Device and method for measuring wall slip velocity of fluid abrasive shear flow

Abstract

The invention discloses a device and method for measuring the wall slip velocity of fluid abrasive shear flow, belonging to the field of fluid abrasives. The measuring device comprises a fixture and a circular cross-section hollow cylindrical sample assembled in the fixture. The sample consists of a sample A and a sample B with the same inner hole diameter but different structures. Sample A is a circular cross-section hollow cylinder. Sample B consists of two coaxial circular cross-section hollow cylinder components, and the outer annular surface of the inner hollow cylinder is firmly connected to the inner annular surface of the outer hollow cylinder. The wall slip velocity of fluid abrasive shear flow is measured based on an abrasive flow processing machine tool and the above-mentioned measuring device. Extrusion flow tests based on sample A and sample B are respectively implemented, and the wall slip velocity under given working conditions is calculated based on the volume flow test measurement values ​​of the fluid abrasive samples in the two tests. The measuring device and method provided by the invention are simple and easy to operate, and can measure the flow velocity of fluid abrasive on processing surfaces with various roughnesses.

Description

Technical Field

[0001] The patent of this invention belongs to the field of fluid abrasives, and specifically relates to a device and method for measuring the wall slip velocity of fluid abrasive shear flow. Background Art

[0002] Fluid abrasives are solid-liquid two-phase mixtures composed of a uniform blend of liquid polymers, hard particles, and additives such as lubricants. Due to their excellent processing accessibility, wide material adaptability, and high surface quality, they are widely used for precision and ultra-precision machining of rough surfaces. The ability to accurately control the flow velocity (i.e., wall slip velocity) of the fluid abrasive during shear flow on the workpiece surface directly impacts machining quality. However, due to the viscosity and large particle size of the fluid abrasive, as well as the severe wear on the measuring element caused by the fluid abrasive in a shear flow state, direct measurement of the wall slip velocity is difficult.

[0003] In order to solve the above problems, the patent application number 201611029020.7 proposes a viscoelastic fluid abrasive two-phase flow abrasive slip velocity measurement device and its measurement method, that is, the wall slip velocity is calculated by using the inclination angle of the spiral scratches formed on the inner hole surface when the fluid abrasive is squeezed and flows in a uniformly rotating circular hole of equal cross-section. However, the above-mentioned measurement device and measurement method are only applicable to smooth surfaces. Since the surface processed by fluid abrasives is generally rough, the scratches formed by the flow of fluid abrasives are difficult to distinguish and measure due to the interference of surface morphology, and thus the above-mentioned device and method are difficult to apply. Therefore, seeking a wall slip velocity measurement device and measurement method that can be applied to both smooth and rough surfaces is a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems mentioned in the background technology and to provide a device and method for measuring the wall slip velocity of fluid abrasive shear flow, which can measure the wall slip velocity of fluid abrasive on smooth processing surfaces and on rough processing surfaces.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0006] A device for measuring the wall slip velocity of fluid abrasive shear flow, characterized in that it includes a fixture and a sample, the fixture clamps the sample, the sample includes sample A and sample B, both samples A and B are hollow cylinders, and the hollow parts of the two are of the same shape and size; sample A is made of homogeneous rigid material, and sample B is composed of two coaxial hollow cylindrical components, the outer hollow cylinder is made of homogeneous rigid material, and the inner hollow cylinder is made of high molecular polymer flexible material, and the outer side surface of the inner hollow cylinder is fixedly connected to the inner side surface of the outer hollow cylinder, so that the fluid abrasive can flow through the hollow parts of samples A and B respectively.

[0007] Preferably, the inner hollow cylinder is made of a high molecular polymer flexible material, which can form a strong bonding effect when in contact with the fluid abrasive at normal temperature and pressure.

[0008] Preferably, the clamp includes a pressure cover, a support ring and a base, the inner diameter of the support ring is larger than the outer diameter of the sample, and the sample is located inside the support ring, and the support ring is connected between the pressure cover and the base; the pressure cover and the base are provided with the same center hole, the sample is detachably installed between the pressure cover and the base, the center hole matches the sample, and after the clamp clamps the sample, the sample is completely consistent with the center holes of the pressure cover and the base.

