Visualized abrasion combined action mechanism testing device and method based on ultrasonic cavitation

Abstract

The present invention discloses a device and method for testing the combined action mechanism of visual abrasion based on ultrasonic cavitation, comprising a stirring water tank, the top of which is connected upwardly to a transparent water tank, a sediment circulation pump being provided in the stirring water tank, the sediment circulation pump being connected to a cavitation generator with a bottom opening and extending into the top of the transparent water tank through a pipe extending upwardly from the stirring water tank, a specimen mounting fixture being provided below the cavitation generator and a PIV shooting device, a high-speed camera shooting device, and shooting auxiliary equipment being provided on the outside of the transparent water tank, all of which are electrically connected to a synchronizer and a computer. The present invention uses a single experimental device to conduct multi-angle cavitation, erosion, wear, and abrasion experiments, thereby better comparing and analyzing the four types of hydraulic mechanical damage. At the same time, dynamic capture is performed through high-speed camera and PIV technology analysis to analyze the effects of different hydraulic conditions on different damage processes and microscopic development mechanisms.

Description

Technical Field

[0001] The present invention belongs to the technical field of cavitation and erosion visualization research, and specifically relates to a device for testing the combined action mechanism of visualization and abrasion based on ultrasonic cavitation. The present invention also relates to a method for testing the combined action mechanism of visualization and abrasion based on ultrasonic cavitation. Background Art

[0002] With the rapid development of renewable clean energy and the transformation of water resources, new hydropower stations and water diversion projects are currently being planned or under construction, most of which are located in sandy rivers. Fluid machinery in sandy water flows is primarily subject to two types of damage: cavitation and wear. Cavitation is the phenomenon of cave-like corrosion damage on metal surfaces in contact with the fluid under conditions of high-speed flow and pressure fluctuations. Wear is the damage caused by the impact of sandy water on fluid machinery, resulting in impact, friction, and collision on the surface of the fluid machinery. Relevant research shows that the combined damage of cavitation and wear is far greater than the combined effect of the two. The synergistic effect of cavitation and sediment erosion not only reduces the efficiency and lifespan of fluid machinery, but also increases operating and maintenance costs. Cavitation erosion is a major obstacle to improving the operating power, stability, and service life of fluid machinery.

[0003] As modern hydraulic machinery develops towards large-scale, large-capacity, high-speed and high-performance, the synergistic effect of cavitation and sediment erosion is becoming a serious problem. The lack of accurate prediction of the damage mechanism of the abrasion process has severely restricted the reliability, stability and safe operation of hydraulic machinery under sediment conditions.

[0004] Researchers at home and abroad have investigated sediment abrasion using disc abrasion tests and ultrasonic vacuum tests. Scanning electron microscopy has been used to analyze the mechanism of abrasion, providing preliminary insights into the causes of abrasion. However, due to a lack of quantitative analysis techniques, the characteristics and proportions of wear and cavitation damage in abrasion remain controversial, and key information about the damage process has not been obtained, leaving the mechanism of abrasion unclear. Ultrasonic cavitation, a primary cavitation research method, has been used. Some researchers have added a certain volume concentration of sediment to a cavitation reaction vessel for combined cavitation and wear damage analysis. The sediment is stirred by a rotating agitator within the reaction vessel and then moved to the specimen surface. However, in practical engineering applications, the combined cavitation and sediment interaction often aligns with the direction of the cavitation bubble jet, making such experimental studies inaccurately reflective of the combined cavitation and wear mechanisms. Existing abrasion test benches have limited functionality, precluding the ability to conduct multifunctional, integrated tests of cavitation, wear, and abrasion in the same abrasion test setup. A highly precise and reliable experimental setup is urgently needed to experimentally investigate the combined cavitation and wear mechanisms under sediment conditions. Summary of the Invention

[0005] The purpose of the present invention is to provide a visual abrasion combined action mechanism testing device based on ultrasonic cavitation, which solves the problem that the existing abrasion experimental device cannot accurately reflect the abrasion combined action mechanism.

[0006] Another object of the present invention is to provide a method for testing the combined action mechanism of visual abrasion based on ultrasonic cavitation.

