited, especially the lack of equipment that can quantitatively test the effect of bubble porosity in water on the slamming load of structures.

[0005] In order to achieve the above-mentioned purpose and other related purposes, the present invention provides the following technical solutions:

[0006] A liquid bubble porosity and marine structure slamming load correlation test device comprises two support frames, a gas-liquid two-phase environment simulation mechanism located between the two support frames, a liquid bubble porosity measurement subsystem arranged corresponding to the gas-liquid two-phase environment simulation mechanism, a high-speed vertical motion simulation mechanism installed between the two support frames and located above the gas-liquid two-phase environment simulation mechanism, and a slamming load test subsystem arranged corresponding to the high-speed vertical motion simulation mechanism; wherein the liquid bubble porosity measurement subsystem comprises a wire mesh sensor for measuring the bubble porosity in water, a first signal amplifier, a data acquisition computer and a power supply system, the wire mesh sensor is electrically connected to the first signal amplifier through a wire, the first signal amplifier is electrically connected to the data acquisition computer through a wire, the wire mesh sensor comprises two layers of electrodes arranged orthogonally and parallel to each other, one layer of the electrodes is a transmitting end, the other layer of the electrodes is a receiving end, the two layers of the electrodes form a grid, and each intersection of the grid is a measuring point.

[0007] In one embodiment of the present invention, the gas-liquid two-phase environment simulation mechanism includes an air compressor, a flow control valve, a transparent water cylinder located between the two support frames, and a bubble generator installed on the bottom side of the transparent water cylinder, and the wire mesh sensor is also located in the transparent water cylinder, the outlet of the air compressor is connected to the inlet of the flow control valve through a gas connecting pipe, the outlet of the flow control valve is connected to the inlet of the bubble generator through a gas connecting pipe, and the outlet of the bubble generator is connected to the interior of the transparent water cylinder.

[0008] In one embodiment of the present invention, the high-speed vertical motion simulation mechanism includes a first support assembly and a second support assembly installed on the support frame, a first fixed frame is installed on the first support assembly and the second support assembly, an electric push rod is installed in the first fixed frame, an electromagnetic release controller is installed at the bottom end of the telescopic rod on the electric push rod, and a water entry structure is provided on the bottom side of the electromagnetic release controller.

[0009] In one embodiment of the present invention, two guide frames are installed on the water entry structure, which are located on both sides of the electric push rod and can slide up and down. A slider is installed on the side of the guide frame close to the first fixed frame, and a guide rail slidably connected to the slider is installed on the first fixed frame.

[0010] In one embodiment of the present invention, gas springs installed on the second support assembly are provided on the sides of the two guide frames, the top ends of the gas springs are installed on the second support assembly via a mounting plate, and the bottom ends of the gas springs are connected to the water entry structure via a steel wire rope.

[0011] In one embodiment of the present invention, a second fixing frame is provided in one of the support frames, and a laser displacement sensor is installed on the second fixing frame, which is located above the water-entering structure and is used to obtain displacement data of the water-entering structure during the falling process. The laser displacement sensor is electrically connected to the first high-speed collector through a wire.

[0012] In one embodiment of the present invention, the impact load test subsystem includes a pressure sensor, a second signal amplifier and a second high-speed collector installed on the bottom side of the water-entering structure, the pressure sensor is electrically connected to the second signal amplifier through a wire, and the second signal amplifier is electrically connected to the second high-speed collector through a wire.

[0013] As described above, the liquid bubble porosity and marine structure slamming load correlation testing device of the present invention has the following beneficial effects:

[0014] 1. Adjustable bubble generation system: The bubble generation system can adjust the flow and concentration of bubbles according to experimental requirements to achieve precise control of the bubble void ratio, which is suitable for simulating complex marine environments with different bubble contents. By precisely controlling bubble generation, the effect of bubble void ratio on slamming load can be evaluated, which increases the flexibility and adaptability of experimental conditions.

