Plane cascade experimental device with adjustable mounting angle and use method thereof

Abstract

The invention provides a plane cascade experimental device with an adjustable mounting angle and a use method thereof. The plane cascade experimental device comprises an upper grid plate (1) and a lower grid plate (2) which are provided with grooves (20); the first spacing column (3) and the second spacing column (4) are used for connecting the upper grid plate (1) and the lower grid plate (2); a plurality of blades; each group of blade fixing clamping plates comprises an upper grid plate blade fixing clamping plate and a lower grid plate blade fixing clamping plate; wherein each blade in the plurality of blades is fixed with the group of upper grid plate blade fixing clamping plates and the group of lower grid plate blade fixing clamping plates by inserting corresponding blade-shaped holes (18) in the group of upper grid plate blade fixing clamping plates and the group of lower grid plate blade fixing clamping plates; and the upper grid plate blade fixing clamping plate and the lower grid plate blade fixing clamping plate on which blades are fixed are respectively arranged in the grooves (20) on the upper grid plate (1) and the lower grid plate (2).

Description

Technical Field

[0001] The present invention relates to the field of planar cascade experimental devices, and more specifically, to a planar cascade experimental device with adjustable installation angle and its usage method. Background Art

[0002] Planar cascade experiment is a basic experimental technology developed to meet the experimental verification requirements of airfoil aerodynamic performance. It has the advantages of being convenient to control and easy to test, and has been widely used in various aspects such as the research of airfoil design methods for high-performance turbomachinery, the verification of airfoil engineering design, the exploration of internal flow mechanisms in turbomachines, and the verification of new technologies. The development and improvement of planar cascade experimental technology provide strong support for the progress of aerodynamic design technology of modern aeroengine compressors and turbine airfoils. Traditional planar cascade experimental devices mainly consist of several blades and two grid plates with airfoil holes. The blades are fixedly connected to the upper and lower grid plates through the airfoil holes to form a cascade channel. The disadvantage of such traditional experimental devices is that the installation angle of the cascade is fixed and non-adjustable. For cascade experiments with different installation angles, multiple sets of experimental parts need to be processed, and the experimental parts need to be repeatedly disassembled and assembled on and off the platform, which is time-consuming and laborious.

[0003] Some planar cascade experimental devices with adjustable installation angle have been proposed in the prior art. For example, a method for independently adjusting the installation angle of each blade of a planar cascade is proposed in Chinese Patent Application (CN202110210800.6). Each blade forms an independent installation angle adjustment unit through the design of a pressing plate, a turntable, and a grid plate structure. By applying an operating tool to the operating hole, the turntable rotates, driving the pressing plate to rotate synchronously. When the required installation angle of the blade is reached, the screw is tightened to fix the position of the turntable. This method can achieve independent control of the installation angle of each blade. However, its disadvantage is that the angle adjustment accuracy of the installation angle is low, and the repeated loosening and tightening of the screw will further amplify the error, thus deviating from the installation angle accuracy requirements of the cascade experiment. In addition, in order to achieve independent adjustability of the installation angle, the introduced mechanism is too complex, greatly increasing the cost and complexity of the experimental device. Summary of the Invention

[0004] The present disclosure is provided to introduce some concepts that will be further described in the following detailed embodiments in a simplified form. The present disclosure is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to help determine the scope of the claimed subject matter.

[0005] One of the objectives of the present disclosure is to solve the problems of the fixed and non-adjustable installation angle of the traditional planar cascade experimental piece and the inconvenience caused by repeated disassembly and assembly on and off the platform. To this end, the present invention proposes a method for adjusting the installation angle of a planar cascade and an experimental device. By respectively opening grooves on the inner sides of the upper and lower grid plates for inserting blade fixing plates with blade-shaped holes, the blade-shaped holes on the plates are used to determine the installation angle of each blade. Each set of plates corresponds to different experimental installation angles. By replacing the blade fixing plates with different blade-shaped holes, the adjustable installation angle of the blades is realized. According to specific experimental requirements, multiple sets of blade fixing plates with different installation angles can be prepared in advance for experimental replacement. The design of the plate takes into account the requirements for measuring the surface pressure of the blade. A wire groove is opened on the blade fixing plate with a static pressure hole, so that the plate can be directly replaced on the cascade test bench.

