Ice water pool test simulation method for restrained upward floating icebreaking process of underwater vehicle

Abstract

The invention provides an ice water pool test simulation method for an underwater vehicle restrained upward floating icebreaking process, and particularly belongs to the technical field of ice water pool tests. Through the arrangement of a rotary supporting shaft and a fixed cushion block, the underwater vehicle body model can adjust the floating inclination angle, a transmission lead screw is driven by a servo motor, and through the threaded connection of a movement base and the transmission lead screw, the underwater vehicle body model can set the floating speed and stroke. Therefore, the upward-floating icebreaking behaviors of the underwater vehicle body model at different postures and speeds can be effectively simulated. The device comprises a supporting frame and a cross beam base, and further comprises a camera, an underwater vehicle body model, a lifting assembly and a posture adjusting assembly. A lifting assembly is arranged on the inner side of the supporting frame, one end of the lifting assembly is connected with a posture adjusting assembly, the other end of the posture adjusting assembly is connected with a cross beam base, an underwater vehicle body model is installed on the top face of the cross beam base, and a camera is arranged above the underwater vehicle body model.

Description

Technical Field

[0001] The present invention relates to a method for simulating an ice pool test of the constrained upward ice-breaking process of an underwater vehicle, and specifically belongs to the technical field of ice pool tests. Background Art

[0002] The Arctic region is rich in natural resources. As an important area for marine shipping, its development and utilization have received great attention from the international community. With global warming and the reduction of Arctic ice, the development of the Arctic shipping route has gradually become an international hotspot. In ice-covered waters, underwater vehicles play a key role in communication, navigation calibration, and environmental monitoring. When performing tasks, the vehicle often needs to break through the ice to surface in order to complete data transmission or respond to emergencies. Therefore, studying the upward ice-breaking behavior of the vehicle under the ice surface is of great significance for improving the design and mission execution capabilities of polar vehicles;

[0003] When studying the upward ice-breaking behavior of the vehicle, the ice pool model test, as an important method, is widely used because of its unique advantages. Compared with the ice-block - structure interaction test in a non-freezing ice pool environment, the ice pool model test can simulate the real ice-water system in a controllable test environment. By adjusting the ice cover thickness, mechanical properties in the ice pool, and the speed and attitude of the vehicle, the ice pool test can accurately reproduce the complex interaction process between the vehicle and the ice-water system. These characteristics make the ice pool test irreplaceable in studying complex dynamic behaviors and obtaining high-precision test data;

[0004] However, the existing ice pool test methods still have some deficiencies in simulating the upward ice-breaking behavior of the vehicle: First, there is a lack of a special device that can effectively simulate the changes in the upward angle and speed of the vehicle; second, there is no clear understanding of the complex ice-water-vehicle interaction process during the upward ice-breaking process of the vehicle; third, the control of test conditions and the test accuracy of physical quantities need to be further improved. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for simulating an ice pool test of the constrained upward ice-breaking process of an underwater vehicle, so as to systematically study the complex dynamic behavior between the vehicle and the ice layer in a highly controllable ice pool test environment, provide accurate test data support for theoretical research and numerical simulation methods, and provide support for the development of the upward ice-breaking technology of polar vehicles.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: The invention includes a support frame and a crossbeam base, and also includes a camera, an underwater vehicle body model, a lifting assembly, and an attitude adjustment assembly;

[0007] An elevating component is arranged inside the support frame. One end of the elevating component is connected with an attitude adjusting component, and the other end of the attitude adjusting component is connected with a crossbeam base. The top surface of the crossbeam base is installed with an underwater vehicle body model, and a camera is arranged above the underwater vehicle body model.

[0008] Furthermore, the elevating component mainly provides the upward floating power, can accurately control the upward floating speed, and ensure the stability of the vertical movement of the submersible. The attitude adjusting component is mainly used to adjust the inclination angle of the submersible model and ensure that the model is constrained and fixed to meet the simulation requirements of the underwater vehicle floating in different postures.

[0009] The elevating component includes a servo motor, a transmission lead screw, a moving base, a vertical extension member and a horizontal extension member; the servo motor is fixedly installed on the top surface of the support frame, the end of the output shaft of the servo motor is fixedly connected with the transmission lead screw, the transmission lead screw is inserted into a groove arranged inside the support frame, the outside of the transmission lead screw is connected with the moving base, the moving base is embedded and installed inside the support frame, one side of the moving base is fixedly connected with the vertical extension member, one end of the vertical extension member is fixedly connected with the horizontal extension member, and the other end of the horizontal extension member is connected with the attitude adjusting component;

[0010] Furthermore, the servo motor can drive the transmission lead screw to rotate inside the support frame. Due to the threaded connection between the transmission lead screw and the moving base, the moving base can move vertically, and the cooperation of the vertical extension member and the horizontal extension member improves the stability of the device support.

