CN110907118B - Plane cascade experimental device and experimental method with variable installation angle - Google Patents

Abstract

The invention provides a plane blade cascade experimental device and an experimental method with a variable installation angle. The device includes: an upper grid plate, a lower grid plate, a fixed column, a blade, an upper stepped shaft, a lower stepped shaft and an installation angle adjustment mechanism; the installation angle The adjustment mechanism includes a connecting rod, a crank, an installation angle positioning hole and a positioning bolt; the installation angle adjustment mechanism is arranged above the upper grid plate; a plurality of the installation angle positioning holes are opened on the upper grid plate; each The installation angle positioning holes are located at the periphery of the corresponding one of the upper stepped holes, and the arrangement angles of the installation angle positioning holes relative to the corresponding upper stepped holes are different from each other. The advantages are: the present invention realizes the continuous and precise adjustment of the installation angle, which not only reduces the experimental cost of the experimental research on the performance law of the adjustable guide vane/static vane, but also has the advantages of convenient and fast adjustment, time and labor saving, simple operation, high adjustment accuracy, and leakage. The advantages of small loss and wide application range can effectively solve the problems raised in the background art.

Description

Plane cascade experimental device and experimental method with variable installation angle

technical field

The invention belongs to the technical field of plane blade cascade experimental devices, and in particular relates to a plane blade cascade experimental device with variable installation angle and an experimental method.

Background technique

The plane cascade wind tunnel is the basic experimental equipment for the research of axial flow impeller machinery.

At present, as shown in Figure 1, in order to carry out the principle structure diagram of the experimental section of the plane cascade wind tunnel, the method adopted is: (1) First, according to the size and periodic requirements of the experimental section 1 of the cascade wind tunnel, design the plane cascade The experimental piece, among which, the plane cascade experimental piece is composed of several identical straight blades, upper grid plates and lower grid plates. According to the installation angle and consistency required by the design, all blades are fixed between the upper grid plate and the lower grid plate. The upper grid plate, the lower grid plate and the blades together form a geometrically determined cascade flow channel. (2) Then, put the designed plane cascade test piece on the rotatable disc 2 of the experimental section of the cascade wind tunnel. In Figure 1, 3 represents the placement position of the cascade; (3) It is realized by adjusting the rotatable disc. The angle of attack of the blade incoming flow is adjusted.

In the process of realizing the present invention, the inventor found that the plane cascade test piece in the prior art mainly has the following problems: For the plane cascade test piece, its structure is: several identical straight blades are arranged in accordance with a certain installation angle and The grid pitch is fixedly installed between the upper grid plate and the lower grid plate. Therefore, the blade installation angle of the plane cascade test piece is fixed. Therefore, for a plane cascade test piece, the aerodynamic performance of the cascade can only be measured at a specific installation angle. Therefore, in order to meet the requirements of wind tunnel experiments with different installation angles, it is usually necessary to process multiple sets of plane cascade experimental parts with different installation angles, which not only increases the processing cost of the plane cascade experimental parts, but also because of the multiple disassembly of the plane cascade experiments It will greatly increase the wind tunnel test time and reduce the wind tunnel test efficiency.

SUMMARY OF THE INVENTION

In view of the defects existing in the prior art, the present invention provides a plane blade cascade experimental device and an experimental method with a variable installation angle, which can effectively solve the above problems.

The technical scheme adopted in the present invention is as follows:

The invention provides a plane blade cascade experimental device with variable installation angle, comprising: an upper grid plate (4), a lower grid plate (5), a fixed column (6), a blade (7), an upper stepped shaft (8), Lower stepped shaft (9) and installation angle adjustment mechanism;

The upper grid plate (4) and the lower grid plate (5) are arranged opposite to each other up and down, and the four corner positions of the upper grid plate (4) pass through the fixing column (6) and the lower grid plate (5) respectively. connection and fixation; the upper grid plate (4) is provided with N upper stepped holes (4-1); the lower grid plate (5) is symmetrically provided with N lower stepped holes (5-1); the blade (7) The number of installations is N, each of the blades (7) is vertically arranged, and the upper step matching the upper step hole (4-1) is fixedly installed at the center position of the upper end face of each of the blades (7). A shaft (8), the lower stepped shaft (9) matched with the lower stepped hole (5-1) is fixedly installed at the center of the lower end face of each of the blades (7); each of the blades (7) The upper stepped shaft (8) of each blade (7) can be rotatably installed to the corresponding upper stepped hole (4-1); the lower stepped shaft (9) of each of the blades (7) can be rotatably installed to the corresponding the lower stepped hole (5-1), so that the vane assembly constituted by the vane (7), the upper stepped shaft (8) and the lower stepped shaft (9) can be rotated, and the vane (7) ) is in contact with the bottom surface of the upper grid plate (4), and the lower end surface of the blade (7) is in contact with the top surface of the lower grid plate (5);

