An experimental device and method for researching high-speed instability interval of rotor oil

Abstract

The application discloses an experimental device and method for researching high-speed instability interval of rotor oil liquid, and the experimental device comprises a frame, a rotating shaft, an oil tank, a first bearing, a second bearing, a storage plate, a plurality of partition plates and a processor; a circular hole is formed in the middle of the top plate and the storage plate, the first bearing and the second bearing are respectively installed in the circular hole of the top plate of the storage plate and the frame through a first bearing seat and a second bearing seat; the rotating shaft vertically penetrates the first bearing and the second bearing from top to bottom, is connected with the oil tank between the storage plate and the bottom plate, and rotates horizontally under the action of a motor; the plurality of partition plates are detachably and evenly distributed and installed in the oil tank, one end of the partition plate is connected with a stand column located in the center of the oil tank, the other end is connected with the inner side of the oil tank, and the oil tank is evenly separated into a plurality of sub-regions. The application can effectively simulate the vibration phenomenon of the oil liquid under the condition of the baffle, the baffle is convenient to assemble and disassemble, and is suitable for the research on the oil liquid rotary vibration of the rotor dynamics.

Description

Technical Field

[0001] This invention belongs to the field of vibration testing technology, specifically relating to an experimental apparatus and method for studying the high-speed instability range of rotor oil. Background Technology

[0002] In the field of high-speed rotating machinery research, the dynamic stability of aero-engine systems has always been a key research focus. As rotor speed increases, instability and buckling phenomena inevitably occur.

[0003] In the past decade or so, rotating machinery has been developing for a long time due to the needs of the industrial sector, especially the aerospace sector, and rotor dynamics, as an important research area of ​​rotating machinery, has also received much attention. As rotors develop towards larger, heavier loads, and higher speeds, many instability phenomena have emerged. Therefore, ensuring the stability of rotor system operation has become an important task of rotor dynamics.

[0004] Aero engines inevitably accumulate a viscous, incompressible liquid called oil during operation. This oil buildup leads to an exponential increase in engine disturbance. At certain speeds, the interaction between the solid and liquid components creates fluid-structure interaction (FSI). Furthermore, the coupling of friction and gyroscopic forces causes rotor instability at certain speeds, resulting in an unstable range. To explore this unstable range and investigate the laws and principles of rotor instability, this patent constructs an experimental setup for studying the high-speed instability range of rotor oil. This setup further investigates the influence of aero-engine dynamic parameters on stability, revealing the instability mechanism of aero-engines.

[0005] Chinese patent application number 2023106157250 discloses a rotor oil accumulation test device to solve the problem of rotor-stator rubbing test at high temperatures. However, this patent has shortcomings in its use: first, assembly difficulties arise when assembling the oil; second, it cannot add baffles to change the baffle parameters. These shortcomings prevent the device from simulating the vibration phenomenon of oil under baffle conditions. Summary of the Invention

[0006] Technical problem solved: This invention proposes an experimental device and method for studying the high-speed instability range of rotor oil, which can effectively simulate the vibration phenomenon of oil under different baffle conditions, and the baffles are easy to install and remove, making it suitable for rotor dynamics research on oil rotation vibration.

[0007] Technical solution:

[0008] In a first aspect, the present invention discloses an experimental apparatus for studying the high-speed instability range of rotor oil, the experimental apparatus comprising a frame, a rotating shaft, an oil tank, a first bearing, a second bearing, a storage plate, multiple partitions, and a processor;

[0009] The frame consists of four square columns and a top plate and a bottom plate that are parallel to each other; the shelf is installed in the middle of the frame; the first bearing and the second bearing are respectively installed on the shelf and the top plate of the frame through the first bearing seat and the second bearing seat.

[0010] A circular hole is provided between the top plate and the shelf. The first bearing and the second bearing are installed in the circular hole of the shelf and the top plate of the frame through the first bearing seat and the second bearing seat, respectively. The rotating shaft passes vertically from top to bottom through the first bearing and the second bearing and is connected to the oil tank located between the shelf and the bottom plate. Under the action of the motor, it carries the oil tank to rotate horizontally.

[0011] The multiple partitions are detachably and evenly distributed inside the oil tank. One end of each partition is connected to a column located in the center of the oil tank, and the other end is connected to the inner side of the oil tank, thus dividing the oil tank into several sub-areas. Water or oil is poured into the oil tank.

[0012] For two oil tank states—one with no baffles and the other with varying numbers of baffles—the processor controls a motor to drive a rotating shaft, gradually increasing its speed from 0 to a steady state. This causes the oil in the tank to vibrate violently. The processor records the rotor speed at the steady state and drives displacement and vibration sensors fixed to the shaft to record the shaft's displacement and vibration parameters in real time as the speed increases. It also drives a high-speed camera to capture real-time images of the oil vibration within the tank. The processor performs time-domain analysis on the displacement and vibration parameters, generating a vibration waveform. A Fourier transform is then used to obtain the corresponding spectrum. Analyzing the spectrum reveals the relevant frequency components and harmonic components of the vibration signal. If the rotor displacement increases sharply, the rotor system is considered unstable. Combining the rotor speed at the steady state with the oil vibration images, the processor analyzes the rotor stability and oil vibration patterns. If a modal transition occurs in the oil image, the rotor is considered unstable, thus determining the high-speed instability range of the rotor oil.

[0013] Furthermore, the shelf is installed in the middle of the frame by a stabilizer; the stabilizer is a rectangular steel plate with a square hole in the middle, the size of the stabilizer is consistent with the outer dimensions of the frame, and there are screw holes on the side that correspond to the screw holes on the side of the square column of the frame.

