A Venturi orifice plate test device for testing the cavitation resistance of materials

Abstract

The invention discloses a venturi orifice plate test device for testing the cavitation resistance of materials, comprising a venturi tube front section, a venturi tube rear section, a converging orifice plate, a specimen adjustment bolt, an anti-cavitation specimen, a single-head bolt, a nut and a specimen position adjustment hole bolt. The venturi tube front section comprises a flange, the venturi tube rear section comprises a flange and a specimen position adjustment hole group, and the specimen position adjustment hole group comprises a plurality of specimen position adjustment holes. The converging orifice plate is built into a cylindrical cavity formed after the front and rear sections of the venturi tube are joined, the bolt holes of the flanges of the front and rear sections of the venturi tube overlap, and are fixed by the cooperation of the single-head bolts and nuts, the specimen adjustment bolt penetrates into the specimen position adjustment hole of the gradually expanding section, and the anti-cavitation specimen is fixed on the specimen adjustment bolt. The invention utilizes a converging orifice plate to strengthen the cavitation strength in the device; the specimen position is changed by penetrating the specimen adjustment bolt into different specimen position adjustment holes, and the optimal cavitation test efficiency is achieved under each working condition, thereby reducing the experimental energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of cavitation, in particular to a Venturi orifice plate test device for testing the cavitation resistance of materials. Background Art

[0002] For a long time, cavitation has seriously affected the performance and service life of valves, pumps, turbine flow parts and ship propellers. Turbines often suffer from local cavitation in flow parts, which leads to reduced efficiency and even endangers normal operation, resulting in alarming energy and material losses. As fluid machinery such as ships and turbines continue to develop in the direction of high speed and high power, the cavitation problem has become more prominent. This puts higher requirements on the cavitation resistance of materials, and the research and application of cavitation-resistant materials has become the key.

[0003] The Venturi orifice cavitation water tunnel is one of the means to study the cavitation resistance of materials. Since the holes of the orifice are evenly distributed, the cavitation bubbles are evenly dispersed, the cavitation intensity is low, there is no concentrated cavitation collapse area, the experimental cycle is long, and the energy consumption is large. At the same time, the position of the cavitation resistance test piece in the Venturi water tunnel cannot be adjusted, and it cannot be guaranteed to be located in the cavitation concentration area under all working conditions, and the experimental efficiency is low. Therefore, a Venturi orifice test device for material cavitation resistance that can form a high-intensity cavitation area and adjust the position of the test piece has become one of the technical keys in this field. Summary of the invention

[0004] The main technical problem solved by the present invention is to provide a Venturi orifice test device for testing the cavitation resistance of materials, which can enhance the cavitation intensity of the cavitation test area, shorten the test cycle, reduce the test energy consumption, and also adjust the relative position of the test piece in the Venturi tube to achieve the effect of exposing the test piece to the optimal cavitation test area under various hydraulic conditions.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0006] A Venturi orifice plate test device for testing the cavitation resistance of materials, comprising a Venturi tube front section 1 with a cylindrical orifice plate groove at the throat, a Venturi tube rear section 2, a converging orifice plate 3, a specimen adjustment bolt 4, an anti-cavitation specimen 5, a single-head bolt a6, a single-head bolt b7, a single-head bolt c8, a single-head bolt d9, a nut a10, a nut b11, a nut c12, a nut d13, a specimen position adjustment hole bolt a14, a specimen position adjustment hole bolt b15 and a specimen position adjustment hole bolt c16; wherein the Venturi tube front section 1 comprises a flange a101, the Venturi tube rear section 2 comprises a flange b201 and a specimen position adjustment hole group 202, and the specimen position adjustment hole group 202 comprises a specimen position adjustment hole a2021, a specimen position adjustment hole a2022, a specimen position adjustment hole a2023, a specimen position adjustment hole a2024, a specimen position adjustment hole a2025, a specimen position adjustment hole a2026, a specimen position adjustment hole a2027, a specimen position adjustment hole a2028, a specimen position adjustment hole a2029, a specimen position adjustment hole a2030, a specimen position adjustment hole a2031, a specimen position adjustment hole a2032, a specimen position adjustment hole a2033, a specimen position adjustment hole a2034, a specimen position adjustment hole a2035, a specimen position adjustment hole a2036, a specimen position adjustment hole a2037, a specimen position adjustment hole a2038, a specimen position adjustment hole a2039, a specimen position adjustment hole a2040, a specimen position adjustment hole a2041, a specimen position adjustment hole a2042, a specimen position adjustment hole a2043, a specimen position adjustment hole a2044, a specimen position adjustment hole a2045, a specimen position adjustment hole a2 Position adjustment hole b2022, specimen position adjustment hole c2023 and specimen position adjustment hole d2024; after the front section 1 of the venturi tube and the rear section 2 of the venturi tube are joined, a raised cylindrical cavity is formed at the throat, and this cavity serves as an orifice plate groove, and a converging orifice plate 3 is built therein, and the surface fits tightly with the inner wall of the cavity, and the bolt holes of the flange a101 of the front section 1 of the venturi tube and the flange b201 of the rear section 2 of the venturi tube coincide with each other, and each single-head bolt is inserted and fixed by the nuts to complete the connection and fixation of the front section 1 of the venturi tube and the rear section 2 of the venturi tube, and the specimen adjustment bolt 4 is inserted into the specimen position adjustment hole a2021 of the gradually expanding section of the rear section 2 of the venturi tube, and the anti-cavitation specimen 5 is rotatably fixed on the screw head of the specimen adjustment bolt 4 inserted into the gradually expanding section.

