Compressor blade test device and method

Abstract

The present invention provides a compressor blade cascade test device and method, belonging to the field of blade cascade wind tunnel experiments; including a main frame, a circumferential spacing adjustment module, an axial spacing adjustment module, and a blade tip clearance adjustment module, wherein the circumferential spacing adjustment module, the axial spacing adjustment module, and the blade tip clearance adjustment module are integrated on the main frame; the front blade cascade and the rear blade cascade are installed in series through the main frame, and a gap is left between the blade tip and the bottom surface of the main frame; the space between the blade cascade installation surface and the bottom surface of the main frame is used as a test section flow channel of the wind tunnel; the circumferential spacing and axial spacing blade tip clearance of the series blade cascade are adjusted respectively through the circumferential spacing adjustment module, the axial spacing adjustment module, and the blade tip clearance adjustment module. The present invention can meet the needs of the current series blade cascade variable geometry parameter experiment, save the test piece processing cost and save the experiment time.

Description

Technical Field

[0001] The invention belongs to the field of blade cascade wind tunnel experiments, and in particular relates to a compressor blade cascade experimental device and method. Background Art

[0002] As the performance requirements of aircraft engines continue to increase, the compressor, as one of the key components of aircraft engines, faces the challenge of bearing higher and higher loads, and whether a compressor with superior performance can be designed often determines the performance of the engine. However, the higher the load of the compressor, the higher the boost capacity each row of blades needs to provide, and the higher the aerodynamic design requirements for the blades will be.

[0003] Increasing the turning angle of the airflow after passing through the blades is one of the methods to improve the boosting capacity of the compressor. When a row of blades cannot impose a sufficient airflow turning angle on the airflow, two rows of similar blades can be considered to apply deflection to the airflow respectively. This is the basic idea of ​​the tandem blade grid. The idea of ​​the tandem blade grid was first proposed by Betz A in the 1920s. He proposed a slotted wing to delay the occurrence of boundary layer separation, thereby greatly increasing lift. When the row of blades is changed from one row to two rows of blades, the tandem blade grid has more geometric parameters representing the relative positions of the front and rear rows of blades, including axial spacing and circumferential spacing. For a tandem blade grid, the axial spacing is defined as the distance in the axial direction between the trailing edge of the front row blades and the leading edge of the rear row blades. When the front row blades and the rear row blades do not overlap in the axial direction, the axial spacing is considered to be greater than 0, and when there is overlap, the axial spacing is considered to be less than 0. The circumferential spacing of the tandem blades is defined as the distance between the trailing edge of the front row blades and the leading edge of the rear row blades in the circumferential direction. Both of them are key geometric parameters for determining a tandem blade and play an important role in the flow characteristics of the blades. Only when the tandem blades have appropriate axial spacing and circumferential spacing can their combination achieve better aerodynamic performance.

[0004] In actual compressor operation, the rotor blades rotate at high speed, while the hub is stationary, so there needs to be a certain gap between the tip of the rotor blade and the hub so that the rotor can rotate normally. Similarly, there is generally a gap between the tip of the stator blade and the hub. The value of the gap is generally very small, but this gap will have a great impact on the aerodynamic performance of the compressor. The airflow through the gap causes leakage flow, which will mix the airflows with different energies, affecting the flow field on both sides of the blades, resulting in reduced work capacity and efficiency of the blade row. The size of the blade tip gap is an important parameter in the compressor design process, which will have a considerable impact on the aerodynamic performance and stability of the compressor.

[0005] Plane blade experiments are an important part of compressor blade design and improvement. Although with the development of modern computers, people can use numerical calculation methods to perform detailed aerodynamic calculations on compressor blades, the flow field inside the compressor is very complex. It is still a great challenge to accurately simulate the flow field environment inside the compressor, so the accuracy of numerical calculations still needs to be verified by experiments.

[0006] At present, there are studies on the wake characteristics of tandem blade cascades by changing the axial spacing and circumferential spacing, or exploring the changing rules and action mechanisms of the flow field structure and aerodynamic performance of tandem blade cascades. In the prior art, axial grooves and circumferential grooves are opened in the cascade plate, and the position is adjusted by a slider that can move axially and circumferentially. The blade cascade device designed by this invention can achieve different axial and circumferential position adjustments with a set of blade cascades, but it cannot set the blade tip clearance because the blades must be inserted into the cascade plates at both ends to fix the blades.