[0011] The attitude adjusting component includes a rotating support shaft, a fixed cushion block, a crossbeam base and a force measuring sensor; the end of the horizontal extension member is connected with the rotating support shaft, the crossbeam base is arranged above the rotating support shaft, a fixed cushion block is arranged between the rotating support shaft and the crossbeam base, the underwater vehicle body model is installed on the top surface of the crossbeam base, and force measuring sensors are arranged at equal intervals between the underwater vehicle body model and the crossbeam base;

[0012] Furthermore, the attitude of the underwater vehicle body model is adjusted by the cooperation of the rotating support shaft and the fixed cushion block, so as to facilitate the simulation of different situations of the experiment.

[0013] An ice pool test simulation method for the constrained floating and icebreaking process of an underwater vehicle, the specific steps include;

[0014] Step 1: Test device design;

[0015] Furthermore, the test device in Step 1 adopts a segmented structure design. An independent force-measuring sensor is connected between each segment and the beam base. The shape and size of each segment can be changed, and the force independence between the segments of the segmented structure is high, which can more accurately capture the details of the load distribution of the ice-submersible interaction during the ice-breaking process of the submersible surfacing. Moreover, it is convenient for disassembly and adjustment. By changing the shape or size of the segments, it can quickly adapt to different design requirements and changes in ice cover conditions, which is beneficial to improving the flexibility and operability of the test. At the design and manufacturing levels, the segmented model needs to ensure the force independence between segments, avoid the mutual coupling and interference of the forces on each segment, and ensure the authenticity and repeatability of the measurement data.

[0016] Step 2: Preparation of the model ice cover;

[0017] Furthermore, the preparation method in Step 2 includes the links of refrigeration and cooling, spray seeding, cooling and freezing, and shutdown and warming, ensuring that the physical and mechanical parameters of the model ice cover meet the similarity requirements with natural sea ice; making the failure mode of the ice cover in the test similar to the real situation, and the ice-breaking load measured in the test can predict the prototype results according to the similarity criterion;

[0018] Step 3: Data acquisition and recording;

[0019] Furthermore, through the equipped high-precision force-measuring sensors and high-definition cameras, the load changes and crack propagation processes during the process of the underwater submersible body model are synchronously recorded. Among them, the force-measuring sensors are arranged at the bottom of the underwater submersible model to measure the vertical load acting on the structural model; the high-definition cameras are arranged above the submersible model-ice interaction area to record in detail the ice crack propagation mode and the submersible-ice interaction process; the test data is connected to the corresponding data system, and the sampling frequency needs to meet the requirement of effectively reflecting the interaction process.

[0020] Step 4: Test process

[0021] Furthermore, the process in Step 4 includes a preparation stage, an execution stage, and a data analysis stage. Prepare a model ice cover that meets the similarity requirements according to the ITTC procedure method. When the thickness and strength of the model ice cover reach the target values, start the test. Conduct multiple repeated tests for the same test conditions to ensure the repeatability of the test results. Connect the ice cover failure process with the ice load time history and analyze the correlation between the failure phenomenon and the load.

[0022] The beneficial effects of the present invention are:

[0023] 1. By setting the rotating support shaft and the fixed cushion block, the underwater vehicle body model can adjust the floating inclination angle. The servo motor drives the transmission lead screw. Through the threaded connection between the moving base and the transmission lead screw, the floating speed and stroke of the underwater vehicle body model can be set, so as to effectively simulate the floating ice-breaking behavior of the underwater vehicle body model in different postures and speeds.

[0024] 2. By equipping with high-precision force sensors and high-definition cameras, the time history and distribution of the ice-breaking load during the structure floating and the failure mode and crack propagation process of the ice cover are recorded in real time, providing reliable data support for analyzing the ice-breaking performance of the submersible and providing systematic technical support for the research on the ice-breaking performance and structural design optimization of the underwater vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 is a schematic diagram of the method flow of the present invention.

[0027] 1. Support frame; 2. Servo motor; 3. Transmission lead screw; 4. Moving base; 5. Vertical elongation member; 6. Horizontal elongation member; 7. Rotating support shaft; 8. Fixed cushion block; 9. Crossbeam base; 10. Force sensor; 11. Camera. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will combine the attached Figure 1-2 , and clearly and completely describe the technical solutions in the embodiments.