[0007] The first technical solution adopted by the present invention is: a visual abrasion combined action mechanism testing device based on ultrasonic cavitation, including a stirring water tank, the top of the stirring water tank is upwardly connected to a transparent water tank, a sediment circulation pump is arranged in the stirring water tank, the sediment circulation pump is connected to a cavitation generator with a bottom opening and extending into the top of the transparent water tank through a pipe extending upward from the stirring water tank, a specimen mounting fixture mounted in the transparent water tank is arranged below the cavitation generator, a PIV shooting device, a high-speed camera shooting device and shooting auxiliary equipment are arranged on the outside of the transparent water tank, and the PIV shooting device, the high-speed camera shooting device and the shooting auxiliary equipment are electrically connected to a synchronizer and a computer.

[0008] The first technical solution of the present invention is also characterized in that:

[0009] The length direction of the transparent water tank is arranged along the longitudinal direction, the upper part is a rectangular parallelepiped, and the two opposite sides of the lower part are contracted inwardly along the width direction to form a square cone.

[0010] The specimen installation fixture includes an inverted door-shaped fixing frame, and slide grooves are arranged longitudinally on the outside of both sides of the top of the fixing frame, and a slider is arranged in the slide groove. The outer side of the slider is fixedly connected to an adjusting screw with one end extending outward from the top of the transparent water tank. The adjusting screw passes through a splint with one bottom side resting on the outer wall of the top of the transparent water tank. The end of the adjusting screw away from the slider is connected with an adjusting nut. A pair of tensioning plates for clamping the specimen are fixed in parallel on the bottom end of the fixing frame.

[0011] The tensioning plate is a right-angled trapezoid, and two concentric arc holes are opened on the tensioning plate with its non-right-angled vertex as the center of the circle. A plurality of tensioning holes are evenly spaced along the arc direction concentric with the two arc holes on the outside. A tensioning screw is coaxially connected between the two corresponding tensioning holes on the two tensioning plates.

[0012] The top of the mixing water tank is connected to the transparent water tank through a pipe equipped with a flow regulating valve. An agitator connected to an external motor is provided in the mixing water tank. An observation window is provided at the bottom of the mixing water tank. A prism and a brightness sensor are provided below the mixing water tank corresponding to the observation window. A cooling circulating water pipeline and a temperature sensor are connected to the outside on one side of the mixing water tank.

[0013] An electromagnetic flowmeter is provided on the connecting pipe between the sediment circulation pump and the cavitation generator. The sediment circulation pump adopts a positive displacement pump body, and a pressure stabilizing device is provided at the pump body outlet.

[0014] The stirring water tank is connected to a tracer particle adding device.

[0015] A bracket is provided on the stirring water tank, a lifting device is mounted on the bracket and is located above the transparent water tank, and the top end of the cavitation generator is connected to the bottom end of the lifting device.

[0016] The shooting auxiliary equipment includes a laser generator and a high-intensity lighting group arranged corresponding to the two wide sides of the transparent water tank. The laser generator and the high-intensity lighting group are electrically connected to the synchronizer. Photoelectric detectors are provided on the optical paths of the laser generator and the high-intensity lighting group. The photoelectric detectors are electrically connected to the computer via an oscilloscope.

[0017] The second technical solution adopted by the present invention is: a test method based on a visual abrasion combined action mechanism test device of ultrasonic cavitation, including four test states: starting the cavitation generator alone to conduct a cavitation damage test, starting the cavitation generator and passing water to drive the cavitation bubbles to conduct a cavitation impact damage test, only spraying mud and sand without starting the cavitation generator to conduct a mud and sand wear test, and spraying mud and sand while starting the cavitation generator to conduct an abrasion damage test. During the test, the four test states are dynamically captured by a PIV shooting device and a high-speed camera shooting device. The specific test method is as follows:

[0018] Start the cavitation generator alone to conduct cavitation damage experiments: control the water level of the transparent water tank to the experimental water level, close the flow regulating valve to keep the water level of the transparent water tank stable, start the cavitation generator, and the specimen will only be damaged by ultrasonic cavitation bubbles;