The installation angle adjustment mechanism includes a connecting rod (10), a crank (11), an installation angle positioning hole (12) and a positioning bolt (13); the installation angle adjustment mechanism is arranged above the upper grid plate (4) ; Open a plurality of said mounting angle positioning holes (12) on said upper grid plate (4); each said mounting angle positioning hole (12) is located at the periphery of a corresponding one of said upper stepped holes (4-1) , and the arrangement angles of the installation angle positioning holes (12) relative to the corresponding upper stepped holes (4-1) are different from each other; each of the cranks (11) is arranged in parallel, and each of the cranks ( One end of 11) is fixedly connected to the upper stepped shaft (8); the other end of each crank (11) is hinged with the connecting rod (10) through a pin shaft (19); The main body is provided with a limit hole (11-1) corresponding to the installation angle positioning hole (12); driven by the connecting rod (10), each of the cranks (11) rotates synchronously, and when a specific crank When the limiting hole (11-1) of the crankshaft is turned to be just above the corresponding positioning hole (12) of the installation angle, the positioning bolt (13) passes through the limiting hole (11-1) of the specific crank Screw into the installation angle positioning hole (12), thereby realizing the fixing of the installation angle of the specific crank; when the installation angle of the specific crank is fixed, the installation angles of the N blades (7) are fixed.

Preferably, N is 5; the arrangement angles of the installation angle positioning holes (12) relative to the corresponding upper stepped holes (4-1) are respectively 0°, 10°, 20°, 30°, 40° Mounting angle.

Preferably, the top end of the upper stepped shaft (8) is provided with an inner threaded hole (8-1); one end of the crank (11) is connected to the inner threaded hole of the upper stepped shaft (8) through a fixing bolt (14) Threaded connection is fixed.

Preferably, for the N said blades (7), two pressure measuring blades and N-2 non-pressure measuring blades are included; the two pressure measuring blades are arranged in the middle position of the N said blades (7).

Preferably, the structure of the pressure measuring blade is as follows: a groove (7-1) is formed on the lower end surface of the pressure measuring blade; a plurality of static pressure holes (7-2) are formed on the pressure measuring blade; The static pressure hole (7-2) is L-shaped in three-dimensional space, and its bottom end is located in the groove (7-1), and then extends upwards perpendicular to the lower end of the blade, when it extends to 50% of the blade height, Extends in a direction perpendicular to the airfoil curved surface and protrudes from the airfoil curved surface.

Preferably, for two adjacent pressure measuring vanes located in the center, they are a left pressure measuring vane and a right pressure measuring vane respectively; the static pressure holes (7-2) are arranged on the right blade-shaped curved surface of the left pressure measuring vane. ); the static pressure hole (7-2) is arranged on the left blade-shaped curved surface of the right pressure measuring blade, and then the flow field distribution at a central flow channel is measured.

Preferably, a measuring device is also included; the measuring device includes a hollow needle (15), a hose (16), a pressure scanning valve (17) and a measuring terminal (18);

The lower stepped shaft (9) to which the bottom end of the pressure measuring blade is fixed is provided with a pipe-passing hole (9-1); the bottom of the pipe-passing hole (9-1) is fitted with the bottom end surface of the pressure measuring blade ;

The hollow needle tube (15) is located in the groove (7-1), and the top end of the hollow needle tube (15) is sealed and inserted into the corresponding port of the static pressure hole (7-2); the hose One end of (16) is connected and fixed with the bottom end of the hollow needle tube (15); the other end of the hose (16) is passed through the tube passage hole (9-1) of the lower stepped shaft (9), and connected to the interface of the pressure scanning valve (17); the pressure scanning valve (17) is connected with the measuring terminal (18).

The present invention also provides an experimental method for a plane blade cascade experimental device with a variable installation angle, comprising the following steps:

Step 1, assemble each pressure measuring blade and non-pressure measuring blade between the upper grid plate (4) and the lower grid plate (5); wherein, the upper stepped shaft (8) of the pressure measuring blade and the non-pressure measuring blade is The upper stepped holes (4-1) of the grid plate (4) are installed together, and the lower stepped shafts (9) of the pressure measuring vanes and the non-pressure measuring vanes are installed together with the lower stepped holes (5-1) of the lower grid plate (5). , to avoid the airflow leakage of the wall end wall; in addition, the blades are arranged according to the following rules: each pressure measuring blade is located at the center of the blades arranged in sequence;

Step 2, adjust all the pressure measuring vanes and non-pressure measuring vanes to the first specific installation angle, the method is as follows:

Step 2.1, operate the connecting rod (10) to make the connecting rod (10) move; when the connecting rod (10) moves, all cranks (11) are driven to rotate synchronously; if the installation angle of the first specific crank locates the hole (12) The arrangement angle is the first specific installation angle, then observe the rotation position of the first specific crank, and stop operating the connecting rod when the first limit hole of the first specific crank coincides with the corresponding first installation angle positioning hole;

Step 2.2, use the positioning bolt (13) to pass through the first limit hole and screw it into the first installation angle positioning hole to realize the fixation of the first specific crank and the upper grid plate (4);

After the first specific crank and the upper grid plate (4) are fixed, the installation angles of all the pressure-measuring vanes and non-pressure-measuring vanes have been fixed, and the installation angles are the first specific installation angles;

Step 3, using the plane blade cascade experimental device adjusted in step 2, to carry out the wind tunnel experiment under the first specific installation angle;

Step 4, when the wind tunnel experiment at the first specific installation angle is over, unscrew the positioning bolt (13), and then adjust all the pressure measuring vanes and non-pressure measuring vanes to the second specific installation angle, the method is as follows:

