CN116577050A - Method for testing dynamic damping ratio of aero-engine compressor rotor blade - Google Patents
Method for testing dynamic damping ratio of aero-engine compressor rotor blade Download PDFInfo
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- CN116577050A CN116577050A CN202310529663.1A CN202310529663A CN116577050A CN 116577050 A CN116577050 A CN 116577050A CN 202310529663 A CN202310529663 A CN 202310529663A CN 116577050 A CN116577050 A CN 116577050A
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- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000013016 damping Methods 0.000 title claims abstract description 31
- 238000012360 testing method Methods 0.000 title claims abstract description 25
- 239000013307 optical fiber Substances 0.000 claims abstract description 32
- 230000005284 excitation Effects 0.000 claims abstract description 25
- 230000001360 synchronised effect Effects 0.000 claims abstract description 23
- 238000004458 analytical method Methods 0.000 claims abstract description 10
- 238000004364 calculation method Methods 0.000 claims description 2
- 238000013461 design Methods 0.000 abstract description 4
- 238000009434 installation Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 2
- 238000001208 nuclear magnetic resonance pulse sequence Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005316 response function Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000010408 sweeping Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
- G01H9/004—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means using fibre optic sensors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
- G01M7/025—Measuring arrangements
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The application belongs to the field of aero-engine design, and discloses a method for testing dynamic damping ratio of air compressor rotor blades of an aero-engine, wherein excitation tests of the air compressor rotor blades are carried out through the number of optical fiber sensors, and acquisition signals of the optical fiber sensors are sent to output acquisition equipment; then calculating the actual amplitude of the blade according to the time deviation of the rotor blade of the compressor reaching any sensor, acquiring the vibration frequency of the blade by adopting a circumferential sine fitting synchronous vibration analysis method, and measuring the vibration characteristics of the rotor blade by a plurality of optical fiber sensors to obtain a amplitude frequency response curve and a phase frequency response curve of each rotor blade; judging whether the blade is in a synchronous vibration state according to the amplitude frequency response curve and the phase frequency response curve, and if so, calculating the dynamic damping ratio of the rotor blade according to the amplitude frequency response curve and the phase frequency response curve. The optical fiber sensor has simple installation structure, does not need to greatly change the structure of the engine, and has longer service life.
Description
Technical Field
The application belongs to the field of aero-engine design, and particularly relates to a method for testing dynamic damping ratio of a rotor blade of an aero-engine compressor.
Background
The rotor blade of the compressor bears various loads in the working state, the problem of vibration of the blade is one of main reasons for vibration faults of the aero-engine, and the damping ratio is an important parameter in the vibration damping design of the blade. At present, the dynamic working performance of the blade is mainly evaluated by using a static damping ratio test result or a contact dynamic damping ratio test result of the blade in China, and the two methods can be measured by contact.
In the prior art, a contact test method is adopted, micro-processing is carried out on the surface of a rotor blade, a strain gauge is stuck, vibration signals of corresponding points of the rotor blade of the compressor in the slow frequency sweeping process are recorded in real time, a blade vibration amplitude frequency response curve is drawn, and the damping ratio is calculated by utilizing the frequency at a half power point. The method needs to refit the compressor blade, is easy to influence the working performance of the blade, has high rotation speed of the rotor blade, bears various extreme loads, is not small in test on the arrangement of the strain gauge and the lead-out of the lead, and can greatly influence the service life of the strain gauge. In addition, the method can only obtain vibration data of a few blades in the test process, and the strain gauge is difficult to install for all the blades.
How to make effective measurements for all blades is a problem to be solved.
Disclosure of Invention
The application aims to provide a method for testing the dynamic damping ratio of a rotor blade of an aero-engine compressor, which aims to solve the problem that the existing measuring method is used for measuring the damping ratio and only a few vibration data of the blades can be obtained, and the strain gauge is difficult to install for all the blades.
The technical scheme of the application is as follows: a method for testing dynamic damping ratio of a rotor blade of an aero-engine compressor comprises the following steps:
determining the number of optical fiber sensors, fixing a plurality of optical fiber sensors at the mounting hole of an outer casing of the air compressor along the radial direction, performing an excitation test of a rotor blade of the air compressor, and transmitting acquisition signals of the optical fiber sensors to output acquisition equipment;
obtaining the diameter of a blade, the number of the blades and the rotating speed of a rotor of the air compressor, calculating the actual amplitude of the blade according to the time deviation of the rotor blade of the air compressor reaching any sensor, obtaining the vibration frequency of the blade by adopting a circumferential sine fitting synchronous vibration analysis method, and measuring the vibration characteristics of the rotor blade by a plurality of optical fiber sensors to obtain an amplitude frequency response curve and a phase frequency response curve of each rotor blade;
judging whether the blade is in a synchronous vibration state according to the amplitude frequency response curve and the phase frequency response curve, if so, calculating the dynamic damping ratio of the rotor blade according to the amplitude frequency response curve and the phase frequency response curve; if not, changing the excitation frequency until reaching the synchronous vibration state.
