Evaluation Device and Evaluation Method for Rotor Blade Vibration Test System by Tip Timing Method

Abstract

The invention discloses an evaluation device for a rotor blade vibration test system by tip-timing method, which includes a driving motor, an analog impeller connected to the output shaft of the driving motor, a strong magnetic excitation component arranged around the analog impeller for generating a magnetic field excitation to cause resonance when the analog blades on the analog impeller rotate, a strain component arranged on the analog blades of the analog impeller for measuring and obtaining the strain signal of the blade body of the analog blade, a telemetry system electrically connected to the strain component for transmitting the strain signal, a first data processor electrically connected to the telemetry system for processing the strain signal to obtain the vibration frequency of the analog blade and the vibration stress of the blade body of the analog blade, an analog casing arranged peripherally around the analog impeller in the circumferential direction, a timing sensor arranged on the analog casing for sensing the time series of the arrival moment of the analog blade tip, a second data processor electrically connected to the timing sensor, and an analog analyzer.

Description

Technical Field

[0001] The present invention relates to the field of engine evaluation technology, and more particularly to a device for evaluating a rotor blade vibration test system using a blade tip timing method. Furthermore, the present invention also relates to a method for evaluating a rotor blade vibration test system using the device for evaluating a rotor blade vibration test system using a blade tip timing method. Background Art

[0002] Aircraft engine blades are one of the most critical components of aircraft engines. They operate in harsh environments, require complex design and testing techniques, and require high processing and inspection technology. They are knowledge-intensive and technology-intensive products. Aircraft engine blades are susceptible to vibrations during operation due to gas and mechanical excitation forces. Vibration in rotating machinery blades is a key factor in mechanical failure, making real-time monitoring of rotating blade vibration essential. Foreign military engine general specifications and civil aviation airworthiness regulations place a high priority on blade dynamic stress measurement. They require that aircraft engine blades avoid resonance caused by known excitation sources during the design phase and undergo verification testing to ensure that the blade's vibration characteristics are within acceptable limits compared to the expected design characteristics. These verification tests include measuring the blade's vibration stress and frequency during operation in components, core engines, or complete units.

[0003] In the field of rotor blade vibration testing technology, a number of research institutions at home and abroad have carried out a great deal of research work and achieved certain results. At present, the main methods for rotor blade vibration testing are: "contact strain gauge method" and "non-contact tip-timing method". Among them, the "contact strain gauge method" is to paste a certain number of strain gauges on the blade, and transmit the strain signal to the external strain testing equipment through a slip ring for testing. This technology has high testing accuracy, but the patch lead process is complex, the preparation period is long, the technical difficulty is large, and due to the harsh working environment, the strain measurement points are also very easy to fail. Moreover, it can only test the vibration of the blades with strain gauges pasted, and the number of blades that can be tested at one time is limited. In addition, the structural modification for testing will have more or less impact on the mechanical performance and aerodynamic performance of the engine. This technology cannot be used as a means for long-term monitoring of blade vibration. In the implementation process of the "non-contact tip-timing method", the sensor is installed on the relatively stationary casing rather than on the rotating blade, that is, the measured blade and the measurement sensor do not contact each other, and there is no need for major modification of the engine structure. It has the characteristics of a relatively short preparation period, a long working time of the sensor, the ability to simultaneously test the vibration of all blades of the same stage, and a small impact on the engine performance. It can be used as a means for long-term monitoring of blade vibration. The tip-timing method is the research focus of the current non-contact rotating blade vibration testing technology, and it is developed based on the discontinuous phase method and the pulse modulation method. The basic principle of the tip-timing method is to install a tip-timing sensor on the casing, and use the sensor to sense the arrival time of the blade tip. If the blade vibrates, the arrival time of the blade tip will be advanced or delayed. By processing this time series through different tip-timing processing algorithms, information such as blade vibration frequency and tip vibration displacement can be obtained. Since the tip-timing method belongs to a typical under-sampling method, its working principle and data processing algorithm are very special, so it is very difficult to calibrate the measurement accuracy of the test system based on the tip-timing principle through conventional metrological verification methods in practical applications.