[0006] According to one aspect of the present disclosure, there is provided a planar cascade experimental device, comprising:

[0007] an upper grid plate and a lower grid plate, wherein grooves are respectively opened on the inner sides of the upper grid plate and the lower grid plate;

[0008] a first distance post and a second distance post for connecting the upper grid plate and the lower grid plate;

[0009] a plurality of blades; and

[0010] multiple sets of blade fixing plates, each set of blade fixing plates includes an upper grid plate blade fixing plate and a lower grid plate blade fixing plate, wherein corresponding blade-shaped holes for fixing the blades are respectively opened on the upper grid plate blade fixing plate and the lower grid plate blade fixing plate,

[0011] wherein each blade among the plurality of blades is fixed to a corresponding set of upper grid plate blade fixing plate and lower grid plate blade fixing plate by inserting into the corresponding blade-shaped holes on the set of upper grid plate blade fixing plate and lower grid plate blade fixing plate, and the upper grid plate blade fixing plate and the lower grid plate fixing blade with the blade fixed are respectively installed into the grooves on the upper grid plate and the lower grid plate.

[0012] According to a further embodiment of the present invention, the blade-shaped holes of the multiple sets of blade fixing plates are configured to provide different blade installation angles.

[0013] According to a further embodiment of the present invention, convex platforms are provided at both ends of the blade, and the blade-shaped hole has a cross-section matching the convex platform, so that the blade can be fixed by inserting the convex platform into the blade-shaped holes on the upper grid plate blade fixing plate and the lower grid plate blade fixing plate.

[0014] According to a further embodiment of the present invention, the plurality of blades include blades with static pressure holes and blades without static pressure holes. The upper grid blade fixing clamp includes an upper grid blade fixing clamp with static pressure holes and an upper grid blade fixing clamp without static pressure holes. The lower grid blade fixing clamp includes a lower grid blade fixing clamp with static pressure holes and a lower grid blade fixing clamp without static pressure holes.

[0015] Among them, the upper grid blade fixing clamp with static pressure holes and the lower grid blade fixing clamp with static pressure holes are used to fix the blades with static pressure holes, and the upper grid blade fixing clamp without static pressure holes and the lower grid blade fixing clamp without static pressure holes are used to fix the blades without static pressure holes.

[0016] According to a further embodiment of the present invention, the blade with static pressure holes is provided with one or more static pressure holes on one or both of the pressure surface and the suction surface of the blade, and one or more blade tip through holes for leading out the pressure signal of the static pressure holes are provided at the blade tip.

[0017] According to a further embodiment of the present invention, a card board wiring groove is provided on the upper grid blade fixing clamp with static pressure holes, so that the lead wire led out through the blade tip through hole can pass through when replacing the blade fixing clamp with different blade installation angles.

[0018] According to a further embodiment of the present invention, one or more lead holes penetrating the upper grid are provided in the groove of the upper grid for the lead wire led out through the blade tip through hole to pass through.

[0019] According to a further embodiment of the present invention, the blade fixing clamp and the groove are in the shape of a parallelogram.

[0020] According to a further embodiment of the present invention, the blade fixing clamp is processed in a segmented manner, or processed in a whole piece manner corresponding to the shape of the groove and including a plurality of blade profile holes.

[0021] On the other hand, according to the present invention, a method for using a planar cascade experimental device as described in the present invention is provided, including:

[0022] Select a blade fixing clamp that meets the blade installation angle according to the experimental requirements of the planar cascade experiment;

[0023] Insert the boss of the blade into the blade profile hole of the blade fixing clamp to fix the blade to the corresponding blade fixing clamp;

[0024] Insert the blade fixing clamp with the fixed blade into the grooves of the upper grid and the lower grid respectively;

[0025] Tighten the first fixed distance column and the second fixed distance column with bolts to compress the upper grid, the lower grid, the blade fixing clamp and the blade; and

[0026] After completing the current planar cascade experiment, loosen the bolts to remove the blade fixing plate and the blades to replace the blade fixing plate corresponding to the next set of planar cascade experiments.