[0007] It can be seen that researchers have conducted a lot of research on tandem blades using numerical simulation and experimental methods. However, in the experimental research method, for tandem blades with different geometric parameters, multiple sets of different tandem blades are usually designed and manufactured, and then experiments are carried out in a wind tunnel environment. In this way, if the experiment requires a large number of combinations of geometric parameters such as blade tip clearance, axial spacing, circumferential spacing, etc., the processing cost will increase greatly. If only one set of blade test pieces can be processed to realize the experiment of blades with different geometric parameters, the cost can be greatly saved. Although there is also a solution that can use a set of blade test pieces to achieve different axial spacing and circumferential spacing, it cannot set the blade tip clearance. Therefore, in order to further reduce the processing cost of blade test pieces and save experimental time, it is necessary to improve the current blade test device. Summary of the invention

[0008] Technical issues to be solved:

[0009] In order to avoid the shortcomings of the prior art, the present invention proposes a compressor blade grid experimental device, through which the front blade tip clearance, rear blade tip clearance, axial spacing and circumferential spacing of the tandem blade grid can be adjusted simultaneously, which can meet the needs of the current tandem blade grid variable geometry parameter experiment, save the test piece processing cost and save experimental time.

[0010] The technical solution of the present invention is: a compressor blade cascade experimental device, characterized in that: it includes a main frame, a circumferential spacing adjustment module, an axial spacing adjustment module, and a blade tip clearance adjustment module, wherein the circumferential spacing adjustment module, the axial spacing adjustment module, and the blade tip clearance adjustment module are integrated on the main frame;

[0011] The front blade cascade and the rear blade cascade are installed in series through the main frame, and a gap is left between the blade top and the bottom surface of the main frame; the space between the blade cascade installation surface and the bottom surface of the main frame is used as the test section flow channel of the wind tunnel;

[0012] The circumferential spacing of the series blade cascades can be adjusted by the circumferential spacing adjustment module;

[0013] The axial spacing adjustment module is used to adjust the axial spacing of the series blade cascades;

[0014] The tip clearance of the series blade cascade is adjusted by the tip clearance adjustment module.

[0015] A further technical solution of the present invention is: the main frame comprises an upper grid plate, a lower grid plate and a distance column, and the upper grid plate and the lower grid plate are connected parallelly and relatively fixedly by the distance column;

[0016] The blades of the front and rear cascades are installed on the upper cascade plate, and a gap is left between the blade tip and the lower cascade plate to study the effect of the blade tip gap on the flow field.

[0017] A further technical solution of the present invention is that the distance columns are circumferentially arranged between the upper grid plate and the lower grid plate, and the spacing between the upper grid plate and the lower grid plate can be adjusted by adjusting the axial height of the distance columns.

[0018] A further technical solution of the present invention is: the circumferential spacing adjustment module comprises a front leaf slider, a rear leaf slider and a circumferential pad; a plurality of front leaf slider slots are opened along the span direction on the front leaf slider for installing the front leaf; a plurality of rear leaf slider slots are opened along the span direction on the rear leaf slider for installing the rear leaf;

[0019] The cascade installation surface of the main frame is provided with a cascade front slot and a cascade rear slot, which are used to install a front blade slider and a rear blade slider, respectively, and the front blade slider and the rear blade slider are clearance-matched with the cascade front slot and the cascade rear slot;

[0020] The circumferential position of the front blade slider or the rear blade slider in the front groove or the rear groove of the grid plate is determined by the circumferential pad.

[0021] A further technical solution of the present invention is that: the grid plate front groove and the grid plate rear groove are stepped groove structures; the front leaf slider and the rear leaf slider are flat plate structures with steps at both ends, and are installed in coordination with the stepped groove structures of the grid plate front groove and the grid plate rear groove;

[0022] After the position of the front blade slider is determined, the circumferential pad is installed in the circumferential gap between the front blade slider and the front groove of the grid plate to complete the circumferential positioning of the front blade slider; or the circumferential pad is installed in the circumferential gap between the rear blade slider and the rear groove of the grid plate to complete the circumferential positioning of the rear blade slider; and prevent air leakage in the wind tunnel test section.

[0023] A further technical solution of the present invention is: the axial spacing adjustment module comprises a front leaf slider, a rear leaf slider and an axial pad; a plurality of front leaf slider slots are opened along the span direction on the front leaf slider for installing the front leaf; a plurality of rear leaf slider slots are opened along the span direction on the rear leaf slider for installing the rear leaf;

[0024] The cascade installation surface of the main frame is provided with a cascade front slot and a cascade rear slot, which are used to install a front blade slider and a rear blade slider, respectively, and the front blade slider and the rear blade slider are clearance-matched with the cascade front slot and the cascade rear slot;

[0025] The axial position of the front blade slider or the rear blade slider in the front groove or the rear groove of the grid plate is determined by the axial pad.