Step 4.1, operate the connecting rod (10) to make the connecting rod (10) move; when the connecting rod (10) moves, all cranks (11) are driven to rotate synchronously; if the installation angle of the second specific crank locates the hole (12) The arrangement angle is the second specific installation angle, then observe the rotation position of the second specific crank, and stop operating the connecting rod when the second limit hole of the second specific crank coincides with the corresponding second installation angle positioning hole;

Step 4.2, use the positioning bolt (13) to pass through the second limit hole and screw it into the second installation angle positioning hole to realize the fixation of the second specific crank and the upper grid plate (4);

After the second specific crank and the upper grid plate (4) are fixed, the installation angles of all the pressure-measuring vanes and non-pressure-measuring vanes have been fixed, and the installation angles are the second specific installation angles;

Step 5, using the plane blade cascade experimental device adjusted in step 4, to carry out the wind tunnel experiment under the second specific installation angle;

Step 6, and so on, conduct wind tunnel experiments under different specific installation angles.

The plane blade cascade experimental device and experimental method with variable installation angle provided by the present invention have the following advantages:

The invention realizes the continuous and precise adjustment of the installation angle, not only reduces the experimental cost of the experimental research on the performance law of the adjustable guide vane/static vane, but also has the advantages of convenient and quick adjustment, time saving and labor saving, simple operation, high adjustment precision, and small leakage loss. It has the advantages of wide application range and the like, and can effectively solve the problems raised in the background art.

Description of drawings

Fig. 1 is the principle structure diagram of the plane blade cascade wind tunnel experimental section that the prior art provides;

Fig. 2 is the structure diagram of the plane blade cascade experimental device with variable installation angle provided by the present invention;

Fig. 3 is the assembly relation diagram of the upper grid plate, the lower grid plate and the fixed column provided by the present invention;

Fig. 4 is the assembly relation diagram of the installation angle adjustment mechanism and the upper stepped shaft provided by the present invention;

Fig. 5 is the top view of the upper grid plate provided by the present invention;

Figure 6 is a cross-sectional view along A-A of Figure 5;

Fig. 7 is the top view of the lower grid plate provided by the present invention;

FIG. 8 is a cross-sectional view along B-B of FIG. 7;

9 is a perspective view of a blade assembly without a static pressure hole provided by the present invention;

Figure 10 is a front view of the blade assembly without static pressure holes provided by the present invention;

11 is a top view of the blade assembly without static pressure holes provided by the present invention;

Figure 12 is a bottom view of the blade assembly without static pressure holes provided by the present invention;

Figure 13 is a perspective view of the blade assembly with static pressure holes provided by the present invention;

Figure 14 is a top view of the blade assembly with static pressure holes provided by the present invention;

Figure 15 is a bottom view of the blade assembly with static pressure holes provided by the present invention;

Figure 16 is a perspective view of a blade with static pressure holes provided by the present invention;

Figure 17 is a bottom view of the blade with static pressure holes provided by the present invention;

Figure 18 is a schematic diagram of the arrangement of the blade with static pressure holes provided by the present invention;

FIG. 19 is a connection diagram of a plane cascade experimental device with variable installation angle provided by the present invention.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The invention provides a plane blade cascade experimental device with a variable installation angle, which is mainly used to adjust the installation angle of the blade cascade in the experimental research on the performance law of adjustable guide vanes/static vanes, and can realize the function of continuous adjustment of the installation angle. That is, the continuous and precise adjustment of the installation angle can be achieved through a plane blade cascade experimental device, which not only reduces the experimental cost of experimental research on the performance law of adjustable guide vanes/static vanes, but also has the advantages of convenient and fast adjustment, time-saving and labor-saving operation. The advantages of simplicity, high adjustment accuracy, small leakage loss, and wide application range can effectively solve the problems raised in the background art.

The invention provides a plane blade cascade experimental device with variable installation angle, which mainly includes innovative researches in the following aspects:

(1) An installation angle adjustment mechanism that realizes blade angle adjustment;

(2) Ensure the blade angle adjustment accuracy;

(3) Locking and fixing in the direction of rotation when the blade angle is adjusted;

(4) When the blade angle is adjusted, the sealing of the blade rotating connection;

(5) The measurement structure design of the pressure measuring blade.

Referring to Figure 2, the plane cascade experimental device with variable installation angle includes: an upper grid plate 4, a lower grid plate 5, a fixed column 6, a blade 7, an upper step shaft 8, a lower step shaft 9 and an installation angle adjustment mechanism. The following describes each component in detail:

(1) The assembly method of the blade, the upper grid plate and the lower grid plate

Referring to FIG. 3 , the upper grid plate 4 and the lower grid plate 5 are arranged opposite to each other up and down, and the four corner positions of the upper grid plate 4 are connected and fixed with the lower grid plate 5 through the fixing columns 6 respectively.

Referring to FIGS. 5 to 6 , the upper grid plate 4 has N upper stepped holes 4-1; with reference to FIGS. 7 to 8 , the lower grid plate 5 has N lower stepped holes 5-1 symmetrically; the number of blades 7 is N The set number of N is flexibly set according to actual requirements, which is not limited in the present invention, for example, N is 5.