[0027] These and other features and advantages will become apparent by reading the following detailed description and referring to the associated drawings. It should be understood that the foregoing general description and the following detailed description are illustrative only and do not limit the various aspects claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To understand in detail the manner in which the above-described features of the present disclosure are used, the above briefly summarized content may be described more specifically with reference to the embodiments, some aspects of which are shown in the drawings. It should be noted, however, that the drawings only show some typical aspects of the present disclosure and should not be considered to limit its scope, as the description may allow other equally effective aspects.

[0029] Figure 1 A perspective schematic view of a planar cascade experiment device according to an embodiment of the present invention is shown.

[0030] Figure 2 A perspective schematic view of the planar cascade experiment device according to an embodiment of the present invention at another angle is shown.

[0031] Figure 3 A cross-sectional view of the planar cascade experiment device according to an embodiment of the present invention taken along B-B is shown.

[0032] Figure 4 A perspective schematic view of a blade with static pressure holes according to an embodiment of the present invention is shown.

[0033] Figure 5 A perspective schematic view of a blade without static pressure holes according to an embodiment of the present invention is shown.

[0034] Figure 6 A perspective schematic view of a single-piece blade fixing plate with static pressure holes according to an embodiment of the present invention is shown.

[0035] Figure 7 A perspective schematic view of a single-piece blade fixing plate without static pressure holes according to an embodiment of the present invention is shown.

[0036] Figure 8 A perspective schematic view of a segmented blade fixing plate according to an embodiment of the present invention is shown.

[0037] Figure 9 A perspective schematic view of an integral blade fixing plate according to an embodiment of the present invention is shown.

[0038] Figure 10A perspective schematic view of an upper grid plate according to an embodiment of the present invention is shown.

[0039] Figure 11 An assembly schematic view of a blade fixing clamping plate and a grid plate according to an embodiment of the present invention is shown.

[0040] Figure 12 A top view of a segmented blade fixing clamping plate according to an embodiment of the present invention is shown.

[0041] Figure 13 An example flowchart of the usage method of a planar cascade experimental device according to an embodiment of the present invention is shown.

[0042] Among them, the above-mentioned drawings include the following reference numerals:

[0043] 1. Upper grid plate; 2. Lower grid plate;

[0044] 3. First distance-fixed column; 4. First distance-fixed column;

[0045] 5. Blade with static pressure holes; 6. Blade without static pressure holes;

[0046] 7. Static pressure hole on the pressure surface; 8. Static pressure hole on the suction surface;

[0047] 9. Blade fixing clamping plate of the upper grid plate with static pressure holes;

[0048] 10. Blade fixing clamping plate of the upper grid plate without static pressure holes;

[0049] 11. Blade fixing clamping plate of the lower grid plate with static pressure holes;

[0050] 12. Blade fixing clamping plate of the lower grid plate without static pressure holes;

[0051] 13. Bolt; 14. Central bolt hole; 15. Side bolt hole;

[0052] 16. Blade boss; 17. Through hole at the blade tip; 18. Blade profile hole;

[0053] 19. Clamping plate wire groove; 20. Groove; 21. Lead hole Detailed implementation manners

[0054] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0055] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0056] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments of the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0057] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0058] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the scope of protection of the present application; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0059] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper", etc. can be used here to describe the spatial positional relationship between a device or feature shown in a figure and other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure for the device. For example, if the device in the attached figure is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways, rotated 90 degrees or in other orientations, and corresponding interpretations are made for the spatial relative descriptions used here.

[0060] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is merely for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus cannot be construed as limiting the protection scope of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand this application not only through the actual terms used, but also through the meanings implied by each term.

[0061] Figure 1 and Figure 2 FIG. shows a three-dimensional schematic diagram of a planar cascade experimental device according to an embodiment of the present invention. As Figure 1 and Figure 2 shown, the planar cascade experimental device may include an upper grid plate 1, a lower grid plate 2, a first distance post 3 and a second distance post 4 for connecting the upper grid plate 1 and the lower grid plate 2, and a plurality of blades. According to the needs of the experiment, the blades may include blades 5 with static pressure holes and blades 6 without static pressure holes. Each blade may be fixed by a set of blade fixing clamps, and the blade fixing clamps may be further fixed in grooves 20 opened on the inner sides of the upper grid plate 1 and the lower grid plate 2.

