An experimental device for generating shear flow driven by water vortex

Abstract

The application discloses a kind of vortex driving shear flow generation experimental device of water flow, including the water flow injection system and water flow discharge system installed on vortex generation system;Opening water injection valve, water flow enters water injection pipeline, through water injection hole, guide enters upper guide rail, falls into lower guide rail after accumulation overflow in upper guide rail, water flow is evenly flowed down along wall surface by slotting at barrel wall edge, and the water surface of injected fluid is far from vortex core, so as to avoid affecting vortex stability.Opening water delivery valve, the water in barrel is in drainage state in the process of water flow flowing out through drain hole, and due to the action of gravity, irrotational point sink is formed.Meanwhile, under the action of Coriolis force, water surface will form rotational point vortex.Water surface shear flow vortex is formed by superposition of point vortex and point sink.The shear flow basin of the application is larger, the principle is clear, the structure is simple and reliable, and enough large shear flow can be provided to provide the required test environment for structural model.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fluid experiment equipment, and particularly relates to a water flow vortex driven shear flow generation experiment device. BACKGROUND

[0002] Shear flow is a flow mode with a transverse velocity gradient field, plays an important role in the study of the hydrodynamic performance of underwater vehicles such as torpedoes and UUVs, and is also an environmental factor that cannot be ignored in the actual marine environment. However, most underwater explosion spark bubble tests cannot consider the effect of shear flow. Since most experiments on shear flow are difficult to implement, many scholars have numerically simulated the state of objects in shear flow. At present, the experimental equipment for studying shear flow environment mainly includes a rheometer, but the rheometer has high precision and cannot meet the size requirements of the environment for large-scale experiments. Therefore, such a large shear flow generation device is needed to realize the experimental simulation of objects in shear flow. SUMMARY

[0003] The purpose of the present application is to.

[0004] The purpose of the present application is achieved by the following technical solutions.

[0005] A water flow vortex driven shear flow generation experiment device, comprising a water flow injection system and a water flow discharge system installed on a vortex generation system, and a PIV observation system; the vortex generation system comprises a water injection port connected with the water flow injection system, a vortex generation barrel, a drainage hole connected with the water flow discharge system, a vortex generation barrel support, an upper guide rail and a lower guide rail; the vortex generation barrel support is installed below the vortex generation barrel, and double-layer guide rails are embedded on the inner side wall of the vortex generation barrel; the upper guide rail is arranged obliquely on the barrel wall and is completely connected with the barrel wall, and the height of the upper guide rail is lower than that of the water injection port; after the water flow enters the water flow injection system and is introduced into the upper guide rail through the water injection port, the water flow accumulates and overflows in the upper guide rail, and then falls into the lower guide rail through the downward vertical drainage chamfer arranged at the edge of the guide rail; the lower guide rail is discontinuously provided with a slot at the connection with the barrel wall, so that the water flow in the lower guide rail flows down along the wall surface uniformly and away from the water surface of the vortex core, thereby avoiding affecting the stability of the vortex; finally, the water flow is discharged through the drainage hole and then discharged into the water flow discharge system; during the process of flowing out of the barrel through the drainage hole, the water in the barrel forms a point sink under the action of gravity, and at the same time, under the action of the Coriolis force, a point vortex is formed on the water surface; the point vortex and the point sink are superimposed to form a water surface shear flow vortex, and the PIV observation system is used for observing the shear flow.

[0006] Further, the water flow injection system comprises a water injection pipeline and a water injection valve installed on the pipeline, and the water injection valve controls the water flow speed; the water flow discharge system comprises a drainage pipeline and a water delivery valve installed on the pipeline, and the water delivery valve controls the water flow speed; the diameter D 注水Greater than the diameter of the drain pipe D 排水 The upper limit of the water injection capacity per unit time is greater than the upper limit of the drainage capacity; the valve controls the water injection and drainage capacity per unit time.

[0007] Further, the inner diameter of the lower guide rail is smaller than that of the upper guide rail; the upper guide rail is completely connected with the barrel wall, and the distance from the upper guide rail to the lower bottom is H4, and the vertical height of the inclined surface is h4, and the included angle with the horizontal is 60°; the water accumulated in the upper guide rail overflows and falls into the lower guide rail; the distance from the lower guide rail to the lower bottom is H5, and the vertical height of the inclined surface is h5, and the included angle with the horizontal is 45°; wherein, H4

[0008] Further, the lower guide rail at the edge of the barrel wall is slotted at equal intervals to make the water flow uniformly distributed; each slot is trapezoidal, and the width is not more than 5%-10% of the total circumference of the barrel wall.