Referring to FIG. 4 , each blade 7 is arranged vertically, the center position of the upper end surface of each blade 7 is fixedly installed with the upper stepped shaft 8 matching the upper stepped hole 4-1, and the center position of the lower end surface of each blade 7 is fixedly installed with the lower step. The lower stepped shaft 9 matched with the hole 5-1; in practical application, the upper end face of the blade 7 and the upper stepped shaft 8 can be fixed by welding, and similarly, the lower end face of the blade 7 and the lower stepped shaft 9 are fixed by welding. The advantages of the welding fixing method are: to ensure that there is no displacement between the stepped shaft and the blade, and to achieve the firmness of the fixing. Because the installation angle adjustment mechanism is locked together with the upper stepped shaft and the blade position in the blowing experiment, the force of the airflow on the blade will react to the entire installation angle adjustment mechanism. In order to ensure the reliability of the structure, the welding of the upper stepped shaft and the blade should be ensured during welding. Strength; because the lower stepped shaft is not affected by large torque during the experiment, its welding strength is not too high.

The upper stepped shaft 8 of each blade 7 is rotatably mounted to the corresponding upper stepped hole 4-1; the lower stepped shaft 9 of each blade 7 is rotatably mounted to the corresponding lower stepped hole 5-1, so that the The blade assembly formed by the stepped shaft 8 and the lower stepped shaft 9 is rotatable, and the upper end surface of the blade 7 is in contact with the bottom surface of the upper grid plate 4 , and the lower end surface of the blade 7 is in contact with the top surface of the lower grid plate 5 .

The assembly method of the blade, the upper grid plate and the lower grid plate has the following characteristics:

(1) The upper grid plate 4 and the lower grid plate 5 are used to fix the blades to ensure the geometric periodicity of the flow channel;

(2) The fixing column 6 is used to fix the relative positions of the upper grid plate 4 and the lower grid plate 5, so as to avoid the deviation due to the vibration of the wind tunnel during the experiment and affect the symmetry of the flow channel.

(3) The designed blade is a two-dimensional airfoil that can achieve specific aerodynamic characteristics.

(4) The blade is a blade with specific aerodynamic performance. The stepped shafts at both ends of the blade are two small cylinders with unequal diameters, which are welded on the upper and lower end faces of the blade. The upper stepped shaft 8 has a threaded inner hole for fixing the crank.

(5) Both ends of the blade are assembled into the stepped holes of the grid plate through the stepped shafts. When the stepped shafts are two small cylinders with unequal diameters, the stepped holes correspond to stepped circular holes, and the matching of the stepped shafts and the stepped holes is adopted. In this way, the sealing of the end wall can be achieved while the blade is rotating, and the leakage can be reduced. In addition, the diameter of the stepped shaft is designed to be small, which can meet the needs of large-consistency cascades.

The stepped hole and the stepped shaft at both ends of the blade can rotate smoothly by controlling the manufacturing tolerance and surface roughness.

(6) For cascade blowing experiments with different consistency, the consistency requirement can be achieved only by changing the spacing of the stepped holes of the grid plate and the length of the connecting rod.

(7) Generally, the adjustable vanes are mostly adjustable guide vanes at the compressor inlet and compressor stator vanes. For the inlet adjustable guide vane, the flow channel is generally convergent, the airflow is accelerated, the flow is not easy to separate, the flow field is periodic, and its consistency (referring to the density of the blade) is small, so the general N Choose a smaller value, for example, 5-6 leaves. For the compressor stator vane, the flow channel is expanded, the flow is decelerated and diffused, and the consistency is generally larger, so a larger value of N is selected, for example, 7-9.

(2) Installation angle adjustment mechanism

The installation angle adjustment mechanism includes a connecting rod 10, a crank 11, an installation angle positioning hole 12 and a positioning bolt 13;

(2.1) Mounting corner positioning holes

The installation angle adjustment mechanism is arranged above the upper grid plate 4; a plurality of installation angle positioning holes 12 are opened on the upper grid plate 4; each installation angle positioning hole 12 is located at the periphery of a corresponding upper stepped hole 4-1, and is installed The arrangement angles of the corner positioning holes 12 relative to the corresponding upper stepped holes 4-1 are different from each other; as a specific embodiment, referring to FIG. 5, there are five upper stepped holes 4-1, namely: E1, E2, E3, E4 and E5, therefore, the arrangement angles of each installation angle positioning hole 12 relative to the corresponding upper stepped hole 4-1 are respectively 0°, 10°, 20°, 30°, and 40° installation angles. That is: in Figure 5, the arrangement angle of the first installation angle positioning hole relative to the upper stepped hole E1 is 0°; the second installation angle positioning hole, relative to the upper stepped hole E2, its arrangement angle I1 is 10° °; the third installation angle positioning hole, relative to the upper step hole E3, its arrangement angle I2 is 20°; the fourth installation angle positioning hole, relative to the upper step hole E4, its arrangement angle I3 is 30°; the fifth Each installation angle positioning hole, relative to the upper stepped hole E5, the arrangement angle I4 is 40°.

In practical applications, the mounting angle positioning holes 12 may be non-threaded holes. The positioning hole at the installation angle of the upper grid plate is precisely processed to ensure the positioning accuracy.

Of course, for the requirements of different installation angles, when processing the grid plate, the position of the installation angle positioning holes can be changed to meet the requirements of the installation angle required by the experiment.

(2.2) Crank connecting rod mechanism

Each crank 11 is arranged in parallel, and one end of each crank 11 is fixedly connected with the upper stepped shaft 8; for example, the top end of the upper stepped shaft 8 is provided with an internal threaded hole 8-1; Internally threaded holes are threaded for fixation.