[0029] DETAILED DESCRIPTION OF THE EMBODIMENTS I: As Figure 1 shown, the overall device consists of a support frame 1, a lifting assembly and an attitude adjustment assembly. The servo motor 2 is fixedly installed on the top surface of the support frame 1 through bolts. The output shaft end of the servo motor 2 is fixedly connected with a transmission lead screw 3. The transmission lead screw 3 is inserted into the vertical slide rail opened inside the support frame 1. The outside of the transmission lead screw 3 is threadedly connected with a moving base 4. The moving base 4 is slidably installed in the vertical slide rail, so that the moving base 4 can move vertically;

[0030] One side of the moving base 4 facing away from the support frame 1 is fixedly installed with a vertical elongation member 5. The end of the vertical elongation member 5 is welded and fixed with a horizontal elongation member 6. The horizontal elongation member 6 and the vertical elongation member 5 cooperate to form an "L" - shaped structure, so as to improve the stability of the overall structure of the device;

[0031] The horizontal extension member 6 is rotatably connected to a rotary support shaft 7. Above the rotary support shaft 7, there is a crossbeam base 9. A fixed cushion block 8 is arranged between the rotary support shaft 7 and the crossbeam base 9. By adjusting the fixed cushion block 8, the inclination angle of the crossbeam base 9 can be adjusted synchronously, so as to facilitate the comparative use of different groups, improve the repeatability of the test. The top surface of the crossbeam base 9 is installed with an underwater vehicle body model. Force sensors 10 are arranged at equal intervals between the underwater vehicle body model and the crossbeam base 9. Data can be collected through the force sensors 10, so as to facilitate the subsequent systematic technical support for the research on the ice-breaking performance and structural design optimization of the underwater vehicle body model.

[0032] Specific Embodiment 2: As Figure 2 shown, a method for simulating an ice tank test of the constrained floating ice-breaking process of an underwater vehicle specifically includes the following steps;

[0033] Step 1: Design of the test device;

[0034] The lifting power of the underwater vehicle body model is provided by the cooperation of the support frame 1 and the lifting assembly in the device, and the upward floating speed of the underwater vehicle body model can be accurately controlled to ensure the stability of the vertical movement of the underwater vehicle body model;

[0035] The inclination angle of the underwater vehicle body model is adjusted by using the vertical extension member 5 and the horizontal extension member 6 that form an "L" shape in cooperation with the attitude adjustment assembly, and the restraint and fixation of the underwater vehicle body model are ensured to meet the simulation requirements of the underwater vehicle body model floating upward in different postures;

[0036] At this time, the force sensor 10 is connected to the outer shell of the underwater vehicle body model. When it is necessary to measure the distribution of the upward floating ice-breaking load of the structural underwater vehicle body model, a segmented structural model type can be adopted for the underwater vehicle body model, and each segment is connected to the crossbeam base 9 through an independent force sensor 10; when only the total upward floating ice-breaking load of the underwater vehicle body model needs to be measured, the number of force sensors 10 can be appropriately reduced;

[0037] For the segmented underwater vehicle body model, independent force sensors 10 are arranged between each segment and the crossbeam base 9 for connection, which can more accurately capture the load distribution details of the ice-vehicle interaction during the upward floating ice-breaking process of the underwater vehicle body model, and is convenient for disassembly, installation and adjustment. By changing the segmented shape or size, it can quickly adapt to the changes of different design requirements and ice cover conditions, which is beneficial to improving the flexibility and operability of the test. At the design and manufacturing level, the segmented underwater vehicle body model needs to ensure the independence of the force between each segment, avoid the mutual coupling and interference of the forces of each segment, and ensure the authenticity and repeatability of the measurement data;

[0038] The installation and debugging process of the test device is as follows: Install the support frame 1 and the lifting component in the ice pool to ensure accurate assembly among components such as the moving base 4, the vertical extension member 5, the horizontal extension member 6, the rotating support shaft 7, and the fixed cushion block 8, and ensure the overall horizontal stability of the device; Adjust the parameters of the servo motor 2, including the lifting speed range. The speed of the selected motor can be accurately controlled between 1 - 300 mm / s, and the control accuracy is 0.02 mm / s; Debug the operating state of the servo motor 2 to ensure smooth movement of the moving base 4 without jitter during the loading and unloading processes; Determine the installation position of the force measuring sensor 10 to ensure that it can capture the contact load between the submersible model and the ice cover in real time; The range of the force measuring sensor 10 is 500 kgf, the accuracy is 0.05% F.S., the operating temperature range is -20°C to 80°C, the protection level is IP68, and the sampling frequency is 100 Hz; And install a high-definition camera 11 at a fixed position; These devices can synchronously record the load changes and crack propagation process during the upward floating of the submersible;