[0009] Further, the point sink is a radial liquid inflow and an extreme point discharge, and the flow rate per unit time is Q; the point vortex is a liquid without radial flow, and the streamline is a concentric circle with the center at the extreme point; according to the Helmholtz theorem, the speed circulation of each streamline on the water flow vortex is a constant value Γ; the velocity field distribution of the water surface shear flow domain is: In the formula, V is the flow velocity of the drain, V r is the radial velocity, V θ is the tangential velocity, Q is the flow rate per unit time, and Γ is the speed circulation.

[0010] Further, the vortex generating barrel is provided with a test object or a 220V underwater low-voltage electric spark generating device above the barrel; during the experiment, the test object or the 220V underwater low-voltage electric spark generating device is placed at different positions in the test area in the water in the barrel, and the shear flow with different speeds is observed and obtained through PIV technology.

[0011] The test area is away from the boundary layer and the vortex core; the thickness of the boundary layer is:

[0012]

[0013] Wherein, Re is the Reynolds number, d is the characteristic length, λ is the barrel wall friction factor, δ is the boundary layer thickness, v is the flow velocity of the shear flow at the barrel wall, μ is the viscosity coefficient, and ρ is the density of water;

[0014] The radius of the vortex core is:

[0015]

[0016] Wherein, τ is the shear stress;

[0017] The test area range is:

[0018]

[0019] D3 is the diameter of the bucket at the tested height;

[0020] The test radius on the water surface where the vortex is located is:

[0021]

[0022] Further, the water injection pipeline, the vortex generating bucket and the drainage pipeline are all made of acrylic material.

[0023] The present application has the following advantages:

[0024] The present application can generate a shear flow with controllable flow rate, and has clear generation principle, simple structure, obvious effect and large size, so that it can be used to test the state characteristics of large objects in the shear flow, and the shear flow is stable and controllable, thereby providing convenience for various shear flow related experiments. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Fig. 1 is a structural schematic view of a water flow vortex driven shear flow generating device;

[0026] Figure 2 Fig. 2 is a schematic view of a transverse cross-sectional structure of a water flow vortex driven shear flow generating device;

[0027] Figure 3 Fig. 3 is a schematic view of a transverse cross-sectional structure of a double-layer guide rail and a water injection pipeline;

[0028] Figure 4 Fig. 4 is a schematic view of a test area at a water surface in the bucket.

[0029] Figure 5 Fig. 5 is a schematic view of a fluid motion state observation test under the influence of an object.

[0030] Figure 6 Fig. 6 is a schematic view of a 220V underwater low-voltage electric spark bubble test in the shear flow. DETAILED DESCRIPTION

[0031] The present application will be further described below with reference to the accompanying drawings.

[0032] Referring to the accompanying drawings Figures 1 to 4The application is a kind of water flow vortex driven shear flow generating device, which comprises a water injection valve 1, a water injection pipeline 2, a water injection port 3, a vortex generating barrel 4, a drainage hole 5, a vortex generating barrel support 6, a water delivery valve 7, a drainage pipeline 8, an upper guide rail 9, a lower guide rail 10 and a PIV observation system. The vortex generating barrel 4 is provided with the vortex generating barrel support 6, and the vortex generating barrel support 6 is placed on the ground. The water injection valve 1 is opened, the water flow enters the water injection pipeline 2, passes through the water injection hole 3, is guided into the upper guide rail 9, and falls into the lower guide rail 10 after being accumulated and overflowing in the upper guide rail 9. The water flow passes through the slot at the edge of the barrel wall and flows down uniformly along the wall surface. The injected fluid is far away from the water surface of the vortex core, so that the stability of the vortex is avoided. The vortex generating barrel 4 is provided with the drainage hole 5 at the bottom, and the radius of the drainage hole 5 is smaller than that of the water injection hole 3. The water delivery valve 7 is opened, and the water in the barrel is in a drainage state in the process of flowing out through the drainage hole 5. Due to the action of gravity, a non-rotation point sink is formed. At the same time, under the action of the Coriolis force, a rotation point vortex is formed on the water surface. The water surface shear flow vortex is formed by superposition of the point vortex and the point sink. For the point sink, the liquid flows radially into the pole and is discharged, and the flow rate per unit time is Q. For the point vortex, the liquid does not flow radially, and the streamline is a concentric circle with the pole as the center. According to the Helmholtz theorem, the velocity circulation of each streamline on the water flow vortex is a constant value Γ.

