Measuring device based on limited vortex structure under expansion wall surface and application thereof

Abstract

The invention discloses a measuring device based on a limited vortex structure under an expanded wall surface and application of the measuring device, the device comprises a motor measurement control device, and a rectifying device, an expanded wall surface limited vortex generating device and a frame structure which are arranged in a water tank, the frame structure is located on one side of the motor measurement control device, and the motor measurement control device is connected with the rectifying device. And the rectifying device positioned in the frame structure is fixedly connected with the output end of the motor measurement control device after being connected with the vortex generating device with the limited expansion wall surface, aiming at the defects that the influence of the expansion wall surface on the vortex ring is neglected in the prior art, and the principle of the vortex ring generating device is inconsistent with the practical application. By applying the device, the speed type of the moving wall surface is accurately controlled, vortex rings which stably grow in different modes are generated, the growth evolution process of the vortex structure can be synchronously measured and researched, the device has important significance on theoretical research of the vortex rings, and meanwhile, an experimental basis can be provided for parameter formulation and cylinder design of the heart function vortex structure.

Description

Technical Field

[0001] The invention relates to the technical field of fluid mechanics experimental devices, in particular to a measuring device based on a restricted vortex structure under an expansion wall and an application thereof. Background Art

[0002] The study of confined vortex structures under expanding walls has important theoretical and application value in proposing new vortex ring parameters to reflect cardiac function and optimizing fluid mixing and heat transfer efficiency in industrial processes, such as in the optimization of automobile cylinder design. One of the important factors affecting the morphology of vortex structures is the growth environment. Based on this, how to create a vortex ring growth environment with a controllable expanding wall and a confined cavity is of great significance to the theoretical research of vortex rings and the corresponding engineering practice.

[0003] Existing experimental techniques only create limited environments, such as Figure 1 The figure shows a confined vortex ring generating device designed by Kelley C. Stewart in 2012 and a related research article published in the journal Experiments in fluids - "Vortex rings in radially confined domains". The device relies on a traditional piston to push the fluid in a small pipe. The boundary layer of the fluid rolls up at the pipe mouth to form a vortex ring, which grows and evolves in a circumferentially confined large pipe. This experimental method is still somewhat different from real engineering applications. The key source of the gap is that it ignores the influence of the expanding moving wall. Similar to the heart and the cylinder, the generation of vortex rings is caused by the expansion of the environmental wall, which causes the flow of fluid and then forms a vortex ring at the pipe mouth, such as Figure 2 As shown in the figure, when applying the vortex ring related theory, such as the formation number, to the diagnosis of ventricular function, the ideal results were not obtained. The formation number of the vortex ring in the patient's ventricle is almost the same as that of the normal person, indicating that the vortex ring generated in the ventricle is very different from the vortex ring in the existing experimental environment. The incomplete consideration of the experimental environment and the insufficient understanding of the principle of vortex ring generation have led to the inability of the existing traditional vortex ring theory to be applied to theoretical practice. Summary of the invention

[0004] Purpose of the invention: In order to solve the shortcomings of the prior art, the present invention provides a measurement device based on a confined vortex structure under an expanding wall and its application. The device aims to solve the shortcomings of the prior art that the influence of the expanding wall on the vortex ring is ignored and the principle of the vortex ring generating device is inconsistent with the actual application. By applying the device, it is possible to accurately control the moving wall velocity type and generate vortex rings with stable growth in different modes. It can also synchronously measure and study the growth and evolution process of the vortex structure, which is of great significance for the theoretical research on the vortex ring. At the same time, it can provide an experimental basis for the formulation of cardiac function vortex structure parameters and cylinder design.

[0005] Technical solution: In order to achieve the above objectives, the present invention provides a measuring device based on a restricted vortex structure under an expansion wall, which includes: a motor measurement and control device, and a rectifier device, an expansion wall restricted vortex generating device and a frame structure placed in a water cylinder. The frame structure is located on one side of the motor measurement and control device. The rectifier device and the expansion wall restricted vortex generating device located in the frame structure are connected and fixed to the output end of the motor measurement and control device. The rectifier device and the expansion wall restricted vortex generating device are limited and fixed by multiple flanges vertically installed in the frame structure.