[0026] A further technical solution of the present invention is that: the grid plate front groove and the grid plate rear groove are stepped groove structures; the front leaf slider and the rear leaf slider are flat plate structures with steps at both ends, and are installed in coordination with the stepped groove structures of the grid plate front groove and the grid plate rear groove;

[0027] After the position of the front blade slider is determined, the axial pad is installed in the axial gap between the front blade slider and the front groove of the grid plate to complete the axial positioning of the front blade slider; or the axial pad is installed in the axial gap between the rear blade slider and the rear groove of the grid plate to complete the axial positioning of the rear blade slider; and prevent air leakage in the wind tunnel test section.

[0028] A further technical solution of the present invention is: a front slot and a rear slot of the grid plate are opened in the middle of the series blade installation surface of the main frame, wherein the front slot of the grid plate is in the upstream direction of the wind tunnel, and the rear slot of the grid plate is in the downstream direction of the wind tunnel, and the middle parts of the front and rear slots of the grid plate pass through the grid plate and are connected to each other.

[0029] A further technical solution of the present invention is: the blade tip clearance adjustment module comprises a front blade fixing block, a rear blade fixing block, a front blade clearance adjustment pad block and a rear blade clearance adjustment pad block; the front blade fixing block and the rear blade fixing block are respectively installed above the tandem blade cascade installation surface of the main frame through the front blade clearance adjustment pad block and the rear blade clearance adjustment pad block,

[0030] The front blade fixing block has a plurality of front blade fixing block slots formed along the span direction, corresponding one-to-one with the blades in the front blade cascade, and used for fixing and installing the front blades; the rear blade fixing block has a plurality of rear blade fixing block slots formed along the span direction, corresponding one-to-one with the blades in the rear blade cascade, and used for fixing and installing the rear blades;

[0031] By adjusting the height of the front blade gap adjustment pad and the rear blade gap adjustment pad, the distance between the front blade fixing block, the rear blade fixing block and the series blade grid mounting surface of the main frame is adjusted, and the distance between the front blade top, the rear blade top and the bottom surface of the main frame is adjusted synchronously, that is, the blade tip gap is adjusted.

[0032] A further technical solution of the present invention is: the shapes of the front leaf fixing block slot and the rear leaf fixing block slot match the shapes of the roots of the front blade and the rear blade, and the front blade and the rear blade are inserted into the front leaf fixing block slot and the rear leaf fixing block slot to form a clearance fit, and the front blade and the rear blade are pressed and fixed by radial screws.

[0033] A compressor blade test method, characterized in that: a front blade cascade and a rear blade cascade are installed in series on the main frame, and the circumferential, axial and blade tip clearances of the front blade cascade and the rear blade cascade are adjusted respectively by a circumferential spacing adjustment module, an axial spacing adjustment module and a blade tip clearance adjustment module; then the compressor blade cascade test device is connected to a blade cascade wind tunnel test device to ensure the sealing of the test section flow channel; the experiment is started and the test results of the tandem blade cascades with different geometric parameters are obtained.

[0034] Beneficial Effects

[0035] The beneficial effects of the present invention are as follows: the present invention realizes flexible adjustment of the front blade tip clearance, rear blade tip clearance, axial spacing and circumferential spacing of a set of tandem blade grid test pieces through the structure in which the circumferential spacing adjustment module, the axial spacing adjustment module and the blade tip clearance adjustment module are integrated into the main frame: the adjustment range of the blade tip clearance is 0 to 10 mm, which can fully meet the needs of conventional blade tip clearance research; due to structural limitations, the adjustment range of the axial spacing cannot be less than 0.

[0036] The three modules, namely, the circumferential spacing adjustment module, the axial spacing adjustment module and the blade tip clearance adjustment module, are independently designed and can complete the individual adjustment of the circumferential spacing, the axial spacing and the blade tip clearance, and can also adjust the three at the same time without causing mutual interference.

[0037] The present invention can greatly save the processing cost of the plane blade cascade test piece. If the performance and flow characteristics of the tandem blade cascade under the combination of 5 axial positions and 8 circumferential positions are obtained, if the traditional blade cascade test piece scheme is adopted, 40 sets of blade cascade test pieces need to be manufactured; if the performance of the tandem blade cascade under the combination of 3 different front blade tip clearances and 8 circumferential positions is obtained, if the traditional blade cascade test piece scheme is adopted, 24 sets of blade cascade test pieces need to be manufactured, the manufacturing and assembly costs are high, and there are also many inconveniences in management.

