Magnetorheological damper-fan rotor similar vibration test bench and design method

Abstract

The invention belongs to the technical field of vibration testing, and relates to a magnetorheological damper-fan rotor similar vibration test bench and a design method thereof. The magnetorheological damper-fan rotor similar vibration test bench comprises an electrical control system for controlling a rotor variable frequency motor; the supporting rigidity is changed through a mouse cage, a magneto-rheological damper and a supporting structure, and a combined supporting rotor system for carrying out a vibration suppression test is carried out; the sensor testing system is used for acquiring vibration signals in real time; and the coil current of the magneto-rheological damper is adjusted, the rigidity of an oil film area is changed, and the vibration suppression control system for suppressing the amplitude of the rotor is realized. The method comprises the steps that a fan rotor system serves as a whole to construct a kinetic equation, and the kinetic equation is converted into a similar relation; and realizing the construction of a distortion similar model of the combined support rotor system based on a strain energy weighted dynamic similar method. By applying different currents or different control algorithms to the damper coil, the coil current is adjusted to change along with the vibration state of the rotor, and vibration suppression of the rotor system is achieved.

Description

Technical Field

[0001] The present invention relates to the field of vibration testing technology, and in particular to a magnetorheological damper-fan rotor similarity vibration test bench and a design method thereof. Background Art

[0002] The rotor-support system is a crucial component of an aircraft engine, serving as the heart of the aircraft. Its performance directly impacts the overall performance of the aircraft. The fan rotor system, a key component of an aircraft engine, faces significant challenges in practical operation, including vibration and bolted joint failure. Over 60% of engine failures are caused by rotor vibration and bolted joint failure.

[0003] Magnetorheological fluids (MRFs), as a new type of intelligent material, have broad application prospects in vibration damping and reduction engineering due to their magnetorheological effects. MR dampers, designed based on MR fluid principles, are reliable flexible support elements that can effectively attenuate vibration and suppress nonlinearity in aircraft engine rotor systems. However, in practical engineering applications, the impact of current on the MR damper's vibration suppression behavior and how to achieve optimal vibration suppression by varying the current magnitude are key limitations that hinder the practical application of this novel device. MR dampers, with their simple structure, easy operation and control, fast response, high control accuracy, and low energy consumption, can effectively improve the performance of aircraft rotor systems. However, rotor support systems using MR dampers operating under high loads and high speeds can cause nonlinear vibrations in the rotor system, significantly impacting aircraft engines. Extensive experimental research and theoretical analysis are still needed to effectively apply MR dampers to rotating machinery. Current research is primarily focused on mechanistic studies, and optimization of damper structure and parameters is insufficient. Furthermore, current magnetorheological dampers, based on semi-active vibration suppression regulated by fixed current, struggle to meet real-time variations in rotor operating conditions. These factors hinder their effectiveness and reliability in aviation engineering applications. However, vibration testing of magnetorheological dampers and aircraft engine fan rotor systems is currently rare among those skilled in the art. Active vibration suppression of rotor systems by actively controlling the damper current remains a key challenge.

[0004] Due to the complex structure, long development cycle, and high testing risks of aircraft engines, there are many limitations in conducting dynamic characteristics testing directly on the entire aircraft. Therefore, similarity theory is used to design a rotor system with an elastic ring squeeze film damper. Its vibration characteristics and nonlinear suppression mechanism are analyzed to reveal the dynamic characteristics of a full-scale aircraft engine.

[0005] Current mainstream squeeze film damper rotor test benches have several drawbacks. In practical engineering applications, their vibration damping performance is unstable and may even lead to rotor instability. Furthermore, a lack of understanding of the damper's dynamics, poor modeling and analysis accuracy, and inadequate design methods have limited its widespread application in high-speed rotating machinery. In practical applications, inappropriate damper design not only fails to improve rotor dynamics but can also exacerbate rotor and overall machine vibration, increasing design risks.

[0006] With the increasing demands for aircraft engine performance, research on vibration suppression in fan rotor systems is urgent. Currently, scholars at home and abroad have recognized the important impact of magnetorheological dampers on aircraft engine rotor systems and have conducted theoretical research on several types of magnetorheological dampers. However, a comprehensive theoretical framework for magnetorheological damper rotor systems is still lacking. Therefore, the application of magnetorheological dampers in fan rotor systems has significant significance and benefits for vibration suppression during engine operation. To achieve this goal, a similar-scale magnetorheological damper rotor system test bench and vibration testing methods for aircraft engine fan rotors with active control capabilities are needed. Summary of the Invention

[0007] In response to the technical problems raised above, a magnetorheological damper-fan rotor similarity vibration test bench and design method are provided. The present invention mainly designs a magnetorheological damper rotor system test bench with bolt connection, and develops a vibration test method applicable thereto. The relationship between the physical quantities of the fan rotor prototype and the scaled model is studied through the similarity relationship of the fan rotor shaft segments and the strain energy distortion similarity theory, and the size parameters of the scaled model are designed according to the dynamic similarity scaled theory. In terms of structure, the present invention introduces a magnetorheological damper and a bolted connection structure into a similar scaled simplified model of the fan rotor system, adopts a DC power supply and a current controller to power the magnetorheological damper coil, controls the system coil current through the current, and then changes the damper oil film bearing capacity to achieve vibration suppression of the rotor system.