[0006] As a further preferred embodiment of the present invention, the motor measurement control device comprises a stepper motor controlled by a single chip microcomputer, driving a lead screw and a piston rod, the output end of the stepper motor fixed on the base is fixedly connected to the lead screw, and a nut sleeved on the lead screw is fastened to one end of the piston rod;

[0007] When the stepper motor rotates forward or reverse, the output end of the stepper motor drives the lead screw to rotate forward or reverse, and the nut sleeved on the lead screw moves horizontally forward and backward under the rotation of the lead screw, thereby driving the piston rod fixed on the nut to move horizontally forward and backward. The relative movement of the nut and the lead screw here applies the lead screw nut transmission principle. When working, the nut is connected to the parts that need to make linear reciprocating motion. The rotation of the lead screw drives the nut to make linear reciprocating motion, thereby driving the parts to make linear reciprocating motion. Since the principle here is the existing technology, the structural drawings will not be introduced in detail.

[0008] As a further preferred embodiment of the present invention, the rectifying device comprises an inlet section, a rectifying section and a contraction section which are threadedly connected in sequence. The rectifying section is clamped on a flange used to fix the limiting rectifying device so that the fluid entering the device flows evenly. After the ambient fluid is sucked into the inlet section, it passes through the rectifying section composed of multiple rectifying nets, flows through the contraction section, and then enters the expansion wall restricted vortex generating device.

[0009] As a further preferred embodiment of the present invention, the outlet end of the contraction section is smaller than the inlet end, and the flow rate of the fluid is accelerated by gradually reducing the cross-sectional area of ​​the channel, the kinetic energy of the fluid is increased, the fluid is made more uniform and stable, and the turbulence is reduced. The contraction curve of the inner surface of the contraction section is:

[0010]

[0011] Where x is the distance from the outlet to the inlet, a 2 =3*L 2 , R1 is the inlet size, R2 is the outlet size, and L is the length of the contraction curve.

[0012] As a further preferred embodiment of the present invention, the expansion wall-limited vortex generating device comprises an acrylic nozzle, an adapter, a glass tube and a particle inlet, the two ends of the adapter are respectively horizontally fixedly connected to the acrylic nozzle and the glass tube, the other end of the acrylic nozzle is fixedly connected to the contraction section, the other end of the glass tube is fastened to the particle inlet, and the piston rod passing through the glass tube and the particle inlet moves horizontally and linearly under the power of the stepping motor;

[0013] The piston rod drives the piston at its end to move horizontally in the glass cylindrical tube. The volume inside the glass cylindrical tube increases or decreases, realizing the expansion change of the wall surface, thereby simulating different expansion wall conditions in engineering practice. When the piston starts to move, the fluid flows in from the inlet section and forms a separation shear layer at the acrylic nozzle mouth. The separation shear layer then rolls up to form a vortex ring in the glass tube.

[0014] As a further preference of the present invention, by setting the distance between the piston and the nozzle orifice and adjusting the diameter ratio of the acrylic nozzle and the glass tube to change the growth and evolution environment of the vortex ring, the key parameters affecting the growth and evolution of the vortex ring can be studied, providing a more precise and controllable experimental environment for the study of confined vortex rings under the expansion wall, which helps to deeply understand the generation mechanism of the vortex ring.

[0015] An application method of a measuring device based on a confined vortex structure under an expansion wall comprises the following steps:

[0016] Step 1: Fix the rectifier and the expansion wall-limited vortex generator horizontally in the frame structure with an adjustable flange, insert one end of the piston rod through the particle inlet and into the glass tube, and then place the frame structure as a whole in a water cylinder with a size that matches the frame structure to ensure that the frame can completely rest against the inner edge of the water cylinder;

[0017] The other end of the piston rod is passed through the through hole on the side wall of the water cylinder and connected to the screw rod. The screw rod and the stepper motor are fastened. A sealing ring is provided in the hole on the side wall of the water cylinder for placing the piston rod. The piston rod and the sealing ring on the side wall of the water cylinder are interference fit;