[0009] Preferably, the center holes of the pressure cover and the base are countersunk through holes, the countersunk hole diameter is equal to the outer diameter of the sample, and the bottom hole diameter is equal to the inner diameter of the sample; the lower surface of the pressure cover and the upper surface of the base are provided with a first annular groove matching the support ring; the upper surface of the pressure cover is provided with a second annular groove matching the opening of the upper abrasive cylinder, and the upper abrasive cylinder is clamped on the upper surface of the pressure cover through the second annular groove and is connected to the countersunk through hole of the pressure cover.

[0010] Preferably, the base is mounted on the upper surface of a machine tool worktable, and the machine tool worktable is provided with a through hole matching the countersunk through hole of the base; a lower abrasive cylinder is fixedly connected to the lower surface of the machine tool worktable, and the lower abrasive cylinder is connected to the countersunk through hole of the base; the fluid abrasive is installed in the lower abrasive cylinder, and the lower abrasive cylinder has an abrasive cylinder piston built in. The abrasive cylinder piston is connected to the machine tool, and the abrasive cylinder piston is used to squeeze the fluid abrasive in the lower abrasive cylinder into the sample; when the hollow cylinder inside the sample B is made of silicone or latex, its wall thickness shall not be greater than 2 mm.

[0011] A method for measuring the wall slip velocity of a fluid abrasive shear flow, characterized in that: using the fluid abrasive shear flow wall slip velocity measuring device described in the claim, the fluid abrasive is flowed through the hollow parts of samples A and B at the same pressure and time, and the volume flow rate of the fluid abrasive in samples A and B is obtained. and Wall slip velocity of fluid abrasive shear flow

[0012]

[0013] Among them, Wall slip velocity, is the fluid abrasive volume flow test measurement value corresponding to sample A, is the fluid abrasive volume flow rate test measurement value corresponding to sample B, and D is the inner hole diameter of sample A.

[0014] As an advantage, the method comprises the following steps:

[0015] Sample preparation: Design the sample geometry and material according to the measurement purpose and the physical properties of the fluid abrasive to be measured;

[0016] Extrusion flow test based on sample A: Load the fluid abrasive to be tested into the lower abrasive cylinder, and assemble sample A with the fixture and place it on the machine tool workbench; set the machine tool working pressure and working time, start the machine tool, and the fluid abrasive flows out of the inner hole of sample A under the pressure of the abrasive cylinder piston and enters the upper abrasive cylinder. Measure the extruded volume of the fluid abrasive in the upper abrasive cylinder.

[0017] Extrusion flow test based on sample B: Remove sample A from the fixture, assemble sample B with the fixture and place it on the machine table. Perform the steps using the same working pressure and working time to measure the extrusion volume of the fluid abrasive.

[0018] Data analysis: The wall slip velocity of the fluid abrasive in the extrusion flow in sample A is calculated by the following formula:

[0019] Preferably, the aspect ratio of the inner hole of sample A is not less than 5.0; when the sample to be tested is a fluid abrasive formed by a uniform mixture of liquid organopolysiloxane, solid particles and lubricant, or a fluid abrasive formed by a uniform mixture of colloid, solid particles and lubricant, the inner hole diameter of sample A and the inner annular surface diameter of the inner hollow cylinder of sample B are not less than 10 times the maximum particle size of the solid particles in the fluid abrasive.

[0020] Preferably, when the sample to be tested is a fluid abrasive formed by a uniform mixture of liquid organopolysiloxane, solid particles and lubricant, or a fluid abrasive formed by a uniform mixture of colloid, solid particles and lubricant, the settings of the machine tool working pressure and working time need to meet the following conditions: under a given working pressure and working time, the fluid abrasive volume flow test measurement value based on sample A is not less than 1.05 times the fluid abrasive volume flow test measurement value based on sample B, and the inner hole surface roughness value of sample A after the test is not less than 95% of that before the test.

