Aero-engine rotor unsteady-state thermally induced vibration test system

Abstract

The invention relates to the technical field of aero-engine rotor vibration tests, in particular to an aero-engine rotor unsteady-state thermally induced vibration test system which comprises a rotor experiment table, an air inlet and exhaust system, a lubricating oil system, a protection system and a heating system. The rotor experiment table comprises a first supporting system, a second supporting system, a rotor outer protection casing, a gas compressor disc, a gas compressor sealing disc, a turbine disc, a turbine front sealing disc, a front shaft diameter, an inter-disc drum, a rear shaft diameter, a first squirrel-cage elastic support, a ball bearing, a second squirrel-cage elastic support and a rolling rod bearing. The first supporting system is composed of a first squirrel-cage type elastic support and a ball bearing, meanwhile, an air inlet is formed in the first supporting system, and the ball bearing in the first supporting system is connected with the front shaft diameter in an interference fit mode. Rotor unsteady-state characteristics considering heating conditions are finally created, and vibration response and durability of a wheel disc structure under the unsteady-state thermal load condition are studied in combination with test conditions such as temperature vibration and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aero-engine rotor vibration test, in particular to an aero-engine rotor unsteady thermal-induced vibration test system. BACKGROUND

[0002] Domestic research work on aero-engine thermal-structure coupling started late, especially lacking experimental research. The airworthiness standards of aircraft and engines have not yet considered thermal-induced vibration problems. Even so, domestic industrial parties have begun to realize that unsteady thermal-structure coupling is an important reason for limiting the maturity of domestic independent research and development technology in engine design and production practice. However, due to the poor repeatability of fault characteristics under whole machine conditions, component-level testers face great technical challenges in non-steady non-uniform temperature field loading, accurate measurement of transient temperature field and structural response, etc., thus leading to slow progress in related basic data accumulation and theoretical research, far from forming a theoretical mechanism and effective method that can guide engine safety design and airworthiness verification.

[0003] Defects of prior art

[0004] 1. Aero-engine rotor test bench

[0005] Traditional rotor test benches have certain limitations in simulating the thermal environment of real aero-engines, especially in creating rapidly changing temperature fields. In real aero-engine operation, the rotor will experience complex temperature changes in a very short time, which are usually related to engine operating conditions such as take-off, flight, and landing. For example, the engine may rapidly heat up during take-off, while rapidly cooling down during landing. This temperature transient has a direct impact on the thermal stress and fatigue life of rotor materials. However, traditional test benches often struggle to accurately reproduce this complex and dynamic temperature environment. Some common reasons include: traditional test benches usually use electric heaters or cooling lines to control temperature. These methods are less efficient in reaching the required high or low temperature levels, especially when rapid temperature changes are needed. The response time of heating and cooling may not be sufficient to simulate the rapid temperature changes in actual flight conditions. Achieving uniform distribution and precise control of rotor surface temperature on the test bench is extremely challenging. Non-uniform temperature distribution can lead to inaccurate test results, which cannot truly reflect the performance of the rotor in the actual working environment.

[0006] 2. Rotor temperature, vibration and deformation measurement

[0007] The way of measuring rotor temperature with thermocouples has the following defects: first, thermocouples are designed to measure the local temperature at their installation location. When a more extensive area temperature distribution is needed, this single-point measurement method is difficult to meet the demand. In complex equipment such as aircraft engine rotors, the data of a single measuring point may not fully reflect the thermal state of the entire component, thereby affecting the overall assessment of the equipment operating state. Second, installing thermocouples on high-speed rotating parts such as rotors involves fixing and wiring issues, which not only increases the complexity of installation, but also may affect the balance and performance of the rotor. In addition, thermocouples are more susceptible to damage in high-temperature, high-speed environments and need to be replaced and maintained regularly. Third, although thermocouples can provide accurate temperature readings, their response time may be slow and not suitable for capturing rapidly changing temperature fields. This may not be ideal in applications where the rotor's temperature changes rapidly during operation.

[0008] The way of measuring rotor vibration with vibration sensors has the following defects: the installation location of the vibration sensor is crucial to the accuracy of the data. Improper installation may lead to misreading, such as if the sensor is installed in a location that is heated or has other environmental interference, it may capture inaccurate vibration data. In addition, installing vibration sensors may require drilling holes or making other modifications to the equipment, which may affect the structural integrity of the equipment.

[0009] 3、The way of measuring rotor deformation with strain gauges or laser displacement sensors has the following defects: strain gauges are mainly used to measure small deformations on the surface of materials, and may not be sensitive or accurate enough for large-scale deformation or overall deformation of large structures. Strain gauges are very sensitive to environmental conditions, such as temperature and humidity changes, which can affect their performance. Strain gauges need to be precisely attached to the measurement point, and the installation process is tedious and prone to errors. Improper installation can directly affect the accuracy of the measurement results. The measurement accuracy of laser displacement sensors depends on the reflective properties of the target surface. Surface roughness, color variation, or different gloss can affect the reflection of laser light, thereby affecting the measurement results. SUMMARY

[0010] To solve the above technical problems, the present application provides an aircraft engine rotor non-steady thermal vibration test system that ultimately creates a rotor non-steady state feature considering heating conditions, combines temperature vibration test conditions, and studies the durability of vibration response and wheel disc structure under non-steady thermal load conditions.