[0008] The technical means adopted in the present invention are as follows:

[0009] A magnetorheological damper-fan rotor similar vibration test bench comprises: an electrical control system, a vibration suppression control system, a combined support rotor system and a sensor test system, wherein the combined support rotor system and the sensor test system are arranged on a T-slot, wherein:

[0010] The electrical control system includes an electrical control cabinet and a rotor frequency conversion motor. The electrical control cabinet is provided with an emergency stop button, a motor start button and a control panel for controlling the rotor frequency conversion motor.

[0011] The combined support rotor system includes a rotor and a combined support connected by bolts, and is used to change the support stiffness through a squirrel cage, a magnetorheological damper and a support structure to carry out vibration suppression testing;

[0012] The sensor testing system includes: a sensor bracket and an eddy current sensor for collecting vibration signals in real time and transmitting them to a vibration suppression control system;

[0013] The vibration suppression control system includes a programmable DC power supply, a Dspace control system, and a computer. The Dspace control system is used to receive vibration signals collected in real time by a sensor test system and calculate the output current value through a control algorithm. The programmable DC power supply receives control signals from the Dspace control system to adjust the coil current of the magnetorheological damper, change the stiffness of the oil film area, and suppress the rotor amplitude.

[0014] Furthermore, the combined support is fixed on the bearing seat, and the combined support includes a bearing end cover, a bearing, a squirrel cage, an O-ring and a magnetorheological damper; the squirrel cage is fixed to the damper support by bolts.

[0015] The magnetorheological damper includes: a large end cover of the damper, a small end cover of the damper, a middle part of the damper, a magnetic isolation ring, a coil, a sealing ring, an oil plug and a magnetorheological fluid; the middle part of the damper is connected to the large end cover and the small end cover of the damper by bolts; the magnetorheological fluid is injected through the oil filling port of the middle part of the damper to form an oil film area between the inner sleeve of the squirrel cage and the magnetorheological damper; the coil is arranged in a cavity formed by the middle part of the damper and the large end cover and the small end cover of the damper, and the magnetic field strength of the oil film area is changed by adjusting the current in the coil; the O-ring is installed in the sealing groove between the squirrel cage and the large end cover and the small end cover of the damper to achieve radial sealing of the oil film area; the sealing ring is arranged between the coil and the magnetorheological fluid, and adopts axial end sealing to prevent the magnetorheological fluid from seeping into the space of the coil.

[0016] Furthermore, the rotor connected by bolts includes: a front shaft, a turntable, a front flange, a rear flange, a tension sleeve and a rear shaft, wherein:

[0017] The front axle and the rear axle are connected by multiple groups of bolts fixed on the front flange and the rear flange. The front flange, the rear flange and the rotating disk are fixed on the rotating shaft by a tightening sleeve.

[0018] Furthermore, the sensor testing system also includes a vibration acquisition device, a power amplifier and a Dspace vibration testing device, which are fixed on the sensor bracket. The Dspace vibration testing device is used to collect the axis trajectory, time domain response, frequency response curve and waterfall diagram during the rotor system testing process; the vibration acquisition device is used to collect the vibration signal of the rotor system.

[0019] Furthermore, a rotor variable frequency motor control system is provided inside the electrical control system, and the rotor variable frequency motor control system includes a frequency converter, an AC contactor and a fuse; the emergency stop button and the motor start button are used to control the start and stop of the rotor variable frequency motor, and the frequency converter adjusts the speed of the rotor variable frequency motor.

[0020] Furthermore, the rotor variable frequency motor is fixed on the motor support; the rotor variable frequency motor transmits torque to the combined support rotor system through a flexible coupling.

[0021] Furthermore, a plurality of groups of anchor bolts are provided on the T-slot for fixing the motor support, the bearing seat and the sensor bracket.

[0022] The present invention also provides a design method for a magnetorheological damper-fan rotor similarity vibration test bench, comprising:

[0023] The fan rotor system is taken as a whole to construct the dynamic equation, and the equation analysis method is used to convert the dynamic equation into a similarity relationship;

[0024] The distortion similarity model of the combined support rotor system is constructed based on the dynamic similarity method based on strain energy weighting.