Preferably, the circumferential sine fitting synchronous vibration analysis method comprises the following steps: setting a target equation:
y i ＝Asin(E o Ωt i +Φ)+C
wherein E is o To the excitation order, y i For the vibration amplitude of the blade, C is the normal deflection of the vibration balance position of the blade, t i Time, Ω is rotational speed frequency;
selecting a frequency multiplication value to substitute into a target equation, and calculating residual errors by using a least square method to obtain:
the simplification is as follows: y=bx;
the residual vector is obtained as follows: r is R k ＝BX k -Y
Known excitation order E o B and Y are obtained through a least square method, a main vibration frequency multiplication range is estimated, then a frequency multiplication value is screwed out of the main vibration frequency multiplication range and substituted into a residual vector, and the least two is usedMultiplication to obtain X k Then calculating residual error of estimated value and measured value Y to obtain X of residual error minimum value k Namely, the frequency multiplication number of synchronous vibration of the blade is as follows:
ω＝E o Ω。
according to the method for testing the dynamic damping ratio of the air compressor rotor blade of the aeroengine, the vibration excitation test of the air compressor rotor blade is carried out through the number of the optical fiber sensors, and the acquisition signals of the optical fiber sensors are sent to the output acquisition equipment; then calculating the actual amplitude of the blade according to the time deviation of the rotor blade of the compressor reaching any sensor, acquiring the vibration frequency of the blade by adopting a circumferential sine fitting synchronous vibration analysis method, and measuring the vibration characteristics of the rotor blade by a plurality of optical fiber sensors to obtain a amplitude frequency response curve and a phase frequency response curve of each rotor blade; judging whether the blade is in a synchronous vibration state according to the amplitude frequency response curve and the phase frequency response curve, and if so, calculating the dynamic damping ratio of the rotor blade according to the amplitude frequency response curve and the phase frequency response curve. The optical fiber sensor has simple installation structure, does not need to greatly change the engine structure, has longer service life, and can simultaneously obtain the multi-mode dynamic damping ratio parameters of all blades of a certain level of rotor.
Drawings
In order to more clearly illustrate the technical solution provided by the present application, the following description will briefly refer to the accompanying drawings. It will be apparent that the figures described below are merely some embodiments of the application.
FIG. 1 is a schematic diagram of the response curve method of the present application;
FIG. 2 is a schematic overall flow chart of the present application;
FIG. 3 is a schematic diagram of a tip timing test of the present application;
FIG. 4 is a schematic representation of a multi-lobe amplitude-frequency response curve of a rotor of a certain stage according to the present application;
FIG. 5 is a schematic diagram of the amplitude-frequency response curve of the multi-blade slow scan process of the present application;
FIG. 6 is a schematic diagram of a single-blade slow-scan phase frequency response curve of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application become more apparent, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application.
Method for testing dynamic damping ratio of aero-engine compressor rotor blade
Non-contact rotor blade dynamic damping measurement test method and principle
In engineering application, it is customary to measure vibration damping of an object by using a response curve method, the method uses the frequency response function characteristics of a vibration system after excitation to obtain a specific value of damping ratio, a steady-state simple harmonic excitation mode is required to be adopted in practical test, vibration amplitude of the object is measured by changing vibration excitation frequency from low to high near the resonance frequency of the system, then a frequency response curve is drawn, the method measures dynamic damping ratio of the object based on the principle of a half-power method, vibration excitation frequency is changed to enable the object to be measured to resonate, vibration excitation frequency is changed near the resonance frequency, amplitude of the object to be measured under each vibration excitation frequency is recorded, and a frequency response curve is drawn to obtain a resonance frequency f 0 Amplitude y 0 And 0.707y 0 Frequency f at time 1 And f 2 As shown in fig. 1, the damping ratio of the test piece can be obtained using the following formula:
the method is realized by adopting a non-contact measuring method and using a plurality of optical fiber sensors based on a blade tip timing principle, as shown in fig. 2, the optical fiber sensors are radially fixed at the mounting hole of the outer casing of the air compressor, 1 pulse signal can be generated when the rotor blade rotates once passing through the sensors, if the diameter, the number and the rotation speed of the blade are known, the actual amplitude of the blade can be calculated by utilizing the time deviation of the sensor when the blade vibrates, and the vibration frequency of the blade can be obtained by utilizing the circumferential sine fitting synchronous vibration analysis method.