[0007] The front section 1 and the rear section 2 of the Venturi tube are formed by radially cutting a Venturi tube section with a protruding cylindrical cavity at the throat along the midpoint of the side generatrix of the cylindrical cavity. The cylindrical cavity is located at the end of the throat and is connected to the inlet of the gradually expanding section. The side generatrix of the inner wall is 2 cm long and the diameter of the circular cross section is 10 cm. After the cutting, a circular annular flange a101 is arranged at the cutting line of the front section 1 of the Venturi tube. Four single-headed bolt through holes are opened on the circular annular wall surface at 90 degree intervals in the circumferential direction. The axis of each single-headed bolt through hole is equidistant from the axial center line of the circular annular flange. The cylindrical cavity of the throat of the rear section 2 of the Venturi tube is connected to the inlet of the gradually expanding section. Along the axis direction of the Venturi tube, the cylindrical cavity is respectively At the positions of 3cm, 5cm, 7cm and 9cm from the entrance of the gradually expanding section, there are respectively radially opened specimen position adjustment holes a2021, specimen position adjustment holes b2022, specimen position adjustment holes c2023 and specimen position adjustment holes d2024 with a diameter of 1cm, the axis of each specimen position adjustment hole intersects with the axis of the venturi tube, passes through the outer wall of the gradually expanding section of the venturi tube and ends at the inner wall, a flange b201 is arranged at the dividing line of the rear section 2 of the venturi tube, and four single-headed bolt through holes are opened on the circular wall surface at 90 degree intervals in the circumferential direction, the axis of each single-headed bolt through hole is equidistant from the axial center line of the circular flange, and the axis of the single-headed bolt through hole intersects with the axis of the specimen position adjustment hole.

[0008] The converging orifice plate 3 is a circular orifice plate with a circular cross-section diameter of 10 cm and a thickness of 2 cm; 6 groups of openings are arranged symmetrically along the axis of the cylindrical orifice plate, with an interval of 60° between each group, and each group contains three openings; the opening angles of the three holes in each group are different, the opening closest to the axis of the cylindrical orifice plate has an angle of 15° with it, the opening farthest from the axis of the cylindrical orifice plate has an angle of 45° with it, the third opening between the above two openings has an angle of 30° with the axis of the cylindrical orifice plate, and the extension lines of the center lines of each opening meet at one point.

[0009] The specimen adjusting bolt 4 is a hexagonal single-head bolt, the circular cross-section diameter of the screw rod is 1 cm, the length is 10 cm, and the entire length is tapped with threads matching the adjusting holes.

[0010] The specimen adjusting bolt 4 is a hexagonal single-head bolt, the circular cross-section diameter of the screw rod is 1 cm, the length is 10 cm, and the entire length is tapped with threads matching the adjusting holes.

[0011] The anti-cavitation test piece 5 is a rectangular test piece, 4 cm long, 4 cm high, and 2 cm wide. A threaded hole with a diameter of 1 cm and a depth of 3 cm is opened vertically downward along the geometric center of its top surface, which can be tightly connected with the top of the screw rod of the test piece adjusting bolt 4; the test piece material is determined by the specific test material.

[0012] The converging orifice plate 3 is built into the cylindrical orifice plate groove of the venturi tube, and the center lines of the openings thereon converge at a point on the central axis of the gradually expanding section of the venturi tube. When the cavitation experiment is carried out, a high-intensity cavitation concentration area will be formed at the rear of the orifice plate.