[0011] An aircraft engine rotor non-steady thermal vibration test system of the present application includes a rotor test bench, an air intake and exhaust system, an oil system, a protection system, and a heating system.

[0012] The rotor test bed comprises a first supporting system, a second supporting system, a rotor outer protection casing, a compressor disc, a compressor sealing disc, a turbine disc, a turbine front sealing disc, a front shaft diameter, a disc drum, a rear shaft diameter, a first squirrel-cage elastic support, a ball bearing, a second squirrel-cage elastic support and a roller bearing, the first supporting system is composed of the first squirrel-cage elastic support and the ball bearing, meanwhile, the first supporting system is provided with an air inlet hole, the ball bearing in the first supporting system is connected with the front shaft diameter through interference fit, the turbine disc, the disc drum, the front shaft diameter and the rear shaft diameter are connected through a stop opening positioning bolt, the front shaft diameter is provided with a front rotor supporting hole, the rear shaft diameter is provided with a rear rotor supporting hole, the second supporting system is composed of the second squirrel-cage elastic support and the roller bearing, meanwhile, the second supporting system is provided with an air outlet hole, the rear shaft diameter is connected through the roller bearing in the second supporting system through interference fit, the compressor sealing disc and the turbine front sealing disc are arranged on the turbine disc;

[0013] The inlet and outlet system is provided with three flow paths, and is supplied with air by a ground air source with a pressure of 1 MPa, the first flow path is a main flow purging gas, the main flow purging gas enters from the upper half air inlet seat of the first supporting system, passes through the edge of the compressor disc and the edge of the turbine disc, and is then discharged from the upper air outlet seat of the second supporting system, and then is mixed with the disc cavity temperature regulation flow path and discharged, in order to realize the cooling of the surface of the disc, an air guiding seat is designed on the outer ring end face of the first supporting system to guide air to the rotor outer protection casing and the rotor, and an air guiding seat is designed at the outer ring end face of the ball bearing to guide the cooling air to flow out;

[0014] The second flow path is a disc cavity temperature regulation flow path, which is supplied with air by the first supporting system, enters through the front rotor supporting hole and is discharged through the rear rotor supporting hole,

[0015] In order to realize the disc cavity temperature regulation, an air guiding seat is designed on the first supporting system, a gas collecting chamber is designed inside, teeth are designed at the connection between the two ends of the gas collecting chamber and the rotor, air guiding holes are uniformly distributed in the circumferential direction of the front shaft diameter to guide air to the center of the compressor disc, air guiding holes are also uniformly distributed in the circumferential direction of the rear shaft diameter to guide the disc center cooling air to flow backward, a gas collecting chamber is designed inside the second supporting system, teeth are used for sealing at the connection between the two ends of the gas collecting chamber and the rotor, an air guiding seat is designed on the second supporting system to finally guide the disc center cooling air out, and smooth air flow is realized;

[0016] The third flow path is a bearing sealing flow path, which is supplied with air from the first supporting system, seals the first squirrel-cage elastic support and the ball bearing, and is then discharged from the rear rotor supporting hole after being combined with the second flow path,

[0017] Since the disc core cooling air flow has a certain temperature, in order to prevent the first support system, the second support system and the sliding oil from being affected by the heat of the disc cavity temperature control gas, a sealing cavity is designed between the sliding oil cavity and the disc cavity cooling gas collecting cavity inside the first support system and the second support system, sealing gas is introduced from the outside of the first support system for sealing, the sliding oil cavity is heat insulated, and the sliding oil leakage is prevented;

[0018] The main flow purging flow path in the three flow paths is a separate flow path, and the other two flow paths are intersection flow paths, finally entering the exhaust tower from the gas mixing chamber;

[0019] The sliding oil system is connected with the first support system and the second support system through the inlet and outlet oil pipe lines;

[0020] The heating system adopts high-frequency inductive heating with a heating power of 120KW, the inductive heating coil is fixed inside the protection system at the outer edge of the turbine disc; during the rotation of the rotor, it is necessary to change the thermal environment of the key connection position of the rotor through the heating system, therefore, a corresponding test piece inner flow channel needs to be designed to support the thermal environment required by the rotor test piece, at the same time, the test piece bearing cavity needs to be sealed by sealing gas to prevent the sliding oil from leaking, the rotor disc edge adopts inductive heating, in order to assist heating and improve the heating rate, at the same time, the disc edge is purged after the test to achieve the purpose of rapid cooling;

[0021] The rotor system is driven by a motor, a shaft coupling and the like to create the rotational speed, temperature difference and vibration characteristics of the engine during operation, and the vibration response caused by heat and rotation is studied; during the experiment, the high-speed motor is controlled by the electrical control system, the test piece is driven to rotate at a specific speed through a gear box, a shaft coupling and the like, the rotor disc edge is heated by using the inductive heating system, the appropriate rotor temperature difference is created by using the cold gas flowing into the disc cavity, and the appropriate lubrication characteristics are provided for the bearing by using the sliding oil system, finally, the rotor non-steady state characteristics considering the heating condition are created, the vibration response and the durability of the wheel disc structure under the non-steady state thermal load condition are studied in combination with the temperature vibration and other test conditions.