As shown in fig. 2, the method specifically comprises the following steps:
step S100, determining the number of optical fiber sensors, fixing a plurality of optical fiber sensors at the mounting hole of the outer casing of the compressor along the radial direction, selecting specific positions according to space requirements, performing excitation tests of the rotor blades of the compressor, and sending acquisition signals of the optical fiber sensors to output acquisition equipment. As shown in fig. 3, the lower left corner compressor rotor and its blades, (1), (2) and (3) are optical fiber sensors at different positions respectively, and the right side in the figure is the collected data, specifically, a blade pulse sequence and a rotation speed pulse sequence.
The data collected by each optical fiber sensor is classified and time-divided by the collecting equipment and then sent to the background equipment for data processing.
Because the optical fiber sensor is arranged on the stator structure, the optical fiber sensor can be directly fixed in a threaded mode and the like, and the installation structure is simple.
Step S200, obtaining the diameter of the blades, the number of the blades and the rotating speed of the rotor of the air compressor, calculating the actual amplitude of the blades according to the time deviation of the rotor blades of the air compressor reaching any sensor, obtaining the vibration frequency of the blades by adopting a circumferential sine fitting synchronous vibration analysis method, and measuring the vibration characteristics of the rotor blades by a plurality of optical fiber sensors to obtain a amplitude frequency response curve and a phase frequency response curve of each rotor blade.
Preferably, the circumferential sine fitting synchronous vibration analysis method comprises the following steps: setting a target equation:
y i ＝Asin(E o Ωt i +Φ)+C
wherein E is o To the excitation order, y i For the vibration amplitude of the blade, C is the normal deflection of the vibration balance position of the blade, t i Time, Ω is rotational speed frequency;
and selecting a frequency multiplication value to be substituted into a target equation, calculating residual errors by using a least square method, obtaining residual errors of the measured value and calculated displacement and an effective value of the residual errors, wherein the vibration resonance order of the blade to be identified is the frequency multiplication when the residual errors are minimum, and the actual vibration frequency, amplitude and initial phase of the blade can be obtained on the basis. The target equation is first converted into:
the simplification is as follows: y=bx;
wherein:
Y＝(y 1 ，y 1 ，y 2 …y n ) T
the residual vector is obtained as follows: r is R k ＝BX k -Y
At least 4 sensors are arranged, the excitation order E is known o B and Y are obtained through a least square method, a main vibration frequency multiplication range is estimated, then a frequency multiplication value is screwed out of the main vibration frequency multiplication range and substituted into a residual vector, and X is obtained through least square calculation k Then calculating residual error of estimated value and measured value Y to obtain X of residual error minimum value k Namely, the frequency multiplication number of synchronous vibration of the blade is as follows:
ω＝E o Ω。
on the basis, a plurality of optical fiber sensors are used for measuring the vibration characteristics of the rotor blades, amplitude frequency response curves of the rotor blades in the slow-sweep and rising speed process of the compressor are shown in fig. 4 and 5, and phase frequency response curves are shown in fig. 6.
Step S300, judging whether the blade is in a synchronous vibration state according to the amplitude frequency response curve and the phase frequency response curve, if so, calculating the dynamic damping ratio of the rotor blade according to the amplitude frequency response curve and the phase frequency response curve; if not, changing the excitation frequency until reaching the synchronous vibration state.
Because the selectable excitation frequencies are multiple, in order to improve the test efficiency, a node is selected according to the vibration frequency multiplication range of the estimated position and each vibration interval according to the set vibration interval, when one excitation frequency and the blade do not resonate, an adjacent excitation frequency is selected from small to large or from large to small for years, and judgment is carried out again until a synchronous vibration state is achieved, so that the required excitation frequency can be accurately and rapidly found for testing.
