Aero-engine vibration imbalance phase testing device and testing method

Abstract

The invention provides an aero-engine vibration phase testing device. The aero-engine vibration phase testing device comprises an optical fiber sensor, a photoelectric converter, a triaxial accelerometer, a vibration analyzer and a test computer. The vibration analyzer is responsible for collecting signals and performing related processing on the signals through a built-in data processing module; and the test computer is connected with the vibration analyzer through the Ethernet to realize data real-time transmission and program end data processing, and is accessed to a test run data monitoring interface. The invention discloses an aero-engine vibration imbalance phase test method. The method comprises the following steps: marking key phase blades; preparation before installation of the optical fiber sensor; installing an optical fiber sensor; performing photoelectric conversion; a triaxial accelerometer is installed; picking up a rotor key phase positioning signal; solving a vibration imbalance phase under multiple rotating speeds; and carrying out counter weight adding test run verification. The method has the advantage that the unbalanced phase is efficiently and accurately obtained. The reliability and accuracy of vibration phase test data are improved, and the follow-up engine balancing quality is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft engine test running, and in particular to an aircraft engine vibration imbalance phase test device and a test method. Background Art

[0002] The vibration problem of modern aircraft engines has always been the most concerned technical issue in the industry, and the engine rotor vibration imbalance phase testing technology is particularly critical, which directly affects the subsequent engine balancing quality and engine test cost.

[0003] The existing aircraft engine vibration imbalance phase test device uses sensors installed at multiple locations on the engine rotor casing to monitor engine vibration and speed, and uses digital signal processing technology to complete the reference phase determination and vibration imbalance phase extraction. Due to the complex rotor-casing structure inside the engine and the high temperature and high pressure working environment of the rotor, the above method cannot directly install optical fiber sensors or other sensors in the engine duct to collect the reference phase, but obtains the rotor vibration reference phase value through indirect test conversion. Summary of the invention

[0004] The present invention proposes an aero-engine vibration imbalance phase test device and test method. Under the premise of not destroying or changing the engine structure, the key phase blade of the high-pressure compressor is marked as the phase reference, and the high-pressure rotor speed signal is picked up by a non-contact optical fiber sensor to pick up the vibration reference phase, thereby realizing the direct test of the rotor vibration reference phase and obtaining the rotor imbalance phase through correlation processing. Compared with the existing method, the reliability and accuracy of the vibration imbalance phase test data are improved, thereby improving the subsequent engine trim quality.

[0005] The invention provides an aircraft engine vibration imbalance phase test device and a test method, comprising a test device and a test method.

[0006] The present invention provides an aero-engine vibration phase test device, comprising an optical fiber sensor, a photoelectric converter, a triaxial accelerometer, a vibration analyzer, and a test computer. The optical fiber sensor is installed near the tip of the engine rotor, and the output end is connected to the input end of the photoelectric converter through an optical fiber extension line; the photoelectric converter converts the optical signal into an electrical signal, and its output end is connected to the input end of the vibration analyzer through a signal line; the triaxial accelerometer is installed on the engine intermediate casing through a vibration bracket, and the output end is connected to the input end of the vibration analyzer through a vibration equipment line adapter box; the vibration analyzer is responsible for collecting signals and performing relevant processing on the signals through a built-in data processing module; the test computer is connected to the vibration analyzer through Ethernet to realize real-time data transmission and program-side data processing, and is connected to the test data monitoring interface.

[0007] The present invention provides an aircraft engine vibration imbalance phase test method, comprising the following steps:

[0008] Step 1: Mark the key phase blades;

[0009] Before the engine is assembled, one blade is selected from the blades of a certain stage of the core rotor high-pressure compressor as a marking blade and sprayed with a special coating. When the optical fiber sensor is used to emit the return spectrum, the ordinary blade and the coated blade have different absorption degrees of the spectrum, which are then converted into different voltage values ​​through the photoelectric converter.

[0010] Step 2: Preparation before installing the fiber optic sensor;

[0011] Here, a fiber optic sensor is used to pick up the engine speed. The maximum operating temperature of the front section of the probe can reach 1200 degrees. Keep the engine rotor stationary. Before installing the fiber optic sensor, remove the engine outer casing and inner casing plugs.

[0012] Step 3: Install the fiber optic sensor;

[0013] Keep the engine rotor stationary, and insert the fiber optic sensor probe into the engine through the engine outer casing hole and inner casing hole.