[0033] The water flow vortex is formed by superposition of the point sink and the point vortex, and the velocity field distribution of the water surface shear flow flow field can be described as: In the formula, V r is the radial velocity, V θ is the tangential velocity, Q is the flow rate per unit time, and Γ is the velocity circulation. According to the flow velocity V of the drainage port obtained from the liquid level, the flow rate Q is obtained in combination with the diameter of the drainage port. According to the simulation software, the velocity circulation Γ is obtained.

[0034] The application forms a vortex by means of gravity and the Coriolis force, so that the shear flow is driven by the vortex. At the same time, the water flow velocity can be controlled by cooperating with the valve to meet the flow velocity requirements of different tests. According to the vortex non-birth and non-death theorem, the point vortex formed by the Coriolis force will not change with time under ideal conditions, that is, the stable tangential velocity of the water flow vortex in the barrel can be maintained under the condition of low drainage capacity. The test area in the vortex generating barrel is far away from the boundary layer and the vortex core. The thickness of the boundary layer is Wherein, Re is the Reynolds number, d is the characteristic length, λ is the barrel wall friction factor, δ is the boundary layer thickness, v is the flow velocity of the shear flow at the barrel wall, μ is the viscosity coefficient, and the vortex core radius is On the water surface where the vortex is located, the test radius is In addition, the device has a large volume, which can provide convenience for experiments of large-sized objects in the shear flow.

[0035] The water injection pipeline 2, the vortex generating barrel 4 and the drain pipeline 9 are all made of acrylic material. The acrylic material has good transparency, chemical stability and weather resistance, and can improve the observability of fluid and objects in the fluid.

[0036] The calculation method of the test radius of the application is as follows:

[0037] The shear flow generating device is a trapezoidal cylindrical barrel with a wide upper part and a narrow lower part, and is provided with an upper base diameter D1, a lower base diameter D2, a height H1, a liquid surface height H2, a test height H3, a water injection hole diameter d in , a drain hole diameter d out , a water injection amount Q in , a drain amount Q out , and a water viscosity coefficient v.

[0038] The calculation method of the radial velocity and the tangential velocity is as follows:

[0039] The barrel diameter at the position corresponding to the test height:

[0040] The barrel radius at the position corresponding to the test height: R3=D3 / 2;

[0041] The radial velocity at the test height of 0.5 meters:

[0042] The radial velocity at the drain port:

[0043] The velocity circulation:

[0044] The tangential velocity:

[0045] The calculation method of the boundary layer thickness is as follows:

[0046] The boundary layer thickness formula is:

[0047] Wherein: the barrel wall surface friction factor is λ; the characteristic length d=D3; the velocity v=V θ ; the Reynolds number is

[0048] Substitute the boundary layer thickness formula:

[0049]

[0050] The calculation method of the vortex core radius is as follows:

[0051] The drain port radius: r out =d out / 2

[0052] The velocity at the vortex core:

[0053] The vortex core radius formula is:

[0054] Wherein, τ is the shear stress, generally τ = 1 Pa.

[0055] The calculation method of the area range that can be used for shear flow test is as follows:

[0056] The test area range is:

[0057]

[0058] The overall structure size design of the water flow vortex driven shear flow generation experimental device, assuming that the spark bubble test is carried out in the device, the generated bubble radius range requires R max ∈(R max1 ,R max2 ), in order to avoid the influence of the structural wall surface on the bubble, the distance between the structural wall surface and the bubble center / the maximum bubble radius should be greater than 4 times, that is, (D3 / 2) / R max > 4. Since the wall effect of the shear flow generation experimental device also needs to consider the boundary layer thickness and the vortex core radius, the distance between the structural wall surface and the bubble center / the maximum bubble radius should be greater than 5 times, that is, (D3 / 4) / R max > 5, (H3 / 2) / R max > 5. The barrel diameter at the corresponding position of the test height: D3> 20R max2 ; test height: H3> 10R max2。

[0059] In order to improve the utilization efficiency of the device, 1.2 < D1 / D2 < 1.5, 1.3 < H1 / H2 < 1.8 can be set, and at the same time, the following conditions need to be met:

[0060] H2 / H3 = 2.