[0038] The present invention integrates the adjustment method of the relative position of the front and rear blades and the blade tip clearance into a cascade test piece. In this way, after a cascade blowing test is completed, it is not necessary to completely remove the test piece. Only the relevant structure needs to be adjusted to complete the adjustment of the variable parameters, saving the time cost of the experiment. Therefore, the cascade test piece structure of the present invention can greatly save the test piece processing cost and the time of the experimenter, can meet the current needs of the cascade variable geometric parameter experiment, and is conducive to the development of cascade experimental research. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is an overall three-dimensional view of a compressor blade cascade experimental device of the present invention;

[0040] Figure 2 It is an overall three-dimensional view of a compressor blade cascade experimental device of the present invention at another viewing angle;

[0041] Figure 3 It is an exploded view of the assembly relationship of the front blade, the front blade slider, the front blade fixing plate and the upper grid plate of a compressor cascade experimental device of the present invention;

[0042] Figure 4 It is an exploded view of the assembly relationship of the rear blade, the rear blade slider, the rear blade fixing plate and the upper grid plate of a compressor cascade experimental device of the present invention;

[0043] Figure 5 It is a three-dimensional diagram of an upper grid plate of a compressor cascade experimental device of the present invention;

[0044] Figure 6 It is a top view and a cross-sectional view of an upper grid plate of a compressor cascade experimental device of the present invention;

[0045] Figure 7 It is a three-dimensional diagram of a lower grid plate of a compressor cascade experimental device of the present invention;

[0046] Figure 8 It is a top view of a lower grid plate of a compressor cascade experimental device of the present invention;

[0047] Fig. 9 It is a stereoscopic diagram of a front blade slider of a compressor cascade experimental device of the present invention;

[0048] Fig.10 It is a top view, a bottom view and a cross-sectional view of a front blade slider of a compressor cascade experimental device of the present invention;

[0049] Fig.11 It is a three-dimensional diagram of a rear blade slider of a compressor cascade experimental device of the present invention;

[0050] Fig.12It is a top view, a bottom view and a cross-sectional view of a rear blade slider of a compressor cascade experimental device of the present invention;

[0051] Fig.13 It is a three-dimensional diagram of a front blade fixing block of a compressor blade cascade experimental device of the present invention;

[0052] Fig.14 It is a front view, a top view and a cross-sectional view of a front blade fixing block of a compressor blade cascade experimental device of the present invention;

[0053] Fig.15 It is a three-dimensional diagram of a rear blade fixing block of a compressor cascade experimental device of the present invention;

[0054] Fig.16 It is a front view, a top view and a cross-sectional view of a rear blade fixing block of a compressor blade cascade experimental device of the present invention;

[0055] Fig.17 It is a three-dimensional diagram of the front blade of a compressor cascade experimental device of the present invention;

[0056] Fig.18 It is a front view of a front blade of a compressor cascade experimental device of the present invention;

[0057] Fig.19 It is a three-dimensional diagram of the rear blade of a compressor cascade experimental device of the present invention;

[0058] Fig. 20 It is a front view of a rear blade of a compressor cascade experimental device of the present invention;

[0059] Fig.21 It is a three-dimensional diagram of a circumferential pad of a compressor blade cascade experimental device of the present invention;

[0060] Fig. 22 It is a stereoscopic diagram of an axial spacer block of a compressor blade cascade experimental device of the present invention;

[0061] Fig.23 It is a three-dimensional diagram of a front blade clearance adjustment pad of a compressor cascade experimental device of the present invention;

[0062] Fig.24 It is a three-dimensional diagram of a rear blade clearance adjustment pad of a compressor cascade experimental device of the present invention;

[0063] Fig.25 It is a three-dimensional diagram of a front blade slider pressure plate of a compressor cascade experimental device of the present invention;

[0064] Fig.26 It is a three-dimensional diagram of a rear blade slider pressure plate of a compressor cascade experimental device of the present invention;

[0065] Explanation of the reference numerals: 1—upper grid plate, 2—lower grid plate, 3—front blade slider, 4—rear blade slider, 5—front blade fixing block, 6—rear blade fixing block, 7—front blade, 8—rear blade, 9—front blade clearance adjustment pad, 10—rear blade clearance adjustment pad, 11—circumferential pad, 12—axial pad, 13—front blade slider pressure plate, 14—rear blade slider pressure plate, 15—distance column, 16—distance column mounting through hole, 17—grid plate front groove, 18—grid plate rear groove, 19—front blade slider slot, 20—rear blade slider slot, 21—front blade fixing block slot, 22—rear blade fixing block slot, 23—pressure plate fixing hole, 24—front blade fixing block fixing hole, 25—rear blade fixing block fixing hole, 26—circumferential pad fixing hole, 27—front blade fixing hole, 28—rear blade fixing hole DETAILED DESCRIPTION

[0066] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0067] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0068] The present embodiment is a compressor blade grid experimental device, comprising a main frame, a circumferential spacing adjustment module, an axial spacing adjustment module, and a blade tip clearance adjustment module, wherein the circumferential spacing adjustment module, the axial spacing adjustment module, and the blade tip clearance adjustment module are integrated on the main frame; specifically, the front blade tip clearance, the rear blade tip clearance, the axial spacing, and the circumferential spacing of the tandem blade grid can be adjusted.