[0022] Preferably, the compressor disc, the compressor sealing disc, the turbine disc, the turbine front sealing disc, the front shaft diameter, the drum between the discs and the rear shaft diameter form a rotor structure, the joints are all interference fit, the interference amount is designed according to the strength requirement to ensure the coaxiality and connection rigidity, the outer edge of the compressor disc, the compressor sealing disc and the turbine disc is designed with a balanced material removal position, the outer edge of the turbine front sealing disc is designed with a balance screw, a single disc is balanced statically, and the whole assembly is balanced dynamically, the front end of the front shaft diameter is designed with a connecting flange for connecting the output shaft of the gear box.

[0023] Preferably, the first squirrel-cage elastic support and the second squirrel-cage elastic support are externally designed with extruded oil film structures, the first support system and the second support system are designed with oil inlet pipes, oil nozzles, oil return holes and joints for bearing lubricating oil, and are designed with bearing cavity vent holes and joints for cavity pressure relief, the first squirrel-cage elastic support and the second squirrel-cage elastic support are designed with leather cup sealing structures in front and back for sealing lubricating oil between the rotor and the stator, the first squirrel-cage elastic support and the second squirrel-cage elastic support are designed with shaft air inlet holes and sealing cavities, the sealing cavities are sealed between the rotor and the stator by using pen teeth in front and back, the surface of the casing corresponding to the pen teeth is designed with an easy-to-wear coating, in order to prevent the shaft air inlet from affecting the sealing of the bearing leather cup, a separate sealing cavity is designed between the two, air is introduced from the outside to protect the leather cup structure, the sealing cavity is also designed with air inlet holes and joints, and the first squirrel-cage elastic support and the second squirrel-cage elastic support are designed with segmented stator casings between the casings, the casings are positioned by using a stop and are connected by bolts, the stop is matched with a small gap, the first support system and the second support system are opened at the end surface of the casing for observing the turbine disc and the sealing disc stop, the opening is designed with a glass to prevent air leakage, and the casing is designed with an eddy current installation ring.

[0024] Preferably, the first squirrel-cage elastic support and the second squirrel-cage elastic support are designed with two supports below the casings respectively for supporting the experimental piece, the bottom of the support is designed with an adjustment structure to adjust the support height, and the support has a certain axial displacement capacity to adapt to the axial thermal expansion of the experimental piece.

[0025] Preferably, the high-precision synchronous measurement system comprises a temperature acquisition system, a vibration measurement unit, a deformation measurement unit and a data acquisition synchronization unit.

[0026] The temperature acquisition system is used for measuring the transient temperature of the rotor wheel under high-speed working conditions, and adopts a non-contact infrared thermal imager to acquire temperature field data. The temperature acquisition system comprises an infrared thermal imager body, cameras of different wavelengths and different types of filters, can satisfy 640x512 full-resolution thermal image shooting at a maximum of 1004 Hz, and has a temperature measurement range of 1200℃.

[0027] The vibration measurement unit adopts a non-contact laser sensor to acquire vibration data.

[0028] The deformation measurement unit processes and analyzes pictures shot by a high-speed camera to obtain displacement and deformation data of the rotor wheel disc surface. In order to achieve the above-mentioned target, the high-speed camera has a shooting frame rate of 10000 frames / second.

[0029] The data acquisition synchronization unit is used for measuring the rotor deformation and vibration under the action of the non-steady thermal load, and needs to synchronously measure the temperature field data, vibration data and rotor deformation data, and a signal transmitter is used to emit a high-level voltage signal to synchronously trigger the measurement of the temperature field, vibration and deformation data; the data acquisition is completed through a high-speed camera, a laser vibration measuring instrument and an infrared thermal imager; the rotation speed control system and the temperature control system are synchronously triggered with the three data acquisition devices through a synchronous triggering device, and high-precision synchronous measurement is completed; the three-dimensional images of specific positions are captured by using multiple high-speed cameras, and then the deformation, stress and strain are obtained through post-processing; the vibration response of selected components is measured by using a three-dimensional laser vibration measuring instrument; and the temperature field of selected areas is measured by using an infrared thermal imager.

