A rotor rubbing-induced internal resonance characteristic research system and research method

Abstract

A rotor rubbing induced internal resonance characteristic research system comprises an R1 rotor, an R2 rotor, an M1 disk, an M2 disk, a ring, a displacement sensor and a speed sensor; a driving motor sequentially connects the R1 rotor and the R2 rotor through a spring coupling, the R1 rotor and the R2 rotor are in a vertical posture, a vertical key phase mark is provided on the R1 rotor, and the speed sensor is arranged at a position opposite to the key phase mark; the M1 disk is locked on the R1 rotor through a self-locking structure, and the position of the M1 disk on the R1 rotor is adjustable; the M2 disk is fixed to the lowermost end of the R2 rotor; the ring is fixed above the M2 disk in an adjustable manner, the ring is in a horizontal posture, and the R2 rotor passes through the center point of the ring; the displacement sensor is arranged on the outside of the ring, and the present invention simulates the rotor motion by building an experimental platform, adopts a displacement sensor to directly measure the lateral displacement data of the rotor to obtain the rotor axis trajectory, and combines the simulation result of a simulation machine, combines theory with practice, and explores the motion characteristics of the rotor when the internal resonance phenomenon occurs.

Description

Technical Field

[0001] The invention belongs to the technical field of rotating machinery collision detection, and in particular relates to a rotor rubbing-induced internal resonance characteristic research system and a research method thereof. Background Art

[0002] When the engine is working, various loads act on the rotor and stator. Some of these loads are offset or partially offset in the parts themselves or in adjacent parts, and the total residual loads such as thrust, residual torque, gravity, maneuvering overload, etc. are transmitted to the aircraft through the engine installation section. Some components not only bear their own loads or the loads of the assembly, but also transmit the loads of adjacent components. The casing (shell) and components that bear and transmit these loads constitute the engine's stator load-bearing system.

[0003] For flexible rotor systems, the sudden increase in effective stiffness due to contact also makes the global response nonlinear. During abnormal operation of rotating machinery, rotor-to-stator contact friction may occur. Friction involves several physical phenomena, most notably impact, rubbing, and the increase in stiffness when maintaining contact, so the system properties become highly nonlinear.

[0004] At present, acceleration sensors are commonly used in China to measure data and calculate axis trajectory, which results in large errors. However, leading foreign companies use high-speed cameras and other methods to measure, which results in small errors. Once internal resonance occurs in an aircraft engine, it will bring about a huge disaster, so this project will be committed to solving this technical problem. Summary of the invention

[0005] The purpose of the present invention is to simulate the motion of the rotor by building an experimental platform, depict the motion trajectory of the rotor with the help of a displacement sensor, and then explore the motion characteristics when the rotor rubs and produces internal resonance.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a rotor friction-induced internal resonance characteristic research system, comprising an R1 rotor, an R2 rotor, an M1 disk, an M2 disk, a ring, a displacement sensor, and a speed sensor; the motor is connected to one end of the R1 rotor through a spring coupling, and the other end of the R1 rotor is connected to one end of the R2 rotor through a spring coupling, the R1 rotor and the R2 rotor are in a vertical posture, a vertical key phase mark is provided on the R1 rotor, and the key phase mark is parallel to the axial center line of the R1 rotor; the speed sensor is provided at a position opposite to the key phase mark, and is used to obtain the R1 rotor. The key phase signal is generated when the rotor rotates; the M1 disc is locked on the R1 rotor through a self-locking structure, and the M1 disc can adjust its position on the R1 rotor; the M2 disc is fixed at the bottom of the R2 rotor; the M1 disc and the M2 disc are used to simulate the real rotor load system to make the R1 rotor and the R2 rotor rotate stably; the ring is fixed above the M2 disc in an adjustable way, the ring is in a horizontal posture, and the R2 rotor passes through the center point of the ring. The ring is used to limit the displacement of the R2 rotor when it rotates; the displacement sensor is set on the outside of the ring to obtain the displacement data of the R2 rotor when it rotates.

[0007] Furthermore, the aforementioned research system also includes a device frame for supporting an external drive motor, and the device frame is composed of a top plate, a bottom plate, and at least 4 support columns, and each support column is vertically supported between the top plate and the bottom plate, and the top plate and the bottom plate are in a relative posture; each device of the system is placed between the top plate and the bottom plate; an opening is opened in the top plate for connecting the motor above the top plate with the R1 rotor under the top plate.