[0021] Preferably, the wall shear rate and wall shear force of the fluid abrasive in the sample A during extrusion flow are obtained by theoretical calculation or flow field simulation. When theoretical calculation is used, the following formula is used:

[0022]

[0023] in, is the wall shear rate, τ w is the wall shear force, η is the shear rate of the fluid abrasive The corresponding viscosity is shown below.

[0024] The beneficial effects of the present invention are:

[0025] 1. By measuring the outflow volume of the fluid abrasive when passing through different samples under the same conditions, the flow rate of the fluid abrasive can be indirectly obtained. This measurement method not only avoids the wear of the measuring instrument by the fluid abrasive, but also can measure the flow rate of the fluid abrasive on surfaces of various roughness.

[0026] 2. The fixture consisting of a pressure cover, a support ring, and a base can provide a relatively closed environment for the sample, avoid external interference, and improve measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the measuring device of the present invention;

[0028] Figure 2 is a schematic diagram of the structure of sample A;

[0029] Figure 3 is a schematic diagram of the structure of sample B;

[0030] Figure 4 It is a flow chart of the measurement method of the present invention.

[0031] Names marked in the figure: 1. Upper abrasive cylinder, 2. Pressure cover, 3. Sample, 4. Fluid abrasive, 5. Support ring, 6. Base, 7. Machine tool worktable, 8. Lower abrasive cylinder piston, 9. Lower abrasive cylinder, 10. Inner hollow cylinder, 11. Outer hollow cylinder. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

[0033] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0034] like Figure 1-3 As shown, a device for measuring the wall slip velocity of fluid abrasive shear flow includes a fixture and a sample 3. The sample 3 includes sample A and sample B. Samples A and B are both hollow cylinders, and the hollow parts of the two are of the same shape and size. Sample A is made of a homogeneous rigid material, and sample B is composed of two coaxial hollow cylindrical components. The outer hollow cylinder 11 is made of a homogeneous rigid material, and the inner hollow cylinder 10 is made of a high molecular polymer flexible material. The high molecular polymer flexible material must be able to form a strong bonding effect when in contact with the fluid abrasive 4 at room temperature and pressure, and the outer side surface of the inner hollow cylinder 10 is fixedly connected to the inner side surface of the outer hollow cylinder 11.

[0035] The outer hollow cylinders 11 of Samples A and B can be made of rigid, wear-resistant materials such as aluminum alloy, carbon steel, alloy steel, or composite materials. The flexible polymer material used in the inner hollow cylinder 10 of Sample B should be selected based on the physical properties of the fluid abrasive to be tested, including but not limited to silicone, latex, polyurethane, and polydimethylsiloxane. When the test sample is a fluid abrasive formed by a uniform mixture of liquid organopolysiloxane, solid particles, and additives such as lubricants, or a fluid abrasive formed by a uniform mixture of colloids, solid particles, and additives such as lubricants, the flexible polymer material is preferably silicone, latex, or polyurethane.

[0036] The thickness of the inner hollow cylinder 10 of the sample B is determined according to the hardness of the material. The greater the hardness of the material, the greater the maximum allowable wall thickness. When silicone and latex materials are selected, the wall thickness shall not exceed 2.0 mm.

[0037] The inner hollow cylinder 10 and the outer hollow cylinder 11 of the sample B can be connected in the following two or other ways: (1) coating the inner ring surface of the outer hollow cylinder of the sample B with a layer of high molecular polymer flexible material by spraying or PVD method; (2) bonding the inner ring surface of the outer hollow cylinder of the sample B to the outer ring surface of the prefabricated inner hollow cylinder by gluing method;

[0038] The fixture includes a gland 2, a support ring 5 and a base 6. The inner diameter of the support ring 5 is larger than the outer diameter of the sample 3, and the sample 3 is located inside the support ring 5. The lower surface of the gland 2 and the upper surface of the base 6 are provided with a first annular groove that matches the support ring 5. The support ring 5 is clamped in the first annular groove of the gland 2 and the base 6.