[0004] In engineering, to evaluate the accuracy of the test results of the tip-timing method, generally, the contact strain gauge method is used to obtain the vibration stress of the blade body. Then, the finite element analysis is used to obtain the corresponding relationship between the tip vibration displacement and the vibration stress of the blade body. Finally, with the help of this corresponding relationship, the results obtained by the strain gauge method are quantitatively compared, analyzed, and evaluated with the blade tip vibration displacement results obtained by the non-contact tip-timing method. The existing evaluation device for the rotor blade vibration test system using the tip-timing method generally designs a special rotor test piece and a casing, pastes strain gauges at the blade body of the rotor blade, and then installs the test piece on a large rotor tester for rotational drive. The high-speed air flow is used as the vibration excitation source during the rotation of the blade. The slip ring electrical collector is used as the signal transmission device, and the vibration strain signal on the rotating blade is transmitted to the relatively stationary strain test system through the frictional contact between the brush ring and the brush wire inside the electrical collector. During the test, the rotor part of the electrical collector is firmly connected to the cantilever end of the measured rotor, and the stator part (such as the electrical collector housing) is fixed on the test piece casing or a special support. At the same time, the rotor blade vibration test system based on tip-timing is used to test the vibration of the rotating blade, so as to obtain the two vibration test results within the same time period, and thus evaluate the accuracy of the test results of the tip-timing method.

[0005] However, since the existing evaluation device for the rotor blade vibration test system using the tip-timing method usually uses an electrical collector as the signal transmission device for the "contact strain gauge method", its equipment composition and the installation procedures of each link are very complex, and the requirements for test operators are very high. Moreover, during the test, it is necessary to continuously lubricate the bearings of the electrical collector and cool the brush ring and brush wire inside the electrical collector, which requires the test site to be equipped with a complex cooling system for the electrical collector. Even so, the test still has a high risk because there is a possibility of being burned out if there is a slight mistake in the lubrication and cooling links of the electrical collector. To ensure the smooth progress of the test, multiple operation positions need to be set during the test, and multiple people cooperate to complete the work of each link during the test.

[0006] In summary, the deficiencies of the existing evaluation device for the rotor blade vibration test system using the tip-timing method are that the structure is complex, the operation is cumbersome, the test risk is high, and it consumes a lot of human and material resources. Summary of the Invention

[0007] The present invention provides an evaluation device for a rotor blade vibration test system using the tip-timing method to solve the technical problems of the existing evaluation device for the rotor blade vibration test system using the tip-timing method, such as complex structure, cumbersome operation, high test risk, and high consumption of human and material resources.

[0008] According to one aspect of the present invention, there is provided an evaluation device for a rotor blade vibration test system using tip-timing method, including a driving motor, a simulation impeller connected to the output shaft of the driving motor, a strong magnetic excitation member disposed around the simulation impeller for emitting a magnetic field excitation to cause resonance when the simulation blades on the simulation impeller rotate, a strain component disposed on the simulation blades of the simulation impeller for measuring and obtaining the strain signal of the blade body of the simulation blade, a telemetry system electrically connected to the strain component for transmitting the strain signal, a first data processor electrically connected to the telemetry system for processing the strain signal to obtain the vibration frequency of the simulation blade and the vibration stress of the blade body of the simulation blade, a simulation casing disposed peripherally around the simulation impeller in the circumferential direction, a timing sensor disposed on the simulation casing for sensing the time series of the arrival moment of the tip of the simulation blade, a second data processor electrically connected to the timing sensor for processing the time series of the arrival moment of the tip of the simulation blade to obtain the vibration frequency of the simulation blade and the vibration displacement of the tip of the simulation blade, and a simulation analyzer for performing modal analysis on the simulation blade to obtain the correspondence relationship between the vibration displacement of the tip of the simulation blade and the vibration stress of the blade body of the simulation blade at the resonance speed of the simulation blade.