[0015] 2. Accurate bubble porosity and load measurement: Through the high-precision combination of wire mesh sensors and pressure sensors, real-time monitoring of bubble porosity and accurate measurement of the slamming load on the structure when entering the water can be achieved. This precise measurement helps to deeply understand the buffering effect of the bubble field on the slamming load and provide reliable data for the design and safety assessment of marine structures.

[0016] 3. High precision and repeatability of experimental data: The present invention can ensure high-precision collection of experimental data through the collaborative work of multiple sensors. All data are transmitted to the industrial control computer in real time for analysis and storage, ensuring the reliability of data processing. Multiple experiments have shown that the experimental results are highly consistent, ensuring the repeatability of the results, and providing a stable reference basis for engineering design in practical applications.

[0017] 4. Enhance the safety of structural design: In marine engineering, the presence of bubbles will significantly affect the slamming loads borne by the structure. The present invention helps researchers to deeply analyze the impact of the bubble field on the safety of the structure by simulating working conditions with different bubble porosity, thereby improving the reliability and durability of the structural design and reducing structural damage caused by slamming force.

[0018] 5. Wide applicability: The present invention is applicable to gas-containing water entry experiments of various structures, and has important application prospects in the design and safety assessment of marine engineering structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It shows a schematic diagram of the overall three-dimensional structure of a test device for correlation between liquid bubble porosity and marine structure slamming load disclosed in an embodiment of the present invention;

[0020] Figure 2 It shows a right front view stereoscopic diagram of a middle support frame, a transparent water tank and a high-speed vertical motion simulation mechanism of a liquid bubble void ratio and marine structure slamming load correlation test device disclosed in an embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of a liquid bubble void ratio measurement subsystem in a liquid bubble void ratio and marine structure slamming load correlation testing device disclosed in an embodiment of the present invention;

[0022] Figure 4 It shows a schematic diagram of the overall three-dimensional structure of a high-speed vertical motion simulation mechanism in a test device for correlation between liquid bubble porosity and marine structure slamming load disclosed in an embodiment of the present invention;

[0023] Figure 5 It shows a schematic diagram of the three-dimensional structure of a high-speed vertical motion simulation mechanism that is not connected to the first high-speed collector in the liquid bubble void ratio and marine structure slamming load correlation test device disclosed in an embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of a slamming load test subsystem in a test device for correlation between liquid bubble porosity and marine structure slamming load disclosed in an embodiment of the present invention;

[0025] Figure 7 It is a schematic diagram showing the relationship between the liquid bubble void ratio and the structure slamming load in the liquid bubble void ratio and marine structure slamming load correlation testing device disclosed in an embodiment of the present invention;

[0026] Component number description

[0027] 1. Support frame; 2. Air compressor; 3. Flow control valve; 4. Transparent water cylinder; 5. Bubble generator; 6. Bubble; 7. First fixed frame; 8. Guide frame; 9. Second fixed frame; 10. Laser displacement sensor; 11. Gas spring; 12. Water entry structure; 13. First support assembly; 14. Second support assembly; 15. Electric push rod; 16. Silk screen sensor; 17. First signal amplifier; 18. Data acquisition computer; 19. Electromagnetic release controller; 20. First high-speed collector; 21. Pressure sensor; 22. Second signal amplifier; 23. Second high-speed collector. DETAILED DESCRIPTION

[0028] The following specific embodiments illustrate the implementation of the present invention, and those familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0029] See also Figures 1 to 7 The present invention provides a test device for correlation between liquid bubble porosity and marine structure slamming load, which is suitable for studying the influence of bubble porosity in water on marine structure entry slamming load, comprising two support frames 1, and also comprising a gas-liquid two-phase environment simulation mechanism located between the two support frames 1, the gas-liquid two-phase environment simulation mechanism comprising an air compressor 2, a flow control valve 3, a transparent water cylinder 4 located between the two support frames 1, and a bubble generator 5 installed in the bottom side of the transparent water cylinder 4, the outlet of the air compressor 2 is connected to the inlet of the flow control valve 3 through a gas connecting pipe, the outlet of the flow control valve 3 is connected to the inlet of the bubble generator 5 through a gas connecting pipe, and the outlet of the bubble generator 5 is connected to the inside of the transparent water cylinder 4; it should be noted that the gas-liquid two-phase environment simulation mechanism is used to generate bubble fields of different concentrations in the transparent water cylinder 4, which is suitable for simulating complex marine environments with different bubble contents; the gas flow is adjusted by the flow control valve 3, so that the size and porosity of the bubble 6 can be controlled, thereby ensuring the controllability of the water environment during the experiment.

