An excitation device for a blade with high rigidity

Abstract

The present invention provides an excitation device for a high-rigidity blade, comprising: a sealed hatch cover is arranged on the top of a test cabin, the test cabin and the sealed hatch cover constitute a first accommodating chamber; a driving mandrel is arranged in the first accommodating chamber, one end of the driving mandrel passes through the sealed hatch cover and extends into the center of the first accommodating chamber, and the other end of the driving mandrel is connected to a rotating driving device; a cover plate and an inclusion component are both arranged in the first accommodating chamber, the cover plate is arranged on the top of the inclusion component, the inclusion component and the cover plate constitute a cylindrical second accommodating chamber, a transfer component is arranged in the second accommodating chamber, and the transfer component is fixed on the driving mandrel; a rotating blade and an exciter are both arranged in the second accommodating chamber, the rotating blade is fixed on the transfer component, and the exciter is fixed on the inclusion component or the cover plate. The aircraft engine casing is simulated by the inclusion component, and the excitation of the rotating blade under a certain gas pressure is realized by the exciter, so as to achieve the purpose of effective excitation of the high-rigidity blade.

Description

Technical Field

[0001] This specification relates to the technical field of blade excitation, and particularly relates to an excitation device for large-rigidity blades. Background Art

[0002] The aerodynamic forces acting on the rotor blades of an aeroengine in actual working conditions are mainly caused by components such as stator blades, struts or webs. After the air flow passes through these structures, periodic forces and torques are generated on the blades. When the frequency of these force changes is the same as or in a certain multiple relationship with the natural frequency of the blades, the blades will resonate. Therefore, conducting the damping screening test and high-low cycle composite fatigue test on the rotating blades of an aeroengine are important means to study the blade vibration and fatigue life. Compared with the vibration table test, it can accurately simulate the centrifugal load of the blades and is closer to the actual working conditions of the aeroengine. However, under rotating conditions, sufficient excitation energy needs to be given to the blades to achieve an effective resonance response of the blades.

[0003] Currently, for the excitation test of large-rigidity blades, there are situations such as insufficient excitation energy and overly concentrated lubricating oil excitation energy resulting in blade damage. This makes tests such as the damping characteristic test of large-rigidity blades can only be arranged in the whole-machine test, which has problems such as a long test cycle, high test costs, and high test risks, bringing difficulties to test verification. Summary of the Invention

[0004] In view of this, the embodiments of this specification provide an excitation device for large-rigidity blades to achieve the purpose of effectively exciting large-rigidity blades.

[0005] The embodiments of this specification provide the following technical solutions:

[0006] An excitation device for large-rigidity blades, comprising:

[0007] A test cabin body and a sealed cabin cover, the sealed cabin cover is arranged on the top of the test cabin body, and the test cabin body and the sealed cabin cover form a first accommodation chamber;

[0008] A driving core shaft, the driving core shaft is arranged in the first accommodation chamber, one end of the driving core shaft passes through the sealed cabin cover and extends to the central position of the first accommodation chamber, and the other end of the driving core shaft is connected to a rotary driving device;

[0009] A cover plate, a containment assembly and an adapter assembly, both the cover plate and the containment assembly are arranged in the first accommodation chamber, the cover plate is arranged on the top of the containment assembly, the containment assembly and the cover plate form a cylindrical second accommodation chamber, and the adapter assembly is arranged in the second accommodation chamber and is fixed on the driving core shaft;

[0010] A rotating blade and an exciter, both the rotating blade and the exciter are arranged in the second accommodation chamber, the rotating blade is fixed on the adapter assembly, and the exciter is fixed on the containment assembly or the cover plate.

[0011] Further, the actuator is in a sheet structure, and an actuator arc surface is provided on one side of the actuator facing the rotating blade. The arc length of the actuator arc surface of the test piece is greater than or equal to 2 cm, and the radian of the actuator arc surface is greater than or equal to 30°.

[0012] Further, the number of actuators provided is the same as the required excitation order, and multiple actuators 4 are evenly distributed along the circumferential direction of the second accommodation chamber.

[0013] Further, fixing bolt holes are provided on the actuator, and the actuator is fixed to the containment assembly or the cover plate through the fixing bolt holes.

[0014] Further, the adapter assembly includes an adapter section and a test piece. One end of the adapter section is connected to the drive mandrel, the other end of the adapter section is connected to multiple test pieces, the test pieces are coaxially arranged with the containment assembly, and the ends of the test pieces are respectively connected to the trailing ends of the rotating blades.