[0039] The lower surface of the gland 2 and the upper surface of the base 6 are provided with the same countersunk through-hole, the diameter of which is equal to the outer diameter of the sample 3, and the diameter of the bottom hole is equal to the inner diameter of the sample 3; the sample 3 is installed in the countersunk holes of the gland 2 and the base 6, and the hollow part thereof is connected with the bottom hole and completely matches. A sealing ring can be placed at the contact point between the sample 3 and the countersunk hole to increase the sealing performance of the connection between the sample 3 and the bottom hole. The lower surface of the base 6 is installed on the upper surface of the machine tool workbench 7, and the machine tool workbench is provided with a through-hole matching the countersunk through-hole of the base 6;

[0040] The upper surface of the gland 2 is provided with a second annular groove that matches the opening of the upper abrasive cylinder 1. The upper abrasive cylinder 1 is clamped in the second annular groove on the upper surface of the gland 2. A sealing gasket is installed at the connection between the two to increase the sealing performance. The upper abrasive cylinder 1 is connected to the countersunk through hole of the gland 2; a lower abrasive box 9 is welded on the lower surface of the machine tool workbench, and the fluid abrasive 4 is installed in the lower abrasive cylinder 9. The lower abrasive cylinder 9 has an abrasive cylinder piston 8 built in. The abrasive cylinder piston 8 is connected to the machine tool, and the abrasive cylinder piston 8 is driven by the machine tool to squeeze the fluid abrasive 4 into the sample 3 through the through hole of the machine tool workbench. After the fluid abrasive 4 fills the sample 3, it will enter the upper abrasive cylinder 1 through the countersunk through hole of the gland 2;

[0041] The fluid abrasive 4 includes but is not limited to the following: (1) a fluid abrasive formed by uniformly mixing liquid organic polysiloxane, solid particles and additives such as lubricants; (2) a fluid abrasive formed by uniformly mixing colloids, solid particles and additives such as lubricants; (3) magnetorheological fluid abrasive; (4) electrorheological fluid abrasive.

[0042] The invention provides a device for measuring the wall slip velocity of a fluid abrasive shear flow. The device is used according to the following principles:

[0043] Add enough fluid abrasive 4 into the lower abrasive cylinder 9, then fix the base 6 on the machine tool workbench, clamp the support ring 5 and sample A on the base 6 through the first annular groove and the countersunk through-hole, add a pressure cover 2 above the support ring 5 and sample A, and also clamp it into the first annular groove and the countersunk through-hole of the pressure cover 2, then clamp the upper abrasive box 1 on the pressure cover 2 through the second annular groove, and press the entire device to fix the sample A firmly; set the pressure and working time specified by the machine tool, squeeze the fluid abrasive 4 into the sample A through the abrasive cylinder piston 8, and then flow into the upper abrasive cylinder 1. After the machine tool working time is up, the abrasive cylinder piston 8 stops moving, and the volume of the fluid abrasive 4 in the upper abrasive cylinder 1 at this time is collected and measured. Then remove the upper abrasive cylinder 1 and the pressure cover 2, replace the sample A with the sample B, and then reinstall the upper abrasive cylinder 1 and the pressure cover 2. Repeat the above process, set the same pressure and working time of the machine tool, collect and measure the volume of the fluid abrasive 4 in the upper abrasive cylinder 1 to obtain

[0044] like Figure 4 As shown, a method for measuring the wall slip velocity of a fluid abrasive shear flow comprises the following steps:

[0045] 1. Sample preparation:

[0046] Specimen design: The specimens consist of specimens A and B, which have the same inner diameter but different structures. Specimen A was manufactured using additive manufacturing, using nickel-based alloy powder as the material. It has an outer diameter of 50 mm, an inner diameter of 20 mm, a height of 100 mm, and an inner surface roughness of approximately Ra30 μm. Specimen B consists of two coaxial hollow cylindrical components with circular cross-sections. The outer hollow cylinder 12 is machined using 304 stainless steel wire cutting, with an outer diameter of 50 mm, an inner diameter of 24 mm, a height of 100 mm, and an inner surface roughness of Ra2.0 μm. The inner hollow cylinder 10 is made of a silicone sealing gasket, with an outer diameter of 24 mm, an inner diameter of 20 mm, and a height of 100 mm. The outer annular surface of the inner hollow cylinder 10 is bonded to the inner annular surface of the outer hollow cylinder 12 using epoxy resin adhesive, resulting in strong adhesion at their contact interface 11.