[0030] like Figure 3 As shown, it also includes a liquid bubble porosity measurement subsystem corresponding to the gas-liquid two-phase environment simulation mechanism, and the liquid bubble porosity measurement subsystem includes a wire mesh sensor 16 for measuring the bubble porosity in the water body and located in the transparent water cylinder 4, a first signal amplifier 17, a data acquisition computer 18 and a power supply system, the wire mesh sensor 16 is electrically connected to the first signal amplifier 17 through a wire, and the first signal amplifier 17 is electrically connected to the data acquisition computer 18 through a wire; it should be noted that the wire mesh sensor 16 is used to accurately measure the porosity of the bubbles 6 in the water body, and the wire mesh sensor 16 realizes accurate measurement of multiphase flow by measuring the conductivity of the fluid, which is particularly suitable for the detection of the gas-liquid two-phase system;

[0031] The wire mesh sensor 16 includes two layers of electrodes arranged orthogonally and parallel to each other, one layer of electrodes is the transmitting end, and the other layer of electrodes is the receiving end. The layer spacing is generally 0.35 to 3 mm. The two layers of electrodes form a grid, and the intersection of each grid is a measuring point. Usually, the spacing between each layer of electrodes is 0.5 to 15 mm, which determines the spatial resolution of the measurement; the conductive material is selected from materials with high conductivity and low resistivity to ensure the accuracy and response speed of the measurement; and the electrical quantity collected by the wire mesh sensor 16 is transmitted to the data acquisition computer 18 through the first signal amplifier 17, thereby completing the real-time measurement of the bubble void fraction data in the liquid. The wire mesh sensor 16 can capture the distribution and concentration of the bubbles 6 in real time, ensuring the high precision and high resolution of the bubble void fraction data during the experiment.

[0032] See also Figure 4 and Figure 5 , and also includes a high-speed vertical motion simulation mechanism installed between the two support frames 1 and located above the gas-liquid two-phase environment simulation mechanism, the high-speed vertical motion simulation mechanism includes a first support assembly 13 and a second support assembly 14 installed on the support frame 1, a first fixed frame 7 is installed on the first support assembly 13 and the second support assembly 14, an electric push rod 15 is installed in the first fixed frame 7, an electromagnetic release controller 19 is installed at the bottom end of the telescopic rod on the electric push rod 15, and a water entry structure 12 is provided on the bottom side of the electromagnetic release controller 19; two guide frames 8 located on both sides of the electric push rod 15 and capable of sliding up and down are installed on the water entry structure 12, a slider is installed on the side of the guide frame 8 close to the first fixed frame 7, and a slider is installed on the first fixed frame 7 A guide rail slidably connected to the slider is installed; a gas spring 11 installed on the second support assembly 14 is provided on the side of the two guide frames 8, the top of the gas spring 11 is installed on the second support assembly 14 through a mounting plate, the bottom end of the gas spring 11 is connected to a steel wire rope, the bottom end of the steel wire rope is connected to the water structure 12, the function of the gas spring 11 and the steel wire rope is to reduce the vibration of the entire device and prevent the water structure 12 from leaving the track; a second fixed frame 9 is provided in one of the support frames 1, and a laser displacement sensor 10 located above the water structure 12 and used to obtain the displacement data of the water structure 12 during the falling process is installed on the second fixed frame 9, and the laser displacement sensor 10 is electrically connected to the first high-speed collector 20 through a wire;