[0025] Furthermore, the fan rotor system is taken as a whole to construct a dynamic equation, and the dynamic equation is converted into a similarity relationship using an equation analysis method, including:

[0026] Taking the fan rotor system as a whole, the dynamic equation is expressed as:

[0027]

[0028] Where m represents the mass of the fan rotor system, c represents the damping of the fan rotor system, k represents the stiffness of the fan rotor system, x represents the vibration displacement of the fan rotor system, e represents the eccentricity of the turntable, and ω represents the rotational speed;

[0029] Using equation analysis, the kinetic equation is converted into a similarity relationship as follows:

[0030]

[0031] Among them, λ m represents the mass similarity ratio, λ x represents the vibration displacement similarity ratio, λ t represents the temporal similarity ratio, λ c represents the damping similarity ratio, λ k represents the stiffness similarity ratio, λ e represents the similarity ratio of the turntable eccentricity, λ ω It indicates the speed similarity ratio;

[0032] Since the speed and time are reciprocals of each other, according to the equation analysis method, the similarity relationship between the speed and time is:

[0033]

[0034] Then the similarity relationship between the turntable eccentricity and vibration displacement is:

[0035] λ x =λ e

[0036] The speed and natural frequency have the same dimension, and the similarity relationship between speed and natural frequency is also the same:

[0037]

[0038] The similarity ratio represents the ratio of the prototype parameters of the fan rotor system to the model parameters of the combined support rotor system.

[0039] Furthermore, the strain energy weighted dynamic similarity method specifically includes:

[0040] λ k is the similarity ratio of the stiffness of the entire system, including the similarity ratio of the stiffness of the first support λ k1 , similarity ratio of the second support stiffness λ k2 and rotor stiffness similarity ratio λ k3 , the strain energy is introduced into the distribution of the rotor system stiffness similarity ratio to achieve the distortion similarity prediction of the combined support rotor system. The specific distribution method is as follows:

[0041]

[0042] Among them, U all is the strain energy of the entire system, U1, U2 and U3 are the strain energies of the first support, the second support and the rotor respectively;

[0043] The shaft stiffness and support stiffness are determined according to the similarity ratio, the dimensional parameters of each section of the rotating shaft and the structural parameters of the support structure and the magnetorheological damper are determined, and the dimensional parameters of the similar scaled model of the magnetorheological damper rotor system are determined. The rotor model for the test is processed and manufactured, and vibration tests are carried out on the processed magnetorheological damper rotor system with bolted connections.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] The magnetorheological damper-fan rotor similar vibration test bench and design method provided by the present invention achieves vibration amplitude suppression of similar rotors by adopting an extruded magnetorheological damper. The present invention achieves technical verification of the application of magnetorheological dampers in engine rotors by simulating the effects of magnetorheological dampers and bolted connection structures in fan rotors, avoiding technical problems such as high cost and high difficulty of real machine experiments. Compared with the existing technology, the solution of the present invention can avoid technical problems such as high cost and high difficulty of real machine experiments, and achieves accurate simulation and testing of the vibration characteristics of the fan rotor system of an aircraft engine by simulating the effects of magnetorheological dampers and bolted connection structures in fan rotors, solving the problem in the existing technology that it is difficult to verify the influence of magnetorheological dampers on fan rotor vibration.

[0046] The magnetorheological damper-fan rotor vibration test bench and design method provided by the present invention simulates and tests the effects of bolted connection structural parameters on aircraft engine fan rotor systems by designing a similar-scale magnetorheological damper rotor system test bench with bolted connections. Compared to existing technologies, the present invention effectively verifies the impact of bolted rotor structure on the vibration characteristics of similar-scale rotors. By adjusting the assembly sequence and number of bolts in the bolted connection structure, tests are conducted to determine the effect of changes in bolted connection structural parameters on the vibration characteristics of a similar-scale magnetorheological damper rotor in a fan rotor. This solves the problem in existing technologies that makes it difficult to accurately assess the impact of bolted connection structures on rotor vibration characteristics.

[0047] The magnetorheological damper-fan rotor vibration test bench and design method provided by this invention utilizes a DC power supply with an adjustable fixed current to power the magnetorheological damper's coil, effectively verifying the effects of varying current intensities on the vibration characteristics of the magnetorheological damper's rotor system. Compared to existing technologies, this solution allows for manual control of the magnetorheological damper by varying fixed currents, thereby varying the stiffness of the damper's oil film. This allows for precise control and testing of the rotor system's vibration characteristics, addressing the existing limitations in studying the effects of current on the vibration characteristics of a magnetorheological damper's similarly scaled rotor system.