[0062] Figure 4 and Figure 5 FIGS. respectively show three-dimensional schematic diagrams of a blade 5 with static pressure holes and a blade 6 without static pressure holes according to an embodiment of the present invention. As Figure 4 shown, the blade 5 with static pressure holes is provided with a pressure surface static pressure hole 7 on the pressure surface of the blade. Similarly, a suction surface static pressure hole 8 may be provided on the suction surface of the blade (as Figure 2as shown. The number of static pressure holes 7 and 8 can be set according to the needs of the planar cascade experiment. Taking the static pressure hole 7 on the pressure surface as an example, as Figure 4 shown, the static pressure hole 7 on the pressure surface can be arranged horizontally at the 50% blade height position. Each static pressure hole is perpendicular to the pressure surface and is used to collect the pressure signal on the blade surface. It can be understood that the opening position of the static pressure hole can also be set according to the needs of the planar cascade experiment.

[0063] In addition, as Figure 4 shown, a tip through hole 17 is opened at the top of the blade 5 with static pressure holes, which is used to lead out the pressure signal of the static pressure hole. The number of tip through holes 17 can depend on the number of static pressure holes. One tip through hole 17 can be set for each static pressure hole 7 or 8, or several static pressure holes 7 or 8 can share one tip through hole 17. In Figure 4 the example, multiple tip through holes 17 are opened near the mean camber line at the top of the blade. Such a distribution is beneficial to concentrating the through hole positions and facilitating the setting of lead holes 21 on the upper grid plate 1, which will be further described in detail below in combination with Figure 10 this.

[0064] At both the upper and lower ends of the blade 5 with static pressure holes, there are convex platforms 16 respectively. As an example, the convex platforms 16 can be processed by removing part of the material at the leading edge and trailing edge respectively. The convex platform 16 has a first height h1 and is respectively used to be inserted into the corresponding blade profile holes 18 of the upper grid plate static pressure hole blade fixing clamp 9 and the lower grid plate static pressure hole blade fixing clamp 11 for fixing and limiting the blade 5 with static pressure holes. In this example, the convex platforms 16 at both the upper and lower ends of the blade 5 with static pressure holes are shown to be symmetric, which is beneficial to processing and manufacturing. However, it can be understood that this is not necessary, and different shapes can be set for the convex platforms at the upper and lower ends according to needs.

[0065] Referring to Figure 5 this, similar blade convex platforms 16 are also processed at both ends of the blade 6 without static pressure holes, and the convex platform height is also h1, which are respectively used for fixing and limiting the blade 6 with the upper grid plate non-static pressure hole blade fixing clamp 10 and the lower grid plate non-static pressure hole blade fixing clamp 12.

[0066] According to the installation position of the blade fixing clamp, the blade fixing clamp can be divided into the upper grid plate blade fixing clamp installed in the groove 20 of the upper grid plate 1 and the lower grid plate blade fixing clamp installed in the groove 20 of the lower grid plate 2. According to whether the installed blade is the blade 5 with static pressure holes or the blade 6 without static pressure holes, the blade fixing clamp can be further divided into the upper grid plate static pressure hole blade fixing clamp 9, the upper grid plate non-static pressure hole blade fixing clamp 10, the lower grid plate static pressure hole blade fixing clamp 11, and the lower grid plate non-static pressure hole blade fixing clamp 12.

[0067] Figure 6 andFigure 7 Stereo schematic views of a monolithic blade fixing chuck with static pressure holes and a monolithic blade fixing chuck without static pressure holes according to an embodiment of the present invention are respectively shown. As Figure 6 and Figure 7 shown, a blade profile hole 18 is formed in the blade fixing chuck. The blade profile hole 18 may have a shape matching the cross-section of the boss 16 of the blade, so that the blade can be fixed to the blade fixing chuck by inserting the boss 16 into the blade profile hole 18. The upper and lower ends of a blade can be respectively inserted into the blade profile holes of a set of upper grid plate blade fixing chucks and lower grid plate blade fixing chucks. It can be understood that the blade profile holes of a pair of upper grid plate blade fixing chucks and lower grid plate blade fixing chucks constituting a set are symmetric to each other.