[0013] The specimen adjustment bolt 4 can be inserted into different specimen position adjustment holes. According to different cavitation test conditions, its insertion position is changed, and the cavitation concentrated collapse position under each condition is selected to perform the specimen surface cavitation resistance test, thereby realizing the function of changing the position of the anti-cavitation specimen 5 in the diffusion section of the Venturi tube.

[0014] The beneficial effects of the present invention are:

[0015] The present invention discloses a venturi orifice plate test device for testing the cavitation resistance of materials. The device utilizes a converging orifice plate in the middle of a venturi tube to form a cavitation test area with high bubble density and cavitation intensity. Compared with a conventional cavitation resistance test device, the cavitation test cycle is shortened and the test energy consumption is reduced. The device has the function of adjusting the position of a test piece, and the test piece can be adjusted to be placed in the area with the most severe cavitation under different hydraulic conditions, thereby improving the test effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A first assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0017] Figure 2 A second assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0018] Figure 3 A third assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0019] Figure 4 A fourth assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0020] Figure 5 A fifth assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0021] Figure 6 A sixth assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0022] Figure 7 The seventh assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0023] Figure 8 The eighth assembly diagram of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0024] Fig. 9 The ninth assembly diagram of a venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0025] Fig.10 A three-dimensional view of a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0026] Fig.11 A three-dimensional view of a converging orifice plate in a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0027] Fig.12 A plan view of a converging orifice plate in a Venturi orifice plate test device for testing the cavitation resistance of a material according to the present invention;

[0028] Fig.13 A three-dimensional view of a cavitation resistance test piece in a venturi orifice plate test device for testing cavitation resistance of a material according to the present invention;

[0029] Fig.14 This is a three-dimensional view of the front section of the Venturi tube in a Venturi orifice plate test device for testing the cavitation resistance of materials according to the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0031] The present invention is a Venturi orifice plate test device for testing the cavitation resistance of materials, comprising a Venturi tube front section 1 with a cylindrical orifice plate groove at the throat, a Venturi tube rear section 2, a convergent orifice plate 3, a specimen adjustment bolt 4, an anti-cavitation specimen 5, a single-head bolt a6, a single-head bolt b7, a single-head bolt c8, a single-head bolt d9, a nut a10, a nut b11, a nut c12, a nut d13, a specimen position adjustment hole bolt a14, a specimen position adjustment hole bolt b15 and a specimen position adjustment hole bolt c16. The Venturi tube front section 1 comprises a flange a101, the Venturi tube rear section 2 comprises a flange b201 and a specimen position adjustment hole group 202, and the specimen position adjustment hole group 202 comprises a specimen position adjustment hole a2021, a specimen position adjustment hole b2022, a specimen position adjustment hole c2023 and a specimen position adjustment hole d2024.

[0032] As a preferred embodiment of the present invention, Figure 1 , place the rear section 2 of the venturi tube horizontally, and the axis of each specimen position adjustment hole is vertically upward; Figure 2 , screw the specimen adjustment bolt 4 clockwise into the specimen position adjustment hole a2021 of the venturi tube rear section 2 gradually expanding section, and the vertical height of the screw head position is close to the center height of the circular inlet of the venturi tube rear section 2 gradually expanding section; Figure 3 For the material to be tested for cavitation resistance, the internal threaded hole of the cavitation resistance test piece 5 is screwed into the screw head of the test piece adjusting bolt 4, so that the two are tightly matched, and the cavitation resistance test piece 5 is fixed to the screw head of the adjusting bolt 4, and the axis of the venturi tube is perpendicular to the surface where its long side and high side are located; Figure 4 , place the front section 1 of the venturi tube horizontally opposite to the rear section 2 of the venturi tube, and align the bolt holes of the flange a101 with the bolt holes of the flange b201; Figure 5 , place the converging orifice plate 3 in the raised cylindrical cavity at the throat of the front section 1 of the venturi tube; Figure 6 , push the front section 1 of the venturi tube in the horizontal direction to make it join with the rear section 2 of the venturi tube to form a complete venturi tube section, the cylindrical side surface of the converging orifice plate 3 is tightly fitted with the inner wall of the raised cylinder at the end of the throat of the venturi tube, perpendicular to the horizontal direction, the outer edge positions of the front and rear circular surfaces of the converging orifice plate 3 are tightly fitted with the inner walls of the front and rear circular rings of the raised cylindrical cavity at the end of the throat, and the bolt holes of the flange a101 coincide with the bolt holes of the flange b201; Figure 7 , insert the single-head bolt a6, single-head bolt b7, single-head bolt c8 and single-head bolt d9 into the bolt holes of flange a101 and flange b201 respectively; Figure 8 , respectively, tightly fit the nuts a10, b11, c12 and d13 in the parts where the single-head bolts a6, b7, c8 and d9 pass through the threaded holes of the flange; Fig. 9 The screws of the specimen position adjustment hole bolt a14, the specimen position adjustment hole bolt b15 and the specimen position adjustment hole bolt c16 are respectively facing the specimen position adjustment hole b2022, the specimen position adjustment hole c2023 and the specimen position adjustment hole d2024. Push each bolt in the direction of the arrow in the figure and screw it into each position adjustment hole clockwise to finally achieve the following result. Fig.10 The assembly effect is shown, at this time, the converging orifice plate 3 is fixed to the end of the venturi throat, and the anti-cavitation test piece 5 is facing the openings of the converging orifice plate 3, forming a Venturi orifice plate test device for testing the cavitation resistance of the entire material.