[0048] The magnetorheological damper-fan rotor similarity vibration test bench and design method provided by the present invention utilizes a computer to program different active control algorithms into a Dspace control system, effectively verifying their impact on the vibration suppression of the magnetorheological damper rotor system. Compared to existing technologies, the present invention utilizes eddy current sensors to acquire rotor system vibration signals in real time. The Dspace vibration testing device processes the signals, and the Dspace control system calculates the output current based on the vibration signals, adjusting the current in the damper coil in real time to achieve active vibration suppression of the rotor system. This addresses the existing inability to verify the vibration suppression effect of active control algorithms on the magnetorheological damper rotor.

[0049] Based on the above reasons, the present invention can be widely promoted in technical fields such as vibration testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0051] Figure 1 It is a structural schematic diagram of the magnetorheological damper-fan rotor similarity vibration test bench in the present invention.

[0052] Figure 2 Schematic diagram of the vibration suppression control system structure in the present invention.

[0053] Figure 3 It is a schematic diagram of the structure of the electrical control system in the present invention.

[0054] Figure 4 This is a schematic diagram of the rotor structure connected by bolts in the present invention.

[0055] Figure 5 It is a schematic diagram of the combined support structure in the present invention.

[0056] Figure 6 This is a structural diagram of the sensor testing system in the present invention.

[0057] Figure 7 Schematic diagram of vibration characteristic test of similar scaled-down rotor system in an embodiment of the present invention.

[0058] In the figure: 1. Electrical control cabinet; 2. Programmable DC power supply; 3. Dspace control system; 4. Computer; 5. Rotor frequency conversion motor; 6. Flexible coupling; 7. Motor support; 8. Bearing seat; 9. Sensor bracket; 10. T-slot; 11. Emergency stop button; 12. Motor start button; 13. Control panel; 14. Front axle; 15. Turntable; 16. Front flange; 17. Rear flange; 18. Tensioning sleeve; 19. Rear axle; 20. Small end cover of damper; 21. Bearing; 22. Bearing end cover; 23. Coil; 24. Magnetorheological fluid; 25. Middle part of damper; 26. Oil plug; 27. Seal ring; 28. Magnetic isolation ring; 29. ​​Large end cover of damper; 30. O-ring; 31. Squirrel cage; 32. Damper support; 33. Eddy current sensor. DETAILED DESCRIPTION

[0059] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0060] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0061] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0062] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0063] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0064] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0065] like Figure 1 As shown, the present invention provides a magnetorheological damper-fan rotor similar vibration test bench, comprising: an electrical control system, a vibration suppression control system, a combined support rotor system and a sensor test system, wherein the combined support rotor system and the sensor test system are arranged on a T-slot 10, wherein:

[0066] The electrical control system includes an electrical control cabinet 1 and a rotor frequency conversion motor 5. The electrical control cabinet 1 is provided with an emergency stop button 11, a motor start button 12 and a control panel 13 for controlling the rotor frequency conversion motor 5.

[0067] The combined support rotor system includes a rotor and a combined support connected by bolts, and is used to change the support stiffness through a squirrel cage, a magnetorheological damper and a support structure to carry out vibration suppression testing;

[0068] The sensor testing system includes: a sensor bracket 9 and an eddy current sensor 33 for collecting vibration signals in real time and transmitting them to the vibration suppression control system;

[0069] The vibration suppression control system includes a programmable DC power supply 2, a Dspace control system 3, and a computer 4. The Dspace control system 3 is used to receive vibration signals collected in real time by the sensor test system and calculate the output current value through a control algorithm. The programmable DC power supply 2 receives the control signal of the Dspace control system 3 to adjust the coil current of the magnetorheological damper, change the stiffness of the oil film area, and suppress the rotor amplitude.

[0070] In specific implementation, as a preferred embodiment of the present invention, the combined support is fixed on the bearing seat 8, and the combined support includes a bearing end cover 22, a bearing 21, a squirrel cage 31, an O-ring 30 and a magnetorheological damper; the squirrel cage 31 is fixed to the damper support 32 by bolts.