[0068] As Figure 6 shown, a chuck wiring groove 19 is formed in the upper grid plate blade fixing chuck 9 with static pressure holes. In this example, the chuck wiring groove 19 is formed on the suction surface side of the blade profile wheel 18 corresponding to the blade, communicating the blade profile wheel 18 and the outside of the upper grid plate blade fixing chuck 9 with static pressure holes. As will be described in more detail below, when it is necessary to replace and install the upper grid plate blade fixing chuck 9 with static pressure holes, the chuck wiring groove 19 can be used as a clamping channel for the transmission line for measuring the blade surface pressure signal led out through the blade top through hole 17. It can be understood that the position of the chuck wiring groove 19 can also be set at any other position on the static pressure hole blade fixing chuck 9, as long as it can communicate the blade profile wheel 18 and the outside, facilitating the removal of the upper grid plate blade fixing chuck 9 with static pressure holes from the blade 5 with static pressure holes while keeping the static pressure hole lead wire led out from the blade top through hole 17 of the blade 5 with static pressure holes connected to the instrument, and installing the blade 5 with static pressure holes onto the newly adopted upper grid plate blade fixing chuck 9 through the chuck wiring groove 19 of the newly adopted upper grid plate blade fixing chuck 9. Similarly, as Figure 7 shown, a blade profile hole 18 matching the boss 16 of the blade is also formed in the upper grid plate blade fixing chuck 10 without static pressure holes for the insertion and fixing of the blade and the chuck.

[0069] As described above, the blade is first fixed by the blade fixing chuck, and then the blade fixing chuck is fixed to the upper grid plate and the lower grid plate. At this time, the blade installation angle of each blade is uniquely determined by the blade profile hole 18 of the blade fixing chuck to which it is fixed. Figure 12 The top view of a split-type blade fixing chuck according to an embodiment of the present invention is shown. As Figure 12 shown, θ 1 -θ 6Correspond to the installation angles of each blade respectively. Before conducting a planar cascade experiment, several sets of blade fixing plates can be pre-processed according to the requirements of the experimental task, corresponding to different blade installation angles, for use in experimental replacement. Using this method to determine the installation angle has high precision, and the installation angle of each blade is independently customized. The same blade is fixed by two blade fixing plates on the upper and lower grid plates, and the number of sets of fixing plates can match the number of blades in the cascade experimental device. In the example shown in the drawings of the present invention, the cascade experimental device includes 6 blades, but more or fewer blades can also be set according to needs.

[0070] See Figure 8 and Figure 9 , the blade fixing plates can be processed in two ways: block type or integral type. As Figure 8 shown, in the scenario where the cascade experimental device includes 6 blades, multiple sets of blade fixing plates can be set, and each set of blade fixing plates (one upper grid plate blade fixing plate and one lower grid plate blade fixing plate) provides an installation angle for one blade. When in use, according to the requirements of the current experiment, select 6 sets of blade fixing plates that respectively provide the required blade installation angles for the experiment. After fixing the blades respectively, insert them into the grooves 20 of the upper grid plate 1 and the upper grid plate 2. As Figure 8 shown, among these 6 blades, the two middle blades adopt the blade 5 with static pressure holes. Therefore, correspondingly, multiple sets of upper grid plate blade fixing plates 9 with static pressure holes and lower grid plate blade fixing plates 11 with static pressure holes with different installation angles need to be processed for the blade 5 with static pressure holes for backup. Similarly, multiple sets of upper grid plate blade fixing plates 10 without static pressure holes and lower grid plate blade fixing plates 12 without static pressure holes are processed for the blades 6 without static pressure holes for backup. When conducting the next set of cascade experiments, only the blade fixing plates corresponding to the blades with changed installation angles need to be replaced. The thickness of each blade fixing plate can be the second height h2.

[0071] Alternatively, according to another embodiment of the present invention, as Figure 9 shown, the blade fixing plates can be processed integrally. For example, a set of blade fixing plates is processed for the 6 blade installation angles of a set of cascade experimental devices, including an upper grid plate blade fixing plate with 6 blade profile holes and a corresponding lower grid plate blade fixing plate with 6 blade profile holes. Similarly, for the blade with static pressure holes, a card plate wiring groove 19 can also be provided at the corresponding blade position on the upper grid plate blade fixing plate. When conducting the next set of cascade experiments, the upper grid plate blade fixing plate and the lower grid plate blade fixing plate corresponding to the new 6 blade installation angles are replaced integrally.