[0008] Furthermore, the aforementioned device frame also includes an intermediate plate, which is arranged between the M1 disk and the ring to fix the ring; a hole is opened on the intermediate plate for the R1 rotor and the R2 rotor to pass through; the intermediate plate and each fixing point of the ring are connected by thin columns respectively; at least one connection between the intermediate plate and each supporting column, the connection between the ring and each thin column, and the connection between the intermediate plate and each thin column is connected in an adjustable manner to achieve adjustable position of the ring in the vertical direction.

[0009] Furthermore, the research method based on the above rotor rubbing induced internal resonance characteristic research system includes the following steps:

[0010] S1: Start the motor, the motor drives the R1 rotor and the R2 rotor to rotate, the speed gradually increases, the speed sensor 10 obtains the key phase signal of the R1 rotor, and the displacement sensor obtains the displacement signal of the R2 rotor, until the displacement signal has a peak value, and the phase difference between the displacement signal and the key phase signal is 180°, the current speed is recorded as the critical speed;

[0011] S2: The stiffness and damping that should be set for the simulator are calculated based on the critical speed, and the initial parameters of the simulator are set with the calculated stiffness and damping, and the simulator starts simulating;

[0012] S3: Using the internal resonance characteristic research system, a simulation experiment is started from a speed of 0, and the speed is increased in an orderly manner to a preset maximum speed. The following operations are repeated at each speed: after the R2 rotor enters a steady state for the first time, an instantaneous disturbance is applied to the R2 rotor laterally, and after the R2 rotor enters a steady state again, a displacement peak value of the R2 rotor in the steady state is obtained through a displacement sensor; if the R2 rotor collides with the ring, the radius of the ring is recorded as the displacement peak value of the R2 rotor;

[0013] S4: Using the speeds obtained in S3 and the displacement peaks of the R2 rotor at each speed, a bifurcation diagram is drawn, and the internal resonance speed range is obtained through the bifurcation diagram; wherein the horizontal axis of the bifurcation diagram is the speed, and the vertical axis is the displacement peak;

[0014] S5: Select a preset number of speeds in the internal resonance speed range in order, and conduct simulation experiments again at each selected speed. The displacement sensor records the real-time displacement data of the R2 rotor at each speed, and generates the axis trajectory diagram at each speed. Compare the shape of each axis trajectory diagram with the axis trajectory diagram simulated by the simulator to explore the characteristics of the axis trajectory diagram when the rotor resonates internally.

[0015] S6: Based on the axis trajectory diagram of the R2 rotor at each speed obtained in S5, a displacement time domain curve diagram of the R2 rotor at each speed is generated based on a preset direction, wherein the horizontal axis of the displacement time domain curve diagram is time, and the vertical axis is the displacement in the preset direction;

[0016] S7: First, perform Fourier transform on the time domain curves at each speed to obtain the frequency spectrum of each time domain curve. Then, obtain the forward vortex frequency and reverse vortex frequency at each speed from each frequency spectrum, and calculate the forward and reverse vortex frequency ratio. Then, compare the forward and reverse vortex frequency ratio at each speed with the forward and reverse vortex frequency ratio simulated by the simulator to explore the characteristics of the forward and reverse vortex frequency ratio when the rotor resonates.

[0017] The rotor rubbing-induced internal resonance characteristic research system and research method of the present invention adopt the above technical scheme and have the following technical effects compared with the prior art:

[0018] 1. The present invention simulates the rotor motion by building an experimental platform, and combines the simulation results of the simulator, combines theory with practice, obtains the rotor motion trajectory, and explores the motion characteristics of the rotor when it produces internal resonance;

[0019] 2. The present invention uses a displacement sensor to directly measure the lateral displacement data of the rotor, thereby obtaining the axis trajectory. Compared with the traditional method of indirectly measuring the axis trajectory displacement through an acceleration sensor, the experimental method of the present invention is simple, has a small amount of calculation, a small measurement error, and a more accurate simulation of the resonant motion of the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a rendering of a rotor friction-induced internal resonance characteristic research system in the present invention;

[0021] Figure 2 It is a front view of the rotor friction-induced internal resonance characteristic research system of the present invention;

[0022] Figure 3 This is a left view of the rotor rubbing-induced internal resonance characteristic research system of the present invention;

[0023] Figure 4 is a bifurcation diagram drawn according to real experimental data in this embodiment;