[0018] Step 2: Fill the water tank with water to ensure that the water level can submerge the entire device except the frame. Use the microcontroller to control the stepper motor to drive the piston at the end of the piston rod to move to 5 cm away from the nozzle, which is the initial position;

[0019] Step 3: Sow hollow glass microspheres with a diameter of 60 μm to 100 μm in the water tank, and use a water pump connected to the inside of the water tank to circulate the hollow glass microspheres in the water, turn on the laser located under the water tank, adjust the position of the sheet light plane to ensure that it coincides with the center plane of the glass tube, and illuminate the entire flow field through the reflection of the hollow glass microspheres;

[0020] Step 4: Set the acceleration and deceleration time, movement distance and maximum speed of the MCU program to meet the speed type requirements. When studying the influence of the distance between the piston and the acrylic nozzle on the growth and evolution of the vortex ring, it is necessary to control the variables, that is, to keep the speed type consistent. The stepper motor drives the piston rod to move while the synchronizer drives the high-speed camera to start shooting. The synchronizer controls the operation of the high-speed camera and the laser at the same time. The response time of the synchronizer is 10s to 12s.

[0021] Step 5: The particle map of the entire flow field is obtained by taking a high-speed camera, and the velocity field, vorticity field, annular value, diameter and deformation of the restricted vortex ring under the expansion wall and the entire flow field are obtained by solving the PIV post-processing software Fluere, and stability and swing uncertainty analysis is performed;

[0022] Step 6: After completing the experiment, stop the stepper motor drive, reset the piston rod to its initial position, and repeat the experimental steps 4 and 5 to obtain the growth evolution of the confined vortex ring generated by the expansion wall at different initial wall distances.

[0023] As a further preferred embodiment of the present invention, in step 1, a mitral valve is added to the acrylic nozzle of the expansion wall-limited vortex generating device. By adding the mitral valve, the regurgitation phenomenon can be studied, which provides a new experimental means for studying heart valve diseases.

[0024] As a further preferred embodiment of the present invention, in step 2, a force sensor is provided between the piston rod and the screw rod. By providing the force sensor, the force exerted on the glass tube as a wall when the piston moves can be measured, that is, the force generated by simulating ventricular expansion, which provides a new experimental means for studying heart disease.

[0025] As a further preference of the present invention, in step 4, the speed type is a ramp speed type, that is, the movement is divided into two parts, acceleration and deceleration, the acceleration time is 0.4s, the deceleration time is 0.6s, and the maximum speed is 1.0cm / s. This device is adapted to all speed type requirements, and the speed type can be adjusted according to needs in the experiment.

[0026] Beneficial effects: Compared with the prior art, the measuring device based on the confined vortex structure under the expansion wall and its application described in the present invention have the following advantages:

[0027] (1) This device solves the problem of the growth and evolution of vortex ring structures under the expansion wall in vortex ring experimental technology, and realizes the observation and analysis of confined vortex rings under the expansion wall;

[0028] (2) By using this device, the velocity profile of the moving wall can be precisely controlled, thereby generating vortex rings with stable growth in different modes;

[0029] (3) To provide experimental basis for the research on the confined vortex structure under the expansion wall, such as the formulation of cardiac function vortex structure parameters and cylinder design;

[0030] (4) By using this device, the growth evolution parameters of the vortex ring observed under the same experiment are consistent, which proves the stability and reliability of the experimental device and meets the requirements of experimental research. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a limited vortex ring generating device in the prior art;

[0032] Figure 2 This is a schematic diagram of applying vortex ring theory to ventricular function diagnosis;

[0033] Figure 3 It is a structural schematic diagram of the present invention;

[0034] Figure 4 Schematic diagram of the internal structure of the contraction section;

[0035] Figure 5 It is a connection diagram of the motor measurement control device, the rectifier device and the expansion wall limited vortex generating device;

[0036] Figure 6 It is a schematic diagram of the framework structure;

[0037] Figure 7 This is a schematic diagram of the opening and closing state of the mitral valve;

[0038] Figure 8 A cross-sectional view of a simulated heart. DETAILED DESCRIPTION

[0039] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0040] As shown in the accompanying drawings, the present invention relates to a measuring device based on a restricted vortex structure under an expansion wall, which comprises: a motor measurement control device consisting of a piston rod 9, a driving screw 10 and a stepping motor 11, a rectifying device consisting of an inlet section 1, a rectifying section 2 and a contraction section 4, an expansion wall restricted vortex generating device consisting of an acrylic nozzle 5, a transfer port 6, a glass tube 7 and a particle inlet 8, and a frame structure for limiting and fixing the rectifying device and the expansion wall restricted vortex generating device.