[0069] like Figure 1 and Figure 2As shown, a compressor tandem blade experimental device proposed in this embodiment includes an upper grid plate 1, a lower grid plate 2, a front blade slider 3, a rear blade slider 4, a front blade fixing plate 5, a rear blade fixing plate 6, a front blade 7, a rear blade 8, a front blade gap adjustment gasket 9, a rear blade gap adjustment gasket 10, an axial pad 12, a circumferential pad 11, a front blade slider pressure plate 13, a rear blade slider pressure plate 14, and a distance column 15. The upper grid plate 1 and the lower grid plate 2 of the device are connected to each other through the distance column 15, which can ensure that the upper and lower grid plates are parallel to each other and the distance between the upper and lower grid plates can be adjusted by adjusting the height of the distance column 15. Between the upper grid plate 1 and the lower grid plate 2 is the test section flow channel of the wind tunnel. This device needs to ensure the sealing of the test section flow channel and minimize air leakage. The front blade 7 and the rear blade 8 are blade tops near the lower grid plate, and there is a certain gap between the blade top and the lower grid plate 2, so that the influence of the blade top gap on the flow field can be studied.

[0070] The structure of the upper grid plate 1 is as follows Figure 5 and Figure 6 The upper grid plate is 15 mm thick, with a front grid plate slot 17 and a rear grid plate slot 18 in the middle, wherein the front grid plate slot 17 is located in the upstream direction of the wind tunnel, and the rear grid plate slot 18 is located in the downstream direction of the wind tunnel, and the middle of the two slots penetrates the grid plate and is connected to each other. Figure 3 As shown, the front blade slider 3 is installed in the front slot 17 of the grid plate, and the position can be adjusted in the slot along the circumferential direction. According to the experimental requirements for the circumferential spacing, after adjusting the front blade slider 3 to a suitable circumferential position, the circumferential pad 11 is used to fill the remaining position on the lower side of the upper grid plate 1, so that the circumferential position of the front blade slider 3 can be fixed and air leakage in the wind tunnel test section can be prevented. In fact, the size of the circumferential pad 11 determines the position of the front blade slider 3, and also determines the relative circumferential position of the front and rear blades of the cascade, that is, the circumferential spacing. Figure 4As shown, the rear blade slider 4 is installed in the rear slot 18 of the grid plate, and the position can be adjusted in the axial direction in the slot. According to the experimental requirements for the axial spacing, after the rear blade slider 4 is adjusted to a suitable axial position, the remaining position in the slot is filled with the axial pad 12, so that the axial position of the rear blade slider 4 can be fixed and air leakage in the wind tunnel test section can be prevented. In fact, the size of the axial pad 12 determines the position of the rear blade slider 4, and also determines the relative axial position of the front and rear blades of the cascade, that is, the axial spacing. However, in order to ensure that the front blade slider can slide in the circumferential direction without air leakage in the wind tunnel test section, the axial clearance can only be adjusted within a range greater than 0, that is, this device is not suitable for the case where the axial spacing of the cascade is <0. There are four circumferential pad fixing holes 26 in the upstream direction of the front slot 17 of the grid plate, all of which are threaded through holes, which are used to install set screws to fix the circumferential pad 11. In order to facilitate the installation in the cascade wind tunnel test section, 10 spacing column installation through holes 16 are provided on both sides of the upper cascade plate 1 for installing the spacing columns 15. When installing, holes that will not interfere can be selected according to the actual situation of the wind tunnel test section. The front blade slider pressure plate 13 and the rear blade slider pressure plate 14 are used to fix the front blade slider 3 and the rear blade slider 4 respectively. There are several pressure plate fixing holes 23 on the upper side of the upper cascade plate 1, all of which are threaded blind holes, for fixing the front blade slider pressure plate 13 and the rear blade slider pressure plate 14 to the upper cascade plate 1.

[0071] The structure of the lower grid plate 2 is as follows Figure 7 and Figure 8 As shown, there are 10 spacing column installation holes 16 on it, and each spacing column 15 is installed in the middle of the upper grid plate 1 and the lower grid plate 2 by two screws, one on the left and one on the right, to connect, fix and control the distance between the upper and lower grid plates. Because the lower grid plate is at the blade tip gap, the fluid flow effect during the experiment is complex, so it is necessary to ensure that the wall surface is flat and smooth.