[0030] Preferably, the test piece lubricating oil supply and return system comprises an oil tank for storing oil; two oil supply pumps for providing an oil supply pressure of up to 1MPa; a lubricating oil filter arranged at the oil outlet and the oil return port of the oil tank for filtering particulate matters in the oil to prevent the particulate matters from entering the bearing system; a flow meter for recording the oil supply flow; a return oil pump set comprising two return oil pumps for providing pressure for return oil to prevent the oil from gathering in the bearing system; a brazed heat exchanger for cooling the lubricating oil flowing back to the oil tank; an oil mist separator for discharging the oil mist generated during the experiment from the oil tank; and a pressure gauge, a temperature gauge, a pressure sensor and a temperature sensor for recording the working conditions of the lubricating oil pressure and temperature.

[0031] Preferably, the main flow of the purge gas is mainly used for assisting heating and cooling the rotor test piece, and the maximum flow is 0.5kg, and the gas is supplied at room temperature.

[0032] Preferably, the turbine front sealing disc is made of GH4169 forgings, the compressor disc, the compressor sealing disc, the turbine disc and the drum between the discs are made of 1Cr17Ni2 forgings, the first support system, the second support system and the support are made of 45 steel, and fasteners and joints are standard parts.

[0033] Preferably, the rotor center is 1000mm high, and the rotor span is 1040mm.

[0034] Compared with the prior art, the rotor rotates in the process, and the heat environment of the key connection position of the rotor needs to be changed through a heating system, so that a corresponding flow channel in the test piece is designed to support the heat environment required by the rotor test piece, at the same time, the bearing cavity of the test piece needs to be sealed by sealing gas to prevent lubricating oil from leaking, the rotor disc rim is heated by inductance, in order to assist heating and improve the heating rate, at the same time, the disc rim is purged after the test to achieve the purpose of rapid cooling.

[0035] By driving the rotor system with a motor and coupling, the speed, temperature difference, and vibration characteristics of an engine during operation are simulated to study the vibration response caused by heat and rotation. During the experiment, the high-speed motor is controlled by the electrical control system according to the experimental requirements. The experimental piece is driven to rotate at a specific speed through the gearbox and coupling. At the same time, the rotor disk rim is heated by an inductive heating system, and a suitable rotor temperature difference is created by the flow of cold air into the disk cavity. The bearings are provided with suitable lubrication characteristics through the lubrication system. Finally, the unsteady characteristics of the rotor considering the heating conditions are created. Combined with temperature and vibration test conditions, the vibration response and the durability of the disk structure under unsteady thermal load conditions are studied. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the rotor test bench structure of the present invention;

[0037] Figure 2 This is a schematic diagram of the flow path structure of the rotor experimental piece;

[0038] Figure 3 This is a schematic diagram of the rear bearing sealing flow path structure;

[0039] Figure 4 This is a schematic diagram of the flow path structure for controlling the temperature of the disk cavity;

[0040] Figure 5 This is a schematic diagram of the main flow path purging flow path structure.

[0042] The following labels are used in the attached diagram: 1. First support system; 2. Second support system; 3. Rotor outer protective casing; 4. Compressor disc; 5. Compressor sealing disc; 6. Turbine disc; 7. Turbine front sealing disc; 8. Front shaft diameter; 9. Inter-disc drum; 10. Rear shaft diameter; 11. First squirrel-cage elastic support; 12. Ball bearing; 21. Second squirrel-cage elastic support; 22. Roller bearing. Detailed Implementation

[0043] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0044] Example 1

[0045] like Figures 1 to 5 As shown, the present invention provides a test system for unsteady thermal vibration of an aero-engine rotor, comprising a rotor test bench, an intake and exhaust system, a lubricating oil system, a protection system, and a heating system.

[0046] The rotor test bed comprises a first support system 1, a second support system 2, a rotor outer protection casing 3, a compressor disc 4, a compressor sealing disc 5, a turbine disc 6, a turbine front sealing disc 7, a front shaft diameter 8, a disc drum 9, a rear shaft diameter 10, a first squirrel-cage elastic support 11, a ball bearing 12, a second squirrel-cage elastic support 21 and a roller bearing 22, the first support system 1 is composed of the first squirrel-cage elastic support 11 and the ball bearing 12, and the first support system 1 is provided with an air inlet hole, the ball bearing 12 in the first support system 1 is connected with the front shaft diameter 8 through interference fit, the turbine disc 6, the disc drum 9, the front shaft diameter 8 and the rear shaft diameter 10 are connected through a stop opening positioning bolt, the front shaft diameter 8 is provided with a front rotor support hole, the rear shaft diameter 10 is provided with a rear rotor support hole, the second support system 2 is composed of the second squirrel-cage elastic support 21 and the roller bearing 22, and the second support system 2 is provided with an air outlet hole, the rear shaft diameter 10 is connected with the second support system 2 through the roller bearing 22, and the compressor sealing disc 5 and the turbine front sealing disc 7 are arranged on the turbine disc 6.