[0033] The front section 1 and the rear section 2 of the venturi tube are obtained by radially cutting a venturi tube section with a convex cylindrical cavity at the throat along the midpoint of the side generatrix of the cylindrical cavity. The cylindrical cavity is located at the end of the throat and connected to the inlet of the gradually expanding section. The side generatrix of the inner wall is 2 cm long and the diameter of the circular section is 10 cm. Figure 1 The throat cylindrical cavity of the rear section 2 of the Venturi tube is connected to the entrance of the gradually expanding section. Along the axis direction of the Venturi tube, there are radially opened test piece position adjustment holes a2021, test piece position adjustment holes b2022, test piece position adjustment holes c2023 and test piece position adjustment holes d2024 with a diameter of 1 cm at positions 3 cm, 5 cm, 7 cm and 9 cm away from the entrance of the gradually expanding section of the Venturi tube. The axis of each test piece position adjustment hole intersects with the axis of the Venturi tube, and passes through the outer wall of the gradually expanding section of the Venturi tube to the inner wall. A flange b201 is provided at the dividing line of the rear section 2 of the Venturi tube, and four single-head bolt through holes are opened on the circular wall surface at 90 degree intervals in the circumferential direction. The axis of each single-head bolt through hole is equidistant from the axial center line of the circular flange, and the axis of the single-head bolt through hole intersects with the axis of the test piece position adjustment hole. Fig.14 A circular flange a101 is arranged at the dividing line of the front section 1 of the venturi tube after the cutting, and four single-head bolt through holes are opened on the circular wall surface at 90 degree intervals in the circumferential direction, and the axis of each single-head bolt through hole is equidistant from the axial center line of the circular flange.

[0034] like Fig.11 The converging orifice plate 3 is a circular orifice plate with a circular cross-section diameter of 10 cm and a thickness of 2 cm; 6 groups of openings are arranged symmetrically along the axis of the cylindrical orifice plate, with an interval of 60° between each group, and each group contains three openings. Fig.12, from left to right are the front view, rear view and cross-sectional view along the center axis of the front view of the converging orifice plate 3. The opening angles of the three holes in each group are different. The opening closest to the axis of the cylindrical orifice plate has an angle of 15° with it, the opening farthest from the axis of the cylindrical orifice plate has an angle of 45° with it, and the third opening between the above two openings has an angle of 30° with the axis of the cylindrical orifice plate, and the extension lines of the center lines of each opening intersect at one point.

[0035] like Fig.13 The anti-cavitation specimen 5 is a rectangular specimen, the long side of the bottom surface is the length of the rectangular specimen, the short side of the bottom surface is the width of the rectangular specimen, the vertical side of the rectangular specimen is the height of the rectangular specimen, 4 cm long, 2 cm wide, and 4 cm high; a threaded hole with a diameter of 1 cm and a depth of 3 cm is opened vertically downward along the geometric center of its top surface, which can be tightly connected with the top of the screw rod of the specimen adjusting bolt 4; the specimen structure is fixed, and the material is determined by the specific test material.