[0072] Front leaf slider 3 Fig. 9 and Fig.10As shown, the thickness is 15mm, and its size can ensure clearance fit with the grid plate front groove 17, and can slide in the groove along the circumferential direction. The front leaf slider 3 is provided with 7 through front leaf slider slots 19 at equal intervals along the circumferential direction. The front leaf slider slot 19 is a step groove, and the height from the 19A plane to the 19B plane in the groove is 10mm, and the shape matches the blade profile of the 7A part of the front blade 7; the height from the 19B plane in the groove to the 19C plane is 5mm, and the shape matches the blade profile of the 7B part of the front blade 7, so that the front blade 7 can pass through the front leaf slider slot 19 through clearance fit. The recommended situation is: when the 7C plane of the front blade 7 is adjusted to be coplanar with the 19A plane of the front blade slider slot 19, the front blade tip clearance is 0, that is, the tip of the front blade 7 touches the lower grid plate 2. In this case, when the 7C plane of the front blade 7 is adjusted to be coplanar with the 19B plane of the front blade slider slot 19, the front blade tip clearance is 10mm, so that the tip clearance can be adjusted from 0mm to 10mm. There are 4 front blade fixing plate fixing holes 24 on one side of the front blade slider 3, all of which are threaded blind holes, used to connect the front blade slider 3 with the front blade fixing plate 5.

[0073] Rear leaf slider 3 Fig.11 and Fig.12 As shown, the thickness is 15mm, and its size can ensure clearance fit with the grid plate rear groove 18, and can slide axially in the groove. The rear leaf slider 4 is provided with 7 through rear leaf slider slots 20 at equal intervals along the circumferential direction. The rear leaf slider slots 20 are step grooves, and the height from the 20A plane to the 20B plane in the groove is 10mm, and the shape matches the blade profile of the 8A part of the rear blade 8; the height from the 20B plane in the groove to the 20C plane is 5mm, and the shape matches the blade profile of the 8B part of the rear blade 8, so that the rear blade 8 can pass through the rear leaf slider slots 20 through clearance fit. The recommended situation is: when the 8C plane of the rear blade 8 is adjusted to be coplanar with the 20A plane of the rear blade slider slot 20, the rear blade tip clearance is 0, that is, the tip of the rear blade 8 touches the lower grid plate 2. In this case, when the 8C plane of the rear blade 8 is adjusted to be coplanar with the 20B plane of the rear blade slider slot 20, the rear blade tip clearance is 10mm, so that the tip clearance can be adjusted from 0mm to 10mm. There are 4 rear blade fixing plate fixing holes 25 on one side of the rear blade slider 4, all of which are threaded blind holes, used to connect the rear blade slider 4 with the rear blade fixing plate 6.

[0074] Front leaf fixed block 5 Fig.13 and Fig.14As shown. The thickness of the front leaf fixing block 5 is 12 mm, and 7 front leaf fixing block slots 21 are opened on it at equal intervals along the circumferential direction. The shape of the slot matches the blade shape of the 7A part of the front blade 7, so that the front blade 7 can pass through the slot to form a gap fit with it. Front leaf fixing holes 26 are opened on one side of the front leaf fixing block 5, all of which are threaded holes, used to install pointed set screws to fix the front blade 7. There are 2 front leaf fixing holes 26 in each front leaf fixing block slot 21. Using 2 set screws to fix 1 front blade can ensure the stability of the installation. The front leaf slider 3 and the front leaf fixing plate 5 are connected in the middle by the front leaf gap adjustment pad 9. Because the front leaf slider 3 is fixedly connected to the upper grid plate 1, and the front leaf fixing plate 5 is fixedly connected to the front blade 7, the spanwise position of the front blade 7 can be adjusted by adjusting the thickness of the front leaf gap adjustment pad 9, that is, the blade tip gap of the front leaf can be changed.

[0075] Posterior leaflet fixation block 6 Fig.14 and Fig.15 As shown. The thickness of the rear leaf fixing block 6 is 12 mm, and there are 7 rear leaf fixing block slots 22 that are evenly spaced and circumferentially connected thereon. The shape of the slots matches the blade shape of the 8A part of the rear blade 8, so that the rear blade 8 can pass through the slots to form a clearance fit with it. One side of the rear leaf fixing block 6 is provided with rear leaf fixing holes 27, which are all threaded holes for installing pointed set screws to fix the rear blade 8. There are two rear leaf fixing holes 27 in each rear leaf fixing block slot 22, and using two set screws to fix one rear blade can ensure the stability of the installation. The middle of the rear leaf slider 4 and the rear leaf fixing plate 6 is connected by the rear leaf gap adjustment pad 10. Because the rear leaf slider 4 is fixedly connected to the upper grid plate 1, and the rear leaf fixing plate 6 is fixedly connected to the rear blade 8, the spanwise position of the rear blade 8 can be adjusted by adjusting the thickness of the rear leaf gap adjustment pad 10, that is, the blade top gap of the rear leaf can be changed.