[0047] The inlet and outlet system is provided with three flow paths, and is supplied with air from a ground air source with a pressure of 1 MPa, the first flow path is a main flow purging gas, the main flow purging gas enters from the upper half air inlet seat of the first support system 1, passes through the edge of the compressor disc 4 and the edge of the turbine disc 6, and is then discharged from the upper air outlet seat of the second support system 2, and is then discharged after being mixed with the disc cavity temperature regulation flow path, in order to realize the cooling of the surface of the disc, an air guide seat is designed on the outer ring end face of the first support system 1 to guide air to the rotor outer protection casing 3 and the rotor, and an air guide seat is designed at the outer ring end face of the ball bearing 12 to guide the cooling air to flow out, so that the cooling air flows smoothly.

[0048] The second flow path is a disc cavity temperature regulation flow path, which is supplied with air from the first support system 1, enters through the front rotor support hole and is discharged through the rear rotor support hole,

[0049] In order to realize the disc cavity temperature regulation, an air guide seat is designed on the first support system 1, and a gas collection chamber is designed inside, in order to ensure the sealing of the gas collection chamber, teeth are designed at the connection between the two ends and the rotor, circumferentially distributed air guide holes are opened on the front shaft diameter 8 to guide air to the disc core of the compressor disc 4, circumferentially distributed air guide holes are also opened on the rear shaft diameter 10 to guide the disc core cooling air to flow backward, a gas collection chamber is designed inside the second support system 2, and teeth are used for sealing at the connection between the two ends and the rotor, an air guide seat is designed on the second support system 2 to finally guide the disc core cooling air out, so that the air flows smoothly.

[0050] The third flow path is a bearing sealing flow path, which is supplied with air from the first support system 1, seals the first squirrel-cage elastic support 11 and the ball bearing 12, and is then discharged from the rear rotor support hole after being combined with the second flow path,

[0051] In order to prevent the first support system 1, the second support system 2 and the sliding oil from being affected by the heat of the disc cavity temperature control gas, a sealing cavity is designed between the sliding oil cavity and the disc cavity cooling gas collecting cavity in the first support system 1 and the second support system 2, sealing gas is introduced from the outside of the first support system 1 to seal, the sliding oil cavity is heat-insulated, and the sliding oil leakage is prevented;

[0052] The main flow purging flow path in the three flow paths is a separate flow path, and the other two flow paths are intersection flow paths, finally entering the exhaust tower from the gas mixing cavity;

[0053] The sliding oil system is connected with the first support system 1 and the second support system 2 through the inlet and outlet oil pipes;

[0054] The heating system adopts high-frequency inductive heating with a heating power of 120 KW, and the inductive heating coil is fixed on the inside of the protection system and the outer edge of the turbine disc 6;

[0055] The compressor disc 4, the compressor sealing disc 5, the turbine disc 6, the turbine front sealing disc 7, the front shaft diameter 8, the disc drum 9 and the rear shaft diameter 10 form a rotor structure, the joints are all interference fit, the interference amount is designed according to the strength requirement, the coaxiality and the connection rigidity are ensured, the outer edge of the compressor disc 4, the compressor sealing disc 5 and the turbine disc 6 is designed with a balanced material removal position, the outer edge of the turbine front sealing disc 7 is designed with a balance screw, a single disc is balanced statically, and the whole assembly is balanced dynamically, the front end of the front shaft diameter 8 is designed with a connecting flange for connecting the output shaft of the gear box;

[0056] In the embodiment, in the process of rotating the rotor, it is necessary to change the thermal environment of the key connection position of the rotor by the heating system, therefore, the corresponding test piece inner flow channel needs to be designed to support the thermal environment required by the rotor test piece, at the same time, the test piece bearing cavity needs to be sealed by sealing gas to prevent the sliding oil from leaking, the rotor disc edge adopts inductive heating, in order to assist heating and improve the heating rate, at the same time, the disc edge is purged after the test to achieve the purpose of rapid cooling;

[0057] The rotor system is driven by a motor, a shaft coupling and the like to create the rotational speed, temperature difference and vibration characteristics of the engine during operation, the vibration response caused by heat and rotation is researched, during the experiment, the high-speed motor is controlled by the electrical control system, the test piece is rotated at a specific speed by the gear box, the shaft coupling and the like, the rotor disc edge is heated by the inductive heating system, the appropriate rotor temperature difference is created by the cold gas flowing into the disc cavity, the appropriate lubrication characteristics are provided for the bearing by the sliding oil system, finally, the rotor non-steady state characteristics considering the heating condition are created, the vibration response and the durability of the wheel disc structure under the non-steady state thermal load condition are researched in combination with the temperature vibration and other test conditions.