[0041] The output end of the stepper motor 11 fixed on the base 110 is fixedly connected to the screw rod 10, and the nut 101 sleeved on the screw rod 10 is fastened to one end of the piston rod 9. When the stepper motor 11 rotates forward or reversely, the output end of the stepper motor 11 drives the screw rod 10 to make a forward or reverse rotational motion, and the nut 101 sleeved on the screw rod 10 moves horizontally forward and backward under the rotation of the screw rod 10, thereby driving the piston rod 9 fixed on the nut 101 to move horizontally forward and backward.

[0042] The other end of the piston rod 9 passes through the particle inlet 8 and extends into the glass tube 7. The piston rod 9 drives the piston at its end to move horizontally in the glass cylindrical tube 7, so that the volume inside the glass cylindrical tube 7 increases or decreases, realizing the wall expansion change, thereby simulating different expansion wall conditions in engineering practice.

[0043] Example 1

[0044] Step 1: Fix the rectifier and the expansion wall-limited vortex generator horizontally in the frame structure with an adjustable flange 12, insert one end of the piston rod 9 through the particle inlet 8 and then extend it into the glass tube 7, and then place the frame structure as a whole in a water cylinder 16 with a size that matches the frame structure to ensure that the frame can completely abut against the inner edge of the water cylinder 16;

[0045] The other end of the piston rod 9 is passed through the through hole on the side wall of the water cylinder 16 and connected to the screw rod 10, and the screw rod 10 and the stepping motor 11 are fastened;

[0046] Step 2: Fill the water cylinder 16 with water to ensure that the water level can submerge the entire device except the frame, and control the stepper motor 11 through the single chip microcomputer to drive the piston at the end of the piston rod 9 to move to 5 cm away from the nozzle, which is the initial position;

[0047] Step 3: Sow hollow glass microspheres with a diameter of 60 μm in the water cylinder 16. The hollow glass microspheres are circulated in the water by the water pump 13 connected to the inside of the water cylinder 16. The hollow glass microspheres are mixed with the water in the water cylinder 16 and enter from the inlet section 1, pass through the rectifying section 2, the contraction section 4, the acrylic nozzle 5, the adapter 6, and then enter the glass tube 7, and then collide with the piston. Turn on the laser 14 located below the water cylinder 16, adjust the position of the sheet light plane to ensure that it coincides with the center plane of the glass tube 7, and illuminate the entire flow field through the reflection of the hollow glass microspheres;

[0048] Step 4: Set the acceleration and deceleration time, movement distance and maximum speed of the MCU program. The speed type is a slope triangle with an acceleration time of 0.4s, a deceleration time of 0.6s and a maximum speed of 1.0cm / s. When studying the distance between the piston and the wall, the speed type needs to be kept consistent. The stepper motor 11 drives the piston rod 9 to move while the synchronizer 15 is used to drive the high-speed camera to start shooting. The synchronizer 15 controls the high-speed camera and the laser 14 to work at the same time. The response time of the synchronizer 15 is 10s.

[0049] Step 5: The particle map of the entire flow field is obtained by taking a high-speed camera. Through post-processing, the velocity field, vorticity field, annular value, diameter and deformation of the restricted vortex ring under the expansion wall and the entire flow field can be solved, and stability and swing uncertainty analysis can be performed;

[0050] Step 6: After the experiment is completed, stop driving the stepper motor 11, reset the piston rod 9 to its initial position, repeat the experimental steps 4 and 5, and the growth evolution of the confined vortex ring generated by the expansion wall at different initial wall distances can be obtained.