[0015] Further, the axial distance between the actuator and the test piece is 5 mm to 20 mm.

[0016] Further, the inner diameter of the containment assembly is 20 mm to 30 mm larger than the diameter of the test piece.

[0017] Further, the excitation device for the large stiffness blade further includes a heating component, which includes a heating wire and a furnace plate. The furnace plate is arranged between the first accommodation chamber and the second accommodation chamber, and multiple groups of heating wires are arranged at intervals on the side of the furnace plate facing the second accommodation chamber.

[0018] Further, the heating component further includes a first long screw, and the heating component is fixed to the bottom surface of the sealing hatch cover through the first long screw.

[0019] Further, the excitation device for the large stiffness blade further includes a second long screw, and the containment assembly is fixed to the bottom surface of the sealing hatch cover through the second long screw.

[0020] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification at least include:

[0021] By simulating the gas flow of the aeroengine casing through the containment assembly and realizing the excitation of the rotating blade under a certain gas pressure through the actuator, it is ensured that the blade damping characteristics and the high and low cycle composite fatigue test of the large stiffness blade at a specific excitation frequency can be smoothly implemented, avoiding problems such as insufficient excitation response of the large stiffness blade and blade damage. Description of the Drawings

[0022] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0023] Figure 1 Schematic diagram of the overall structure of the large-rigidity blade excitation device according to an embodiment of the present invention;

[0024] Figure 2 Front view of the exciter of the large-rigidity blade excitation device according to an embodiment of the present invention;

[0025] Figure 3 Side view of the exciter of the large-rigidity blade excitation device according to an embodiment of the present invention.

[0026] Explanation of reference numerals: 1. Sealing hatch cover; 2. Driving mandrel; 3. Test cabin body; 4. Exciter; 401. Arc surface of the exciter; 402. Fixed bolt hole; 5. Rotating blade; 6. Adapter section; 7. Heating assembly; 701. Heating wire; 702. Furnace plate; 703. First long screw; 8. Test piece; 9. Air flow inlet; 10. Containment assembly; 11. Cover plate; 12. Second long screw. Detailed implementation manners

[0027] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0028] The following illustrates the implementation manners of the present application through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0029] It should be noted that the following description relates to various aspects of embodiments within the scope of the appended claims. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is for illustrative purposes only. Based on this application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement a device and / or practice a method. Additionally, this device can be implemented and this method can be practiced using other structures and / or functionality in addition to one or more of the aspects set forth herein.

[0030] It should also be noted that the diagrams provided in the following embodiments only illustrate the basic concept of this application schematically. Only the components related to this application are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in its actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0031] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the aspects described can be practiced without these specific details.

[0032] The following describes the technical solutions provided by each embodiment of this application in conjunction with the accompanying drawings.

[0033] As Figure 1 shown, it includes a test chamber body 3, a sealing hatch cover 1, a driving mandrel 2, an accommodating assembly 10, a cover plate 11, a rotating blade 5, an exciter 4, a second long screw 12, a heating assembly 7, and an adapter assembly.

[0034] The sealing hatch cover 1 is arranged on the top of the test chamber body 3, and the test chamber body 3 and the sealing hatch cover 1 form a first accommodating chamber. The driving mandrel 2 is arranged in the first accommodating chamber. One end of the driving mandrel 2 passes through the sealing hatch cover 1 and extends to the central position of the first accommodating chamber. The other end of the driving mandrel 2 is connected to a rotating driving device. The rotating driving device includes a gearbox driven by a motor or a gas turbine, etc. The driving mandrel 2 is driven to rotate by a gearbox driven by a motor or a gas turbine. The lower end of the driving mandrel 2 passes through the sealing hatch cover 1 and extends into the test chamber body 3.

[0035] The cover plate 11 and the containing assembly 10 are both arranged in the first containing chamber, the cover plate 11 is arranged on the top of the containing assembly 10, the containing assembly 10 and the cover plate 11 constitute a cylindrical second containing chamber, the adapter assembly is arranged in the second containing chamber, and the adapter assembly is fixed on the driving core shaft 2. The adapter assembly includes a transfer section 6 and a test piece 8. One end of the transfer section 6 is connected to the driving core shaft 2, and the other end of the transfer section 6 is connected to a plurality of test pieces 8. The test pieces 8 are coaxially arranged with the containing assembly 10, and the ends of the test pieces 8 are connected one by one with the tail ends of the rotating blades 5. When the driving core shaft 2 rotates, the rotating blades 5 are driven to rotate along the driving core shaft 2 as the axis.