[0071] The magnetorheological damper comprises: a large end cover 29 of the damper, a small end cover 20 of the damper, a middle part 25 of the damper, a magnetic isolation ring 28, a coil 23, a sealing ring 27, an oil plug 26 and a magnetorheological fluid 24; the middle part 25 of the damper is connected to the large end cover 29 of the damper and the small end cover 20 of the damper by bolts; the magnetorheological fluid 24 is injected through the oil filling port of the middle part 25 of the damper to form an oil film area between the inner sleeve of the squirrel cage 31 and the magnetorheological damper; the coil 23 The O-ring 30 is installed in the cavity formed by the damper's middle section 25, the large end cap 29, and the small end cap 20. It modulates the magnetic field strength in the oil film area by adjusting the current in the coil 23. The O-ring 30 is installed in the sealing groove between the cage 31 and the large end cap 29 and the small end cap 20, achieving radial sealing in the oil film area. The sealing ring 27 is installed between the coil 23 and the magnetorheological fluid 24, using an axial end seal to prevent the magnetorheological fluid from seeping into the space between the coils 23. Each damper contains two coils 23.

[0072] In a specific implementation, as a preferred embodiment of the present invention, the rotor connected by bolts includes: a front shaft 14, a turntable 15, a front flange 16, a rear flange 17, a tension sleeve 18 and a rear shaft 19, wherein:

[0073] The front axle 14 and the rear axle 19 are connected by multiple groups of bolts fixed on the front flange 16 and the rear flange 17. The front flange 16, the rear flange 17 and the turntable 15 are fixed on the rotating shaft by a tension sleeve 18.

[0074] A bolted connection structure was designed for the rotor system to verify the vibration suppression effect of the magnetorheological damper and the influence of the bolted connection structure on the rotor system's vibration response. This structure enabled real-time control of the damper coil current through an active control program, enabling similar simulated rotor vibration studies using different control algorithms for the magnetorheological damper rotor system.

[0075] In specific implementation, as a preferred embodiment of the present invention, the sensor testing system also includes a vibration acquisition device, a power amplifier and a Dspace vibration testing device, which are fixed on the sensor bracket 9. The Dspace vibration testing device is used to collect the axis trajectory, time domain response, frequency response curve, and waterfall diagram during the rotor system test process; the vibration acquisition device is used to collect the vibration signal of the rotor system.

[0076] During specific implementation, as a preferred embodiment of the present invention, a rotor variable frequency motor control system is provided inside the electrical control system, and the rotor variable frequency motor control system includes a frequency converter, an AC contactor and a fuse; the emergency stop button 11 and the motor start button 12 are used to control the start and stop of the rotor variable frequency motor 5, and the speed of the rotor variable frequency motor 5 is adjusted by the frequency converter.

[0077] In specific implementation, as a preferred embodiment of the present invention, the rotor variable frequency motor 5 is fixed on the motor support 7; the rotor variable frequency motor 5 transmits torque to the combined support rotor system through the flexible coupling 6.

[0078] In specific implementation, as a preferred embodiment of the present invention, a plurality of groups of anchor bolts are provided on the T-slot 10 for fixing the motor support 7 , the bearing seat 8 and the sensor bracket 9 .

[0079] The present invention also provides a design method for a magnetorheological damper-fan rotor similarity vibration test bench, comprising:

[0080] Reference is made to aircraft engine fan section rotor system data to record the dimensional parameters of the prototype structure. Using the parameters of the fan prototype rotor, a strain energy-weighted dynamic similarity method is used to assign stiffness distortion similarity factors based on the rotor strain energy distribution. This method ensures that the stiffness and mass distribution of the fan rotor prototype and the similar scaled model are consistent. Based on this method, a similar scaled test bench for the fan rotor system is designed.

[0081] The fan rotor system is taken as a whole to construct the dynamic equation, and the equation analysis method is used to convert the dynamic equation into a similarity relationship;

[0082] In a specific implementation, as a preferred embodiment of the present invention, the fan rotor system is taken as a whole to construct a dynamic equation, and the dynamic equation is converted into a similarity relationship using an equation analysis method, including:

[0083] Taking the fan rotor system as a whole, the dynamic equation is expressed as:

[0084]

[0085] Where m represents the mass of the fan rotor system, c represents the damping of the fan rotor system, k represents the stiffness of the fan rotor system, x represents the vibration displacement of the fan rotor system, e represents the eccentricity of the turntable, and ω represents the rotational speed;

[0086] Using equation analysis, the kinetic equation is converted into a similarity relationship as follows:

[0087]

[0088] Among them, λ m represents the mass similarity ratio, λ x represents the vibration displacement similarity ratio, λ t represents the temporal similarity ratio, λ c represents the damping similarity ratio, λ k represents the stiffness similarity ratio, λ e represents the similarity ratio of the turntable eccentricity, λ ω It indicates the speed similarity ratio;

[0089] Since the speed and time are reciprocals of each other, according to the equation analysis method, the similarity relationship between the speed and time is:

[0090]

[0091] Then the similarity relationship between the turntable eccentricity and vibration displacement is:

[0092] λ x =λ e

[0093] The speed and natural frequency have the same dimension, and the similarity relationship between speed and natural frequency is also the same:

[0094]

[0095] The similarity ratio represents the ratio of the prototype parameters of the fan rotor system to the model parameters of the combined support rotor system.