[0009] As a further improvement of the above technical solution:

[0010] Further, the simulation impeller includes a connecting shaft connected to the output shaft of the driving motor and a plurality of simulation blades arranged at intervals in the circumferential direction on the connecting shaft.

[0011] Further, the strain component includes a strain gauge attached to the blade body of the simulation blade and strain transmission leads respectively connected to the strain gauge and the telemetry system.

[0012] Further, the telemetry system includes a telemetry system transmitting end disposed on the cantilever end of the connecting shaft and connected to the strain transmission leads, a telemetry system receiving end radio-connected to the telemetry system transmitting end, and a telemetry system data processor respectively electrically connected to the telemetry system receiving end and the first data processor.

[0013] Further, the connecting shaft is axially provided with a connecting cavity, and the wall surface of the connecting shaft is radially provided with a connecting hole communicating with the connecting cavity, and the strain transmission lead passes through the connecting hole to be connected to the telemetry system transmitting end.

[0014] Further, a first flange mounting edge is disposed on the cantilever end of the connecting shaft, and the telemetry system transmitting end is provided with a second flange mounting edge connected to the first flange mounting.

[0015] According to another aspect of the present invention, there is also provided a method for evaluating a rotor blade vibration test system by tip-timing method, which uses the above-mentioned evaluation device for the rotor blade vibration test system by tip-timing method, and includes the following steps: S1, drive the simulated impeller to rotate by the driving motor, and at the same time make the strong magnetic excitation component emit magnetic field excitation so that the simulated blades on the simulated impeller resonate when rotating; S2, measure the strain signal of the strain condition of the blade body of the simulated blade through the strain component, and then transmit the strain signal to the first data processor through the telemetry system. The first data processor processes the strain signal to obtain the vibration frequency of the simulated blade and the vibration stress of the blade body of the simulated blade; at the same time, the time series of the arrival time of the tip of the simulated blade is sensed by the timing sensor and sent to the second data processor, and the second data processor processes the time series of the arrival time of the tip of the simulated blade to obtain the vibration frequency of the simulated blade and the vibration displacement of the tip of the simulated blade; S3, perform modal analysis on the simulated impeller through the simulation analyzer to obtain the corresponding relationship between the vibration displacement of the tip of the simulated blade and the vibration stress of the blade body of the simulated blade at the resonance speed of the simulated blade, and then according to the corresponding relationship between the vibration displacement of the tip of the simulated blade and the vibration stress of the blade body of the simulated blade and the vibration frequency of the simulated blade and the vibration stress of the blade body of the simulated blade obtained by the first data processor, evaluate the accuracy of the vibration frequency of the simulated blade and the vibration displacement of the tip of the simulated blade obtained by the second data processor.

[0016] As a further improvement of the above technical solution:

[0017] Further, before step S1, there is also a step: S0, determine the wheel body radius of the simulated impeller, the length and thickness of the simulated blade according to the vertical distance from the center of the output shaft of the driving motor to the driving motor base, and then determine the width and number of the simulated blades according to the air resistance effect generated by the surrounding air when the simulated blade rotates and the power of the driving motor, and then obtain the first-order modal frequency of the simulated blade according to the empirical formula. The empirical formula is F = 810092H / I2, where F is the frequency, H is the thickness of the simulated blade, and I is the length of the simulated blade.

[0018] Further, between S0 and S1, there is also a step: Perform modal analysis on the simulated impeller through the simulation analyzer to obtain the first-order modal frequency of the simulated blade to verify the first-order modal frequency of the simulated blade obtained according to the empirical formula, and further verify the feasibility of the design scheme of the structural dimensions of the simulated impeller.

[0019] Further, between S0 and S1, there is also a step: Perform modal analysis on the simulated impeller through the simulation analyzer to obtain the calculation result of the first-order modal vibration stress distribution of the simulated blade, and determine the installation position of the strain component according to the calculation result of the first-order modal vibration stress distribution of the simulated blade, and then install the strain component.