[0076] Front blade 7 Fig.17 and Fig.18 As shown. The front blade 7 is a step structure, and the 7C surface is the junction of the steps. The blade profile of the lower 7A part is a complete blade profile, which is the part that needs to be placed in the wind tunnel test section for blowing. Its blade profile matches the shape of the 19A surface of the front blade slider slot 19; the blade profile of the upper 7B part is a part of the complete blade profile, and its blade profile matches the shape of the 19B surface of the front blade slider slot 19. The front blade 7 and the front blade fixing block 5 are fixed together by installing a pointed set screw in the front blade fixing hole 27.

[0077] Rear blade 8 Fig.19 and Fig. 20As shown. The rear blade 8 is a step structure, and the 8C surface is the junction of the steps. The blade profile of the lower side 8A part is a complete blade profile, which is the part that needs to be placed in the wind tunnel test section for blowing. Its blade profile matches the shape of the 20A surface of the rear blade slider slot 20; the blade profile of the upper side 8B part is a part of the complete blade profile, and its blade profile matches the shape of the 20B surface of the rear blade slider slot 20. The rear blade 8 and the rear blade fixing block 6 are fixed together by installing a pointed set screw in the rear blade fixing hole 28.

[0078] Circumferential pad 11 such as Fig.21 As shown, it is a rectangular parallelepiped, which is used to fill the remaining space of the grid plate front slot 17 on the wind tunnel test side after the circumferential position of the front blade slider 3 is determined, plays the role of fixing and reducing air leakage, and is fixed by the set screws installed in the circumferential pad fixing hole 26 on the upstream side of the grid plate front slot 17. Before the experiment, it is necessary to prepare the circumferential pad 11 of appropriate thickness according to the circumferential spacing of the tandem blades to be set.

[0079] Axial spacer 12 Fig. 22 As shown, after the axial position of the rear blade slider 4 is determined, it is used to fill the remaining space of the grid plate rear slot 18, which plays a role in fixing and reducing air leakage, and its position is fixed by the rear blade slider pressure plate 14. Before the experiment, it is necessary to prepare an axial spacer 12 of appropriate thickness according to the axial spacing of the tandem blade cascade to be set.

[0080] Front leaf clearance adjustment pad 9 Fig.23 As shown, it is a cuboid, and its function is to adjust the distance between the front blade slider 3 and the front blade fixing block 5 by its thickness, so as to control the spanwise position of the front blade 7. Before the experiment, it is necessary to prepare a front blade clearance adjustment pad 9 of appropriate thickness according to the tip clearance of the front blade of the tandem cascade to be set.

[0081] The rear leaf clearance adjustment pad 10 is as follows Fig.24 As shown, it is a rectangular parallelepiped, and its function is to adjust the distance between the rear blade slider 4 and the rear blade fixing block 6 by its thickness, so as to control the spanwise position of the rear blade 8. Before the experiment, it is necessary to prepare a rear blade clearance adjustment pad 10 of appropriate thickness according to the blade tip clearance of the rear blade of the tandem cascade to be set.

[0082] The front leaf slider pressure plate 13 and the rear leaf slider pressure plate 14 are respectively as shown in Fig.25 and Fig.26 As shown, their function is to limit the front blade slider 3, the rear blade slider 4 and the axial pad 12 in the span direction to fix their positions. The pressure plate is fixed by screws installed in the pressure plate fixing holes 23 on the upper grid plate 1. There are three rows of fixing holes on the front blade slider pressure plate 13. When installing, select a suitable row of fixing holes according to the actual circumferential position of the front blade slider 3.