[0096] For the widely used equation analysis method and dimensional analysis method, only when λ k1 ,λ k2 ,λ k3 When they are equal, we can determine λ k However, when designing similar scaled models in actual engineering, it is difficult to ensure that λ k1 ,λ k2 ,λ k3Equal, leading to the distortion similarity problem. The distortion similarity prediction of the combined support rotor system is realized based on the dynamic similarity method weighted by strain energy.

[0097] In specific implementation, as a preferred embodiment of the present invention, the dynamic similarity method based on strain energy weighting specifically includes:

[0098] λ k is the similarity ratio of the stiffness of the entire system, including the similarity ratio of the stiffness of the first support λ k1 , similarity ratio of the second support stiffness λ k2 and rotor stiffness similarity ratio λ k3 , the strain energy is introduced into the distribution of the rotor system stiffness similarity ratio to achieve the distortion similarity prediction of the combined support rotor system. The specific distribution method is as follows:

[0099]

[0100] Among them, U all is the strain energy of the entire system, U1, U2 and U3 are the strain energies of the first support, the second support and the rotor respectively.

[0101] The stiffness of each shaft section of the fan rotor prototype is known, so for the rotor stiffness similarity ratio λ in the above formula k3 , a definite value can be obtained. Similarly, the mass similarity ratio can also be determined, and the stiffness similarity ratio of the entire system is determined according to the distortion similarity relationship.

[0102] The shaft stiffness and support stiffness are determined according to the similarity ratio, the dimensional parameters of each section of the rotating shaft and the structural parameters of the support structure and the magnetorheological damper are determined, and the dimensional parameters of the similar scaled model of the magnetorheological damper rotor system are determined. The rotor model for the test is processed and manufactured, and vibration tests are carried out on the processed magnetorheological damper rotor system with bolted connections.

[0103] Example 1

[0104] This embodiment uses the magnetorheological damper-fan rotor similar vibration test bench of the present invention to verify the influence of the bolted rotor structure on the vibration characteristics of similar scaled rotors. This embodiment is achieved by adding a bolted connection structure to the similar scaled rotor shaft segment, such as Figure 7As shown. The fan shaft section of the aircraft engine rotor realizes the connection between the front and rear shaft sections through a bolt connection structure. After the scaled-down similarity design of each shaft section based on strain energy weighting is carried out, a bolt connection structure is added at the corresponding shaft section position to simulate the prototype rotor. The bolt connection structure connects the front and rear shaft sections together by a stop-bolt connection, and the bolt connection flange is fixed to the rotating shaft by a clamping sleeve. By adjusting the tightness of the clamping sleeve bolts, the position of the bolt connection structure on the rotating shaft can be easily adjusted to change the distance between the front and rear shaft sections, thereby realizing the change of the bolt connection structure and the rotating shaft assembly parameters. When the inner ring of the clamping sleeve is in full contact with the rotating shaft, it can be regarded as that the rotor does not have a bolt connection structure, as shown in FIG. Figure 7 The bolt connection structure requires a total of 10 sets of bolt-nut connections. When the bolt connection parameters need to be adjusted, the number of bolts, bolt arrangement position, and bolt tightening sequence can be changed to conduct a test on the effect of bolt connection structure parameter changes on the vibration characteristics of the fan rotor with a similar-scale magnetorheological damper.

[0105] Example 2

[0106] This example uses the magnetorheological damper-fan rotor similarity vibration test bench described in the present invention to verify the effects of varying current intensities on the vibration characteristics of a magnetorheological damper rotor system. This example uses a DC power supply with an adjustable fixed current to power the four coils of the magnetorheological damper at the rotor's two end supports. The DC power supply has a maximum current of 4A. Manual control is used to apply varying fixed currents to the magnetorheological damper, generating a specific magnetic field in the coils and altering the damper's oil film stiffness in all directions. An electrical control system is used to activate a variable-frequency motor. Eddy current sensors are positioned near the two turntables and the supports, collecting data across the entire speed range and transmitting it to a vibration measurement and acquisition device. Data processing ultimately yields the dynamic vibration characteristics of the rotor system under varying current levels, including axis trajectory, time-domain response, frequency response curve, and waterfall plot. By comparing the dynamic vibration characteristics under varying current levels, the impact of varying current intensities on the vibration characteristics of the magnetorheological damper rotor system is analyzed.