[0047] Note: The aspect ratio of the inner hole of Sample A is not less than 5.0. When the sample to be tested is a fluid abrasive composed of a uniform mixture of liquid organopolysiloxane, solid particles, and lubricant additives, or a fluid abrasive composed of a uniform mixture of colloid, solid particles, and lubricant additives, the inner hole diameter of Sample A and the inner annular surface diameter of the hollow cylinder of Sample B must be not less than 10 times the maximum particle size of the solid particles in the fluid abrasive.

[0048] Fixture design: The fixture consists of a gland 2, a support ring 5, and a base 6. These three components are all made of 45-grade steel. The gland 2 and base 6 share the same structure: a 100mm outer diameter, 10mm thick disc with a countersunk hole in the center. The hole has a diameter of 50.2mm, a depth of 2.0mm, and a bottom hole diameter of 20mm. A 2mm-deep annular groove is designed on one end face of the disc to accommodate the support ring 5. The support ring is made of 45-grade steel, with an outer diameter of 90mm, an inner diameter of 60mm, and a height of 100mm.

[0049] 2. Wall slip velocity measurement test:

[0050] 2.1 Experimental preparation:

[0051] First, the fluid abrasive 4 to be tested is loaded into the lower abrasive cylinder 9 of the abrasive flow machining center; secondly, the base 6 is coaxially placed on the workbench 7 of the abrasive flow machining center, with the end face with the annular groove as the upper end face, and the support ring 5 is coaxially placed in the annular groove on the upper end face of the base 6; then, the sample A is coaxially placed in the countersunk hole on the upper end face of the base 6; finally, the pressure cover 2 is coaxially placed on the support ring 5, so that the upper end face of the support ring 5 is in contact with the bottom face of the annular groove on the pressure cover 2.

[0052] 2.2 Extrusion flow test based on sample A:

[0053] Start the machine and complete the mold closing operation so that the upper abrasive cylinder 1 is pressed tightly against the gland 2. Set the machine operating pressure to 500 psi and the working time to 60 seconds. Start the process. The fluid abrasive 4 flows out of the inner hole of the sample A under the extrusion of the piston 8 of the lower abrasive cylinder of the machine. Measure the extrusion volume of the fluid abrasive.

[0054] 2.3 Extrusion flow test based on sample B:

[0055] Remove sample A from the fixture and assemble sample B with the fixture. Then perform the processing with the same working pressure and working time, and measure the extrusion volume of the fluid abrasive.

[0056] Note: When the sample to be tested is a fluid abrasive uniformly mixed with liquid organopolysiloxane, solid particles, lubricants and other additives, or a fluid abrasive uniformly mixed with colloids, solid particles, lubricants and other additives, the settings of the machine tool working pressure and working time need to meet the following conditions: Under the given working pressure and working time, the fluid abrasive volume flow test measurement value based on sample A is not less than 1.05 times the fluid abrasive volume flow test measurement value based on sample B, and the inner hole surface roughness value of sample A after the test is not less than 95% of the value before the test.

[0057] 3. Data Analysis

[0058] Calculate the volume flow rate of fluid abrasive in sample A and sample B respectively and The extrusion flow of fluid abrasive in a rigid material circular cross-section hollow cylindrical specimen A is a typical shear flow. Its velocity can be divided into two components: wall slip velocity (constant) and no-slip velocity. Correspondingly, the total volume flow rate is It can be divided into the volume flow rate Q corresponding to the wall slip velocity v_s The volume flow rate Q corresponding to the no-slip speed v_r Therefore, the volume flow rate corresponding to the wall slip velocity can be obtained by subtracting the volume flow rate corresponding to the no-slip velocity from the total volume flow rate. The following formula can be used to calculate

[0059]

[0060] Where D is the inner diameter of sample A, the total volume flow rate It can be measured by extrusion flow test based on sample A.