[0020] The present invention has the following beneficial effects:

[0021] For the evaluation device of the tip-timing method rotor blade vibration test system of the present invention, first, a driving motor drives a simulation impeller to rotate synchronously. A magnetic field excitation is emitted by a strong magnetic excitation component to cause resonance when the simulation blades on the simulation impeller rotate. Then, a strain component measures and obtains a strain signal of the strain condition of the blade body of the simulation blade during resonance of the simulation blade. The strain signal is transmitted through a telemetry system, and a first data processor processes the strain signal to obtain the vibration frequency of the simulation blade and the vibration stress of the blade body of the simulation blade. At the same time, a timing sensor senses the time series of the arrival moments of the tips of the simulation blades, and a second data processor processes the time series of the arrival moments of the tips of the simulation blades to obtain the vibration frequency of the simulation blade and the vibration displacement of the tip of the simulation blade. Finally, a simulation analyzer performs modal analysis on the simulation blade to obtain the corresponding relationship between the vibration displacement of the tip of the simulation blade and the vibration stress of the blade body of the simulation blade at the resonance speed of the simulation blade, and evaluates the accuracy of the vibration frequency of the simulation blade and the vibration displacement of the tip of the simulation blade obtained by a second simulator based on the corresponding relationship between the vibration displacement of the tip of the simulation blade and the vibration stress of the blade body of the simulation blade and the vibration frequency of the simulation blade and the vibration stress of the blade body of the simulation blade obtained by a first simulator. In this solution, the driving motor is used as the driving device, which is safe and simple to operate without the need to be equipped with other complex auxiliary equipment. At the same time, the strong magnetic excitation component is used as the excitation source. Compared with the existing excitation source using air or other fluids as the excitation medium, the installation and operation of the strong magnetic excitation component are more convenient. And the telemetry system is used as the strain signal transmission device. Compared with the slip ring in the prior art, the telemetry system does not require lubrication and cooling, significantly reducing the risk level during the test and saving human and material resources.

[0022] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The following will refer to the drawings to further elaborate on the present invention in detail. Description of the Drawings

[0023] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0024] Figure 1 is a schematic structural diagram of the evaluation device of the tip-timing method rotor blade vibration test system of the preferred embodiment of the present invention;

[0025] Figure 2 is Figure 1 the A-A sectional view of the evaluation device of the tip-timing method rotor blade vibration test system shown;

[0026] Legend Explanation:

[0027] 1. Driving and rotating motor; 2. Simulated impeller; 21. Connecting shaft; 211. Connecting hole; 22. Simulated blade; 3. Strain component; 31. Strain gauge; 32. Strain transmission lead; 4. Telemetry system; 41. Telemetry system transmitting end; 5. Simulated casing. Specific implementation manner

[0028] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways defined and covered by the following.

[0029] Figure 1 It is a schematic structural diagram of an evaluation device for a tip-timing method rotor blade vibration test system according to a preferred embodiment of the present invention; Figure 2 is Figure 1 The A-A sectional view of the evaluation device of the tip-timing method rotor blade vibration test system shown in the figure.