[0051] Example 2

[0052] Step 1: Fix the rectifier and the expansion wall-limited vortex generator horizontally in the frame structure with an adjustable flange 12, insert one end of the piston rod 9 through the particle inlet 8 and then extend it into the glass tube 7, and then place the frame structure as a whole in a water cylinder 16 with a size that matches the frame structure to ensure that the frame can completely abut against the inner edge of the water cylinder 16;

[0053] The other end of the piston rod 9 is passed through the through hole on the side wall of the water cylinder 16 and connected to one end of the force sensor 17. The other end of the force sensor is connected to the screw rod 10. The screw rod 10 and the stepping motor 11 are fastened. The force sensor 17 is used to measure the force exerted on the piston rod 9 when it moves so as to study the force generated by ventricular expansion.

[0054] Step 2: Fill the water cylinder 16 with water to ensure that the water level can submerge the entire device except the frame, and control the stepper motor 11 through the single chip microcomputer to drive the piston at the end of the piston rod 9 to move to 5 cm away from the nozzle, which is the initial position;

[0055] Step 3: Sow hollow glass microspheres with a diameter of 80 μm in the water cylinder 16, and use the water pump 13 connected to the inside of the water cylinder 16 to circulate the hollow glass microspheres in the water. The hollow glass microspheres and the water in the water cylinder 16 are mixed and enter from the inlet section 1, pass through the rectifying section 2, the contraction section 4, the acrylic nozzle 5, the adapter 6, and then enter the glass tube 7, and then collide with the piston. Turn on the laser 14 located below the water cylinder 16, adjust the position of the sheet light plane to ensure that it coincides with the center plane of the glass tube 7, and illuminate the entire flow field through the reflection of the hollow glass microspheres;

[0056] Step 4: Set the acceleration and deceleration time, movement distance and maximum speed of the MCU program. The acceleration time is 0.4s, the deceleration time is 0.6s, and the maximum speed is 1.0cm / s. The speed type is a slope triangle. When studying the distance between the piston and the wall, the speed type needs to be kept consistent. The stepper motor 11 drives the piston rod 9 to move while the synchronizer 15 is used to drive the high-speed camera to start shooting. The synchronizer 15 controls the high-speed camera and the laser 14 to work at the same time. The response time of the synchronizer 15 is 11s.

[0057] Step 5: The particle map of the entire flow field is obtained by taking a high-speed camera. Through post-processing, the velocity field, vorticity field, annular value, diameter and deformation of the restricted vortex ring under the expansion wall and the entire flow field can be solved, and stability and swing uncertainty analysis can be performed;

[0058] Step 6: After the experiment is completed, stop driving the stepper motor 11, reset the piston rod 9 to its initial position, repeat the experimental steps 4 and 5, and the growth evolution of the confined vortex ring generated by the expansion wall at different initial wall distances can be obtained.

[0059] Example 3

[0060] Step 1: Fix the rectifier and the expansion wall-limited vortex generator horizontally in the frame structure with an adjustable flange 12, insert one end of the piston rod 9 through the particle inlet 8 and the glass tube 7 in sequence and then extend it into the acrylic tube 5 with the mitral valve installed, and then place the entire frame structure in a water cylinder 16 that matches its size to ensure that the frame can completely abut against the inner edge of the water cylinder 16;

[0061] The other end of the piston rod 9 is passed through the through hole on the side wall of the water cylinder 16 and connected to one end of the force sensor 17. The other end of the force sensor is connected to the screw rod 10. The screw rod 10 and the stepper motor 11 are fastened. After the drive motor 11 is started, the piston rod 9 moves backward. When water flows to the mitral valve device 18 made of plastic, the pressure of the fluid acts on the two valve flaps of the mitral valve, pushing the valve flaps to open, and the fluid passes through the valve smoothly, which can simulate the growth and evolution of the vortex ring in the ventricle when the mitral valve opens and closes in a real heart. Figure 7 , Figure 8 As shown;

[0062] Step 2: Fill the water cylinder 16 with water to ensure that the water level can submerge the entire device except the frame, and control the stepper motor 11 through the single chip microcomputer to drive the piston at the end of the piston rod 9 to move to 5 cm away from the nozzle, which is the initial position;