[0036] Combination Figure 3 and Fig.10 In order to adjust the position of the anti-cavitation test piece 5 in the gradually expanding section of the Venturi tube so that it is located in the area with the most severe cavitation under different flow conditions, the anti-cavitation test piece 5 should be unscrewed first, and after removing the test piece, the test piece adjustment bolt 4 should be rotated counterclockwise so that the screw head moves up and retracts into the test piece position adjustment hole a2021. After changing the flow parameters, the cavitation situation of the gradually expanding section of the Venturi tube is observed, and the position with the most obvious grayscale contrast in the cavitation area is marked as the test position of the test piece under this condition. Assuming that this position is closest to the test piece position adjustment hole b2022, the test piece position used to seal the test piece position adjustment hole b2022 should be unscrewed counterclockwise first. Place the adjusting hole bolt a14, unscrew the specimen adjusting bolt 4 counterclockwise, swap the specimen adjusting bolt 4 with the specimen position adjusting hole bolt a14, screw the specimen position adjusting hole bolt a14 clockwise into the specimen position adjusting hole a2021 to seal it, screw the specimen adjusting bolt 4 clockwise into the specimen position adjusting hole b2022, with the screw head height being close to the center height of the converging orifice plate 3, screw the anti-cavitation specimen 5 into the screw head of the specimen adjusting bolt 4, so that the anti-cavitation specimen 5 can still be located in the most severe cavitation area when conducting experiments under the changed flow conditions, thereby shortening the experimental time and reducing the experimental energy consumption.

[0037] When the water flow rate in the Venturi orifice test device is small, the cavitation dense area at the rear of the converging orifice plate 3 is short, the water flow rate in the gradually expanding section is low, the pressure is high, and the cavitation collapse is concentrated at a position closer to the entrance of the gradually expanding section. Therefore, the anti-cavitation specimen is placed at a position closer to the entrance of the gradually expanding section to expose it to the most severe cavitation area, and the cavitation test efficiency is the highest; when the water flow rate in the Venturi orifice test device is large, the cavitation dense area at the rear of the converging orifice plate 3 is long, the water flow rate in the gradually expanding section is high, the pressure is low, and the cavitation collapse is concentrated at a position farther from the entrance of the gradually expanding section. Therefore, the anti-cavitation specimen is placed at a position farther from the entrance of the gradually expanding section to expose it to the most severe cavitation area, and the cavitation test efficiency is the highest.

[0038] In summary, the present invention achieves the purpose of forming a cavitation test area with high bubble density and cavitation intensity by installing a converging orifice plate in the middle of the venturi tube. Compared with conventional cavitation resistance test devices, the cavitation test cycle is shortened and the test energy consumption is reduced. The present invention has the function of adjusting the position of the test piece, and the test piece can be adjusted to be placed in the area with the most severe cavitation under different hydraulic conditions, thereby improving the experimental effect.