[0072] The upper grid plate blade fixing plate and the lower grid plate blade fixing plate are respectively inserted into the grooves 20 of the upper grid plate 1 and the lower grid plate 2. Taking the upper grid plate 1 as an example, as Figure 10As shown in the figure, a groove 20 may be formed on the inner side of the upper grid plate 1 for inserting Figure 8 and Figure 9 the blade fixing clamping plate with different installation angle corresponding leaf-shaped holes shown in the figure. The depth of the grid plate groove is the third height h3. In a non-limiting example, the height of the blade boss 16 (the first height h1), the thickness of the blade fixing clamping plate (the second height h2), and the depth of the grid plate groove (the third height h3) may be set to be equal.

[0073] Still taking the scenario where the cascade experimental device uses 6 blades as an example, the groove 20 has a shape that can match the combination of 6 component blade fixing clamping plates or the integral 6-blade blade fixing clamping plate, so that the blade fixing clamping plate can be inserted and installed in the groove 20. In the examples of the present invention, the blade fixing clamping plate is in the shape of a parallelogram, which is more suitable for arranging blades in a limited space and has a relatively firm structure after assembly. The angle between the hypotenuse and the base of the parallelogram can be designed according to the blade profile, or can be a specific angle, such as 90 degrees (in this case, the parallelogram is a rectangle). Correspondingly, the groove 26 is also in the shape of a parallelogram corresponding to the blade fixing clamping plate to accommodate the blade fixing clamping plate.

[0074] Corresponding to the previous examples, considering the need to set a certain number of blades with static pressure holes, a lead hole 21 penetrating the upper grid plate 1 is opened in the groove 20 of the upper grid plate 1 at the position corresponding to the installation of the upper grid plate with static pressure hole blade fixing clamping plate 9, so that after the blade 5 with static pressure holes is installed on the groove 20 of the upper grid plate 1 through the blade fixing clamping plate, the lead wire of the static pressure hole sensor of the blade can pass through the lead hole 21 to the upper part of the experimental device for further connection to the measuring instrument. The shape and size of the lead hole 21 should be such that it is convenient for wire routing and does not affect the fixing effect of the upper grid plate 1 on the blade fixing clamping plate 9 with static pressure holes. In this example, the shape of the lead hole 21 is a rectangular opening approximately near the mean camber line of the blade, which is convenient for the lead wires of the blades 5 with static pressure holes at different installation angles to pass through the lead hole 21. Figure 11 This is an example of the actual effect after the blade fixing clamping plate is inserted into the groove 20 of the upper grid plate.

[0075] As Figure 10 and 11 Further shown in the figure, both ends of the upper grid plate 1 have two central bolt holes 14, which are respectively used for fixing the upper grid plate 1, the first spacer column 3 and the second spacer column 4. Two side bolt holes 15 are respectively arranged on both sides of the two central bolt holes 14 for fixing the planar cascade test device and the cascade test bench. The positions of these bolt holes can be set at any appropriate position according to needs.

[0076] Figure 13FIG. 1300 is an exemplary flowchart showing a method of using a planar cascade experimental apparatus according to an embodiment of the present invention. The planar cascade experimental apparatus may be the planar cascade experimental apparatus and its variants described previously in connection with Figures 1 - 12 As shown in Figure 13 , method 1300 begins at step 1302, where a blade fixing chuck that matches the blade installation angle is selected according to the experimental requirements of the planar cascade experiment. As previously mentioned, multiple sets of blade fixing chucks with different blade installation angles can be machined before the experiment for experimental needs. Before each set of experiments, the blade fixing chuck providing the corresponding blade installation angle can be selected in sequence according to the blade installation angle of each blade.

[0077] At step 1304, the boss of the blade is inserted into the blade profile hole of the blade fixing chuck to fix the blade to the corresponding blade fixing chuck. It should be noted that for the blade 5 with a static pressure hole, the upper grid plate with a static pressure hole blade fixing chuck 9 and the lower grid plate with a static pressure hole blade fixing chuck 11 providing the required installation angle need to be selected, because the upper grid plate with a static pressure hole blade fixing chuck 9 has a chuck wire groove 19. It can be understood that the lower grid plate with a static pressure hole blade fixing chuck 11 and the lower grid plate without a static pressure hole blade fixing chuck 12 can be the same and interchangeable.