[0036] The containment component 10 is installed on the sealed hatch 1 of the test chamber 3 through the second long screw 12. By adjusting the second long screw 12, the axial position of the containment component 10 relative to the test piece 8 can be adjusted. The main function of the containment component 10 is to simulate the real aircraft engine casing. At the same time, it is necessary to consider the reserved position for installing the blade tip timing sensor, because the inner diameter of the containment component 10 is 20mm to 30mm larger than the diameter of the test piece 8.

[0037] The rotating blade 5 and the exciter 4 are both arranged in the second accommodating chamber. The rotating blade 5 is fixed on the adapter component, and the exciter 4 is fixed on the containing component 10 or the cover plate 11.

[0038] During implementation, the air flow rate entering through the air inlet 9 is controlled to keep a certain pressure in the test chamber 3. When the rotating blades 5 fixed on the test piece 8 rotate, the air flow generates an exciting force through a specific number of exciters 4 arranged near the rotating blades 5. When the exciting frequency is consistent with or in a multiple relationship with the natural frequency of the blades, the rotating blades 5 will resonate.

[0039] The heating assembly 7 includes a heating wire 701, a furnace plate 702 and a first long screw 703. The furnace plate 702 is arranged between the first accommodating chamber and the second accommodating chamber. A plurality of groups of heating wires 701 are arranged around and spaced apart on the side of the furnace plate 702 facing the second accommodating chamber. The heating assembly 7 is fixed to the bottom surface of the sealed hatch 1 through the first long screw 703. The axial position of the heating assembly 7 relative to the rotating blade 5 can be adjusted by adjusting the length of the first long screw 703. The heating assembly 7 is used to provide heat to the excitation device. The heating assembly 7 heats the rotating blade 5 to a required specific temperature, and the blade material properties at a specific temperature can be evaluated.

[0040] like Figure 2 , Figure 3As shown in the figure, the actuator 4 of the embodiment of the present invention is a block structure. An actuator arc surface 401 is provided on one side of the actuator 4, and fixing bolt holes 402 are provided on the actuator 4. During the layout, the actuator arc surface 401 of the actuator 4 should face the rotation direction of the test piece 8, so that when the blade rotates, the airflow can act on the rotating blade 5 after being reflected by the arc surface of the actuator, which can realize the effective and controllable excitation of the high-rigidity blade by the actuator 4 without damaging the blade, so as to ensure the smooth completion of the test.

[0041] The arc length and radian of the actuator arc surface 401 are designed according to specific test requirements. During the design, first, according to the geometric dimensions of the actual rotating blade 5, a range of arc length and radian of the actuator arc surface 401 is set, and a series of arc length and radian values are generated according to the preset values. Specifically, according to the structures of the specific test piece 8 and the test cabin 3, CFD modeling and iteration are carried out, and multiple groups of results are calculated. The optimal solution that meets the actual requirements (the excitation force is greater than 20 MPa) is selected, that is: the arc length of the actuator arc surface 401 is not less than 2 cm, and the radian is not less than 30°. As the actuator 4 used in the final test, the axial distance between the actuator 4 and the test piece 8 should be kept at 5 mm - 20 mm.

[0042] The number of actuators 4 provided is consistent with the excitation order required by the specific test, and multiple actuators 4 are evenly distributed along the circumferential direction of the second accommodation chamber (i.e., the rotation circumference of the rotating blade 5). Usually, the number of actuators 4 provided is 4 - 56, and excitation from the 4th order to the 56th order can be realized. Since the rotating blade 5 has multiple parts such as a suction surface, a pressure surface, and a blade root, and each part has the need for excitation testing, the axial and radial positions of the actuator 4 relative to the rotating blade 5 can be adjusted. The radial position of the actuator 4 relative to the rotating blade 5 can be adjusted by the position where the fixing bolt hole 402 is fixed to the cover plate 11 or the containment assembly 10, and the axial position of the containment assembly 10 relative to the rotating blade 5 can be adjusted by adjusting the length of the second long screw 12, so as to change the axial position relationship between the actuator 4 and the rotating blade 5 on the test piece 8 to meet the excitation requirements of specific different tests.