[0058] Embodiment 2

[0059] On the basis of the embodiment, the aero-engine rotor unsteady thermal vibration test system of the application is characterized in that the first squirrel-cage elastic support 11 and the second squirrel-cage elastic support 21 are designed with extruded oil film structures, the first support system 1 and the second support system 2 are designed with oil inlet pipes, oil injection nozzles, oil return holes and joints for bearing lubricating oil, and are designed with bearing cavity vent holes and joints for cavity pressure relief, the first squirrel-cage elastic support 11 and the second squirrel-cage elastic support 21 are designed with leather cup sealing structures in front of and behind the elastic supports for sealing lubricating oil between the rotor and the stator, the first squirrel-cage elastic support 11 and the second squirrel-cage elastic support 21 are designed with shaft center air inlet holes and sealing cavities, the sealing cavities are sealed between the rotor and the stator by using pen teeth in front of and behind the sealing cavities, the surfaces of the cavities corresponding to the pen teeth are designed with easy-to-abrade coatings, a separate sealing cavity is designed between the shaft center air inlet and the leather cup structure to prevent the shaft center air inlet from affecting the sealing of the leather cup, air is introduced from the outside to protect the leather cup structure, the sealing cavity is also designed with air inlet holes and joints, the first squirrel-cage elastic support 11 and the second squirrel-cage elastic support 21 are designed with segmented stator cavities between the cavities, the cavities are positioned by using a stop and are connected by bolts, the stop is matched with a small gap, the first support system 1 and the second support system 2 are designed with openings on the end surfaces of the cavities for observing the turbine disc and the sealing disc stop, the openings are designed with glass to prevent air leakage, and the cavities are designed with eddy current sensor mounting rings;

[0060] The first squirrel-cage elastic support 11 and the second squirrel-cage elastic support 21 are designed with two supports below the cavities respectively for supporting the test piece, the supports are designed with adjustment structures at the bottoms of the supports to adjust the support height, and the supports have a certain axial displacement capacity to adapt to the axial thermal expansion of the test piece;

[0061] The system also comprises a high-precision synchronous measurement system, and the high-precision synchronous measurement system comprises a temperature acquisition system, a vibration measurement unit, a deformation measurement unit and a data acquisition synchronization unit.

[0062] The temperature acquisition system is used for measuring the transient temperature of the rotor wheel under high-speed working conditions, and a non-contact infrared thermal imager is used for temperature field data acquisition, the temperature acquisition system comprises an infrared thermal imager body, cameras of different wavelengths and different types of filters, can meet the requirements of 640*512 full-resolution thermal image shooting at a maximum of 1004 Hz, and the temperature measurement range is 1200℃.

[0063] The vibration measurement unit adopts a non-contact laser sensor to collect vibration data;

[0064] The deformation measurement unit processes and analyzes the pictures taken by the high-speed camera to obtain the displacement and deformation data of the rotor wheel disc surface, in order to achieve the above-mentioned target, the frame rate of the high-speed camera is 10000 frames per second.

[0065] The data acquisition synchronization unit is used for completing the measurement of rotor deformation vibration under the action of non-steady thermal load, and needs to synchronously measure the temperature field data, vibration data and rotor deformation data, a signal transmitter is used for transmitting a high level voltage signal to synchronously trigger the measurement of the temperature field, vibration and deformation data;

[0066] The test piece lubricating oil supply and return system comprises an oil tank for storing oil, two oil supply pumps for providing an oil supply pressure of 1 MPa at most, a lubricating oil filter arranged at the oil outlet and the oil return port of the oil tank for filtering particulate matters in the oil to prevent the particulate matters from entering the bearing system, a flow meter for recording the oil supply flow, a return oil pump set comprising two return oil pumps for providing pressure for return oil to prevent the oil from gathering in the bearing system, a brazed heat exchanger for cooling and cooling down the lubricating oil flowing back to the oil tank, an oil mist separator for discharging oil mist generated in the experiment from the oil tank, and pressure gauges, temperature gauges, pressure sensors and temperature sensors for recording the working conditions of the lubricating oil pressure and temperature.

[0067] The main purpose of the main flow purging gas is to assist in warming and cooling the rotor test piece, and the maximum flow is 0.5 kg at normal temperature.

[0068] The turbine front sealing disc is made of GH4169 forge piece, the compressor disc 4, the compressor sealing disc 5, the turbine disc 6 and the drum 9 between the discs are made of 1Cr17Ni2 forge piece, the first support system 1, the second support system 2 and the support are made of 45 steel, and fasteners and joints at various positions are standard parts.

[0069] The rotor center is 1000 mm high, and the rotor span is 1040 mm.

[0070] In the embodiment, data acquisition is completed by a high-speed camera, a laser vibration meter and an infrared thermal imager, a speed control system, a temperature control system and the three data acquisition devices are synchronously triggered by a synchronous triggering device, and high-precision synchronous measurement is completed, wherein a plurality of high-speed cameras can shoot three-dimensional images at specific positions, and then the deformation, stress and strain thereof can be obtained through post-processing, the vibration response of selected components can be measured by a three-dimensional laser vibration meter, and the temperature field of selected regions can be measured by an infrared thermal imager.

[0071] The main functions realized by the application are as follows:

[0072] 1. Realize rotor thermal vibration influence experiment test: in the rotor rotation process, the heat environment of the key connection position of the rotor is changed by the heating system, the deformation of the connection interface under the action of thermal stress is simulated, the connection stability and the matching state are changed, and the influence on the vibration response is explored;

[0073] 2. Realize temperature loading and thermal load change at the rotor connecting structure and rotor supporting structure, and realize temperature control of the rotor disc rim from room temperature to 650℃;

[0074] 3. Realize measurement of rotor vibration phase and vibration displacement, support system vibration speed and temperature change in the full rotation speed range.