The other end of each crank 11 is hinged with the connecting rod 10 through the pin shaft 19;

The main body of the crank 11 is provided with a limit hole 11-1 corresponding to the installation angle positioning hole 12; driven by the connecting rod 10, each crank 11 rotates synchronously, when the limit hole 11-1 of a specific crank turns to the corresponding When directly above the installation angle positioning hole 12, the positioning bolt 13 passes through the limit hole 11-1 of the specific crank and is screwed into the installation angle positioning hole 12, thereby realizing the fixed installation angle of the specific crank; When the specific crank installation angle is fixed , the installation angles of the N blades 7 are all fixed.

In Figure 2, the crank connecting rod mechanism is composed of five cranks and a connecting rod, one end of the crank is fixedly connected with the upper stepped shaft of the blade through a set screw, and the other end is connected with the connecting rod through a pin shaft to realize relative rotation; The crank and the connecting rod form a rotating pair. The crank and the vanes transmit torque through the screw, so the crank and the vanes can rotate synchronously; with this structure, all the vanes can be guaranteed to be at the same installation angle when the connecting rod is turned.

The locking mechanism realizes the locking function by connecting the crank and the grid plate with screws. Specifically, the upper grid plate is provided with installation angle positioning holes corresponding to different installation angles, and a hole is opened in the middle of the crank. In the angle positioning hole, the degree of freedom of the installation angle adjustment mechanism is 0, and the installation angle can be fixed.

According to different working conditions, the external force on the blade is different, it is necessary to change the diameter of the positioning bolt 13 or select a bolt material with higher strength to ensure the structural strength, so as to ensure that the positioning bolt 13 is subjected to a larger angle of attack and a larger Mach number. The shear force is less than its ultimate shear force, thus ensuring reliable positioning.

(3) Pressure measuring vanes and non-pressure measuring vanes

For the N blades 7 , two pressure-measuring blades and N-2 non-pressure-measuring blades may be included; the two pressure-measuring blades are arranged in the middle of the N blades 7 . That is to say, for a plane cascade experimental device with a variable installation angle, it is necessary to assemble two types of blades at the same time, namely, the pressure-measuring blade and the non-pressure-measuring blade. In addition, the pressure measuring vanes are assembled at the middle position of each vane, and the number of the pressure measuring vanes is two.

Referring to Figures 9-12, it is a structural diagram of a blade assembly without a static pressure hole.

Referring to Figures 13-18, it is a structural diagram of a blade assembly with static pressure holes. The blade with the static pressure hole is the pressure measuring blade. The structure of the pressure measuring blade is as follows: the lower end surface of the pressure measuring blade is provided with a groove 7-1; the pressure measuring blade is provided with a plurality of static pressure holes 7-2; each static pressure hole 7-2 is L-shaped in three-dimensional space, and its bottom The end is located in the groove 7-1, and then extends upward perpendicular to the lower end of the blade. When it extends to 50% of the blade height, it extends in the direction perpendicular to the curved surface of the airfoil and protrudes from the curved surface of the airfoil.

For the two adjacent pressure measuring vanes located in the center, they are the left pressure measuring vane and the right pressure measuring vane respectively; the static pressure hole 7-2 is arranged on the right blade surface of the left pressure measuring vane; The static pressure hole 7-2 is arranged on the curved surface, and then the flow field distribution at a central flow channel is measured. In the figure, the left pressure measuring blade has a static pressure hole in the blade basin (concave surface), and the right pressure measuring blade has a static pressure hole in the blade back (convex surface).

As shown in Figure 18, the static pressure hole on the blade surface is processed at 50% of the blade height. The static pressure hole is L-shaped in three-dimensional space, one side is perpendicular to the blade curved surface, and the other side is perpendicular to the blade end face.

(4) Measuring device

Also includes a measuring device; with reference to FIG. 19 , the measuring device includes a hollow needle tube 15, a hose 16, a pressure scanning valve 17 and a measuring terminal 18;

The lower stepped shaft 9 fixed at the bottom end of the pressure measuring blade is provided with a pipe hole 9-1; the bottom of the pipe hole 9-1 is fitted with the bottom end face of the pressure measuring blade; for example, when the bottom end face of the pressure measuring blade is crescent-shaped , the passage hole 9-1 is also correspondingly designed as a crescent shape; when the bottom end face of the pressure measuring blade is an irregular polygon, the passage hole 9-1 is also designed as an irregular polygon. The design purpose of the passage hole 9-1 is: 1) The hose connected to the pressure scanning valve can be smoothly led out, which is convenient for measurement; 2) The shape of the passage hole fits the blade shape, and the purpose is to prevent the airflow passing through the pipe hole to the airfoil. Air leak. When the hole through the pipe is too large, there will be holes in the end wall of the blade, so that the main channel will leak air to the outside of the grid plate through the larger hole. In addition, the passage hole is an irregular hole. If the passage hole is a regular round hole, when the diameter of the circle is too large, the main field airflow will flow out from the edge. 3) While reducing air leakage, it can increase the cross-sectional area, so that more hoses can be derived, so that more static pressure holes can be opened, so that there are more measurement points, and the obtained flow field data is more precise.