[0063] Step 3: Sow hollow glass microspheres with a diameter of 100 μm in the water cylinder 16, and use the water pump 13 connected to the inside of the water cylinder 16 to circulate the hollow glass microspheres in the water. The hollow glass microspheres and the water in the water cylinder 16 are mixed and enter from the inlet section 1, pass through the rectifying section 2, the contraction section 4, the acrylic nozzle 5, the adapter 6, and then enter the glass tube 7, and then collide with the piston. Turn on the laser 14 located below the water cylinder 16, adjust the position of the sheet light plane to ensure that it coincides with the center plane of the glass tube 7, and illuminate the entire flow field through the reflection of the hollow glass microspheres;

[0064] Step 4: Set the acceleration and deceleration time, movement distance and maximum speed of the MCU program. The speed type is a slope triangle with an acceleration time of 0.4s, a deceleration time of 0.6s and a maximum speed of 1.0cm / s. When studying the distance between the piston and the wall, the speed type needs to be kept consistent. The stepper motor 11 drives the piston rod 9 to move while the synchronizer 15 is used to drive the high-speed camera to start shooting. The synchronizer 15 controls the high-speed camera and the laser 14 to work at the same time. The response time of the synchronizer 15 is 12s.

[0065] Step 5: The particle map of the entire flow field is obtained by taking a high-speed camera. Through post-processing, the velocity field, vorticity field, annular value, diameter and deformation of the restricted vortex ring under the expansion wall and the entire flow field can be solved, and stability and swing uncertainty analysis can be performed;

[0066] Step 6: After the experiment is completed, stop driving the stepper motor 11, reset the piston rod 9 to its initial position, repeat the experimental steps 4 and 5, and the growth evolution of the confined vortex ring generated by the expansion wall at different initial wall distances can be obtained.

[0067] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable technicians familiar with the technical field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A measuring device based on a confined vortex structure under an expanding wall, characterized in that: It includes: A motor measurement and control device, and a rectifying device, an expansion wall surface limited vortex generating device and a frame structure placed in a water cylinder (16), wherein the frame structure is located on one side of the motor measurement and control device, and the rectifying device and the expansion wall surface limited vortex generating device located in the frame structure are connected and fixed to the output end of the motor measurement and control device, and the rectifying device and the expansion wall surface limited vortex generating device are fixed in position by a plurality of flanges vertically installed in the frame structure.

2. A measuring device based on a confined vortex structure under an expanding wall according to claim 1, characterized in that: The motor measurement control device comprises a stepper motor (11) controlled by a single chip microcomputer, driving a screw rod (10) and a piston rod (9), wherein the output end of the stepper motor (11) fixed on a base (110) is fixedly connected to the screw rod (10), and a nut (101) sleeved on the screw rod (10) is fastened to one end of the piston rod (9); When the stepper motor (11) rotates forward or reverse, the output end of the stepper motor (11) drives the screw rod (10) to perform forward or reverse rotational motion, and the nut (101) sleeved on the screw rod (10) moves forward or backward horizontally under the rotation of the screw rod (10), thereby driving the piston rod (9) fixed on the nut (101) to move forward or backward horizontally.

3. The measuring device based on the confined vortex structure under the expansion wall according to claim 1 is characterized in that: The rectifying device comprises an inlet section (1), a rectifying section (2) and a contraction section (4) which are threadedly connected in sequence. The rectifying section (2) is clamped on a flange used to fix the position-limiting rectifying device. After the environmental fluid is sucked into the inlet section (1), it passes through the rectifying section (2) composed of a plurality of rectifying nets (3), flows through the contraction section (4), and then enters the expansion wall limited vortex generating device.

4. The measuring device based on the confined vortex structure under the expansion wall according to claim 3 is characterized in that: The outlet end of the contraction section (4) is smaller than the inlet end, and the contraction curve of the inner surface of the contraction section (4) is: Where x is the distance from the outlet to the inlet, a 2 =3*L 2 , R1 is the inlet size, R2 is the outlet size, and L is the length of the contraction curve.