[0061] On this basis, the present invention proposes to use the extrusion flow test based on sample B to obtain the volume flow rate Q corresponding to the no-slip velocity under the same working conditions v_r. Sample B is composed of two coaxial circular cross-section hollow cylindrical components. The outer hollow cylinder is made of homogeneous rigid material, and the inner hollow cylinder is made of high molecular polymer flexible material. The outer annular surface of the inner hollow cylinder is firmly connected to the inner annular surface of the outer hollow cylinder. When the fluid abrasive flows through the inner pores of certain specific high molecular polymer materials, adhesion will occur at the contact surface between the fluid abrasive and the high molecular polymer flexible material, thereby eliminating the wall slip phenomenon when the fluid abrasive is in shear flow. Therefore, as long as the process parameters of the extrusion flow test based on sample A and the extrusion flow test based on sample B are the same, the volume flow rate of the extrusion flow test based on sample B That is, the volume flow rate Q corresponding to the no-slip velocity of the fluid abrasive in sample A v_r At this time, the wall sliding velocity of the fluid abrasive in the inner hole of sample A can be calculated using the following formula:

[0062]

[0063] The following method is recommended for flow field simulation of the wall shear rate and wall shear force: refer to the experimental setting for the working pressure, simplify the fluid abrasive as a Newtonian fluid, and use flow field simulation to compare the fluid abrasive volume flow rate in sample A at different shear viscosities until the simulated fluid abrasive volume flow rate matches the experimental measurement value. The corresponding wall shear rate and wall shear force are then obtained. The theoretical calculation of the wall shear rate and wall shear force corresponding to the wall slip velocity is based on the following formula

[0064]

[0065] in, is the wall shear rate, τ w is the wall shear force, η is the shear rate of the fluid abrasive The corresponding viscosity is shown below.

[0066] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method for measuring the wall slip velocity of a fluid abrasive shear flow, characterized by: A device for measuring the wall slip velocity of fluid abrasive shear flow is used. The device comprises: a fixture and a sample (3). The fixture holds the sample (3). The sample (3) comprises a sample A and a sample B. Samples A and B are both hollow cylinders, and the hollow parts of the two are of the same shape and size. Sample A is made of a homogeneous rigid material. Sample B is composed of two coaxial hollow cylindrical components. The outer hollow cylinder (11) is made of a homogeneous rigid material, and the inner hollow cylinder (10) is made of a high molecular polymer flexible material. The outer side surface of the inner hollow cylinder (10) is fixedly connected to the inner side surface of the outer hollow cylinder (11). The fluid abrasive (4) can flow through the hollow parts of samples A and B respectively. The measuring method comprises: flowing the fluid abrasive (4) through the hollow parts of the samples A and B respectively at the same pressure and time, and obtaining the volume flow rate of the fluid abrasive (4) in the samples A and B. and Wall slip velocity of fluid abrasive shear flow Among them, Wall slip velocity, is the fluid abrasive volume flow test measurement value corresponding to sample A, is the fluid abrasive volume flow rate test measurement value corresponding to sample B, and D is the inner hole diameter of sample A.

2. The method for measuring the wall slip velocity of a fluid abrasive shear flow according to claim 1, characterized in that: The inner hollow cylinder (10) is made of a high molecular polymer flexible material and can form a strong bonding effect when in contact with the fluid abrasive (4) at normal temperature and pressure.

3. The method for measuring the wall slip velocity of a fluid abrasive shear flow according to claim 2, characterized in that: The clamp comprises a pressure cover (2), a support ring (5) and a base (6); the inner diameter of the support ring (5) is larger than the outer diameter of the sample (3), and the sample (3) is located inside the support ring (5); the support ring (5) is connected between the pressure cover (2) and the base (6); the pressure cover (2) and the base (6) are provided with the same center hole, the sample (3) can be detachably installed between the pressure cover (2) and the base (6), the center hole matches the sample (3), and after the clamp clamps the sample (3), the sample (3) is completely consistent with the center holes of the pressure cover (2) and the base (6).