[0033] It should be noted that the electromagnetic release controller 19 is connected to the bottom end of the electric push rod 15, and the position of the electromagnetic release controller 19 can be adjusted by the movement of the electric push rod 15; at the beginning of each vertical drop test, the electromagnetic release controller 19 is energized, so that the falling water-entering structure 12 is firmly attached to the electromagnetic release controller 19, which can ensure that the structure is stationary at the required height before falling, and can ensure that the initial state of the structure falling is horizontal; when the water-entering structure 12 starts to fall, the guide frame 8 ensures that the structure always falls along a fixed trajectory to avoid lateral swing or deviation. Thereby ensuring the repeatability of the experiment and the reliability of the data; the high-speed vertical motion simulation mechanism is equipped with a laser displacement sensor 10 and a first high-speed collector 20, which are used to monitor the motion state of the water-entering structure 12 in real time, and obtain the displacement data in the falling process through the laser displacement sensor 10, and use the first high-speed collector 20 to collect and process the data, so as to accurately calculate the instantaneous speed and acceleration of the water-entering structure 12. The high-speed vertical motion simulation mechanism can set different falling heights and initial speeds under different experimental conditions, so as to study the changes of the water-entering impact load under various speeds.

[0034] like Figure 6 As shown, it also includes a slamming load test subsystem corresponding to the high-speed vertical motion simulation mechanism. The slamming load test subsystem includes a pressure sensor 21, a second signal amplifier 22 and a second high-speed collector 23 installed on the bottom side of the water-entering structure 12. The pressure sensor 21 is electrically connected to the second signal amplifier 22 through a wire, and the second signal amplifier 22 is electrically connected to the second high-speed collector 23 through a wire. It should be noted that the slamming load test subsystem is used to measure the slamming load when the structure enters the water. The pressure sensor 21 is arranged on the surface of the structure and can record in real time the change of the slamming force with the bubble porosity. The pressure sensor 21 is connected to the second signal amplifier 22 to transmit the collected data to the second high-speed collector 23 to complete the real-time measurement of the slamming load and the position of the structure.

[0035] Specifically, the working process of the test device for correlation between liquid bubble porosity and marine structure slamming load is as follows: 1. Bubble 6 generation: the bubble generator 5 generates bubble fields of different concentrations in the transparent water tank 4, and the wire mesh sensor 16 monitors the bubble porosity in the water in real time; 2. Structure falling and displacement monitoring: the submerged structure 12 falls vertically along the guide rail, and the laser displacement sensor 10 monitors its position change in real time. By differential processing of the displacement data, the falling speed of the structure and the speed at the time of entering the water are calculated to ensure the accuracy of the data; 3. Water entry slamming measurement: when the structure enters the water, the pressure sensor 21 records the instantaneous slamming force received by the submerged structure 12, and the high-speed camera synchronously records the whole process of the structure entering the water; 4. Data processing and analysis: all data are collected and analyzed in real time by the industrial control computer to generate the correlation data between the bubble porosity and the slamming load. For details, please refer to Figure 7 .

[0036] In summary, the present invention generates and regulates water environments with different bubble porosity, combines an accurate bubble porosity measurement subsystem and a slamming load test subsystem, and realizes a quantitative study of the slamming load of structures entering water under different bubble porosity conditions, thereby effectively simulating a complex marine environment, studying the weakening effect of bubbles on the slamming load, and providing reliable experimental data for the design and safety assessment of the structure; the present invention not only solves the technical difficulties in the study of the correlation between bubble porosity and the slamming load of marine structures, but also provides an efficient, accurate and safe experimental platform, providing important data support for the structural design and safety assessment in marine engineering.