[0107] Example 3

[0108] This embodiment uses the magnetorheological damper-fan rotor similarity vibration test bench of the present invention to verify the effects of different active control algorithms on the vibration suppression of a magnetorheological damper rotor system. This embodiment uses a computer 4 to write different active control algorithms (such as PID control and neural network control) into a Dspace control system 3. Eddy current sensors 33 are used to collect vibration signals in real time from different measurement points in the rotor system in both the X and Y directions. The vibration displacement signals are then negatively fed back to a Dspace controller. The Dspace vibration test device processes the signals, and the Dspace control system calculates the output current based on the vibration signals, changing the current in the damper coil in real time to achieve active vibration suppression of the rotor system. By plotting the axis trajectory, time domain response, frequency response curve, and waterfall plot of the dynamic vibration characteristics of the magnetorheological damper rotor system under different control algorithms, the dynamic characteristics of the rotor system under different control algorithms are compared, and the effects of different active vibration suppression technologies on the real-time control of rotor vibration displacement are analyzed.

[0109] Example 4

[0110] This embodiment uses the magnetorheological damper-fan rotor similar vibration test bench of the present invention to verify the influence of the turntables with different masses and different positions on the vibration characteristics of similar scaled rotors. This embodiment is achieved by changing the turntable mass parameters on the similar scaled rotor shaft segment through the expansion sleeve, such as Figure 4 As shown in the figure, the fan shaft section of an aircraft engine rotor is connected to a turntable via a locking sleeve to simulate the mass distribution of the prototype rotor fan shaft section. The turntable is fixed to the shaft via the locking sleeve. Adjusting the tension of the locking sleeve bolts allows for easy adjustment of the turntable's position on the shaft. Turntables of varying masses and moments of inertia can also be replaced, changing the model rotor's mass parameters to simulate different fan mass distributions. Screws can also be installed at different positions in the threaded holes on the turntable's edge to change the rotor system's mass eccentricity parameters. This allows for testing the effects of rotor mass parameter changes on the vibration characteristics of a similar-scale magnetorheological damper rotor.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetorheological damper-fan rotor similarity vibration test bench, characterized in that: include: An electrical control system, a vibration suppression control system, a combined support rotor system and a sensor testing system, wherein the combined support rotor system and the sensor testing system are arranged on a T-slot (10), wherein: The electrical control system comprises an electrical control cabinet (1) and a rotor frequency conversion motor (5); the electrical control cabinet (1) is provided with an emergency stop button (11), a motor start button (12) and a control panel (13) for controlling the rotor frequency conversion motor (5); The combined support rotor system includes a rotor and a combined support connected by bolts, and is used to change the support stiffness through a squirrel cage, a magnetorheological damper and a support structure to carry out vibration suppression testing; The sensor testing system comprises: a sensor bracket (9) and an eddy current sensor (33) for collecting vibration signals in real time and transmitting the signals to a vibration suppression control system; The vibration suppression control system comprises a programmable DC power supply (2), a Dspace control system (3), and a computer (4); the Dspace control system (3) is used to receive vibration signals collected in real time by a sensor test system and calculate an output current value through a control algorithm; the programmable DC power supply (2) receives a control signal from the Dspace control system (3) to adjust the coil current of a magnetorheological damper, change the stiffness of an oil film region, and achieve suppression of rotor amplitude.

2. The magnetorheological damper-fan rotor similarity vibration test bench according to claim 1, characterized in that: The combined support is fixed on the bearing seat (8), and the combined support includes a bearing end cover (22), a bearing (21), a squirrel cage (31), an O-ring (30) and a magnetorheological damper; the squirrel cage (31) is fixed on the damper support (32) by bolts; The magnetorheological damper comprises: a damper large end cover (29), a damper small end cover (20), a damper middle part (25), a magnetic isolation ring (28), a coil (23), a sealing ring (27), an oil plug (26) and a magnetorheological fluid (24); the damper middle part (25) is connected to the damper large end cover (29) and the damper small end cover (20) by bolts; the magnetorheological fluid (24) is injected through the oil injection port of the damper middle part (25) to form an oil film area between the inner sleeve of the squirrel cage (31) and the magnetorheological damper; the coil ( The coil (23) is arranged in a cavity formed by the middle part (25) of the damper and the large end cover (29) and the small end cover (20) of the damper, and the magnetic field strength of the oil film area is changed by adjusting the current in the coil (23); the O-ring (30) is installed in a sealing groove between the squirrel cage (31) and the large end cover (29) and the small end cover (20) of the damper to achieve radial sealing of the oil film area; the sealing ring (27) is arranged between the coil (23) and the magnetorheological fluid (24), and adopts axial end sealing to prevent the magnetorheological fluid from penetrating into the space of the coil (23).