[0030] As Figure 1 and Figure 2As shown in the figure, the rotor blade vibration test system evaluation device of the tip-timing method in this embodiment includes a driving motor 1, a simulation impeller 2 connected to the output shaft of the driving motor 1, a strong magnetic excitation member disposed around the simulation impeller 2 for generating a magnetic field excitation to cause resonance when the simulation blade 22 on the simulation impeller 2 rotates, a strain component 3 disposed on the simulation blade 22 of the simulation impeller 2 for measuring and obtaining the strain signal of the blade body of the simulation blade 22, a telemetry system 4 electrically connected to the strain component 3 for transmitting the strain signal, a first data processor electrically connected to the telemetry system 4 for processing the strain signal to obtain the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22, a simulation casing 5 disposed peripherally around the simulation impeller 2 in the circumferential direction, a timing sensor disposed on the simulation casing 5 for sensing the time series of the arrival moment of the tip of the simulation blade 22, a second data processor electrically connected to the timing sensor for processing the time series of the arrival moment of the tip of the simulation blade 22 to obtain the vibration frequency of the simulation blade 22 and the vibration displacement of the tip of the simulation blade 22, and a simulation analyzer for performing modal analysis on the simulation blade 22 to obtain the corresponding relationship between the vibration displacement of the tip of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 at the resonance speed of the simulation blade 22.Specifically, for the evaluation device of the tip-timing method rotor blade vibration test system of the present invention, first, the driving motor 1 drives the simulation impeller 2 to rotate synchronously. The strong magnetic excitation component emits a magnetic field excitation to cause the simulation blade 22 on the simulation impeller 2 to resonate when rotating. Then, the strain component 3 measures and obtains the strain signal of the blade body strain of the simulation blade 22 during resonance. The telemetry system 4 transmits the strain signal, and the first data processor processes the strain signal to obtain the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22. At the same time, the timing sensor senses the time series of the arrival moment of the tip of the simulation blade 22, and the second data processor processes the time series of the arrival moment of the tip of the simulation blade 22 to obtain the vibration frequency of the simulation blade 22 and the vibration displacement of the tip of the simulation blade 22. Finally, the simulation analyzer performs modal analysis on the simulation blade 22 to obtain the corresponding relationship between the vibration displacement of the tip of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 at the resonance speed of the simulation blade 22, and evaluates the accuracy of the vibration frequency of the simulation blade 22 and the vibration displacement of the tip of the simulation blade 22 obtained by the second simulator through the corresponding relationship between the vibration displacement of the tip of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 and the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 obtained by the first simulator. In this solution, the driving motor is used as the driving device, which is safe and simple to operate, and does not require other complex auxiliary equipment. At the same time, the strong magnetic excitation component is used as the excitation source. Compared with the existing excitation source using air or other fluids as the excitation medium, the installation and operation of the strong magnetic excitation component are more convenient. And the telemetry system 4 is used as the strain signal transmission device. Compared with the slip ring in the prior art, the telemetry system 4 does not require lubrication and cooling, significantly reducing the risk level during the test and saving human and material resources. Optionally, the strong magnetic excitation component is a strong magnet. Optionally, the first data processor, the second data processor, and the simulation analyzer are computers. It should be understood that the specific structure of the computer belongs to the well-known technology of those skilled in the art and will not be elaborated here.

[0031] As Figure 2 shown, in this embodiment, the simulation impeller 2 includes a connecting shaft 21 connected to the output shaft of the driving motor 1 and a plurality of simulation blades 22 arranged at intervals along the circumference on the connecting shaft 21. Specifically, the driving motor 1 works to drive the connecting shaft 21 to rotate synchronously through the output shaft, and then drive the simulation blades 22 to rotate synchronously, thereby simulating the rotation state of the blade during actual operation. At the same time, the installation and operation of the driving motor 1 are convenient, and no other complex auxiliary equipment is required, saving human and material resources.

[0032] As Figure 2As shown in the figure, in this embodiment, the strain component 3 includes a strain gauge 31 attached to the blade body of the simulation blade 22 and a strain transmission lead 32 respectively connected to the strain gauge 31 and the telemetry system 4. Specifically, a strain signal of the strain condition of the blade body of the simulation blade 22 is measured by the strain gauge 31, and then the strain signal is transmitted to the telemetry system 4 through the strain transmission lead 32. Optionally, the strain gauge 31 is attached to the blade body of the simulation blade 22 by a pasting process. It should be understood that the specific steps of the pasting process are well-known techniques to those skilled in the art and will not be elaborated here.

[0033] As Figure 2 shown in the figure, in this embodiment, the telemetry system 4 includes a telemetry system transmitter 41 disposed on the cantilever end of the connecting shaft 21 and connected to the strain transmission lead 32, a telemetry system receiver radio-connected to the telemetry system transmitter 41, and a telemetry system data processor respectively electrically connected to the telemetry system receiver and the first data processor. Specifically, the telemetry system transmitter 41 receives the strain signal transmitted by the strain transmission lead 32 and transmits the strain signal into the telemetry system receiver, then transmits the strain signal into the telemetry system data processor, and finally transmits the strain signal into the first data processor for processing to obtain the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22. It should be understood that the specific structures of the telemetry system transmitter 41, the telemetry system receiver, and the telemetry system data processor are well-known techniques to those skilled in the art and will not be elaborated here.