[0037] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. All equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A device for testing the correlation between liquid bubble porosity and marine structure slamming load, comprising two support frames (1), characterized in that: It also comprises a gas-liquid two-phase environment simulation mechanism located between the two support frames (1), a liquid bubble void ratio measurement subsystem arranged corresponding to the gas-liquid two-phase environment simulation mechanism, a high-speed vertical motion simulation mechanism installed between the two support frames (1) and located above the gas-liquid two-phase environment simulation mechanism, and a slamming load test subsystem arranged corresponding to the high-speed vertical motion simulation mechanism; The liquid bubble void fraction measurement subsystem comprises a wire mesh sensor (16) for measuring the bubble void fraction in a water body, a first signal amplifier (17), a data acquisition computer (18) and a power supply system for providing power, wherein the wire mesh sensor (16) is electrically connected to the first signal amplifier (17) via a wire, and the first signal amplifier (17) is electrically connected to the data acquisition computer (18) via a wire, and the wire mesh sensor (16) comprises two layers of electrodes arranged orthogonally and parallel to each other, wherein one layer of the electrodes is a transmitting end, and the other layer of the electrodes is a receiving end, and the two layers of the electrodes form a grid, and each intersection of the grids is a measuring point.

2. The device for testing the correlation between liquid bubble porosity and marine structure slamming load according to claim 1, characterized in that: The gas-liquid two-phase environment simulation mechanism comprises an air compressor (2), a flow control valve (3), a transparent water cylinder (4) located between the two support frames (1), and a bubble generator (5) installed in the bottom side of the transparent water cylinder (4), and the wire mesh sensor (16) is also located in the transparent water cylinder (4), the outlet of the air compressor (2) is connected to the inlet of the flow control valve (3) through a gas connecting pipe, the outlet of the flow control valve (3) is connected to the inlet of the bubble generator (5) through a gas connecting pipe, and the outlet of the bubble generator (5) is connected to the interior of the transparent water cylinder (4).

3. The device for testing the correlation between liquid bubble porosity and marine structure slamming load according to claim 1, characterized in that: The high-speed vertical motion simulation mechanism comprises a first support assembly (13) and a second support assembly (14) mounted on the support frame (1); a first fixing frame (7) is mounted on the first support assembly (13) and the second support assembly (14); an electric push rod (15) is mounted inside the first fixing frame (7); an electromagnetic release controller (19) is mounted at the bottom end of the telescopic rod on the electric push rod (15); and a water entry structure (12) is provided on the bottom side of the electromagnetic release controller (19).

4. The device for testing the correlation between liquid bubble porosity and marine structure slamming load according to claim 3, characterized in that: The water entry structure (12) is provided with two guide frames (8) located on both sides of the electric push rod (15) and capable of sliding up and down. A sliding block is provided on the side of the guide frame (8) close to the first fixed frame (7). The first fixed frame (7) is provided with a guide rail slidably connected to the sliding block.

5. The device for testing the correlation between liquid bubble porosity and marine structure slamming load according to claim 4, characterized in that: A gas spring (11) mounted on the second support assembly (14) is provided on the side of the two guide frames (8); the top end of the gas spring (11) is mounted on the second support assembly (14) via a mounting plate, and the bottom end of the gas spring (11) is connected to the water entry structure (12) via a steel wire rope.

6. The device for testing the correlation between liquid bubble porosity and marine structure slamming load according to claim 3, characterized in that: A second fixing frame (9) is provided in one of the support frames (1), and a laser displacement sensor (10) is installed on the second fixing frame (9) and is located above the submerged structure (12) and is used to obtain displacement data of the submerged structure (12) during the falling process. The laser displacement sensor (10) is electrically connected to a first high-speed collector (20) via a wire.

7. The device for testing the correlation between liquid bubble porosity and marine structure slamming load according to claim 3, characterized in that: The slamming load test subsystem comprises a pressure sensor (21), a second signal amplifier (22) and a second high-speed collector (23) installed on the bottom side of the submerged structure (12); the pressure sensor (21) is electrically connected to the second signal amplifier (22) via a wire, and the second signal amplifier (22) is electrically connected to the second high-speed collector (23) via a wire.

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