3. The magnetorheological damper-fan rotor similarity vibration test bench according to claim 1, characterized in that: The rotor connected by bolts comprises: a front shaft (14), a rotating disk (15), a front flange (16), a rear flange (17), a tightening sleeve (18) and a rear shaft (19), wherein: The front axle (14) and the rear axle (19) are connected by multiple groups of bolts fixed on the front flange (16) and the rear flange (17); the front flange (16), the rear flange (17) and the rotating disk (15) are fixed on the rotating shaft by a tightening sleeve (18).

4. The magnetorheological damper-fan rotor similarity vibration test bench according to claim 1, characterized in that: The sensor test system also includes a vibration acquisition device, a power amplifier and a Dspace vibration test device, which are fixed on the sensor bracket (9). The Dspace vibration test device is used to collect the axis trajectory, time domain response, frequency response curve and waterfall diagram during the rotor system test process; and the vibration acquisition device is used to collect the vibration signal of the rotor system.

5. The magnetorheological damper-fan rotor similarity vibration test bench according to claim 1, characterized in that: A rotor frequency conversion motor control system is provided inside the electrical control system, and the rotor frequency conversion motor control system includes a frequency converter, an AC contactor and a fuse; the emergency stop button (11) and the motor start button (12) are used to control the start and stop of the rotor frequency conversion motor (5), and the frequency converter adjusts the speed of the rotor frequency conversion motor (5).

6. The magnetorheological damper-fan rotor similarity vibration test bench according to claim 5, characterized in that: The rotor frequency conversion motor (5) is fixed on a motor support (7); the rotor frequency conversion motor (5) transmits torque to the combined support rotor system through a flexible coupling (6).

7. The magnetorheological damper-fan rotor similarity vibration test bench according to claim 1, characterized in that: The T-slot (10) is provided with a plurality of anchor bolts for fixing the motor support (7), the bearing seat (8) and the sensor bracket (9).

8. A method for designing a magnetorheological damper-fan rotor similar vibration test bench based on the magnetorheological damper-fan rotor similar vibration test bench described in any one of claims 1 to 7, characterized in that: include: The fan rotor system is taken as a whole to construct the dynamic equation, and the equation analysis method is used to convert the dynamic equation into a similarity relationship; The distortion similarity model of the combined support rotor system is constructed based on the dynamic similarity method based on strain energy weighting.

9. The magnetorheological damper-fan rotor similarity vibration test bench design method according to claim 8 is characterized in that: The fan rotor system is taken as a whole to construct a dynamic equation, and the dynamic equation is converted into a similarity relationship using an equation analysis method, including: Taking the fan rotor system as a whole, the dynamic equation is expressed as: Where m represents the mass of the fan rotor system, c represents the damping of the fan rotor system, k represents the stiffness of the fan rotor system, x represents the vibration displacement of the fan rotor system, e represents the eccentricity of the turntable, and ω represents the rotational speed; Using equation analysis, the kinetic equation is converted into a similarity relationship as follows: Among them, λ m represents the mass similarity ratio, λ x represents the vibration displacement similarity ratio, λ t represents the temporal similarity ratio, λ c represents the damping similarity ratio, λ k represents the stiffness similarity ratio, λ e represents the similarity ratio of the turntable eccentricity, λ ω It indicates the speed similarity ratio; Since the speed and time are reciprocals of each other, according to the equation analysis method, the similarity relationship between the speed and time is: Then the similarity relationship between the turntable eccentricity and vibration displacement is: l x =λ e The speed and natural frequency have the same dimension, and the similarity relationship between speed and natural frequency is also the same: The similarity ratio represents the ratio of the prototype parameters of the fan rotor system to the model parameters of the combined support rotor system.

10. The magnetorheological damper-fan rotor similarity vibration test bench design method according to claim 8, characterized in that: The dynamic similarity method based on strain energy weighting specifically includes: λ k is the similarity ratio of the stiffness of the entire system, including the similarity ratio of the stiffness of the first support λ k1 , similarity ratio of the second support stiffness λ k2 and rotor stiffness similarity ratio λ k3 , the strain energy is introduced into the distribution of the rotor system stiffness similarity ratio to achieve the distortion similarity prediction of the combined support rotor system. The specific distribution method is as follows: Among them, U all is the strain energy of the entire system, U1, U2 and U3 are the strain energies of the first support, the second support and the rotor respectively; The shaft stiffness and support stiffness are determined according to the similarity ratio, the dimensional parameters of each section of the rotating shaft and the structural parameters of the support structure and the magnetorheological damper are determined, and the dimensional parameters of the similar scaled model of the magnetorheological damper rotor system are determined. The rotor model for the test is processed and manufactured, and vibration tests are carried out on the processed magnetorheological damper rotor system with bolted connections.

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