[0034] As Figure 2 shown in the figure, in this embodiment, the connecting shaft 21 is axially provided with a connecting cavity, and the wall surface of the connecting shaft 21 is radially provided with a connecting hole 211 communicating with the connecting cavity. The strain transmission lead 32 passes through the connecting hole 211 to be connected to the telemetry system transmitter 41. Specifically, the strain transmission lead 32 passes through the connecting hole 211 to enter the connecting cavity, and then passes through the connecting cavity to be connected to the wiring board of the telemetry system transmitter 41.

[0035] As Figure 2 shown in the figure, in this embodiment, a first flange mounting edge is disposed on the cantilever end of the connecting shaft 21, and the telemetry system transmitter 41 is provided with a second flange mounting edge connected to the first flange. Specifically, through the connection of the first flange mounting edge and the second flange, the telemetry system transmitter 41 is fixed to the cantilever end of the connecting shaft 21, with reliable connection and stable operation.

[0036] As Figure 2As shown in the figure, the evaluation method of the tip-timing rotor blade vibration test system in this embodiment uses the above-mentioned evaluation device of the tip-timing rotor blade vibration test system, and includes the following steps: S1, the driving motor 1 operates to drive the simulation impeller 2 to rotate, and at the same time, the strong magnetic excitation component emits a magnetic field excitation so that the simulation blade 22 on the simulation impeller 2 resonates when rotating; S2, the strain component 3 measures and obtains the strain signal of the strain condition of the blade body of the simulation blade 22, and then the telemetry system 4 transmits the strain signal into the first data processor. The first data processor processes the strain signal to obtain the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22. At the same time, the timing sensor senses the time series of the arrival moment of the tip of the simulation blade 22 into the second data processor, and the second data processor processes the time series of the arrival moment of the tip of the simulation blade 22 to obtain the vibration frequency of the simulation blade 22 and the vibration displacement of the tip of the simulation blade 22; S3, the simulation analyzer performs modal analysis on the simulation impeller 2 to obtain the corresponding relationship between the vibration displacement of the tip of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 at the resonance speed of the simulation blade, and then according to the corresponding relationship between the vibration displacement of the tip of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22, and the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 obtained by the first data processor, the vibration frequency of the simulation blade 22 and the vibration displacement of the tip of the simulation blade 22 obtained by the second data processor are evaluated for accuracy. Specifically, first, the driving motor 1 drives the simulation impeller 2 to rotate to simulate the actual rotation of the simulation impeller 2. The operation of the driving motor 1 is safe and simple. Then, the strong magnetic excitation component excites the simulation blade 22 to resonate when rotating. Using the strong magnetic excitation component as the resonance excitation source, compared with the excitation source using air or other fluids as the excitation medium, the installation operation of the strong magnetic excitation component is safer and simpler. Through the cooperation of the strain component 3, the telemetry system 4 and the first data processing, contact strain testing is realized, and the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 are obtained. During this process, the telemetry system 4 is used as the strain signal transmission device. Compared with the slip ring, the installation operation is simpler and more convenient, and there is no need for lubrication and cold air, significantly reducing the risk during the test. At the same time, through the cooperation of the timing sensor and the second data processor, the vibration frequency of the simulation blade 22 and the vibration displacement of the tip of the simulation blade 22 are obtained, realizing non-contact strain testing. Finally, the simulation analyzer obtains the corresponding relationship between the vibration displacement of the tip of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22, and compares and analyzes the vibration frequency of the simulation blade 22 and the vibration displacement of the tip of the simulation blade 22 obtained by the non-contact strain testing with the vibration frequency of the simulation blade 22 and the vibration stress of the blade body of the simulation blade 22 obtained by the previous contact strain testing, completing the accuracy evaluation of the test results of the non-contact strain testing.