[0078] At step 1306, the blade fixing chucks with fixed blades are respectively inserted into the grooves of the upper grid plate and the lower grid plate. Similarly, it should be noted that after the upper grid plate with a static pressure hole blade fixing chuck 9 of the blade 5 with a static pressure hole is inserted into the groove 20 of the upper grid plate 1, it needs to be adjusted to the position corresponding to the reserved lead hole 21. In one example, when installing the upper grid plate with a static pressure hole blade fixing chuck 9 of the blade 5 with a static pressure hole, the lead wire of the static pressure sensor can be first passed through the lead hole 21, and then the upper grid plate with a static pressure hole blade fixing chuck 9 can be inserted into the groove 20 of the upper grid plate 1.

[0079] At step 1308, the first distance fixing post and the second distance fixing post are tightened by bolts to press the upper grid plate, the lower grid plate, the blade fixing chuck, and the blade. As can be seen from the combination of Figure 1 and Figure 2 in connection with Figure 3 , through tightening the bolt 13, the upper grid plate blade fixing chuck, the blade, and the lower grid plate blade can be pressed between the upper grid plate 1 and the lower grid plate 2. After pressing, the assembly process of the experimental apparatus is completed, and the cascade experiment can be started.

[0080] In step 1310, after completing the current planar cascade experiment, loosen the bolts to remove the blade fixing plate and the blades, and replace the blade fixing plate corresponding to the next set of planar cascade experiments. After completing the current experiment, the blade fixing plate for the next set can be selected according to the blade installation angle requirements of the next set of experiments. By loosening bolt 13, the upper grid plate 1 and the lower grid plate 2 can be relaxed, and at the same time, the upper grid plate blade fixing plate, the blades, and the lower grid plate blades are also relaxed. The upper grid plate blade fixing plate and the lower grid plate blades together with the blades can be taken out from the upper grid plate 1 and the lower grid plate 2. Then, according to which installation angles have changed, replace the blade fixing plates at the corresponding positions, and generally the blades do not need to be replaced. After replacement, only need to reinstall according to the previous steps and tighten bolt 13 to complete the preparation for the next experiment. For the blade 5 with a static pressure hole, if it is necessary to change the blade installation angle of this blade, after loosening bolt 13, the blade 5 with a static pressure hole and its fixed upper grid plate blade fixing plate 9 with a static pressure hole and the lower grid plate fixed plate 11 with a static pressure hole can be taken off as a whole. Without disconnecting the leads of the blade, the leads can be withdrawn through the card plate wire groove 19 on the upper grid plate blade fixing plate 9 with a static pressure hole, and then replace the new upper grid plate blade fixing plate 9 with a static pressure hole. The remaining replacement and assembly steps are the same as those for the blade without a static pressure hole.

[0081] The planar cascade experimental device of the present invention is described above. Compared with the traditional planar cascade experimental device, it has at least the following advantages:

[0082] 1) By respectively opening grooves on the inner sides of the upper and lower grid plates for inserting blade fixing plates with leaf profile holes corresponding to different installation angles, the arbitrary adjustment of the blade installation angle is realized;

[0083] 2) By opening leaf profile holes corresponding to specific blade installation angles on the integral or segmented blade fixing plates, and inserting the blades into the leaf profile holes and the card plates into the grooves on the inner sides of the grid plates, the blade installation angle is uniquely determined. The accuracy of determining the installation angle by this method is high, and the installation angle of each blade is independently customized;

[0084] 3) A wire groove is opened on the blade fixing plate with a static pressure hole, and the card plate can be directly replaced on the planar cascade test bench, avoiding the trouble and inconvenience caused by repeated disassembly and assembly of the planar cascade experimental parts on and off the bench, and improving the experimental efficiency.

[0085] The above-described content includes examples of various aspects of the claimed subject matter. Of course, it is not possible to describe every conceivable combination of components or methods for the purpose of depicting the claimed subject matter, but those of ordinary skill in the art should recognize that many further combinations and permutations of the claimed subject matter are possible. Thus, the disclosed subject matter is intended to cover all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims.