[0019] Start the cavitation generator and flow water to drive the cavitation bubbles to conduct cavitation impact damage experiments: Pour clean water into the mixing water tank, start the sediment circulation pump for circulation, control the water level of the transparent water tank through the flow regulating valve, start the cavitation generator, and the specimen is subjected to the impact damage of ultrasonic cavitation bubbles carried by the water flow;

[0020] The sand abrasion test was conducted by injecting only sand without starting the cavitation generator: the sand and water were injected into the mixing tank, the sand circulation pump was started for circulation, and the water level in the transparent water tank was controlled by the flow regulating valve. The specimen was only damaged by the sand and water abrasion impact.

[0021] The abrasion damage experiment was carried out by starting the cavitation generator while injecting sediment: the sediment water was injected into the stirring water tank, the sediment circulation pump was started for circulation, the water level of the transparent water tank was controlled by the flow regulating valve, and the cavitation generator was started. The specimen was subjected to the combined effects of sediment water abrasion damage and ultrasonic cavitation bubble impact damage.

[0022] The beneficial effects of the present invention are: the visual abrasion combined action mechanism testing device and method based on ultrasonic cavitation of the present invention conducts multi-angle cavitation, erosion, wear and abrasion experiments through a single experimental device, better compares and analyzes the four types of hydraulic mechanical damage, and at the same time uses high-speed cameras and PIV technology analysis to dynamically capture and analyze the effects of different hydraulic conditions on different damage processes and microscopic development mechanisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of the visual abrasion combined action mechanism testing device based on ultrasonic cavitation of the present invention;

[0024] Figure 2 Schematic diagram of the positional relationship between the transparent water tank and the stirring water tank in the ultrasonic cavitation-based visual abrasion combined action mechanism testing device of the present invention;

[0025] Figure 3 It is a perspective schematic diagram of a transparent water tank and a stirring water tank in the ultrasonic cavitation-based visual abrasion combined action mechanism testing device of the present invention;

[0026] Figure 4 Schematic diagram of the structure of the cavitation nozzle in the ultrasonic cavitation-based visual abrasion combined action mechanism testing device of the present invention;

[0027] Figure 5 Schematic diagram of the structure of the transparent water tank in the ultrasonic cavitation-based visual abrasion combined action mechanism testing device of the present invention;

[0028] Figure 6 Schematic diagram of the structure of the test piece mounting fixture in the ultrasonic cavitation-based visual abrasion combined action mechanism testing device of the present invention;

[0029] Figure 7 Schematic diagram of the structure of the tensioning plate in the ultrasonic cavitation-based visual abrasion combined action mechanism testing device of the present invention;

[0030] Figure 8 Schematic diagram of the structure of the test piece in the apparatus for testing the combined action mechanism of visual abrasion based on ultrasonic cavitation of the present invention;

[0031] Figure 9 Schematic diagram of the state of a specimen at an impact angle of 15°-90° in the ultrasonic cavitation-based visualized abrasion combined action mechanism testing device of the present invention;

[0032] Figure 10 It is a schematic diagram of the timing control relationship of the visual abrasion combined action mechanism testing device based on ultrasonic cavitation of the present invention.

[0033] In the figure, 1. transparent water tank, 2. stirring water tank, 3. sediment circulation pump, 4. electromagnetic flowmeter, 5. cavitation generator, 6. tracer particle addition device, 7. PIV imaging device, 8. high-speed camera imaging device, 9. synchronizer, 10. laser generator, 11. high-intensity lighting unit, 12. photoelectric detector, 13. oscilloscope, 14. computer, 15. test piece;

[0034] 101. Fixing frame, 102. Slide groove, 103. Slider, 104. Adjusting screw, 105. Clamp, 106. Adjusting nut, 107. Tensioning plate, 108. Arc hole, 109. Tensioning hole, 110. Tensioning screw;

[0035] 201. Flow control valve, 202. Agitator, 203. Temperature sensor, 204. Cooling water circulation pipeline, 205. Observation window, 206. Brightness sensor, 207. Prism;