[0043] Specifically, when an excitation test needs to be carried out on the upper part of the rotating blade 5, the actuator 4 is fixed to the bottom of the cover plate 11 along the circumferential direction through the fixing bolt hole 402; when an excitation test needs to be carried out on the lower part of the rotating blade 5 on the test piece 8, the actuator 4 is fixed to the inner wall of the lower end of the containment assembly 10 along the circumferential direction through the fixing bolt hole 402; when an excitation test needs to be carried out on the blade root of the rotating blade 5 on the test piece 8, the actuator 4 is fixed to the position of the containment assembly 10 close to the axis (i.e., close to the blade root) along the horizontal direction through the fixing bolt hole 402.

[0044] During implementation, first, the air pressure in the test chamber 3 is pumped to a near-vacuum state by a pumping device. According to the pressure value required by the experiment, dynamic adjustment is carried out, that is, the chamber pressure monitoring sensor feeds back the chamber pressure in real time. When the chamber pressure is too low, external air enters the chamber by opening the chamber pressure regulating solenoid valve; when the chamber pressure is too high, the vacuum pump continues to pump vacuum. By the above method, the air pressure in the test chamber 3 is dynamically adjusted so that the pressure is maintained within the range required by the experiment. According to the test requirements, a plurality of exciters are installed circumferentially in the rotational direction of the test piece 8, and strain gauges are installed at the root position of the rotating blade 5, realizing effective excitation of the turbine blade, successfully realizing effective excitation of the 3rd order mode of the large-rigidity blade, and the result is consistent with the full-machine test, achieving the expected excitation effect. The above test device and method are used to complete the test verification for a certain high-pressure and low-pressure turbine blade under the rotating state.

[0045] In some embodiments, when an excitation test needs to be carried out on the upper side (suction surface or pressure surface) of the rotating blade 5 on the test piece 8, the exciter 4 is fixed to the bottom of the cover plate 11 near the blade through bolts passing through the fixing bolt holes 402, and a plurality of exciters 4 are evenly distributed along the circumferential direction of rotation.

[0046] In some embodiments, when an excitation test needs to be carried out on the lower side (suction surface or pressure surface) of the rotating blade 5 on the test piece 8, the exciter 4 is fixed to the inner wall of the lower end of the containment assembly 10 near the blade through bolts passing through the fixing bolt holes 402, and a plurality of exciters 4 are evenly distributed along the circumferential direction of rotation.

[0047] In some embodiments, when an excitation test needs to be carried out on the blade root of the rotating blade 5 on the test piece 8, the exciter 4 is fixed to the position near the rotation axis at the lower end of the containment assembly 10 through bolts passing through the fixing bolt holes 402, and a plurality of exciters 4 are evenly distributed along the circumferential direction of rotation.

[0048] In some embodiments, 9 exciters are respectively installed circumferentially at the trailing edge position (above the blade) of the rotating blade, strain gauges are installed at the root position of the blade, the rotating blade is heated to 400 °C by the heating assembly, the arc length of the arc-shaped surface of the exciter is 7 cm and the radian is 35°, and the axial distance between the exciter and the test piece should be kept at 6 mm, respectively realizing effective excitation of 9 orders of the turbine blade, successfully realizing effective excitation of the first 3 orders of modes (first-order bending, second-order torsion, and third-order one-bending-one-torsion) of the large-rigidity blade, and the result is consistent with the full-machine test, achieving the expected excitation effect.

[0049] In some embodiments, 10 exciters are respectively installed circumferentially at the trailing edge position (above the blade) of the rotating blade, strain gauges are installed at the root position of the blade, the rotating blade is heated to 400 °C by a heating component, the arc length of the arc-shaped surface of the exciter is 7 cm, the radian is 35°, and the axial distance between the exciter and the test piece should be kept at 6 mm. Effective excitation of 10 orders of the turbine blade is respectively achieved, and effective excitation of the first three modes (first-order bending, second-order torsion, and third-order one-bending-one-torsion) of the blade with high stiffness is successfully achieved. The results are consistent with the full-machine test, and the expected excitation effect is achieved.

[0050] The present invention realizes the excitation of the rotating blade under a certain gas pressure through the exciter device, ensuring the smooth implementation of the blade damping characteristics and the high-low cycle composite fatigue test at a specific excitation frequency. The excitation device of the embodiment of the present invention is particularly suitable for blades with high stiffness. By simulating the real aero-engine casing through the second accommodating cavity and using excitation device structures such as multiple exciters including arc-shaped surfaces, problems such as insufficient excitation response of the blade with high stiffness and blade damage are avoided. It can achieve effective excitation on the basis of no damage to the blade, has great practical application value, and can provide useful technical references for the damping characteristics test and high-low cycle composite fatigue test of the blade with high stiffness.