[0037] In this embodiment, before step S1, there is also a step: S0. According to the vertical distance from the center of the output shaft of the driving and rotating motor 1 to the base of the driving and rotating motor 1, the radius of the wheel body of the simulation impeller 2, the length of the simulation blade 22, and the thickness of the simulation blade 22 are determined. Then, according to the air resistance influence generated by the surrounding air when the simulation blade 22 rotates and the power of the driving and rotating motor 1, the width and the number of the simulation blades 22 are determined. Then, the first-order modal frequency of the simulation blade 22 is obtained according to the empirical formula. The empirical formula is F = 810092H / I2, where F is the frequency, H is the thickness of the simulation blade 22, and I is the length of the simulation blade 22. It should be understood that the design of the simulation impeller 2 fully considers the air resistance influence and the power influence of the driving and rotating motor 1, ensuring that the test of the simulation impeller 2 can be carried out in a normal environment and strong-response resonance can occur within the maximum rotational speed range of the motor.

[0038] In this embodiment, between S0 and S1, there is also a step: performing modal analysis on the simulation impeller 2 through a simulation analyzer to obtain the first-order modal frequency of the simulation blade 22, so as to verify the first-order modal frequency of the simulation blade 22 obtained according to the empirical formula, and further verify the feasibility of the structural dimension design scheme of the simulation impeller 2. Specifically, the first-order modal frequency is obtained through modal analysis to verify the first-order modal frequency obtained by the empirical formula, realizing the feasibility verification of the structural dimension design scheme of the simulation impeller 2 and ensuring the reliability of subsequent test results.

[0039] In this embodiment, between S0 and S1, there is also a step: performing modal analysis on the simulation impeller 2 through a simulation analyzer to obtain the calculation result of the first-order modal vibration stress distribution of the simulation blade 22, so as to determine the installation position of the strain component 3 according to the calculation result of the first-order modal vibration stress distribution of the simulation blade 22, and then install the strain component 3. Specifically, first simulate to obtain the calculation result of the first-order modal vibration stress distribution of the simulation blade 22, and then reasonably install the strain component 3 to improve the accuracy of the strain signal in the subsequent test process, and further indirectly improve the accuracy of the evaluation result.