[0075] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A test system for unsteady thermal-induced vibration of an aero-engine rotor, characterized in that, It includes a rotor test bench, intake and exhaust system, lubrication system, protection system, and heating system; The rotor test bench includes a first support system (1), a second support system (2), a rotor outer protective casing (3), a compressor disc (4), a compressor sealing disc (5), a turbine disc (6), a turbine front sealing disc (7), a front shaft diameter (8), an inter-disc drum (9), a rear shaft diameter (10), a first squirrel-cage elastic support (11), a ball bearing (12), a second squirrel-cage elastic support (21), and a roller bearing (22). The first support system (1) is composed of the first squirrel-cage elastic support (11) and the ball bearing (12). At the same time, the first support system (1) has an air inlet. The ball bearing (12) in the first support system (1) The turbine disk (6), the inter-disc drum (9), the front shaft diameter (8) and the rear shaft diameter (10) are connected by a stop-positioning bolt. The front shaft diameter (8) is provided with a front rotor support hole, and the rear shaft diameter (10) is provided with a rear rotor support hole. The second support system (2) is composed of a second squirrel cage elastic support (21) and a roller bearing (22). At the same time, the second support system (2) has an air outlet hole. The rear shaft diameter (10) is connected by an interference fit through the roller bearing (22) in the second support system (2). The compressor sealing disk (5) and the turbine front sealing disk (7) are set on the turbine disk (6). The intake and exhaust system is set with three flow paths, supplied by a ground air source with a pressure of 1MPa. The first flow path is the main purge air. The main purge air enters from the upper part of the first support system (1) and passes through the edge of the compressor disk (4) and the edge of the turbine disk (6) before being discharged from the upper exhaust seat of the second support system (2). After that, it is mixed with the exhaust air from the disk cavity temperature control flow path and then discharged. In order to achieve cooling of the disk surface, an air intake seat is designed on the outer ring end face of the first support system (1) to draw air to the rotor outer protective casing (3) and between the rotor. At the same time, an air intake seat is designed on the outer ring end face of the ball bearing (12) to draw out the cooling air and realize the flow of cooling air. The second flow path is the disk cavity temperature control flow path, which is supplied with air by the first support system (1), enters through the front rotor support hole and exits through the rear rotor support hole. To achieve temperature control of the disk cavity, an air intake seat is designed on the first support system (1), and an air collection chamber is designed inside. To ensure the air collection chamber is sealed, teeth are designed at both ends where it is connected to the rotor. Circumferentially distributed air intake holes are opened on the front shaft diameter (8) to draw air into the center of the compressor disk (4). Circumferentially distributed air intake holes are also opened on the rear shaft diameter (10) to guide the cooling air of the disk center to flow backward. An air collection chamber is designed inside the second support system (2), and teeth are used to seal the connection between the two ends of the air collection chamber and the rotor. An air intake seat is designed on the second support system (2) to finally draw out the cooling air of the disk center, so as to achieve smooth airflow. The third flow path is the bearing sealing flow path. Air is supplied from the first support system (1), and after sealing the first squirrel cage elastic support (11) and ball bearing (12), it merges with the second flow path and is discharged from the rear rotor support hole. Since the cooling airflow in the disk has a certain temperature, in order to prevent the first support system (1), the second support system (2) and the lubricating oil from being affected by the heat of the disk cavity temperature control gas, a sealing cavity is designed between the lubricating oil cavity and the disk cavity cooling gas collection cavity inside the first support system (1) and the second support system (2). Sealing gas is introduced from outside the first support system (1) to seal the lubricating oil cavity, insulate the lubricating oil cavity, and prevent lubricating oil leakage. Of the three flow paths, the main purge flow path is a separate flow path, while the other two flow paths are converging flow paths, and finally enter the exhaust tower through the mixing chamber. The lubricating oil system is connected to the first support system (1) and the second support system (2) through inlet and outlet oil pipes; The heating system uses a high-frequency inductive heating with a heating power of 120KW. The inductive heating coil is fixed inside the protection system and on the outer edge of the turbine disk (6).

2. The unsteady thermal-induced vibration testing system for aero-engine rotors as described in claim 1, characterized in that, The compressor disc (4), compressor sealing disc (5), turbine disc (6), turbine front sealing disc (7), front shaft diameter (8), disc drum (9), and rear shaft diameter (10) form a rotor structure. All stops are interference fits. The interference is designed according to strength requirements to ensure coaxiality and connection rigidity. The outer edges of the compressor disc (4), compressor sealing disc (5), and turbine disc (6) are designed with balancing material removal positions. The outer edge of the turbine front sealing disc (7) is designed with balancing screws. Each disc is statically balanced, and the whole assembly is dynamically balanced. The front end of the front shaft diameter (8) is designed with a connecting flange for connecting the gearbox output shaft.