The hollow needle tube 15 is located in the groove 7-1, and the top end of the hollow needle tube 15 is sealed and inserted into the port of the corresponding static pressure hole 7-2; one end of the hose 16 is in communication with the bottom end of the hollow needle tube 15; One end passes through the pipe hole 9-1 of the lower stepped shaft 9, and is connected to the interface of the pressure scanning valve 17; the pressure scanning valve 17 is connected to the measuring terminal 18.

The bottom end face of the blade is designed as a groove 7-1 along the blade curve, which is convenient for inserting and fixing the hollow needle tube connected with the hose. Weld the lower stepped shaft with the hole through the tube on this side to effectively reduce the interference between the flow field measurement pipeline and the grid plate when adjusting the installation angle. Because the stepped shaft with the pipe hole is used to lead out the measuring hose, it is not affected by large external force, so its welding strength does not need to be checked.

Therefore, one side of the hose 16 is connected to the static pressure hole, and the other side is connected to the pressure scanning valve, so that the pressure distribution in the cascade channel can be accurately recorded in real time. parameters for real-time feedback.

The present invention also provides an experimental method for a plane blade cascade experimental device with a variable installation angle, comprising the following steps:

Step 1: Assemble each pressure-measuring blade and non-pressure-measuring blade between the upper grid plate 4 and the lower grid plate 5; wherein, the upper stepped shaft 8 of the pressure-measuring blade and the non-pressure-measuring blade and the upper step of the upper grid plate 4 Holes 4-1 are installed together, and the lower stepped shafts 9 of the pressure measuring vanes and non-pressure measuring vanes are installed in conjunction with the lower stepped holes 5-1 of the lower grid plate 5, which can effectively avoid airflow leakage from the end wall of the wall; The following rules are arranged: each pressure measuring blade is located at the center of the blades arranged in sequence;

Step 2, adjust all the pressure measuring vanes and non-pressure measuring vanes to the first specific installation angle, the method is as follows:

Step 2.1, operate the connecting rod 10 to make the connecting rod 10 move; when the connecting rod 10 moves, all the cranks 11 are driven to rotate synchronously; if the installation angle of the first specific crank installation angle positioning hole 12 is the first specific installation angle, Then observe the rotation position of the first specific crank, and stop operating the connecting rod when the first limiting hole of the first specific crank coincides with the corresponding first installation angle positioning hole;

Step 2.2, use the positioning bolt 13 to pass through the first limit hole and screw it into the first installation angle positioning hole to realize the fixation of the first specific crank and the upper grid plate 4;

After the first specific crank and the upper grid plate 4 are fixed, the installation angles of all the pressure-measuring vanes and non-pressure-measuring vanes have been fixed, and the installation angles are the first specific installation angles;

Step 3, using the plane blade cascade experimental device adjusted in step 2, to carry out the wind tunnel experiment under the first specific installation angle;

Step 4, when the wind tunnel experiment at the first specific installation angle is over, unscrew the positioning bolts 13, and then adjust all the pressure-measuring vanes and non-pressure-measuring vanes to the second specific installation angle, as follows:

Step 4.1, operate the connecting rod 10 to make the connecting rod 10 move; when the connecting rod 10 moves, all the cranks 11 are driven to rotate synchronously; if the installation angle of the second specific crank installation angle positioning hole 12 is the second specific installation angle, Then observe the rotation position of the second specific crank, and stop operating the connecting rod when the second limit hole of the second specific crank coincides with the corresponding second installation angle positioning hole;

Step 4.2, use the positioning bolt 13 to pass through the second limit hole and screw it into the second installation angle positioning hole to realize the fixation of the second specific crank and the upper grid plate 4;

After the second specific crank is fixed with the upper grid plate 4, the installation angles of all the pressure-measuring vanes and non-pressure-measuring vanes have been fixed, and the installation angles are the second specific installation angles;

Step 5, using the plane blade cascade experimental device adjusted in step 4, to carry out the wind tunnel experiment under the second specific installation angle;

Step 6, and so on, conduct wind tunnel experiments under different specific installation angles.

According to the method in Fig. 19, the experimental device was assembled as designed, and the blade cascade to be tested was installed in the experimental section of the wind tunnel. Connect the pressure scan valve and the vane to be tested through a hose, and connect other lines.

Take 0° and 20° installation angles as examples to illustrate:

0° installation angle adjustment and measurement process:

(1) Align the first limit hole (through hole) opened by the first crank at the 0° installation angle with the first installation angle positioning hole (threaded non-through hole) at the 0° installation angle of the upper grid plate, and then set the positioning The bolt 13 is screwed into the first installation angle positioning hole through the first limit hole, and the plane cascade experimental device is in a stable state at this time, and the degree of freedom is zero.

(2) Open the wind tunnel so that the incoming Mach number reaches the value to be measured, and after the system is stable, obtain the pressure measuring instrument data; adjust the incoming flow to different Mach numbers, wait for the system to stabilize, and obtain the pressure measuring instrument data; close the wind tunnel.

(3) Unscrew the locating bolt 13 at the 0° installation angle locating hole.

20° installation angle adjustment and measurement process:

a The bolt 13 is screwed into the third installation angle positioning hole through the third limiting hole. At this time, the plane cascade experimental device is in a stable state with zero degrees of freedom.