[0061] The design of the size of the water injection hole 2 and the drain hole 5 of the device is based on the overall structure size of the above shear flow generation device, so that the device can generate shear flow to meet the following conditions: the radial velocity V r ∈(V r1 , V r2 ), the tangential velocity V θ ∈(V θ1 , V θ2 ). In order to maintain the stability of the flow field, it is recommended that V r / V θ ∈(0.1, 0.2). The barrel radius at the corresponding position of the test height: R3 = D3 / 2.

[0062] In order to keep the fluid level in the barrel stable, the water injection amount and the drainage amount need to be equal.

[0063] Flow Q:

[0064] Velocity circulation: Gamma = Gamma out = 2pi(d out / 2)V rout

[0065] The velocity circulation is determined by the tangential velocity:

[0066] Gamma = Gamma out = 2pi(D3 / 2)V θ epsilon(2pi(D3 / 2)V θ1 , 2pi(D3 / 2)V θ2 )

[0067] Solve the two equations:

[0068] Gamma = 2pi(D3 / 2)V

[0069] The water injection hole is larger than the drainage hole, and it is assumed that the water flow velocity V in of the water injection hole is known.

[0070] Water injection hole diameter calculation: After rearrangement,

[0071] Substitute the data:

[0072] Therefore, the diameters of the water injection hole and the drainage hole are:

[0073]

[0074] The size of the double-layer guide rail is designed based on the overall structure size of the shear flow generation experimental device and the diameters of the water injection hole 3 and the drainage hole 5. The upper guide rail 9 connection should be lower than the water injection hole 3, and the inner diameter of the lower guide rail 10 should be smaller than that of the upper guide rail 9.

[0075] The upper guide rail 9 is connected to the barrel wall, and the distance from the lower bottom H4 and the slope height (vertical) h4 is 60° with the horizontal. The water accumulated in the upper guide rail 9 overflows and falls into the lower guide rail 10, so the inner diameter of the lower guide rail 10 should be smaller than that of the upper guide rail 9. The lower guide rail 10 is connected to the barrel wall at a distance of H5 from the lower bottom, and the slope height (vertical) h5 is 45° with the horizontal, wherein H4 < H5, h4 < h5.

[0076] The present application is slotted at equal intervals on the lower guide rail of the barrel wall edge, and the water flow can be uniformly distributed through the slotting, avoiding concentrated injection to a certain position, so as to ensure the symmetrical distribution of flow on the whole water surface. This helps to form a stable vortex structure and avoid disturbance. The upper wide and lower narrow design of the trapezoidal slot can control the gradual contraction of the water flow and avoid turbulence, optimizing the state of water flow into the barrel wall.

[0077] It is recommended that the width of each slot be no more than 5%-10% of the total circumference of the barrel wall to ensure uniform flow distribution. It is recommended that the ratio of the upper width and the lower width of the trapezoidal slot be 1.2:1 or 1.5:1. The number of slots can be selected according to the diameter of the barrel wall, usually between 4-12.

[0078] When the number of slots is selected to be 12, the ratio of the upper width and the lower width of the trapezoidal slot is 1.5:1 for slotting design.

[0079] Diameter of the lower guide rail:

[0080] Upper width of the trapezoidal slot:

[0081] Lower width of the trapezoidal slot:

[0082] The present application can be used for the design of the area range of shear flow test, and the boundary layer thickness and vortex core radius range can be calculated according to the above design basis.

[0083] Reynolds number:

[0084] Substitute the boundary layer thickness formula:

[0085] Assuming that the shear stress τ = 1 Pa, the vortex core radius formula is:

[0086] Test area range:

[0087]

[0088] The present application is a shear flow generation experiment method driven by water flow vortex, which can carry out two types of tests:

[0089] According to Figure 5 , the test name is: fluid motion state observation test under the influence of objects, the specific steps are as follows:

[0090] Step 1: Equipment preparation

[0091] 1) Shear flow generation device, including vortex generation barrel, water injection device, drainage system, guide rail structure, etc.

[0092] 2) Test object, hoisted above the vortex generating barrel, position adjustable.

[0093] 3) PIV system, including laser light source, high-speed camera, particle tracer.