[0039] Fix the underwater submersible body model on the crossbeam base 9 to ensure the stable position of the underwater submersible body model and the center alignment with the rotating support shaft 7; Adjust the rotating support shaft 7 and the fixed cushion block 8 to make the underwater submersible body model reach the required inclination angle, and restrain and fix the underwater submersible body model to simulate the upward floating conditions of the underwater submersible body model in different postures; Check the connection firmness between the underwater submersible body model and the force measuring sensor 10 to ensure accurate transmission of the load signal; Set the upward floating speed of the servo motor 2; Record the initial test data, including parameters such as ice cover thickness, submersible model position, inclination angle, and environmental temperature;

[0040] Step 2: Preparation of the model ice cover;

[0041] To truly reproduce the upward floating and ice breaking process of the underwater submersible body model and accurately measure the structural ice breaking load and its distribution, it is necessary to ensure that the physical and mechanical parameters of the model ice cover meet the similarity requirements with natural sea ice. Among them, the physical and mechanical parameters of the ice cover related to the structural upward floating and ice breaking process include ice thickness, ice bending strength, ice uniaxial compressive strength, ice elastic modulus, and ice Poisson's ratio, etc.; Through links such as refrigeration and cooling, spray seeding, cooling and freezing, and shutdown and warming, prepare a model ice cover whose physical and mechanical parameters meet the similarity with natural sea ice, so that the failure mode of the ice cover in the test is similar to the actual situation, and the ice breaking load measured in the test can predict the prototype result according to the similarity criterion;

[0042] The specific operation of preparing the model ice cover is as follows: Prepare an aqueous urea solution in a proportion of 1.5%, and stir it evenly in a water tank; then use a cold air unit to cool down the laboratory to gradually approach the freezing point of the water temperature; after the water temperature approaches the freezing point, remove large grains and small broken ice cubes in the water, atomize the aqueous urea solution and spray it onto the water surface to form micro-ice crystals as ice nuclei to induce the growth of ice crystals from top to bottom; before the ice thickness reaches the predetermined value, control the strength index of the ice through the warming process, adjust the flexural strength of the ice, and use the cantilever beam method to monitor the ice strength at regular intervals to ensure meeting the test requirements;

[0043] Step 3: Data acquisition and recording;

[0044] By equipping with a high-precision force sensor 10 and a high-definition camera, the load change and crack propagation process during the upward floating process of the underwater vehicle body model can be synchronously recorded. Among them, the force sensor 10 is arranged at the bottom of the underwater vehicle body model section, connecting the underwater vehicle body model and the crossbeam base 9 to measure the vertical load acting on the underwater vehicle body model section of the structure; the high-definition camera is arranged above the underwater vehicle body model-ice interaction area to record in detail the ice crack propagation mode and the underwater vehicle-ice interaction process; the test data is connected to the corresponding data system, and the sampling frequency needs to meet the requirement of effectively reflecting the interaction process;

[0045] Step 4: Test process;

[0046] The test process includes a preparation stage, an execution stage, and a data analysis stage;

[0047] In the preparation stage, prepare a model ice cover that meets the similarity requirements according to the ITTC regulation method. When the thickness and strength of the model ice cover reach the target values, start the test. The underwater vehicle body model is processed and manufactured according to the set geometric scale ratio. The geometric shape and size of the underwater vehicle body model meet the similarity requirements, and it is ensured that the underwater vehicle body model has sufficient rigidity so that the measurement result of the ice-breaking load meets the test requirements. Finally, install, connect, and debug the underwater vehicle body model, the test device, and the test system without errors;

[0048] During the execution phase, the underwater vehicle body model is controlled by the moving base 4 to adjust its entry position and depth into the water. The underwater vehicle body model is extended to a certain distance below the model ice cover to ensure that the free edge of the model ice cover and the pool walls of the fixed boundary ice pool on both sides will not interfere with the upward ice-breaking process. Then, start the moving base 4 and set the upward floating speed and inclination angle. Record the load time history and the ice cover damage process during the ice-breaking process, including the initial contact load, the peak value of the ice-breaking load, and the dynamic changes during the continuous ice-breaking process. Use the high-definition camera 11 to synchronously record the ice-breaking process, including the ice cover deformation, the crack propagation path, and the ice layer damage mode. The underwater camera device monitors the dynamic changes in the contact area between the underwater vehicle's motion state and the ice body. The force sensor 10 records the load changes on the underwater vehicle during the upward floating process in real time. Clean up the broken ice cover, rearrange the underwater vehicle body model to a certain distance below the intact ice cover, and conduct multiple repeated tests under the same test conditions to ensure the repeatability of the test results.