[0036] 501. Lifting device, 502. Cavitation nozzle, 503. Sediment water inlet, 504. Bracket. DETAILED DESCRIPTION

[0037] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] The present invention provides a visual abrasion combined action mechanism testing device based on ultrasonic cavitation, such as Figure 1 and 2 As shown, the system includes a transparent water tank 1, a mixing water tank 2, a sediment circulation pump 3, an electromagnetic flowmeter 4, a cavitation generator 5, a tracer particle addition device 6, a PIV camera 7, a high-speed camera 8, a synchronizer 9, a laser generator 10, a high-intensity lighting system 11, a photodetector 12, an oscilloscope 13, and a computer 14. The high-speed camera 8 is synchronously positioned in the position of the PIV camera 7 to record the trajectory of cavitation bubbles and sediment particles, the volume of cavitation bubbles, and the changes in cavitation shape during cavitation collapse. The PIV camera 7 and the high-speed camera 8 are positioned on the wide side of the transparent water tank 1. Auxiliary equipment for recording the images includes a laser generator 10, a high-intensity lighting system 11, a photodetector 12, and an oscilloscope 13. The laser generator 10 and the high-intensity lighting system 11 are controlled on and off by the synchronizer 9. The photodetector 12 and oscilloscope 13 are used to verify and measure the time difference between the laser and lighting triggers and the light intensity. The computer 14 is used to set the interval and write the trigger instruction for the synchronizer 9; the signals collected by the oscilloscope 13, the PIV shooting device 7 and the high-speed camera shooting device 8 are transmitted to the computer acquisition terminal.

[0040] like Figure 3As shown, the mixing water tank 2 is located at the lower part of the transparent water tank 1. The two water tanks are connected by a pipe in the middle. A flow regulating valve 201 is provided on the pipe. A stirrer 202 with adjustable speed is arranged in the mixing water tank 2 to stir the sediment water in the water tank evenly. A vertical observation window 205 is installed at the bottom of the water tank. The circular observation window 205 and the 45° prism 207 at the bottom are used to observe the sediment state at the bottom. A brightness sensor 206 is provided at the bottom to increase the motor speed of the stirrer 202 when sedimentation occurs to ensure that the sediment water is fully and evenly stirred. A cooling circulating water pipeline 204 and a temperature sensor 203 are installed inside the mixing water tank 2 to control the experimental temperature in the mixing water tank 2. The sediment circulation pump 3 is used to pump the sand and water in the mixing water tank 2 to the cavitation nozzle 502 of the cavitation generator 5, as shown Figure 4 As shown, the cavitation nozzle 502 of the present invention is different from the solid holeless nozzle commonly used in ultrasonic cavitation generators in the prior art. This nozzle can only generate cavitation bubbles through the ultrasonic cavitation effect and cannot pass water at the same time. The cavitation nozzle 502 of the present invention is provided with a through hole along the axial direction, so that water can pass through and spray downward at the same time as ultrasonic cavitation. The electromagnetic flowmeter 4 is used to record the flow of the sediment circulation pump 3 and feed back the deviation signal to the flow regulation of the sediment circulation pump 3 to control the flow of the sediment circulation pump 3 within a stable range. The sediment circulation pump 3 uses a volumetric pump body, and a pressure stabilizing device is provided at the pump body outlet to regulate the stability of the sediment water flow. The tracer particle adding device 6 is located above the stirring water tank 2. During the experiment, tracer particles are added to the stirring water tank 2. The tracer particles circulate in the system along with the sediment water through the sediment circulation pump 3.

[0041] like Figure 5 As shown in the assembly diagram of the transparent water tank 1 and the specimen mounting fixture, the upper part of the transparent water tank 1 is a rectangular parallelepiped, and the lower part is a funnel-shaped cone. The horizontal cross-section of the rectangular parallelepiped is an elongated rectangle, and the length-to-width ratio of the inner cavity is 3:1 to 4:1. A fixing frame 101 is installed inside the rectangular parallelepiped.