[0024] Figure 5 This is a diagram of the axis trajectory of the rotor during internal resonance obtained from a real experiment in this embodiment;

[0025] Figure 6 is a time domain curve diagram of the displacement of the R2 rotor in this embodiment;

[0026] Figure 7 It is a spectrum diagram obtained by Fourier transform in this embodiment. DETAILED DESCRIPTION

[0027] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0028] Various aspects of the invention are described herein with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the invention are not limited to those described in the accompanying drawings. It should be understood that the invention is implemented by any of the various concepts and embodiments described above, as well as the concepts and embodiments described in detail below, because the concepts and embodiments disclosed in the invention are not limited to any implementation. In addition, some aspects disclosed in the invention may be used alone or in any appropriate combination with other aspects disclosed in the invention.

[0029] In this embodiment, if Figure 1As shown, a rotor friction-induced internal resonance characteristic research system comprises a device frame 1, a thin column 3, an intermediate plate 11, an R1 rotor 7, an R2 rotor 8, an M1 disk 5, an M2 disk 6, a ring 4, a displacement sensor 9, and a speed sensor 10; the device frame 1 is composed of a top plate, a bottom plate, an intermediate plate 11 and four support columns, each support column is vertically supported between the top plate and the bottom plate, the intermediate plate 11 is arranged between the top plate and the bottom plate, and the top plate, the intermediate plate 11 and the bottom plate are in a relative posture; a hole is provided on the top plate, and the motor placed on the top plate is connected to the R1 rotor 7 under the top plate; the other end of the R1 rotor 7 is connected to one end of the R2 rotor 8 through a spring coupling, and the R1 rotor 7 and the R2 rotor 8 are in a vertical posture; a hole is provided on the intermediate plate 11 for the R1 rotor 7 and the R2 rotor 8 to pass through; a vertical key is provided on the R1 rotor 7 Phase mark, the key phase mark is parallel to the axial center line of the R1 rotor 7; the speed sensor 10 is set at a position opposite to the key phase mark, the M1 disk 5 is locked on the R1 rotor 7 through a self-locking structure, and the M1 disk 5 can adjust its position on the R1 rotor 7; the M2 disk 6 is fixed at the lower end of the R2 rotor 8; the ring 4 is connected to the middle plate 11 through four thin columns 3, and four nuts are respectively provided at the connection to adjust the distance between the ring 4 and the middle plate 11 and keep the ring 4 in a horizontal posture; the displacement sensor 9 is set on the outside of the ring 4; the middle plate 11 is set between the M1 disk 5 and the M2 disk 6, and holes are opened at the four corners of the middle plate 11 to pass through the four supporting columns of the device frame 1, and four locking devices are respectively provided at the four corners of the middle plate 11 to achieve the adjustable position of the middle plate 11 and keep the middle plate 11 in a horizontal posture.

[0030] Based on the friction induction research system in this embodiment, the rotor internal resonance characteristic research is realized by the following method:

[0031] Step 1: Detect the critical speed of the rotor

[0032] Start the motor, the motor drives the R1 rotor 7 and the R2 rotor 8 to rotate, the speed gradually increases from 0 rpm, the speed sensor 10 obtains the key phase signal of the R1 rotor 7, and the displacement sensor 9 obtains the displacement signal of the R2 rotor 8, until the displacement signal has a peak value, and the phase difference between the displacement signal and the key phase signal is 180°, the current speed is recorded as the critical speed;

[0033] Step 2: Calculate the critical speed under the experiment and set the initial parameters of the simulation machine

[0034] The stiffness and damping that should be set for the simulator are calculated from the critical speed, and the initial parameters of the simulator are set with the calculated stiffness and damping, and the simulator starts simulating. The purpose of adjusting the simulator parameters in this way is to make the actual experiment and the simulation experiment as close as possible, so that the experimental results can be mutually verified, thereby better determining the resonance characteristic mechanism within the rotor.