[0051] Each embodiment in this specification is described in a progressive manner. The same or similar parts between each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the method embodiments described later, since they correspond to the system, the description is relatively simple, and the relevant parts can refer to the partial description of the system embodiments.

[0052] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An excitation device for a blade with high rigidity, characterized in that, Comprising: A test cabin body (3) and a sealing hatch cover (1), the sealing hatch cover (1) is arranged on the top of the test cabin body (3), and the test cabin body (3) and the sealing hatch cover (1) form a first accommodation chamber; A driving mandrel (2), the driving mandrel (2) is arranged in the first accommodation chamber, one end of the driving mandrel (2) passes through the sealing hatch cover (1) and extends into the central position of the first accommodation chamber, and the other end of the driving mandrel (2) is connected with a rotary driving device; A cover plate (11), a containment assembly (10) and an adapter assembly, the cover plate (11) and the containment assembly (10) are both arranged in the first accommodation chamber, the cover plate (11) is arranged on the top of the containment assembly (10), the containment assembly (10) and the cover plate (11) form a cylindrical second accommodation chamber, the adapter assembly is arranged in the second accommodation chamber, and the adapter assembly is fixed on the driving mandrel (2); Rotating blades (5) and exciters (4), the rotating blades (5) and the exciters (4) are both arranged in the second accommodation chamber, the rotating blades (5) are fixed on the adapter assembly, and the exciters (4) are fixed on the containment assembly (10) or the cover plate (11); The exciter (4) is in a sheet structure, and an exciter arc surface (401) is arranged on the side of the exciter (4) facing the rotating blades (5), dynamically adjusting the air pressure in the test cabin body (3) so that the pressure is maintained within the range required by the test, and when the rotating blades (5) rotate, the air flow can act on the rotating blades (5) after being reflected by the arc surface of the exciter (4).

2. The excitation device for a large-stiffness blade according to claim 1, characterized in that, The arc length of the exciter arc surface (401) is greater than or equal to 2 cm, and the radian of the exciter arc surface (401) is greater than or equal to 30°.

3. The excitation device for the large-rigidity blade according to claim 1, characterized in that The number of exciters (4) arranged is the same as the required excitation order, and a plurality of exciters (4) are evenly distributed along the circumferential direction of the second accommodation chamber.

4. The excitation device for a large-stiffness blade according to claim 2, characterized in that, Fixing bolt holes (402) are arranged on the exciter (4), and the exciter (4) is fixed on the containment assembly (10) or the cover plate (11) through the fixing bolt holes (402).

5. The excitation device for a blade with high rigidity according to claim 1, characterized in that, The adapter assembly includes an adapter section (6) and test pieces (8), one end of the adapter section (6) is connected with the driving mandrel (2), the other end of the adapter section (6) is connected with a plurality of test pieces (8), the test pieces (8) are coaxially arranged with the containment assembly (10), and the ends of the test pieces (8) are connected to the blade tails of the rotating blades (5) one by one.

6. The excitation device for a blade with high rigidity according to claim 5, characterized in that, The axial distance between the exciter (4) and the test piece (8) is 5 mm to 20 mm.

7. The excitation device for a blade with high rigidity according to claim 5, characterized in that, The inner diameter of the containment assembly (10) is 20 mm to 30 mm larger than the diameter of the test piece (8).

8. The excitation device for a large-rigidity blade according to claim 1, characterized in that, The excitation device for large stiffness blades further includes a heating component (7), the heating component (7) includes heating wires (701) and a furnace plate (702), the furnace plate (702) is arranged between the first accommodation chamber and the second accommodation chamber, and multiple groups of heating wires (701) are arranged at intervals on the side of the furnace plate (702) facing the second accommodation chamber.

9. The excitation device for a high-rigidity blade according to claim 8, characterized in that, The heating component (7) further includes a first long screw (703), and the heating component (7) is fixed to the bottom surface of the sealing hatch cover (1) through the first long screw (703).

10. The excitation device for a large-stiffness blade according to claim 1, characterized in that, The excitation device of the large-rigidity blade further includes a second long screw (12), and the containment assembly (10) is fixed to the bottom surface of the sealed hatch cover (1) through the second long screw (12).

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