[0042] like Figure 6 The figure shows a specimen installation fixture, the fixing frame 101 can adjust the depth of immersion in water, the top of the fixing frame 101 is longitudinally provided with a slide groove 102 on both sides, the slide groove 102 is matched with a slider 103, the outer side of the slider 103 is fixedly connected to an adjusting screw 104 with one end extending outward from the top of the transparent water tank 1, the adjusting screw 104 passes through a clamping plate 105 with one side of the bottom end resting on the outer wall of the top of the transparent water tank 1, the end of the adjusting screw 104 away from the slider 103 is matched with an adjusting nut 106, and a pair of tensioning plates 107 for clamping the specimen 15 are fixed in parallel on the bottom end of the fixing frame 101.

[0043] like Figure 7The illustrated tensioning plate 107 is a right-angled trapezoid with a base angle of 75° and a top angle of 105°. The impact reference point of the specimen 15 coincides with the fixed point at the upper left corner of the right-angled trapezoid. After the specimen 15 and tensioning plate 107 are assembled, the upper edge of the specimen 15 is free of obstructions to the water flow and the filming process, reducing interference with the impact during the experiment and increasing the visual filming field of view. The tensioning plate 107 has two concentric arc-shaped holes 108 centered at its non-right-angled vertex. Multiple tensioning holes 109 are evenly spaced along the outer sides of these two arc-shaped holes 108, concentric with each other. A tensioning screw 110 is coaxially connected between two corresponding tensioning holes 109 on the two tensioning plates 107.

[0044] like Figure 8 Specimen 15 is shown. Two small bosses are machined on the lower side of specimen 15. When specimen 15 is installed between tension plates 107, the bosses extend into arc-shaped holes 108. This allows the axis of the upper surface of specimen 15 to completely coincide with the line connecting the non-perpendicular vertices of the two tension plates 107 when it rotates. This ensures that when studying the impact weight loss over time of the same specimen, the impact position of specimen 15 does not change after each sampling measurement and reinstallation, thus ensuring the accuracy and reliability of the experiment. To study the changes in the degree of damage to specimen 15 over time, specimen 15 must be frequently removed, weighed, and microscopic images of the damage morphology taken before being installed between tension plates 107. Repeated installations that are inconsistent with the previous position will cause the damage position to migrate, resulting in significant experimental error. Therefore, re-fixing the reference position after each disassembly and reassembly is crucial to experimental accuracy.

[0045] The tensioning plate 107 is provided with two arc-shaped holes 108 and six tensioning holes 109. The center of the arc-shaped hole 108 is the vertex position of the upper left corner of the tensioning plate 107, which corresponds to the reference point position of the specimen 15. The outer edge of the lower tensioning hole 109 is provided with six scale lines for installing the tensioning screw 110 when clamping the specimen 15 at different angles. The positioning of the tensioning hole 109 is respectively the tensioning hole 109 corresponding to the perpendicular bisector of the reference point position of the specimen 15 at the installation angle of the specimen 15 at different experimental angles. When the tensioning screw 110 is installed in the tensioning hole 109 of the perpendicular bisector, the tensioning plate 107 deforms slightly along the perpendicular bisector, which can evenly distribute the friction resistance generated during the clamping process to the lower edge of the specimen 15, thereby increasing the friction resistance and re-checking the placement position and angle of the specimen 15 to ensure that the tensioning plate 107 firmly fastens the specimen 15. The tensioning plate 107 is fixed by surface contact clamping. The reference position of the specimen 15 does not change during the angle adjustment process, which reduces the experimental error caused by the change of the reference impact position of the specimen 15 during the angle adjustment process. The processing angle of the bottom corner of the tensioning plate 107 is 75 degrees. Figure 9 As shown, unobstructed visualization shooting experiments can be performed at impact angles of 15°-90°.

[0046] Example 2

[0047] The operating status of the multifunctional abrasion damage test is divided into:

[0048] 1. Start the cavitation generator 5 alone to conduct a cavitation damage experiment; specific operation method: control the water level of the transparent water tank 1 at the experimental water level, close the flow control valve 201 below to keep the water level of the transparent water tank 1 stable, and start the cavitation generator 5. In this state, the specimen 15 is only damaged by ultrasonic cavitation bubbles.