4. The method for measuring the wall slip velocity of abrasive shear flow according to claim 3, characterized in that: The center holes of the pressure cover (2) and the base (6) are countersunk through holes, the countersunk diameter of which is equal to the outer diameter of the sample (3), and the bottom hole diameter is equal to the inner diameter of the sample (3); the lower surface of the pressure cover (2) and the upper surface of the base (6) are provided with a first annular groove matching the support ring (5); the upper surface of the pressure cover (2) is provided with a second annular groove matching the opening of the upper abrasive cylinder (1); the upper abrasive cylinder (1) is clamped on the upper surface of the pressure cover (2) through the second annular groove and is connected to the countersunk through hole of the pressure cover (2).

5. The method for measuring the wall slip velocity of abrasive shear flow according to claim 4, characterized in that: The base (6) is mounted on the upper surface of a machine tool worktable (7), and the machine tool worktable (7) is provided with a through hole matching the countersunk through hole of the base (6); a lower abrasive cylinder (9) is fixedly connected to the lower surface of the machine tool worktable (7), and the lower abrasive cylinder (9) is communicated with the countersunk through hole of the base (6); the fluid abrasive (4) is installed in the lower abrasive cylinder (9), and the lower abrasive cylinder (9) has an abrasive cylinder piston (8) built in it, and the abrasive cylinder piston (8) is connected to the machine tool, and the abrasive cylinder piston (8) is used to squeeze the fluid abrasive (4) in the lower abrasive cylinder (9) into the sample (3); when the hollow cylinder (10) inside the sample B is made of silica gel or latex material, its wall thickness shall not be greater than 2 mm.

6. The method for measuring the wall slip velocity of abrasive shear flow according to claim 5, characterized in that: The following steps are involved: (1) Sample preparation: Design the sample geometry and material according to the measurement purpose and the physical properties of the fluid abrasive to be measured; (2) Extrusion flow test based on sample A: The fluid abrasive to be tested is loaded into the lower abrasive cylinder, and sample A is assembled with the fixture and placed on the machine tool workbench; the machine tool working pressure and working time are set, and the machine tool is started. The fluid abrasive flows out from the inner hole of sample A under the extrusion of the abrasive cylinder piston and enters the upper abrasive cylinder. The extrusion volume of the fluid abrasive in the upper abrasive cylinder is measured. (3) Extrusion flow test based on sample B: Remove sample A from the fixture, assemble sample B with the fixture and place it on the machine tool workbench, perform step (2) with the same working pressure and working time, and measure the extrusion volume of the fluid abrasive (4) Data analysis: The wall slip velocity of the fluid abrasive in the extrusion flow in sample A is calculated by the following formula:

7. The method for measuring the wall slip velocity of abrasive shear flow according to claim 6, characterized in that: The aspect ratio of the inner hole of sample A is not less than 5.0; when the sample to be tested is a fluid abrasive formed by a uniform mixture of liquid organopolysiloxane, solid particles and lubricant, or a fluid abrasive formed by a uniform mixture of colloid, solid particles and lubricant, the inner hole diameter of sample A and the inner annular surface diameter of the inner hollow cylinder of sample B are not less than 10 times the maximum particle size of the solid particles in the fluid abrasive.

8. The method for measuring the wall slip velocity of abrasive shear flow according to claim 6, characterized in that: When the sample to be tested is a fluid abrasive formed by a uniform mixture of liquid organopolysiloxane, solid particles and lubricant, or a fluid abrasive formed by a uniform mixture of colloid, solid particles and lubricant, the settings of the machine tool working pressure and working time need to meet the following conditions: under a given working pressure and working time, the fluid abrasive volume flow test measurement value based on sample A is not less than 1.05 times the fluid abrasive volume flow test measurement value based on sample B, and the inner hole surface roughness value of sample A after the test is not less than 95% of the value before the test.

9. The method for measuring the wall slip velocity of abrasive shear flow according to claim 6, characterized in that: The wall shear rate and wall shear force of the fluid abrasive in the sample A during extrusion flow are obtained through theoretical calculation or flow field simulation. When theoretical calculation is used, the following formula is used: in, is the wall shear rate, τ w is the wall shear force, η is the shear rate of the fluid abrasive The corresponding viscosity is shown below.

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