[0094] Step 2: Test flow field generation

[0095] Open the water injection valve, water is evenly injected into the vortex generating barrel through the guide rail; the guide rail slot on the barrel wall ensures that the water flow is evenly distributed along the barrel wall and slides down; open the drain valve, the drain hole (smaller than the radius of the water inlet) forms a point sink, the water flow flows radially to the center of the barrel bottom; due to the action of the point sink at the bottom of the barrel and the Coriolis force, a shear flow and vortex are formed on the water surface in the barrel.

[0096] Step 3: Test object placement

[0097] 1) Adjust the height of the object from the barrel bottom to simulate different laminar shear strengths;

[0098] 2) Place the object at different radial positions in the barrel to study the effect of flow field position on shear flow.

[0099] Step 4: PIV observation

[0100] 1) Flow field particle distribution: Add tracer particles such as micron-sized polystyrene particles to the water to ensure uniform distribution and movement with the fluid.

[0101] 2) Laser illumination: Laser light sheet is projected vertically into the fluid, and a specific cross-section (such as near the water surface, near the barrel wall) is selected.

[0102] 3) High-speed imaging: High-speed camera captures the motion image of tracer particles in a short time interval.

[0103] Step 5: Data analysis

[0104] 1) Use PIV software to analyze the particle motion of two images to obtain the velocity vector field.

[0105] 2) Analyze the velocity distribution, vortex structure and shear strength of the fluid in the barrel.

[0106] According to Figure 6 Figure 2, Test Name 2: 220V underwater low-voltage spark bubble test in shear flow, the specific steps are as follows:

[0107] Step 1: Equipment preparation

[0108] 1) Shear flow generating device, including vortex generating barrel, water injection device, drainage system, guide rail structure, etc.

[0109] 2) 220V underwater low-voltage spark generating device, including test support, discharge electrode, power supply.

[0110] 3) Image data acquisition equipment, including high-speed camera, wide-angle lens, LED light source, ruler.

[0111] 4) Pressure acquisition equipment, including piezoelectric sensor, charge amplifier, oscilloscope.

[0112] 5) Experimental data acquisition and analysis system.

[0113] Step 2: Test flow field generation

[0114] Open the water injection valve, and water is uniformly injected into the vortex generation barrel through the guide rail; the guide rail groove on the barrel wall ensures that the water flow is evenly distributed along the barrel wall and slides down; open the drain valve, and the drain hole (smaller than the radius of the water inlet) forms a point sink, and the water flow flows radially to the center of the barrel bottom; due to the action of the point sink at the bottom of the barrel and the Coriolis force, a shear flow and vortex are formed on the water surface in the barrel.

[0115] Step 3: Test equipment placement

[0116] Set up the high-speed camera, connect the lines, connect the lines between the various equipment and check;

[0117] A copper wire with a diameter of 0.5 mm is used to connect the high-pressure working area at the end, and the positive and negative copper wires are connected together before the experiment to ensure that the ignition point is at the contact point of the positive and negative copper wires;

[0118] Place the pressure sensor at the designated position;

[0119] Turn on the LED light source, adjust the position, resolution, and optical lens focal length of the high-speed camera to make the image effect best, and place the ruler for shooting as a size reference;

[0120] Put the high-speed camera and data acquisition card in standby state, send a forced trigger signal from the oscilloscope to ensure that the high-speed camera shooting and the discharge electrode discharge are triggered at the same time, and the entire experimental system works normally;

[0121] Step 4: Bubble generation and data acquisition

[0122] Put the high-speed camera, data acquisition card, and oscilloscope in standby state, close the total switch and charging switch, charge the capacitor to 220V, close the safety switch, and disconnect the charging switch and total switch;

[0123] Press the discharge switch again to check that the high-speed camera, data acquisition card, and oscilloscope are in standby state, press the discharge switch, and the discharge electrode discharges to generate bubbles;

[0124] When the capacitor is discharged to zero, disconnect the safety switch. Turn off the LED light source, save the captured bubble pulsation image video and data acquisition card collected data to the folder.

[0125] Step 5: Data analysis

[0126] 1) Analyze the recorded bubble pulsation image videos to observe the evolution of the bubble in different shear flows over time.

[0127] 2) Analyze the collected pressure data to obtain the effect of shear flow on bubble pulsation pressure.