[0049] 2. Start the cavitation generator 5 and flow water to drive the cavitation bubbles to move and conduct a cavitation impact damage experiment; specific operation method: inject clean water into the mixing water tank 2, start the sediment circulation pump 3 for circulation, control the water level of the transparent water tank 1 through the flow control valve 201, and start the cavitation generator 5. In this state, the specimen 15 is damaged by the impact of ultrasonic cavitation bubbles carried by the water flow.

[0050] 3. Only the sediment is injected without starting the cavitation generator 5 to conduct the sediment wear test; the specific operation method is as follows: a certain concentration of sediment water is injected into the stirring water tank 2, the sediment circulation pump 3 is started for circulation, and the water level of the transparent water tank 1 is controlled by the flow regulating valve 201. In this state, the specimen 15 is only damaged by the impact of sediment water wear.

[0051] 4. Simultaneously with the injection of sediment, the cavitation generator 5 was activated to conduct an abrasion damage experiment. Specific operation methods included injecting sediment water of a certain concentration into the agitation tank 2, starting the sediment circulation pump 3 for circulation, controlling the water level of the transparent water tank 1 via the flow regulating valve 201, and starting the cavitation generator 5. In this state, the specimen 15 was subjected to the combined effects of sediment water abrasion damage and ultrasonic cavitation bubble impact damage.

[0052] Example 3

[0053] During the experiment, tracer particles are added to the stirring water tank 2, and the tracer particles circulate in the system along with the sediment water through the sediment circulation pump 3. At the same time, the above four types of damage are dynamically captured by PIV shooting devices and high-speed camera shooting devices, and the influence of different water conditions on different damage processes and microscopic development mechanisms is analyzed. The cavitation generator 5 adjusts the lifting height of the nozzle through the lifting device 501, and then adjusts the depth of the cavitation nozzle 502 immersed in the transparent water tank. The cavitation generator 5 is provided with a sediment water inlet 503 on the side, which is sprayed from the bottom center of the cavitation nozzle 502. When the cavitation generator 5 is started, cavitation bubbles are generated in the cavitation nozzle 502, and the cavitation bubbles move along the radial direction of the cavitation nozzle 502, and the sediment water in the nozzle moves downward along with the cavitation bubbles. The existing cavitation damage experiment was carried out by starting the cavitation generator 5 alone, the cavitation impact damage experiment was carried out by starting the cavitation generator 5 and passing water to drive the cavitation bubbles to move, the silt wear experiment was carried out by only spraying mud and sand without starting the cavitation generator 5, and the abrasion damage experiment was carried out by starting the cavitation generator 5 while spraying mud and sand.

[0054] like Figure 10The timing control relationship diagram shown in the figure shows that the shaded area corresponds to the startup of each device, and the blank area on the left indicates the startup preparation state. Synchronizer 9 synchronously triggers the PIV camera 7, high-speed camera 8, laser generator 10, and high-intensity lighting system 11. Multiple trigger signals are generated within the exposure time of the PIV camera 7 and high-speed camera 8 to shorten the interval between shots to the minimum time difference t. The laser generator 10 triggers twice within the exposure time of the PIV camera 7 and high-speed camera 8. The PIV camera 7 and high-speed camera 8 are set to the same shooting parameters and synchronously capture cavitation in the same area. The PIV camera 7 is used to capture the flow field, while the high-speed camera 8 is used to record the changes in cavitation state and the relative positions of particles. Currently, damage analysis of hydraulic machinery relies on computer simulation or inferring the damage process by observing the final damage morphology. PIV and high-speed cameras are both important tools for studying dynamic processes, but the jet and shock wave caused by cavitation collapse are extremely fast and difficult to capture with cameras. The secondary triggering during the exposure time of PIV and high-speed camera can capture the microscopic process of the jet in a short nanosecond time within one exposure period. In order to synchronize the high-speed camera image and PIV shooting of the particle speed, a synchronous trigger is used to synchronize the PIV device and the high-speed camera to the exposure moment. The exposure stage and the laser illumination are triggered twice to shoot at the same time to achieve nanosecond shooting capture. By shooting the tracer particles in the transparent water tank 1 with the PIV shooting device 7, the movement speed and acceleration changes of the sediment particles when the cavitation and sediment particles interact can be obtained, and the energy released by the cavitation collapse during the cavitation collapse process and the interaction mechanism between the two can be further calculated and analyzed. It is mixed with PIV tracer particles and sediment to impact the fluid machinery specimen, simulating the wear caused by cavitation and sediment impacting the specimen surface at the same angle. At the same time, the acceleration experiment caused by the impact of cavitation collapse of missing particles is carried out through the technical analysis of the high-speed camera shooting device 8 and the PIV shooting device 7. The sand-water mixture after impact is used for impact again through the sediment circulation pump 3, thereby realizing dynamic and accurate observation and measurement of cavitation, and solving the problem that the existing visualization shooting technology of the damage process in the combined mechanism of sediment cavitation and wear is difficult to capture the impact process at tiny moments.