According to the application, excitation tests of the rotor blades of the air compressor are carried out through the number of the optical fiber sensors, and acquisition signals of the optical fiber sensors are sent to output acquisition equipment; then calculating the actual amplitude of the blade according to the time deviation of the rotor blade of the compressor reaching any sensor, acquiring the vibration frequency of the blade by adopting a circumferential sine fitting synchronous vibration analysis method, and measuring the vibration characteristics of the rotor blade by a plurality of optical fiber sensors to obtain a amplitude frequency response curve and a phase frequency response curve of each rotor blade; judging whether the blade is in a synchronous vibration state according to the amplitude frequency response curve and the phase frequency response curve, and if so, calculating the dynamic damping ratio of the rotor blade according to the amplitude frequency response curve and the phase frequency response curve. The optical fiber sensor has the advantages that the installation structure is simple, the engine structure is not required to be changed greatly, the service life is long, the multi-mode dynamic damping ratio parameters of all blades of a certain level of rotor can be obtained simultaneously, the accuracy of the vibration amplitude frequency response curve of the blades can be improved by using a plurality of optical fiber sensors, the result of the dynamic damping ratio is more approximate to a true value, and meanwhile, the reference can be provided for the damping design of the rotor blades of the air compressor of the aeroengine.
The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present application should be included in the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (2)
1. The method for testing the dynamic damping ratio of the rotor blade of the air compressor of the aeroengine is characterized by comprising the following steps of:
determining the number of optical fiber sensors, fixing a plurality of optical fiber sensors at the mounting hole of an outer casing of the air compressor along the radial direction, performing an excitation test of a rotor blade of the air compressor, and transmitting acquisition signals of the optical fiber sensors to output acquisition equipment;
obtaining the diameter of a blade, the number of the blades and the rotating speed of a rotor of the air compressor, calculating the actual amplitude of the blade according to the time deviation of the rotor blade of the air compressor reaching any sensor, obtaining the vibration frequency of the blade by adopting a circumferential sine fitting synchronous vibration analysis method, and measuring the vibration characteristics of the rotor blade by a plurality of optical fiber sensors to obtain an amplitude frequency response curve and a phase frequency response curve of each rotor blade;
judging whether the blade is in a synchronous vibration state according to the amplitude frequency response curve and the phase frequency response curve, if so, calculating the dynamic damping ratio of the rotor blade according to the amplitude frequency response curve and the phase frequency response curve; if not, changing the excitation frequency until reaching the synchronous vibration state.
2. The method for testing the dynamic damping ratio of an aircraft engine compressor rotor blade according to claim 1, wherein the circumferential sinusoidal fit synchronous vibration analysis method comprises: setting a target equation:
y i ＝Asin(E o Ωt i +Φ)+C
wherein E is o To the excitation order, y i For the vibration amplitude of the blade, C is the normal deflection of the vibration balance position of the blade, t i Time, Ω is rotational speed frequency;
selecting a frequency multiplication value to substitute into a target equation, and calculating residual errors by using a least square method to obtain:
the simplification is as follows: y=bx;
the residual vector is obtained as follows: r is R k ＝BX k -Y
Known excitation order E o B and Y are obtained through a least square method, a main vibration frequency multiplication range is estimated, then a frequency multiplication value is screwed out of the main vibration frequency multiplication range and substituted into a residual vector, and X is obtained through least square calculation k Then calculating residual error of estimated value and measured value Y to obtain X of residual error minimum value k Namely, the frequency multiplication number of synchronous vibration of the blade is as follows:
ω＝E o Ω。
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| Application Number | Priority Date | Filing Date | Title |
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| CN202310529663.1A CN116577050A (en) | 2023-05-11 | 2023-05-11 | Method for testing dynamic damping ratio of aero-engine compressor rotor blade |
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| CN202310529663.1A CN116577050A (en) | 2023-05-11 | 2023-05-11 | Method for testing dynamic damping ratio of aero-engine compressor rotor blade |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117087871A (en) * | 2023-10-16 | 2023-11-21 | 珠海翔翼航空技术有限公司 | Vibration detection system and method for aircraft brake based on composite parameters |
| CN118168791A (en) * | 2024-05-16 | 2024-06-11 | 中国航发四川燃气涡轮研究院 | Maximum stress equivalent measurement method for stator blade of air compressor |
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2023
- 2023-05-11 CN CN202310529663.1A patent/CN116577050A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117087871A (en) * | 2023-10-16 | 2023-11-21 | 珠海翔翼航空技术有限公司 | Vibration detection system and method for aircraft brake based on composite parameters |
| CN117087871B (en) * | 2023-10-16 | 2023-12-19 | 珠海翔翼航空技术有限公司 | Vibration detection system and method for aircraft brake based on composite parameters |
| CN118168791A (en) * | 2024-05-16 | 2024-06-11 | 中国航发四川燃气涡轮研究院 | Maximum stress equivalent measurement method for stator blade of air compressor |
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