[0128] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A water vortex driven shear flow generation experimental device, characterized by: The invention comprises a water flow injection system and a water flow discharge system, and a PIV observation system installed on a vortex generation system; the vortex generation system comprises a water injection port (3) connected to the water flow injection system, a vortex generation barrel (4), a drainage hole (5) connected to the water flow discharge system, a vortex generation barrel bracket (6), an upper guide rail (9), and a lower guide rail (10); a vortex generation barrel bracket (6) is installed below the vortex generation barrel (4); a double-layer guide rail is embedded on the inner side wall, and the upper guide rail (9) is lower than the water injection port (3). The water flows into the water injection system through the water injection hole (3) and then flows into the upper guide rail (9). After the water overflows from the upper guide rail (9), the water flows into the lower guide rail (10) through the vertical downward diversion chamfer provided on the edge of the guide rail. The lower rail (10) is intermittently provided with grooves at the connection with the barrel wall, so that the water in the lower rail (10) flows down evenly along the wall and away from the water surface at the vortex center, thereby avoiding affecting the vortex stability. Finally, the water flows into the water discharge system through the drainage hole (5) and then is discharged. When the water in the barrel flows out through the drain hole (5), the water in the barrel forms a vortex-free sink due to gravity in the drainage state. At the same time, under the action of the Coriolis force, a vortex with vortex is formed on the water surface. The vortex with vortex and the vortex-free sink are superimposed to form a shear flow vortex on the water surface. The PIV observation system is used to observe the shear flow. The inner diameter of the lower guide rail (10) is smaller than that of the upper guide rail (9); the upper guide rail (9) is completely connected to the barrel wall, and the distance from the lower bottom to the upper guide rail is H4, the vertical height of the inclined surface is h4, and the angle with the horizontal is 60 degrees; water accumulates in the upper guide rail and overflows and falls into the lower guide rail; the distance from the lower bottom to the barrel wall at the connection point of the lower guide rail (10) is H5, the vertical height of the inclined surface is h5, and the angle with the horizontal is 45 degrees; wherein, H4<H5, h4<h5; The lower guide rail (10) at the edge of the barrel wall is slotted at equal intervals to distribute the water flow evenly; each slot is trapezoidal, and its width does not exceed 5%-10% of the total circumference of the barrel wall.

2. The water vortex driven shear flow generation experimental device according to claim 1, characterized in that: The water injection system comprises a water injection pipe (2) and a water injection valve (1) installed on the pipe, and the water injection valve (1) controls the water flow rate; the water discharge system comprises a drainage pipe (8) and a water delivery valve (7) installed on the pipe, and the water delivery valve (7) controls the water flow rate; the diameter of the water injection pipe (2) is D 注水 Larger than the diameter D of the drainage pipe (8) 排水 , the upper limit of water injection capacity per unit time is greater than the upper limit of drainage capacity; the valve controls the water injection and drainage volume per unit time.

3. The water vortex driven shear flow generation experimental device according to claim 1, characterized in that: At the point sink, the liquid flows radially into the pole and is discharged, with a flow rate per unit time of Q. At the point vortex, the liquid does not flow radially, and the streamlines are a family of concentric circles with the center at the pole. According to the Helmholtz theorem, the velocity circulation of each streamline on the water vortex is a constant Γ. The velocity field distribution of the shear flow in the water surface is: Where V is the flow rate at the outlet, V r is the radial velocity, V θ is the tangential velocity, Q is the flow rate per unit time, and Γ is the velocity circulation.

4. The water vortex driven shear flow generation experimental device according to claim 1, characterized in that: A test object or a 220V underwater low-voltage electric spark generating device is suspended above the vortex generating barrel (4). During the experiment, the test object or the 220V underwater low-voltage electric spark generating device is placed at different positions of the test area in the water in the barrel, and shear flows of different speeds are obtained by observation using PIV technology.

5. The water vortex driven shear flow generation experimental device according to claim 4, characterized in that: The test area is far away from the boundary layer and the vortex center; The boundary layer thickness is: Where Re is the Reynolds number, d is the characteristic length, λ is the friction factor of the barrel wall, δ is the boundary layer thickness, v is the velocity of the shear flow at the barrel wall, μ is the viscosity coefficient, and ρ is the density of water; The vortex core radius is: Where τ is the shear stress; The test area is: Where D3 is the barrel diameter at the corresponding position of the test height; On the water surface where the vortex is located, the test radius is:

6. The water vortex driven shear flow generation experimental device according to claim 2, characterized in that: The water injection pipe (2), the vortex generating barrel (4) and the drainage pipe (8) are all made of acrylic material.

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