[0055] Through the above-mentioned method, the present invention's visual abrasion combined action mechanism testing device and method based on an ultrasonic cavitation device transforms existing cavitation damage experimental equipment, and can perform multi-angle cavitation, erosion, wear and abrasion experiments through one experimental device. Better comparative analysis of the four types of hydraulic mechanical damage is carried out, while dynamic capture is performed through high-speed camera and PIV technology analysis to analyze the effects of different water conditions on different damage processes and microscopic development mechanisms. The sand-water mixture after impact is circulated through a pipeline and used for impact again, and the impact damage process over a period of time can be continuously observed, thereby realizing dynamic and accurate observation and measurement of various types of damage and destruction processes, and improving the effect of observing various types of damage and destruction processes at the microscopic level. The device has low cost and is simple and easy to use.

Claims

1. A visual abrasion combined action mechanism testing device based on ultrasonic cavitation, characterized in that: The invention comprises a stirring water tank (2), wherein the top of the stirring water tank (2) is connected to a transparent water tank (1) upwards, and the top of the stirring water tank (2) and the transparent water tank (1) are connected via a pipeline provided with a flow regulating valve (201), an agitator (202) connected to an external motor is provided in the stirring water tank (2), an observation window (205) is provided at the bottom of the stirring water tank (2), a prism (207) and a brightness sensor (206) are provided below the stirring water tank (2) corresponding to the observation window (205), and a cooling circulating water pipeline (204) is connected to the outside on one side of the stirring water tank (2). ) and a temperature sensor (203), a sediment circulation pump (3) is provided in the stirring water tank (2), the sediment circulation pump (3) is connected to a cavitation generator (5) having a bottom opening and extending into the top of the transparent water tank (1) through a pipe extending upward from the stirring water tank (2), a specimen mounting fixture mounted in the transparent water tank (1) is provided below the cavitation generator (5), the specimen mounting fixture comprises an inverted door-shaped fixing frame (101), both sides of the top of the fixing frame (101) are longitudinally provided with a slide groove (102), and a slider (103) is provided in the slide groove (102). The outer side of the slider (103) is fixedly connected to an adjusting screw (104) with one end extending outward from the top of the transparent water tank (1). The adjusting screw (104) passes through a clamping plate (105) with one side of the bottom end resting on the outer wall of the top of the transparent water tank (1). The end of the adjusting screw (104) away from the slider (103) is matched with an adjusting nut (106). A pair of tensioning plates (107) for clamping the test piece (15) are fixed in parallel on the bottom end of the fixing frame (101). The tensioning plates (107) are right-angled trapezoids, and the tensioning plates (107) have their non-right-angled vertices as the center of a circle. Two concentric arc holes (108) are provided, and a plurality of tightening holes (109) are evenly spaced along the arc direction concentric with the two arc holes (108) on the outside. A tightening screw (110) is coaxially connected between two tightening holes (109) corresponding to each other on the two tightening plates (107). A PIV shooting device (7), a high-speed camera shooting device (8) and shooting auxiliary equipment are provided on the outside of the transparent water tank (1). The PIV shooting device (7), the high-speed camera shooting device (8) and the shooting auxiliary equipment are electrically connected to a synchronizer (9) and a computer (14).