(2) Open the wind tunnel, make the incoming Mach number reach the value to be measured, and obtain the pressure measuring instrument data after the system is stable; adjust the incoming flow to different Mach numbers, wait for the system to stabilize, and obtain the pressure measuring instrument data; close the wind tunnel.

The invention provides a plane blade cascade experimental device with variable installation angle, which has the following innovations:

(1) Adjustment of variable installation angle

Through the crank connecting rod mechanism, the installation angle of the blade cascade can be stably adjusted.

(2) Precise control of variable installation angle

The installation angle of the blade cascade can be adjusted through the crank connecting rod mechanism. The positioning holes located on the upper grid plate correspond to different installation angles such as 0°, 10°, 20°, 30°, 40°, etc. The position of the positioning holes can be controlled to achieve the required installation angle during design.

(3) Seal of the stepped shaft

The use of traditional cylindrical journals will cause greater leakage loss, and the use of stepped journals in the present invention can reduce the clearance of the end wall of the guide vane and effectively reduce leakage losses.

(4) Installation angle adjustment mechanism

The upper grid plate is provided with installation angle positioning holes corresponding to different installation angles, which are threaded holes. A crank is fixed on the grid plate through a bolt, so as to realize the fixation of the entire installation angle adjustment mechanism.

(5) Measuring structure of pressure measuring blade

By grooving the end face of the pressure-measuring vane and welding the stepped journal with a tube hole, the hose for measuring the static pressure on the vane surface can be smoothly drawn out, so that the aerodynamic parameters on the vane surface can be measured.

In summary, the present invention provides an experimental device and an experimental method for a plane blade cascade with a variable installation angle, which realizes continuous and precise adjustment of the installation angle, and not only reduces the experimental cost of experimental research on the performance law of adjustable guide vanes/static vanes. It also has the advantages of convenient and quick adjustment, time-saving and labor-saving, simple operation, high adjustment accuracy, small leakage loss, and wide application range, which can effectively solve the problems raised in the background technology.

In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc. are based on those shown in the accompanying drawings The orientation or positional relationship is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present application.

In the description of the present invention, the terms "first", "second" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (7)

1. The utility model provides a variable mounting angle's plane cascade experimental apparatus which characterized in that includes: the device comprises an upper grid plate (4), a lower grid plate (5), a fixing column (6), blades (7), an upper stepped shaft (8), a lower stepped shaft (9) and a mounting angle adjusting mechanism;

the upper grid plate (4) and the lower grid plate (5) are arranged oppositely up and down, and the four corners of the upper grid plate (4) are respectively connected and fixed with the lower grid plate (5) through the fixing columns (6); the upper grid plate (4) is provided with N upper stepped holes (4-1); the lower grid plate (5) is symmetrically provided with N lower stepped holes (5-1); the number of the blades (7) is N, each blade (7) is vertically arranged, the upper stepped shaft (8) matched with the upper stepped hole (4-1) is fixedly arranged at the central position of the upper end face of each blade (7), and the lower stepped shaft (9) matched with the lower stepped hole (5-1) is fixedly arranged at the central position of the lower end face of each blade (7); the upper stepped shaft (8) of each blade (7) is rotatably mounted to the corresponding upper stepped hole (4-1); the lower stepped shaft (9) of each blade (7) is rotatably mounted to the corresponding lower stepped hole (5-1) so that the blade assembly of the blade (7), the upper stepped shaft (8) and the lower stepped shaft (9) is rotatable, and the upper end surface of the blade (7) is in contact with the bottom surface of the upper grid plate (4) and the lower end surface of the blade (7) is in contact with the top surface of the lower grid plate (5);

the mounting angle adjusting mechanism comprises a connecting rod (10), a crank (11), a mounting angle positioning hole (12) and a positioning bolt (13); the mounting angle adjusting mechanism is arranged above the upper grid plate (4); a plurality of mounting angle positioning holes (12) are formed in the upper grid plate (4); each mounting angle positioning hole (12) is positioned at the periphery of a corresponding upper stepped hole (4-1), and the arrangement angles of the mounting angle positioning holes (12) relative to the corresponding upper stepped holes (4-1) are different; the cranks (11) are arranged in parallel, and one end of each crank (11) is fixedly connected with the upper stepped shaft (8); the other end of each crank (11) is hinged with the connecting rod (10) through a pin shaft (19); a main body of the crank (11) is provided with a limiting hole (11-1) corresponding to the mounting angle positioning hole (12); under the drive of the connecting rod (10), all the cranks (11) synchronously rotate, and when a limiting hole (11-1) of a specific crank rotates to the position right above the corresponding mounting angle positioning hole (12), the positioning bolt (13) penetrates through the limiting hole (11-1) of the specific crank and is screwed into the mounting angle positioning hole (12), so that the mounting angle of the specific crank is fixed; after the installation angle of the specific crank is fixed, the installation angles of the N blades (7) are all fixed;

wherein N is 5; the mounting angle positioning holes (12) are respectively at mounting angles of 0 degree, 10 degrees, 20 degrees, 30 degrees and 40 degrees relative to the corresponding arrangement angles of the upper stepped holes (4-1).

2. The plane cascade experimental device with the variable mounting angle as claimed in claim 1, wherein the top end of the upper stepped shaft (8) is provided with an internal threaded hole (8-1); one end of the crank (11) is in threaded connection and fixation with the internal thread hole of the upper stepped shaft (8) through a fixing bolt (14).