[0049] Data analysis phase: Based on the high-definition video data of the camera 11, describe the damage process of the model ice cover, including the propagation length of the cracks in the ice, the damage range of the areas where the cracks appear, etc., and analyze the appearance and propagation sequence of the cracks in the ice. On the other hand, synchronously analyze the ice-breaking load time history, including the total load and the load time history on each segment of the segmented underwater vehicle body model, and relate the damage process of the model ice cover to the ice load time history to analyze the correlation between the damage phenomenon and the load.

[0050] Organize the multi-channel data collected in the experiment, including the load time series and the crack propagation images. Comprehensively analyze the load data, draw the relationship curves of the load varying with the underwater vehicle's speed and inclination angle, and reveal the correlation law between the ice-breaking load and the underwater vehicle's motion parameters. Analyze the crack propagation images, extract the dynamic characteristics of crack generation, propagation, and penetration, and discuss the relationship between the ice layer damage mode and the underwater vehicle design in combination with the load data. Compare the results under different test conditions, summarize the influencing factors and main laws of the upward constrained ice-breaking process of the underwater vehicle, and provide data support for the optimization of the theoretical model and engineering applications.

[0051] The above description is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or equivalents by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent replacement, and improvement made to the above embodiments within the spirit and principle of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An ice pool test device for an underwater submersible restrained buoyancy and icebreaking process, comprising a support frame (1) and a beam base (9), characterized in that: It also includes a camera (11), an underwater submersible body model, a lifting component and a posture adjustment component; A lifting assembly is arranged inside the support frame (1), one end of the lifting assembly is connected to a posture adjustment assembly, the other end of the posture adjustment assembly is connected to a crossbeam base (9), an underwater submersible body model is installed on the top surface of the crossbeam base (9), and a camera (11) is arranged above the underwater submersible body model.

2. The ice water pool test device for the underwater submersible restrained buoyancy and icebreaking process according to claim 1 is characterized in that: The lifting assembly comprises a servo motor (2), a transmission screw (3), a motion base (4), a vertical extension member (5) and a horizontal extension member (6); A servo motor (2) is fixedly mounted on the top surface of the support frame (1); a transmission screw (3) is fixedly connected to the end of the output shaft of the servo motor (2); the transmission screw (3) is inserted into a groove provided on the inner side of the support frame (1); a motion base (4) is connected to the outer side of the transmission screw (3); the motion base (4) is embedded in the inner side of the support frame (1); a vertical extension member (5) is fixedly connected to one side of the motion base (4); a horizontal extension member (6) is fixedly connected to one end of the vertical extension member (5); and a posture adjustment component is connected to the other end of the horizontal extension member (6).

3. The ice-water pool test device for the underwater submersible restrained buoyancy and icebreaking process according to claim 1 is characterized in that: The posture adjustment component comprises a rotating support shaft (7), a fixed cushion block (8), a crossbeam base (9) and a force sensor (10); The end of the horizontal elongated member (6) is connected to a rotating support shaft (7), a beam base (9) is arranged above the rotating support shaft (7), a fixed cushion block (8) is arranged between the rotating support shaft (7) and the beam base (9), an underwater submersible body model is installed on the top surface of the beam base (9), and force sensors (10) are arranged at equal intervals between the underwater submersible body model and the beam base (9).

4. An ice pool test simulation method for an underwater submersible restrained buoyancy and icebreaking process, the specific steps comprising: Step 1: Design of experimental device; Step 2: Preparation of model ice sheet; Step 3: Data collection and recording; Step 4: Experimental process.

5. The ice water tank test simulation method for the underwater submersible restrained buoyancy and icebreaking process according to claim 4 is characterized in that: The test device in step 1 adopts a segmented structure design, and an independent force sensor (10) is arranged between each segment and the beam base (9) for connection. The shape and size of the segment can be changed, and the force independence between each segment of the segmented structure is high.

6. The ice water tank test simulation method for the underwater submersible restrained buoyancy and icebreaking process according to claim 4 is characterized in that: The preparation method in step 2 includes refrigeration, spray seeding, cooling and freezing, and shutdown and temperature recovery.

7. The ice water tank test simulation method for the underwater submersible restrained buoyancy and icebreaking process according to claim 4 is characterized in that: The process in step 4 includes the preparation stage, execution stage and data analysis stage. Multiple repetitive tests are carried out on the same test conditions to ensure the repeatability of the test results.

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