Claims

1. A planar cascade experimental device, characterized in that, comprising: an upper grid plate (1) and a lower grid plate (2), wherein grooves (20) are respectively formed on the inner sides of the upper grid plate (1) and the lower grid plate (2); a first fixed-distance column (3) and a second fixed-distance column (4) for connecting the upper grid plate (1) and the lower grid plate (2); a plurality of blades; and multiple groups of blade fixing clamping plates, each group of blade fixing clamping plates includes an upper grid plate blade fixing clamping plate and a lower grid plate blade fixing clamping plate, wherein corresponding blade profile holes (18) for fixing the blades are respectively formed on the upper grid plate blade fixing clamping plate and the lower grid plate blade fixing clamping plate, wherein each of the plurality of blades is fixed to a corresponding group of upper grid plate blade fixing clamping plates and lower grid plate blade fixing clamping plates by inserting into the corresponding blade profile holes (18) on a group of upper grid plate blade fixing clamping plates and lower grid plate blade fixing clamping plates, and the upper grid plate blade fixing clamping plates and lower grid plate fixing blades with the blades fixed are respectively installed into the grooves (20) on the upper grid plate (1) and the lower grid plate (2).

2. The planar cascade experimental device according to claim 1, characterized in that, the blade profile holes (18) of the multiple groups of blade fixing clamping plates are configured to provide different blade installation angles.

3. The planar cascade experimental device according to claim 1, characterized in that, bosses (16) are provided at both ends of the blade, and the blade profile holes (18) have cross-sections matching the bosses (16), so that the blade can be fixed by inserting the bosses (16) into the blade profile holes (18) on the upper grid plate blade fixing clamping plate and the lower grid plate blade fixing clamping plate.

4. The planar cascade experimental device according to claim 1, characterized in that, the plurality of blades include blades (5) with static pressure holes and blades (6) without static pressure holes, the upper grid plate blade fixing clamping plates include an upper grid plate blade fixing clamping plate with static pressure holes (9) and an upper grid plate blade fixing clamping plate without static pressure holes (10), and the lower grid plate blade fixing clamping plates include a lower grid plate blade fixing clamping plate with static pressure holes (11) and a lower grid plate blade fixing clamping plate without static pressure holes (12), wherein the upper grid plate blade fixing clamping plate with static pressure holes (9) and the lower grid plate blade fixing clamping plate with static pressure holes (11) are used to fix the blades (5) with static pressure holes, and the upper grid plate blade fixing clamping plate without static pressure holes (10) and the lower grid plate blade fixing clamping plate without static pressure holes (12) are used to fix the blades (6) without static pressure holes.

5. The planar cascade experimental device according to claim 4, characterized in that, one or more static pressure holes (7, 8) are formed on one or both of the pressure surface and the suction surface of the blade (5) with static pressure holes, and one or more blade top through holes (17) for leading out the pressure signals of the static pressure holes (7, 8) are formed at the top of the blade.

6. The planar cascade experimental device according to claim 5, characterized in that, The upper grid plate with static pressure holes has a card board wire groove (19) on the blade fixing card board (9), so that the lead wire led out through the blade top through hole (17) can pass through when replacing the blade fixing card board (9) with different blade installation angles.

7. The planar cascade experimental device according to claim 5, characterized in that, one or more lead holes (21) penetrating the upper grid plate (1) are arranged in the groove (20) of the upper grid plate (1) for the lead wire led out through the blade top through hole (17) to pass through.

8. The planar cascade experimental device according to claim 1, characterized in that, the blade fixing card board and the groove (20) are in the shape of a parallelogram.

9. The planar cascade experimental device according to claim 1, characterized in that, the blade fixing card board is processed in a segmented manner or in a whole piece manner corresponding to the shape of the groove (20) and including a plurality of blade profile holes (18).

10. A method for using the planar cascade experimental device according to any one of claims 1-9, characterized in that, the method for using includes: selecting a blade fixing card board that meets the blade installation angle according to the experimental requirements of the planar cascade experiment; inserting the boss of the blade into the blade profile hole of the blade fixing card board to fix the blade to the corresponding blade fixing card board; inserting the blade fixing card board with the blade fixed into the grooves of the upper grid plate and the lower grid plate respectively; tightening the first fixed distance column and the second fixed distance column with bolts to press the upper grid plate, the lower grid plate, the blade fixing card board and the blade; and after completing the current planar cascade experiment, loosening the bolts to remove the blade fixing card board and the blade to replace the blade fixing card board corresponding to the next group of planar cascade experiments.

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