[0083] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A compressor blade test device, characterized in that: It includes a main frame, a circumferential spacing adjustment module, an axial spacing adjustment module, and a blade tip clearance adjustment module, wherein the circumferential spacing adjustment module, the axial spacing adjustment module, and the blade tip clearance adjustment module are integrated on the main frame; The front blade cascade and the rear blade cascade are installed in series through the main frame, and a gap is left between the blade top and the bottom surface of the main frame; the space between the blade cascade installation surface and the bottom surface of the main frame is used as the test section flow channel of the wind tunnel; the main frame includes an upper grid plate, a lower grid plate and a distance column, and the upper grid plate and the lower grid plate are connected in parallel and relatively fixedly through the distance column; the blades of the front blade cascade and the rear blade cascade are both installed on the upper grid plate, and a gap is left between the blade top and the lower grid plate, which is used to study the influence of the blade top gap on the flow field; the distance column is arranged between the upper grid plate and the lower grid plate along the circumferential direction, and the spacing between the upper grid plate and the lower grid plate is adjusted by adjusting the axial height of the distance column; The circumferential spacing adjustment module is used to adjust the circumferential spacing of the tandem blade grid; the circumferential spacing adjustment module includes a front blade slider, a rear blade slider and a circumferential pad; a plurality of front blade slider slots are opened along the upper edge of the front blade slider in the span direction for installing the front blades; a plurality of rear blade slider slots are opened along the upper edge of the rear blade slider in the span direction for installing the rear blades; a cascade plate front slot and a cascade plate rear slot are opened on the tandem blade grid installation surface of the main frame, which are used to install the front blade slider and the rear blade slider respectively, and the front blade slider and the rear blade slider are clearance-matched with the front and rear slots of the cascade plate; the circumferential position of the front blade slider or the rear blade slider in the front and rear slots of the cascade plate is determined by the circumferential pad; The axial spacing adjustment module is used to adjust the axial spacing of the tandem blade cascade; the axial spacing adjustment module includes a front blade slider, a rear blade slider and an axial pad; a plurality of front blade slider slots are provided along the upper edge of the front blade slider in the span direction for installing the front blades; a plurality of rear blade slider slots are provided along the upper edge of the rear blade slider in the span direction for installing the rear blades; a cascade front slot and a cascade rear slot are provided on the tandem blade cascade mounting surface of the main frame, which are used to install the front blade slider and the rear blade slider respectively, and the front blade slider and the rear blade slider are clearance-matched with the front slot and the rear slot of the cascade; the axial position of the front blade slider or the rear blade slider in the front slot or the rear slot of the cascade is determined by the axial pad; The tip clearance adjustment module is used to adjust the tip clearance of the tandem blade cascade; the tip clearance adjustment module comprises a front blade fixing block, a rear blade fixing block, a front blade clearance adjustment pad and a rear blade clearance adjustment pad; the front blade fixing block and the rear blade fixing block are respectively installed directly above the tandem blade cascade installation surface of the main frame through the front blade clearance adjustment pad and the rear blade clearance adjustment pad; the front blade fixing block is provided with a plurality of front blade fixing block slots along the span direction, corresponding to the blades in the front blade cascade one by one, for fixing and installing the front blades; the rear blade fixing block is provided with a plurality of rear blade fixing block slots along the span direction, corresponding to the blades in the rear blade cascade one by one, for fixing and installing the rear blades; by adjusting the height of the front blade clearance adjustment pad and the rear blade clearance adjustment pad, the distance between the front blade fixing block, the rear blade fixing block and the tandem blade cascade installation surface of the main frame is adjusted, and the distance between the front blade tip, the rear blade tip and the bottom surface of the main frame is adjusted synchronously, that is, the tip clearance is adjusted.

2. The compressor blade test device according to claim 1, characterized in that: The front and rear grooves of the grid plate are stepped groove structures; the front blade sliders and rear blade sliders are flat plate structures with steps at both ends, and are installed in coordination with the stepped groove structures of the front and rear grooves of the grid plate; After the position of the front blade slider is determined, the circumferential pad is installed in the circumferential gap between the front blade slider and the front groove of the grid plate to complete the circumferential positioning of the front blade slider; or the circumferential pad is installed in the circumferential gap between the rear blade slider and the rear groove of the grid plate to complete the circumferential positioning of the rear blade slider; and prevent air leakage in the wind tunnel test section.

3. The compressor blade test device according to claim 1, characterized in that: The front and rear grooves of the grid plate are stepped groove structures; the front blade sliders and rear blade sliders are flat plate structures with steps at both ends, and are installed in coordination with the stepped groove structures of the front and rear grooves of the grid plate; After the position of the front blade slider is determined, the axial pad is installed in the axial gap between the front blade slider and the front groove of the grid plate to complete the axial positioning of the front blade slider; or the axial pad is installed in the axial gap between the rear blade slider and the rear groove of the grid plate to complete the axial positioning of the rear blade slider; and prevent air leakage in the wind tunnel test section.

4. The compressor blade test device according to claim 1, characterized in that: A front slot and a rear slot are provided in the middle of the series blade installation surface of the main frame, wherein the front slot is in the upstream direction of the wind tunnel, and the rear slot is in the downstream direction of the wind tunnel. The middle parts of the front and rear slots pass through the grid and are connected to each other.

5. A method for testing a compressor cascade using the compressor cascade testing device according to any one of claims 1 to 4, characterized in that: The front blade cascade and the rear blade cascade are installed on the main frame in series, and the circumferential, axial and blade tip clearances of the front blade cascade and the rear blade cascade are adjusted respectively by a circumferential spacing adjustment module, an axial spacing adjustment module and a blade tip clearance adjustment module; then the compressor blade cascade experimental device is connected to the blade cascade wind tunnel experimental equipment to ensure the sealing of the test section flow channel; the experiment is started and the test results of the tandem blade cascades with different geometric parameters are obtained.

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