[0014] Step 4: Perform photoelectric conversion;

[0015] The signal output by the optical fiber sensor is connected to the photoelectric converter for photoelectric conversion.

[0016] Step 5: Install the triaxial accelerometer;

[0017] A vibration bracket is designed, and a triaxial accelerometer is installed on the vibration bracket. The triaxial accelerometer is installed on the outer surface of the engine intermediate casing through the bracket to pick up the horizontal and vertical vibration signals of the engine.

[0018] Step 6: Pick up the rotor key phase positioning signal;

[0019] When the test bench is running, the light signal is shone on the rotor blades. When the marked key phase blades pass through the light signal, a low-amplitude signal is generated, which is transformed and extracted as a reference signal for the rotor unbalance phase.

[0020] Step 7: Obtain the vibration unbalance phase at multiple speeds;

[0021] The vibration signal and the optical fiber speed signal are collected synchronously, and the vibration signal and the optical fiber speed signal are processed by cross-spectrum and the like to obtain the unbalanced phase of the vibration signal at multiple speeds of the engine rotor.

[0022] Step 8: Add counterweight for test run verification;

[0023] According to the influence coefficient method, the vibration unbalance influence coefficient is calculated using the vibration data of two test runs before and after the weight test; the balancing mass and angle are calculated using the initial vibration amount and the calculated unbalance influence coefficient, and a test run is carried out to verify.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The aircraft engine vibration imbalance phase test device and test method described in the present invention adopts an optical fiber sensor, which is suitable for the high temperature and high pressure working environment inside the engine due to its advantages of simple structure, not easily affected by environmental factors, and high sensitivity; a three-axial accelerometer is adopted to pick up the horizontal and vertical multi-directional vibration signals of the engine vibration; a special coating spraying process is used to mark the blades as a reference phase; combined with the powerful signal analysis capability and program-side processing of the vibration analyzer, the imbalance phase is obtained efficiently and accurately. The reliability and accuracy of the vibration phase test data are improved, thereby improving the subsequent engine balancing quality. At the same time, the present invention has good portability, and can be quickly iterated to achieve accurate testing for future new models of engines, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0027] Figure 1 A test flow chart provided for an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the structure of a testing device provided in an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of the structural connection of a test device provided in an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the structure of an optical fiber sensor provided by an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the installation structure of the optical fiber sensor provided in an embodiment of the present invention;

[0032] Figure 6 A schematic diagram of the structure of a tri-axial accelerometer bracket provided in an embodiment of the present invention;

[0033] In the figure, 1 - fiber optic sensor, 2 - photoelectric converter, 3 - triaxial accelerometer, 4 - vibration analyzer, 5 - test computer, 6 - laser connection, 7 - fiber optic receiver connection, 8 - blade tip, 9 - receiving fiber optic, 10 - transmitting fiber optic, 11 - spring top ring, 12 - black arrow on the sensor handle, 13 - fiber optic probe part, 14 - bracket installation left hole, 15 - bracket installation right hole. DETAILED DESCRIPTION

[0034] The present invention will be further explained below in conjunction with specific implementation plans, but the present invention is not limited thereto. The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the restrictive conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0035] The present invention provides an aero-engine vibration phase test device, comprising an optical fiber sensor 1, a photoelectric converter 2, a triaxial accelerometer 3, a vibration analyzer 4, and a test computer 5. The optical fiber sensor 1 is installed near the tip of the engine rotor, and the output end is connected to the input end of the photoelectric converter 2 through an optical fiber extension line; the photoelectric converter 2 converts the optical signal into an electrical signal, and its output end is connected to the input end of the vibration analyzer 4 through a signal line; the triaxial accelerometer 3 is installed on the engine intermediate casing through a vibration bracket, and the output end is connected to the input end of the vibration analyzer 4 through a vibration equipment line adapter box; the vibration analyzer 4 is responsible for collecting signals and performing relevant processing on the signals through a built-in data processing module; the test computer 5 is connected to the vibration analyzer 4 through Ethernet to realize real-time data transmission and program-side data processing, and is connected to the test data monitoring interface.

[0036] The present invention provides an aircraft engine vibration imbalance phase test method, comprising the following steps:

[0037] Step 1: Mark the key phase blades;

[0038] Before the engine is assembled, a blade is selected from the blades of a certain stage of the core rotor high-pressure compressor as a marking blade and sprayed with a special coating. When the optical fiber sensor 1 is used to emit the return spectrum, the ordinary blade and the coated blade have different absorption degrees of the spectrum, which are then converted into different voltage values ​​by the photoelectric converter 2.