[0040] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for evaluating a rotor blade vibration test system by tip timing method, characterized in that, Evaluate using a rotor blade vibration test system evaluation device based on tip timing method. The rotor blade vibration test system evaluation device based on tip timing method includes a driving motor (1), a simulated impeller (2) connected to the output shaft of the driving motor (1), a strong magnetic excitation component arranged around the simulated impeller (2) for emitting magnetic field excitation to cause resonance when the simulated blades (22) on the simulated impeller (2) rotate, a strain component (3) arranged on the simulated blades (22) of the simulated impeller (2) for measuring and obtaining strain signals of the strain conditions of the blade bodies of the simulated blades (22), a telemetry system (4) electrically connected to the strain component (3) for transmitting the strain signals, a first data processor electrically connected to the telemetry system (4) for processing the strain signals to obtain the vibration frequency of the simulated blades (22) and the vibration stress of the blade bodies of the simulated blades (22), a simulated casing (5) arranged circumferentially around the simulated impeller (2), a timing sensor arranged on the simulated casing (5) for sensing the time series of the arrival moments of the tips of the simulated blades (22), a second data processor electrically connected to the timing sensor for processing the time series of the arrival moments of the tips of the simulated blades (22) to obtain the vibration frequency of the simulated blades (22) and the vibration displacement of the tips of the simulated blades (22), and a simulation analyzer for performing modal analysis on the simulated blades (22) to obtain the corresponding relationship between the vibration displacement of the tips of the simulated blades (22) and the vibration stress of the blade bodies of the simulated blades (22) at the resonance speed of the simulated blades (22); The evaluation method includes the following steps: S0. According to the vertical distance from the output shaft center of the driving and rotating motor (1) to the base of the driving and rotating motor (1), determine the wheel body radius of the simulation impeller (2), the length of the simulation blade (22), and the thickness of the simulation blade (22). Then, according to the air resistance effect generated by the surrounding air when the simulation blade (22) rotates and the power of the driving and rotating motor (1), determine the width and the number of the simulation blades (22). Then, obtain the first-order modal frequency of the simulation blade (22) according to the empirical formula. The empirical formula is F = 810092H / I 2 , where F is the frequency, H is the thickness of the simulation blade (22), and I is the length of the simulation blade (22); Perform modal analysis on the simulated impeller (2) through the simulation analyzer to obtain the first-order modal frequency of the simulated blades (22), so as to verify the first-order modal frequency of the simulated blades (22) obtained according to the empirical formula, and further verify the feasibility of the structural dimension design scheme of the simulated impeller (2); Perform modal analysis on the simulated impeller (2) through the simulation analyzer to obtain the calculation result of the first-order modal vibration stress distribution of the simulated blades (22), so as to determine the installation position of the strain component (3) according to the calculation result of the first-order modal vibration stress distribution of the simulated blades (22), and then install the strain component (3); S1, operate the driving motor (1) to drive the simulated impeller (2) to rotate, and at the same time make the strong magnetic excitation component emit magnetic field excitation to cause resonance when the simulated blades (22) on the simulated impeller (2) rotate; S2, measure and obtain the strain signals of the strain conditions of the blade bodies of the simulated blades (22) through the strain component (3), then transmit the strain signals to the first data processor through the telemetry system (4), and process the strain signals through the first data processor to obtain the vibration frequency of the simulated blades (22) and the vibration stress of the blade bodies of the simulated blades (22); at the same time, sense the time series of the arrival moments of the tips of the simulated blades (22) to the second data processor through the timing sensor, and process the time series of the arrival moments of the tips of the simulated blades (22) through the second data processor to obtain the vibration frequency of the simulated blades (22) and the vibration displacement of the tips of the simulated blades (22); S3. Perform modal analysis on the simulated impeller (2) through a simulation analyzer to obtain the corresponding relationship between the vibration displacement at the tip of the simulated blade (22) and the vibration stress of the blade body of the simulated blade (22) at the resonance speed of the simulated blade (22). Then, based on the corresponding relationship between the vibration displacement at the tip of the simulated blade (22) and the vibration stress of the blade body of the simulated blade (22), as well as the vibration frequency of the simulated blade (22) and the vibration stress of the blade body of the simulated blade (22) obtained by the first data processor, evaluate the accuracy of the vibration frequency of the simulated blade (22) and the vibration displacement at the tip of the simulated blade (22) obtained by the second data processor.

2. The method for evaluating a rotor blade vibration test system by the tip timing method according to claim 1, wherein The simulated impeller (2) includes a connecting shaft (21) connected to the output shaft of the driving motor (1) and a plurality of simulated blades (22) arranged at intervals along the circumference on the connecting shaft (21).

3. The evaluation method of the rotor blade vibration test system by the tip timing method according to claim 2, characterized in that The strain component (3) includes a strain gauge (31) attached to the blade body of the simulated blade (22) and a strain transmission lead (32) respectively connected to the strain gauge (31) and the telemetry system (4).

4. The method for evaluating a rotor blade vibration test system by the tip timing method according to claim 3, characterized in that, The telemetry system (4) includes a telemetry system transmitter (41) disposed at the cantilever end of the connecting shaft (21) and connected to the strain transmission lead (32), a telemetry system receiver radio-connected to the telemetry system transmitter (41), and a telemetry system data processor respectively electrically connected to the telemetry system receiver and the first data processor.

5. The method for evaluating a rotor blade vibration test system by using a tip timing method according to claim 4, wherein The connecting shaft (21) is axially provided with a connecting cavity, and the wall surface of the connecting shaft (21) is radially provided with a connecting hole (211) communicating with the connecting cavity. The strain transmission lead (32) passes through the connecting hole (211) to be connected to the telemetry system transmitter (41).

6. The method for evaluating a rotor blade vibration test system by the tip timing method according to claim 4, characterized in that, A first flange mounting edge is disposed at the cantilever end of the connecting shaft (21), and the telemetry system transmitter (41) is provided with a second flange mounting edge connected to the first flange mounting.

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