Claims

1. A Venturi orifice plate test device for testing the cavitation resistance of a material, characterized in that: The invention comprises a front section of a venturi tube (1) having a cylindrical orifice plate groove at the throat, a rear section of the venturi tube (2), a converging orifice plate (3), a specimen adjustment bolt (4), an anti-cavitation specimen (5), a single-head bolt a (6), a single-head bolt b (7), a single-head bolt c (8), a single-head bolt d (9), a nut a (10), a nut b (11), a nut c (12), a nut d (13), a specimen position adjustment hole bolt a (14), a specimen position adjustment hole bolt b (15) and a specimen position adjustment hole bolt c (16); wherein the venturi tube The front section (1) comprises a flange a (101), the rear section (2) of the venturi tube comprises a flange b (201) and a specimen position adjustment hole group (202), the specimen position adjustment hole group (202) comprises a specimen position adjustment hole a (2021), a specimen position adjustment hole b (2022), a specimen position adjustment hole c (2023) and a specimen position adjustment hole d (2024); after the front section (1) of the venturi tube and the rear section (2) of the venturi tube are joined, a raised cylindrical cavity is formed at the throat, and the cavity serves as an orifice plate slot, and a converging orifice plate (3) is built-in wherein the surface is tightly fitted with the inner wall of the cavity, the bolt holes of the flange a (101) of the front section (1) of the Venturi tube and the flange b (201) of the rear section (2) of the Venturi tube overlap, and the single-head bolts are inserted and fixed by nuts to complete the connection and fixation of the front section (1) of the Venturi tube and the rear section (2) of the Venturi tube, the specimen adjustment bolt (4) is inserted into the specimen position adjustment hole a (2021) of the gradually expanding section of the rear section (2) of the Venturi tube, and the cavitation erosion resistance specimen (5) is rotatably fixed to the screw head of the specimen adjustment bolt (4) inserted into the gradually expanding section; the Venturi tube The front section (1) of the inner tube and the rear section (2) of the venturi tube are obtained by radially cutting along the midpoint of the side generatrix of the cylindrical cavity, which is provided with a venturi tube section having a protruding cylindrical cavity at the throat. The cylindrical cavity is located at the end of the throat and is connected to the entrance of the gradually expanding section. The side generatrix of the inner wall is 2 cm long and the diameter of the circular cross section is 10 cm. After the cutting, a circular annular flange a (101) is arranged at the cutting line of the front section (1) of the venturi tube. Four single-head bolt through holes are opened at 90 degree intervals in the circumferential direction of the circular annular wall surface. The axis of each single-head bolt through hole is equidistant from the axial center line of the circular annular flange.The throat cylindrical cavity of the rear section (2) of the Venturi tube is connected to the inlet of the gradually expanding section. Along the axis direction of the Venturi tube, a specimen position adjustment hole a (2021), a specimen position adjustment hole b (2022), a specimen position adjustment hole c (2023) and a specimen position adjustment hole d (2024) with a diameter of 1 cm are respectively opened radially at positions 3 cm, 5 cm, 7 cm and 9 cm away from the inlet of the gradually expanding section of the Venturi tube. The axis of each specimen position adjustment hole intersects with the axis of the Venturi tube and passes through the outer wall surface of the gradually expanding section of the Venturi tube and ends at the inner wall surface. A flange plate b (201) is arranged at the dividing line of the rear section (2) of the Venturi tube. Four single-head bolt through holes are opened on the annular wall surface at 90 degree intervals in the circumferential direction. The axis of each single-head bolt through hole is equidistant from the axial center line of the annular flange, and the axis of the single-head bolt through hole intersects with the axis of the specimen position adjustment hole. ; 2. A Venturi orifice plate test device for testing the cavitation resistance of a material according to claim 1, characterized in that: The converging orifice plate (3) is a circular orifice plate with a circular cross-section diameter of 10 cm and a thickness of 2 cm; 6 groups of openings are arranged symmetrically along the axis of the cylindrical orifice plate, with an interval of 60° between each group, and each group contains three openings; the opening angles of the three holes in each group are different, the opening closest to the axis of the cylindrical orifice plate is 15° with the axis, the opening farthest from the axis of the cylindrical orifice plate is 45° with the axis, the third opening between the above two openings is 30° with the axis of the cylindrical orifice plate, and the extension lines of the center lines of the openings intersect at one point; the converging orifice plate (3) is built into the cylindrical orifice plate groove of the venturi tube, and the center lines of the openings thereon converge at a point on the central axis of the venturi tube's expanding section, and a high-intensity cavitation concentration area is formed at the rear of the orifice plate when a cavitation experiment is performed.

3. A Venturi orifice plate test device for testing the cavitation resistance of a material according to claim 1, characterized in that: The specimen adjusting bolt (4) is a hexagonal single-head bolt, the circular cross-section diameter of the screw rod is 1 cm, the length is 10 cm, and the entire length is tapped with threads matching the adjusting holes.

4. A Venturi orifice plate test device for testing the cavitation resistance of a material according to claim 1, characterized in that: The specimen position adjustment hole bolt a (14), the specimen position adjustment hole bolt b (15) and the specimen position adjustment hole bolt c (16) have the same structure and are hexagonal single-head bolts, the circular cross-section diameter of the screw rod is 1 cm, the length is 1 cm, and the entire length is tapped with threads matching the adjustment holes.

5. The Venturi orifice plate test device for testing the cavitation resistance of a material according to claim 1, characterized in that: The anti-cavitation test piece (5) is a rectangular test piece, 4 cm long, 4 cm high, and 2 cm wide. A threaded hole with a diameter of 1 cm and a depth of 3 cm is vertically opened downward along the geometric center of its top surface, which can be tightly matched and connected with the top end of the screw of the test piece adjusting bolt (4); the material of the test piece is determined by the specific test material.

6. The Venturi orifice plate test device for testing the cavitation resistance of a material according to claim 1, characterized in that: The specimen adjustment bolt (4) can be inserted into different specimen position adjustment holes. According to different cavitation test conditions, its insertion position is changed, and the cavitation concentrated collapse position under each condition is selected to perform the specimen surface cavitation resistance test, thereby realizing the function of changing the position of the cavitation resistance specimen (5) in the diffusion section of the Venturi tube.

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