[0035] Step 3: Simulate the real experiment and record the peak displacement at each speed steady state

[0036] The internal resonance characteristic research system is used to simulate a real experiment starting from a speed of 0, and the speed is increased in an orderly manner to a preset maximum speed. The following operations are repeated at each speed: after the R2 rotor 8 enters a steady state for the first time, an instantaneous disturbance is applied to the R2 rotor 8 laterally, and after the R2 rotor 8 enters a steady state again, the displacement peak value of the R2 rotor 8 in the steady state is obtained through the displacement sensor 9; if the R2 rotor 8 collides with the ring 4, the radius of the ring 4 is recorded as the displacement peak value of the R2 rotor 8;

[0037] Step 4: Draw a bifurcation diagram based on the recorded data to obtain the internal resonance speed range

[0038] Using the speeds obtained by S3 and the displacement peaks of the R2 rotor 8 at each speed, a bifurcation diagram is drawn, as shown in Figure 4 As shown in the figure, the internal resonance speed range is obtained through the bifurcation diagram; the dense area shown in the figure is the resonance speed range. Among them, the horizontal axis of the bifurcation diagram is the speed, and the vertical axis is the displacement peak;

[0039] Step 5: Draw the axis trajectory diagram at each internal resonance speed and explore the characteristics of the axis trajectory diagram;

[0040] 50 groups of speeds are selected in order within the internal resonance speed range, and simulation experiments are conducted again at each selected speed. The displacement sensor 9 records the real-time displacement data of the R2 rotor 8 at each speed, and generates the axis trajectory diagram at each speed; the shape of each axis trajectory diagram is compared with the axis trajectory diagram simulated by the simulator. Figure 5 As shown, within the allowable error range, the axis trajectory diagram presents a non-alternating petal shape when the rotor resonates internally.

[0041] Step 6: Generate a displacement time domain curve graph from the axis trajectory graph

[0042] Based on the axis trajectory diagram of the R2 rotor 8 at each speed obtained in step 5, a direction is selected to generate a displacement time domain curve diagram of the R2 rotor 8 at each speed, such as Figure 6 As shown, the horizontal axis of the displacement time domain curve graph is time, and the vertical axis is the displacement in the selected direction;

[0043] Step 7: Generate a spectrum diagram from the displacement time domain curve to explore the relationship between the forward and reverse vortex frequencies

[0044] First, perform Fourier transform on the time domain curves at each speed to obtain the frequency spectrum of each time domain curve, and obtain the positive vortex frequency and the reverse vortex frequency at each speed from each frequency spectrum, such as Figure 7As shown, the forward and reverse vortex frequency ratio is calculated, and then the forward and reverse vortex frequency ratio at each speed is compared with the forward and reverse vortex frequency ratio simulated by the simulator. The actual experimental results and the simulation experimental results show that, within the allowable error range, the reverse vortex frequency is 2 to 3 times the forward vortex frequency when the rotor resonates.

[0045] A rotor rubbing-induced internal resonance characteristic research system proposed in the present invention is used to simulate a real rotor system, and the motion characteristics of the rotor when internal resonance occurs are explored according to the research method proposed in the present invention. The experimental results are basically consistent within the allowable error range, which verifies that the research system proposed in the present invention is effective and can accurately simulate the motion of the rotor internal resonance.

[0046] Although the present invention has been described above with preferred embodiments, it is not intended to limit the present invention. A person skilled in the art of the present invention may make various modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the definition of the claims.

Claims

1. A rotor friction-induced internal resonance characteristics research system, It is characterized in that Including R 1 Rotor (7), R 2 Rotor (8), M 1 Disc (5), M 2 The disk (6), the ring (4), the displacement sensor (9), the rotation speed sensor (10); the R 1 One end of the rotor (7) is connected to the motor through a spring coupling, R 1 The other end of the rotor (7) is connected to R through a spring coupling. 2 One end of the rotor (8), R 1 Rotor (7) and R 2 The rotor (8) is in a vertical position, R 1 The rotor (7) is provided with a vertical key phase mark parallel to R 1 The rotation speed sensor (10) is arranged at a position opposite to the key phase mark, and is used to obtain R 1 The key phase signal generated when the rotor (7) rotates; M 1 The disc (5) is locked in R by a self-locking structure. 1 On the rotor (7), and M 1 The disc (5) can be adjusted to 1 Position on the rotor (7); M 2 The disc (6) is fixed on R 2 The lower end of the rotor (8); M 1 Disk (5) and M 2 The disk (6) is used to simulate the real rotor load system, so that R 1 Rotor (7) and R 2 The rotor (8) rotates stably; the ring (4) is fixed on the M by an adjustable fixing method. 2 Above the disk (6), the ring (4) is in a horizontal position, R 2 The rotor (8) passes through the center of the ring (4), which is used to limit R 2 The displacement of the rotor (8) when it rotates; the displacement sensor (9) is arranged outside the ring (4) to obtain R 2 Displacement data when the rotor (8) rotates.