[0039] Step 2: Preparation before installing the optical fiber sensor 1;

[0040] Here, the optical fiber sensor 1 is used to pick up the engine speed, and the maximum operating temperature of the front section of the probe can reach 1200 degrees. Keep the engine rotor stationary, and remove the engine outer and inner casing plugs before installing the optical fiber sensor 1. Specifically, it includes removing the engine outer casing plug: install the head of the socket wrench to the hexagonal nut of the secondary borescope hole plug of the outer casing, and turn the wrench counterclockwise; remove the engine inner casing plug: insert the wrench into the threaded hole of the secondary borescope hole seat plug, tighten it, press down the plug, and then turn it 90° clockwise to remove the plug on the borescope hole seat.

[0041] Step 3: Install the optical fiber sensor 1;

[0042] like Figure 4 and Figure 5 As shown, inside the optical fiber sensor is a group of optical fiber bundles, including one emitting optical fiber 10 and six receiving optical fibers 9. The optical fiber sensor is installed on a stationary casing, emitting lasers and receiving the light signals reflected by the blade tips 8 when they pass by, and transmitting them to the subsequent circuit system.

[0043] Keep the engine rotor stationary, and insert the fiber optic sensor probe 13 through the engine outer casing bore probe hole and the inner casing bore probe hole into the engine. Installing the fiber optic sensor on the engine can specifically include: vertically inserting the fiber optic sensor probe 13 into the secondary bore probe hole seat, pressing the sensor down and then turning it 90° clockwise, with the black arrow 12 pointing to the rear of the engine; gently pull the sensor upwards, if the top ring of the spring 11 is locked and the sensor cannot be lifted, it means that the sensor has been completely screwed in.

[0044] Step 4: Perform photoelectric conversion;

[0045] like Figure 2 and Figure 3 As shown, the optical fiber signal output by the optical fiber sensor 1 is connected to the photoelectric converter 2, specifically including: connecting the output end of the optical fiber sensor 1 to the input end Ch1 In of the photoelectric converter 2, and connecting the output end Ch1 Out of the photoelectric converter 2 to the input end CH 1 of the vibration analyzer 4. Flip the photoelectric converter safety switch, and the incident and outgoing light will light up. Step 5: Install the triaxial accelerometer 3;

[0046] like Figure 6 As shown, a vibration bracket is designed, 3 three-axis accelerometers are installed on the vibration bracket, and then installed on the engine intermediate casing through the bracket to pick up the horizontal and vertical vibrations of the engine. Specifically, the 3 three-axis accelerometers are installed on the left side of the engine intermediate casing along the course through the vibration bracket, the screws pass through the left hole 14 of the bracket installation and the right hole 15 of the bracket installation, and the nuts are tightened. The installation direction of the 3 three-axis accelerometers is that the X-axis arrow is vertically upward, and the Z-axis arrow is along the horizontal direction of the engine. Figure 2As shown, the X-axis vertical direction and Z-axis horizontal direction output terminals of the 3 triaxial accelerometers are connected to the input terminals CH 2 and CH 3 of the 4 vibration analyzer respectively.

[0047] Step 6: Pick up the rotor key phase positioning signal;

[0048] When the test bench is running, the fiber optic sensor is used to pick up the high-voltage speed signal. When the fiber optic signal is shone on the high-voltage rotor blade, the marked key phase blade generates a low-amplitude signal when passing the optical signal. A low-amplitude signal appears in every X signals, which is defined as a "low-tooth signal" here. This "low-tooth signal" is used as the singular pulse in the speed pulse signal, that is, the benchmark for the unbalanced phase of the engine vibration. Then, the vibration analyzer DSP module is used to "demodulate" the "low-tooth signal" to generate a rotor-synchronized square wave signal as the benchmark signal for the unbalanced phase of the engine vibration. The vibration signal is the vibration signal of the high-voltage rotor fundamental frequency. Finally, the square wave signal and the vibration signal are "cross-spectrum calculated" to obtain the unbalanced phase of the vibration.

[0049] Step 7: Obtain the vibration unbalance phase at multiple speeds;

[0050] The vibration signal and the optical fiber speed signal are collected synchronously, and the vibration signal and the optical fiber speed signal are processed by cross-spectrum and other methods to obtain the unbalanced phase of the vibration signal at multiple speeds of the engine rotor. The horizontal vibration of the Z axis collected by the three-axis accelerometer is used as the vibration signal for phase calculation, and the vertical vibration of the X axis is used as a backup vibration signal for calculation result verification.