5. The measuring device based on the confined vortex structure under the expansion wall according to claim 1 is characterized in that: The expansion wall-restricted vortex generating device comprises an acrylic nozzle (5), an adapter (6), a glass tube (7) and a particle inlet (8), the two ends of the adapter (6) are respectively horizontally fixedly connected to the acrylic nozzle (5) and the glass tube (7), the other end of the acrylic nozzle (5) is fixedly connected to the contraction section (4), the other end of the glass tube (7) is fastened to the particle inlet (8), and a piston rod (9) inserted into the glass tube (7) and the particle inlet (8) moves horizontally and linearly under the power of a stepping motor (11); The piston rod (9) drives the piston at its end to move horizontally in the glass cylindrical tube (7), and the volume inside the glass cylindrical tube (7) increases or decreases, thereby achieving a change in wall expansion. When the piston starts to move, fluid flows in from the inlet section (1) and forms a separation shear layer at the acrylic nozzle opening (5). The separation shear layer then rolls up to form a vortex ring in the glass tube (7).

6. The measuring device based on the confined vortex structure under the expansion wall according to claim 5, characterized in that: The distance between the piston and the nozzle of the nozzle (5) is set, and the diameter ratio of the acrylic nozzle (5) and the glass tube (7) is adjusted to change the growth and evolution environment of the vortex ring.

7. An application method of a measuring device based on a confined vortex structure under an expanding wall, characterized in that: It includes the following steps: Step 1: Fix the rectifying device and the expansion wall-limited vortex generating device horizontally in the frame structure with a flange (12) of adjustable size, insert one end of the piston rod (9) through the particle input port (8) and then extend it into the glass tube (7), and then place the entire frame structure in a water cylinder (16) of a size that matches the frame structure to ensure that the frame can completely abut against the inner edge of the water cylinder; The other end of the piston rod (9) is passed through a through hole on the side wall of the water cylinder (16) and connected to the screw rod (10), and the screw rod (10) and the stepping motor (11) are fastened; Step 2: Fill the water cylinder (16) with water to ensure that the water level can submerge the entire device except the frame, and drive the piston at the end of the piston rod (9) to move to 5 cm from the nozzle (5) through the single chip microcomputer control stepper motor (11), which is the initial position; Step 3: Sowing hollow glass microspheres with a diameter of 60 μm to 100 μm in the water tank (16), and circulating the hollow glass microspheres in the water using a water pump (13) connected to the inside of the water tank, turning on the laser (14) located below the water tank, adjusting the position of the sheet light plane to ensure that it coincides with the center plane of the glass tube (7), and illuminating the entire flow field through reflection of the hollow glass microspheres; Step 4: setting the acceleration and deceleration time, movement distance and maximum speed of the single-chip computer program to meet the speed type requirements. When studying the influence of the distance between the piston and the acrylic nozzle (5) on the growth and evolution of the vortex ring, it is necessary to control the variables, that is, to keep the speed type consistent. The stepper motor (11) drives the piston rod (9) to move while using the synchronizer (15) to drive the high-speed camera to start shooting. The synchronizer (15) controls the high-speed camera and the laser (14) to work at the same time. The response time of the synchronizer (15) is 10s to 12s. Step 5: The particle map of the entire flow field is obtained by taking a high-speed camera, and the velocity field, vorticity field, annular value, diameter and deformation of the restricted vortex ring under the expansion wall and the entire flow field are obtained by solving the PIV post-processing software Fluere, and stability and swing uncertainty analysis is performed; Step 6: After the experiment is completed, the stepper motor (11) is stopped, the piston rod (9) is reset to its initial position, and the experimental steps 4 and 5 are repeated to obtain the growth evolution of the confined vortex ring generated by the expansion wall at different initial wall distances.

8. The application method of the measuring device based on the confined vortex structure under the expansion wall according to claim 7 is characterized in that: Step one is to install a mitral valve device (18) in an acrylic nozzle (5) of an expansion wall-restricted vortex generating device.

9. The application method of the measuring device based on the confined vortex structure under the expansion wall according to claim 7 is characterized in that: In step 2, a force sensor (17) is provided between the piston rod (9) and the screw rod (10).

10. The application method of the measuring device based on the confined vortex structure under the expansion wall according to claim 7, characterized in that: In step 4, the speed type is a ramp speed type, the acceleration time is 0.4s, the deceleration time is 0.6s, and the maximum speed is 1.0cm / s.

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