2. A rotor rubbing induced internal resonance characteristics research system according to claim 1, It is characterized in that The device also comprises a device frame (1) for supporting an external drive motor, the device frame (1) being composed of a top plate, a bottom plate, and at least four support columns, each support column being vertically supported between the top plate and the bottom plate, the top plate and the bottom plate being in a relative posture; each device of the system is placed between the top plate and the bottom plate; a hole is provided in the top plate for connecting the motor above the top plate and the R below the top plate 1 The rotor (7) is connected.

3. A rotor rubbing induced internal resonance characteristic research system according to claim 2, It is characterized in that The device frame also includes an intermediate plate (11), which is arranged on the M 1 The disc (5) and the ring (4) are used to fix the ring (4); a hole is provided in the middle plate for R 1 Rotor (7) and R 2 The rotor (8) passes through; the intermediate plate (11) and each fixed point of the circular ring (4) are connected via thin columns (3); at least one of the connection points between the intermediate plate (11) and each supporting column, the connection point between the circular ring (4) and each thin column (3), and the connection point between the intermediate plate (11) and each thin column (3) is connected in an adjustable manner, so as to achieve the adjustable position of the circular ring (4) in the vertical direction.

4. A method for studying the internal resonance characteristics of rotors induced by friction based on the system of claim 1, which is used to simulate the internal resonance of dual rotors and obtain the internal resonance characteristics through verification by a simulator. It is characterized in that The following steps are involved: S1: Start the motor, the motor drives R 1 Rotor (7) and R 2 The rotor (8) rotates, and the speed gradually increases. The speed sensor (10) obtains R 1 The key phase signal of the rotor (7) is obtained by the displacement sensor (9) R 2 The displacement signal of the rotor (8) is measured until the displacement signal reaches a peak value and the phase difference between the displacement signal and the key phase signal is 180°, and the current rotation speed is recorded as the critical rotation speed; S2: The stiffness and damping that should be set for the simulator are calculated based on the critical speed, and the initial parameters of the simulator are set with the calculated stiffness and damping, and the simulator starts simulating; S3: using the internal resonance characteristic research system to start a simulation experiment from a rotation speed of 0, and orderly increase the rotation speed to a preset maximum rotation speed, and repeat the following operations at each rotation speed: after the R2 rotor (8) first enters a steady state, apply an instantaneous disturbance to the R2 rotor (8) in the transverse direction, and after the R2 rotor (8) enters a steady state again, obtain the displacement peak value of the R2 rotor (8) in the steady state through the displacement sensor (9); if the R2 rotor (8) collides with the ring (4), the radius of the ring (4) is recorded as the displacement peak value of the R2 rotor (8); S4: using each rotation speed obtained in S3 and the displacement peak value of the R2 rotor (8) at each rotation speed, a bifurcation diagram is drawn, and the internal resonance rotation speed range is obtained through the bifurcation diagram; wherein the horizontal axis of the bifurcation diagram is the rotation speed, and the vertical axis is the displacement peak value; S5: selecting a preset number of speeds in the internal resonance speed range in an orderly manner, and performing simulation experiments again at each selected speed, wherein the displacement sensor (9) records the real-time displacement data of the R2 rotor (8) at each speed, and generates an axis trajectory diagram at each speed; comparing the shape of each axis trajectory diagram with the axis trajectory diagram simulated by the simulator, and exploring the characteristics of the axis trajectory diagram when the rotor is internally resonant; S6: Based on the axis trajectory diagram of the R2 rotor (8) at each rotation speed obtained in S5, a displacement time domain curve diagram of the R2 rotor (8) at each rotation speed is generated based on a preset direction, wherein the horizontal axis of the displacement time domain curve diagram is time, and the vertical axis is the displacement in the preset direction; S7: First, perform Fourier transform on the time domain curves at each speed to obtain the frequency spectrum of each time domain curve. Then, obtain the forward vortex frequency and reverse vortex frequency at each speed from each frequency spectrum, and calculate the forward and reverse vortex frequency ratio. Then, compare the forward and reverse vortex frequency ratio at each speed with the forward and reverse vortex frequency ratio simulated by the simulator to explore the characteristics of the forward and reverse vortex frequency ratio when the rotor resonates.

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