[0051] The vibration imbalance phase is the angle between the rotor phase reference signal and the peak value of the engine rotor fundamental frequency vibration signal. The principle adopted is to synchronously collect the Z-axis horizontal vibration signal and the rotor phase reference signal, perform cross-correlation processing on the vibration signal and the rotor phase reference signal, and obtain the vibration signal phase at multiple engine speeds. Start the engine according to the test procedure, intercept the test data at each speed, and obtain the average value of the phase angle.

[0052] Step 8: Add counterweight for test run verification;

[0053] According to the influence coefficient method, the vibration data of two test runs before and after the test weight are used to calculate the vibration imbalance influence coefficient; the balancing mass and angle are obtained using the initial vibration amount and the calculated imbalance influence coefficient. The test weight size is selected, and the balancing weight is adjusted according to the test calculation results, and the test run verification is carried out. The verification proves that the calculation results of the imbalance phase test are used for engine rotor balancing, and the effect is significant. The proposed method can significantly improve the accuracy and real-time performance of aircraft engine vibration imbalance phase detection, thereby improving the subsequent engine balancing quality.

[0054] Matters not covered by the present invention are known technologies.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An aero-engine vibration phase test device, characterized in that: The aircraft engine vibration phase test device comprises an optical fiber sensor, a photoelectric converter, a triaxial accelerometer, a vibration analyzer, and a test computer; the optical fiber sensor is installed near the tip of the engine rotor, and the output end is connected to the input end of the photoelectric converter through an optical fiber extension line; The photoelectric converter converts the optical signal into an electrical signal, and its output end is connected to the input end of the vibration analyzer through a signal line; the triaxial accelerometer is installed on the intermediate casing of the engine through a vibration bracket, and its output end is connected to the input end of the vibration analyzer through a vibration equipment line adapter box; the vibration analyzer is responsible for collecting the signal and performing relevant processing on the signal through a built-in data processing module; the test computer is connected to the vibration analyzer through Ethernet to realize real-time data transmission and program-side data processing, and is connected to the test data monitoring interface.

2. The aircraft engine vibration imbalance phase test method according to claim 1, comprising the following steps: Step 1: Mark the key phase blades; Before the engine is assembled, one blade is selected from the blades of a certain stage of the core rotor high-pressure compressor as a marking blade and is sprayed with a special coating. When the optical fiber sensor is used to transmit the return spectrum, the ordinary blade and the coated blade have different absorption degrees of the spectrum, which is then converted into different voltage values ​​through the photoelectric converter; Step 2: Preparation before installing the fiber optic sensor; Here, a fiber optic sensor is used to pick up the engine speed. The maximum operating temperature of the front section of the probe is up to 1200 degrees. Keep the engine rotor stationary. Before installing the fiber optic sensor, remove the engine outer casing and inner casing plugs. Step 3: Install the fiber optic sensor; Keep the engine rotor stationary, and insert the fiber optic sensor probe into the engine through the engine outer casing hole and inner casing hole. Step 4: Perform photoelectric conversion; The signal output by the optical fiber sensor is connected to the photoelectric converter for photoelectric conversion; Step 5: Install the triaxial accelerometer; Design a vibration bracket, install the triaxial accelerometer on the vibration bracket, and install it on the outer surface of the engine intermediate casing through the bracket to pick up the horizontal and vertical vibration signals of the engine; Step 6: Pick up the rotor key phase positioning signal; When the test bench is running, the optical signal is shone on the rotor blades. When the marked key phase blades pass through the optical signal, a low amplitude signal is generated, which is transformed and extracted as a reference signal for the rotor unbalance phase; Step 7: Obtain the vibration unbalance phase at multiple speeds; The vibration signal and the optical fiber speed signal are collected synchronously, and the vibration signal and the optical fiber speed signal are processed by cross-spectrum and the like to obtain the unbalanced phase of the vibration signal at multiple speeds of the engine rotor; Step 8: Add counterweight for test run verification; According to the influence coefficient method, the vibration unbalance influence coefficient is calculated using the vibration data of two test runs before and after the weight test; the balancing mass and angle are calculated using the initial vibration amount and the calculated unbalance influence coefficient, and a test run is carried out to verify.

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