2. The visual abrasion combined action mechanism testing device based on ultrasonic cavitation according to claim 1, characterized in that: The length direction of the transparent water tank (1) is arranged longitudinally, the upper part is a rectangular parallelepiped, and the two opposite sides of the lower part are contracted inwardly along the width direction to form a square cone.

3. The visual abrasion combined action mechanism testing device based on ultrasonic cavitation according to claim 1, characterized in that: An electromagnetic flowmeter (4) is provided on the communication pipe between the sediment circulation pump (3) and the cavitation generator (5). The sediment circulation pump (3) uses a positive displacement pump body, and a pressure stabilizing device is provided at the pump body outlet.

4. The visual abrasion combined action mechanism testing device based on ultrasonic cavitation according to claim 1, characterized in that: The stirring water tank (2) is connected to a tracer particle adding device (6).

5. The visual abrasion combined action mechanism testing device based on ultrasonic cavitation according to claim 1, characterized in that: The stirring water tank (2) is provided with a bracket (504), and a lifting device (501) located above the transparent water tank (1) is mounted on the bracket (504), and the top end of the cavitation generator (5) is connected to the bottom end of the lifting device (501).

6. The visual abrasion combined action mechanism testing device based on ultrasonic cavitation according to claim 1, characterized in that: The shooting auxiliary equipment includes a laser generator (10) and a high-intensity lighting lamp group (11) arranged corresponding to the two wide surfaces of the transparent water tank (1), the laser generator (10) and the high-intensity lighting lamp group (11) are both electrically connected to the synchronizer (9), and a photoelectric detector (12) is provided on the optical path of the laser generator (10) and the high-intensity lighting lamp group (11), and the photoelectric detector (12) is electrically connected to the computer (14) via the oscilloscope (13).

7. The testing method of the ultrasonic cavitation-based visual abrasion combined action mechanism testing device according to claim 1, characterized in that: The test includes four test states: starting the cavitation generator (5) alone to conduct a cavitation damage test; starting the cavitation generator (5) and passing water to drive the cavitation bubbles to move to conduct a cavitation impact damage test; only spraying mud and sand without starting the cavitation generator (5) to conduct a mud and sand wear test; and spraying mud and sand while starting the cavitation generator (5) to conduct an abrasion damage test. During the test, the four test states are dynamically captured by a PIV shooting device and a high-speed camera shooting device. The specific test method is as follows: The cavitation generator (5) is started alone to conduct a cavitation damage experiment: the water level of the transparent water tank (1) is controlled at the experimental water level, the flow regulating valve (201) is closed to keep the water level of the transparent water tank (1) stable, the cavitation generator (5) is started, and the specimen (15) is only damaged by ultrasonic cavitation bubbles; The cavitation generator (5) is started and water is passed through to drive the movement of cavitation bubbles to conduct a cavitation impact damage experiment: clean water is injected into the stirring water tank (2), the sediment circulation pump (3) is started for circulation, the water level of the transparent water tank (1) is controlled by the flow regulating valve (201), the cavitation generator (5) is started, and the test piece (15) is subjected to the impact damage of ultrasonic cavitation bubbles carried by the water flow; The sediment wear experiment was conducted by injecting only sediment without starting the cavitation generator (5): sediment water was injected into the stirring water tank (2), the sediment circulation pump (3) was started for circulation, and the water level of the transparent water tank (1) was controlled by the flow regulating valve (201). The test piece (15) was only damaged by the sediment water wear impact; The cavitation generator (5) is started while the sediment is injected to conduct an abrasion damage experiment: sediment water is injected into the stirring water tank (2), the sediment circulation pump (3) is started for circulation, the water level of the transparent water tank (1) is controlled by the flow regulating valve (201), the cavitation generator (5) is started, and the test piece (15) is subjected to the combined effects of sediment water abrasion impact damage and ultrasonic cavitation bubble impact damage.

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