3. The unsteady-state thermally induced vibration testing system for aero-engine rotors as described in claim 1, characterized in that, The first squirrel-cage elastic support (11) and the second squirrel-cage elastic support (21) are designed with an oil film extrusion structure. The first support system (1) and the second support system (2) are designed with an oil inlet pipe, an oil nozzle, an oil return hole and a connector for bearing lubricating oil, and a bearing cavity vent hole and a connector for cavity depressurization. The first squirrel-cage elastic support (11) and the second squirrel-cage elastic support (21) are designed with a cup seal structure at both the front and the rear for sealing lubricating oil between the rotor and stator. The casing of the first squirrel-cage elastic support (11) and the second squirrel-cage elastic support (21) is designed with a shaft vent hole and a sealing cavity. The sealing cavity is sealed with a toothed rod for sealing between the rotor and stator. The casing surface corresponding to the sealing gear is designed with a wear-resistant coating. To prevent the shaft induced air from affecting the bearing cup seal, a separate sealing cavity is designed between the two to induced air from the outside to protect the cup structure. The sealing cavity is also designed with an induced air hole and a connector. A segmented stator casing is designed between the first squirrel cage elastic support (11) and the second squirrel cage elastic support (21). The casing is positioned by a stop and bolted together. The stop is fitted with a small clearance. The end faces of the first support system (1) and the second support system (2) are open for observing the turbine disk and the sealing disk stop. Glass is designed at the opening to prevent air leakage. An eddy current mounting ring is designed at the casing.

4. The unsteady thermal-induced vibration testing system for aero-engine rotors as described in claim 1, characterized in that, The first squirrel cage elastic support (11) and the second squirrel cage elastic support (21) are respectively designed with two supports below the casing to support the experimental piece. The bottom of the support is designed with an adjustment structure to adjust the support height. The support has a certain axial displacement capacity to adapt to the axial thermal expansion of the experimental piece.

5. The unsteady-state thermally induced vibration testing system for an aero-engine rotor as described in claim 1, characterized in that, It also includes a high-precision synchronous measurement system, which comprises a temperature acquisition system, a vibration measurement unit, a deformation measurement unit, and a data acquisition and synchronization unit; To meet the requirements of measuring the transient temperature of the rotor wheel under high-speed conditions, the temperature acquisition system uses a non-contact infrared thermal imager to collect temperature field data. The temperature acquisition system includes the infrared thermal imager body, cameras of different wavelengths, and different types of filters to meet the requirements of capturing full-resolution thermal images at a maximum of 1004Hz and a temperature measurement range of 1200℃. The vibration measurement unit uses a non-contact laser sensor to acquire vibration data; The deformation measurement unit processes and analyzes the images captured by the high-speed camera to obtain displacement and deformation data of the rotor disk surface. To achieve the above objectives, the high-speed camera captures images at a frame rate of 10,000 frames per second. To complete the measurement of rotor deformation and vibration under unsteady thermal load, the data acquisition synchronization unit requires the synchronous measurement of temperature field data, vibration data, and wheel deformation data. A high-level voltage signal is transmitted by a signal transmitter to trigger the synchronous measurement of temperature field, vibration, and deformation data.

6. The unsteady thermal-induced vibration testing system for aero-engine rotors as described in claim 1, characterized in that, It also includes a test specimen lubricating oil supply and return system, which includes an oil tank for storing oil; two oil pumps providing a maximum oil supply pressure of 1 MPa; and an oil filter with one at the oil outlet and one at the oil return port to filter particulate matter in the oil and prevent it from entering the bearing system. Flow meter: used to record the oil supply flow rate; return oil pump set: includes two units, which provide pressure for the return oil and prevent oil from accumulating in the support system; brazed heat exchanger: to cool the lubricating oil flowing back to the lubricating oil tank; Oil mist separator: discharges the oil mist generated during the experiment from the oil tank; pressure gauge, temperature gauge, pressure sensor, and temperature sensor: used to record the working status of the lubricating oil pressure and temperature.

7. The unsteady thermal-induced vibration testing system for an aero-engine rotor as described in claim 1, characterized in that, The main purpose of the purge gas is to assist in heating and cooling rotor test pieces. The maximum flow rate is 0.5 kg, and it is supplied at room temperature.

8. The unsteady thermal-induced vibration testing system for an aero-engine rotor as described in claim 1, characterized in that, The turbine front sealing disc is made of GH4169 forgings, the compressor disc (4), compressor sealing disc (5), turbine disc (6) and inter-disc drum (9) are made of 1Cr17Ni2 forgings, the first support system (1), the second support system (2) and the support are made of No. 45 steel, and all fasteners and joints are made of standard parts.

9. The unsteady-state thermally induced vibration testing system for an aero-engine rotor as described in claim 2, characterized in that, The rotor center height is 1000mm and the rotor span is 1040mm.

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