3. The variable-stagger-angle planar cascade experimental apparatus according to claim 1, wherein for N of the blades (7), comprising two load cells and N-2 non-load cells; two load cells are arranged in the middle of the N said blades (7).

4. The variable-mounting-angle planar blade cascade experimental device as claimed in claim 3, wherein the structure of the pressure measuring blade is as follows: the lower end surface of the pressure measuring blade is provided with a groove (7-1); the pressure measuring blade is provided with a plurality of static pressure holes (7-2); each static pressure hole (7-2) is L-shaped in three-dimensional space, the bottom end of each static pressure hole is positioned in the groove (7-1), then the static pressure holes extend upwards perpendicular to the lower end of the blade, and when the static pressure holes extend to 50% of the height of the blade, the static pressure holes extend in a direction perpendicular to the blade profile curved surface and extend out of the blade profile curved surface.

5. The variable-mounting-angle planar blade grid experimental device as claimed in claim 4, wherein for two adjacent centrally located pressure blades, there are a left pressure blade and a right pressure blade; the static pressure hole (7-2) is arranged on the right blade type curved surface of the left pressure measuring blade; the static pressure holes (7-2) are arranged on the left blade-shaped curved surface of the right pressure measuring blade, and then the flow field distribution at a central flow channel is measured.

6. The variable stagger planar cascade experimental apparatus according to claim 4 further comprising a measuring device; the measuring device comprises a hollow needle tube (15), a hose (16), a pressure scanning valve (17) and a measuring terminal (18);

the lower stepped shaft (9) fixed at the bottom end of the pressure measuring blade is provided with a pipe hole (9-1); the bottom of the pipe passing hole (9-1) is attached to the bottom end face of the pressure measuring blade;

the hollow needle tube (15) is positioned in the groove (7-1), and the top end of the hollow needle tube (15) is hermetically inserted into the corresponding port of the static pressure hole (7-2); one end of the hose (16) is communicated and fixed with the bottom end of the hollow needle tube (15); the other end of the hose (16) penetrates out of a pipe hole (9-1) of the lower stepped shaft (9) and is connected to a port of the pressure scanning valve (17); the pressure scanning valve (17) is connected with the measuring terminal (18).

7. An experimental method of the variable mounting angle planar cascade experimental apparatus as claimed in any one of claims 1 to 6, comprising the steps of:

step 1, assembling each pressure measuring blade and each non-pressure measuring blade between an upper grid plate (4) and a lower grid plate (5); the upper stepped shafts (8) of the pressure measuring blades and the non-pressure measuring blades are matched with the upper stepped hole (4-1) of the upper grid plate (4), and the lower stepped shafts (9) of the pressure measuring blades and the non-pressure measuring blades are matched with the lower stepped hole (5-1) of the lower grid plate (5), so that air flow leakage of the wall surface end wall is avoided; in addition, the blades are arranged according to the following rules: each pressure measuring blade is positioned in the center of the blades which are arranged in sequence;

step 2, all the pressure measuring blades and the non-pressure measuring blades are adjusted to a first specific installation angle, and the method comprises the following steps:

step 2.1, operating the connecting rod (10) to enable the connecting rod (10) to move; when the connecting rod (10) moves, all the cranks (11) are driven to rotate synchronously; observing the rotating position of the first specific crank if the arrangement angle of the mounting angle positioning hole (12) of the first specific crank is a first specific mounting angle, and stopping operating the connecting rod when the first specific crank rotates to the state that the first limiting hole of the first specific crank is overlapped with the corresponding first mounting angle positioning hole;

step 2.2, a positioning bolt (13) is screwed into the first mounting angle positioning hole through the first limiting hole to fix the first specific crank and the upper grid plate (4);

after the first specific crank is fixed with the upper grid plate (4), the installation angles of all the pressure measuring blades and the non-pressure measuring blades are fixed, and the installation angles are the first specific installation angles;

step 3, adopting the plane cascade experimental device adjusted in the step 2 to perform a wind tunnel experiment under a first specific installation angle;

step 4, after the wind tunnel experiment under the first specific installation angle is finished, screwing out the positioning bolt (13), and then adjusting all the pressure measuring blades and the non-pressure measuring blades to a second specific installation angle, wherein the method comprises the following steps:

step 4.1, operating the connecting rod (10) to enable the connecting rod (10) to move; when the connecting rod (10) moves, all the cranks (11) are driven to rotate synchronously; observing the rotating position of the second specific crank if the arrangement angle of the mounting angle positioning hole (12) of the second specific crank is a second specific mounting angle, and stopping operating the connecting rod when the second limiting hole of the second specific crank is rotated to coincide with the corresponding second mounting angle positioning hole;

step 4.2, a positioning bolt (13) is screwed into the second mounting angle positioning hole through the second limiting hole to fix the second specific crank and the upper grid plate (4);

after the second specific crank is fixed with the upper grid plate (4), the mounting angles of all the pressure measuring blades and the non-pressure measuring blades are fixed, and the mounting angles are the second specific mounting angles;

step 5, adopting the plane cascade experimental device adjusted in the step 4 to perform a wind tunnel experiment under a second specific installation angle;

and 6, performing wind tunnel experiments under different specific installation angles by analogy.

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