[0014] Furthermore, a circular hole with a diameter of 20mm is provided between the top plate and the shelf.

[0015] Furthermore, the rotating shaft is a cylindrical steel column with threads at one end;

[0016] The oil tank is equipped with an oil tank top cover, the inner diameter of which is the same as the outer diameter of the oil tank, and a screw hole corresponding to the thread of the rotating shaft is provided in the center of the oil tank top cover.

[0017] Furthermore, the fuel tank adopts a transparent disc with a central slot, and a column is fixed to the bottom of the fuel tank at the center. The lower part of the column is cylindrical, and the upper part of the column is a square column, the diagonal length of which is less than the diameter of the cylinder.

[0018] Furthermore, the oil tank is evenly equipped with three or six partitions.

[0019] Secondly, the present invention discloses an experimental method for studying the high-speed instability range of rotor oil based on the aforementioned experimental apparatus, the experimental method comprising the following steps:

[0020] S1: Establish a rotor oil accumulation fault model based on the NS equation;

[0021] S2: Keep the fuel tank stationary and pour water or oil into the fuel tank without a baffle.

[0022] S3: The motor drives the rotor to rotate, increasing its speed from 0 to a preset stable state. The parameters of the rotor and oil are recorded during the increase, and the rotor speed at the stable state is recorded. The motor is then turned off.

[0023] S4: Based on the rotor speed under steady-state conditions and the rotor oil accumulation fault model, analyze rotor stability and record oil vibration parameters;

[0024] S5: Repeat steps S2-S4. If the analysis results of the rotor oil vibration law are the same in both steps, proceed to step S6; otherwise, repeat steps S2 to S4 until the same analysis result of the rotor oil vibration law as in step S4 is obtained.

[0025] S6, add multiple baffles to the oil tank, execute steps S3 to S4, analyze the oil vibration law under different baffle conditions, and obtain the high-speed instability range of the rotor oil.

[0026] Step S1 further includes the following steps:

[0027] List the frequency equation for radial circular surface waves:

[0028]

[0029] When w≠0, an axial circular surface wave appears; the cyclic characteristic frequency of the two-dimensional surface wave is:

[0030]

[0031] in It represents the positive eddy frequency of the fluid. It represents the reverse eddy frequency of the fluid.

[0032] Furthermore, the experimental method also includes the following steps:

[0033] Based on the forward and reverse eddy frequencies of the fluid at different frequencies obtained in step S1, the intersection of the forward and reverse eddy frequencies and the critical instability line is regarded as instability, and the theoretical instability range is obtained.

[0034] The rotor instability range obtained from the spectrum diagram in step S6 is compared with the theoretical instability range to determine whether the experimental instability range is consistent with the calculated instability range.

[0035] Beneficial effects:

[0036] The experimental apparatus and method for calculating the high-speed instability range of rotor oil of the present invention can effectively simulate the vibration phenomenon of oil under the condition of baffle. The baffle is easy to install and remove. At the same time, theory and experiment are mutually verified. It is suitable for effective monitoring of oil rotation vibration in rotor dynamics. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the experimental setup for studying the high-speed instability range of rotor oil according to the present invention;

[0038] Figure 2 This is a schematic diagram of the framework;

[0039] Figure 3 This is a schematic diagram of a bearing housing;

[0040] Figure 4 This is a schematic diagram of a bearing.

[0041] Figure 5 This is a schematic diagram of the fuel tank;

[0042] Figure 6 This is a schematic diagram of the fuel tank top cover;

[0043] Figure 7 This is a schematic diagram of a three-part partition;

[0044] Figure 8 This is a schematic diagram of a six-partition system.

[0045] Figure 9 The diagram shows a partially fluid-filled rotor chamber with and without a baffle (left figure) and with a baffle (right figure) in the case of self-excitation of a first-order radial circular wave (j=1).

[0046] Figure 10 This diagram illustrates the cyclic frequencies of a basic radial circular surface wave (single node) with and without baffles (Ω1), with three baffles (Ω3), and with six baffles (Ω6). It represents the positive eddy frequency of the fluid. The vortex represents the reverse eddy of the fluid; where (a) represents the forward and reverse eddy frequencies of the fluid in different radial directions, and (b) represents the forward and reverse eddy frequencies of the fluid at different frequencies, with instability occurring at the intersection with the critical instability line. Detailed Implementation

[0047] The following embodiments are provided to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way.

[0048] See Figure 1 The present invention discloses an experimental device for studying the high-speed instability range of rotor oil. The experimental device includes a frame, a rotating shaft, an oil tank, a first bearing, a second bearing, a storage plate, multiple partitions, and a processor.

[0049] The frame consists of four square columns and a top plate and a bottom plate that are parallel to each other; the shelf is installed in the middle of the frame; the first bearing and the second bearing are respectively installed on the shelf and the top plate of the frame through the first bearing seat and the second bearing seat.

[0050] A circular hole is provided between the top plate and the shelf. The first bearing and the second bearing are installed in the circular hole of the shelf and the top plate of the frame through the first bearing seat and the second bearing seat, respectively. The rotating shaft passes vertically from top to bottom through the first bearing and the second bearing and is connected to the oil tank located between the shelf and the bottom plate. Under the action of the motor, it carries the oil tank to rotate horizontally.

[0051] The multiple partitions are detachably and evenly distributed inside the oil tank. One end of each partition is connected to a column located in the center of the oil tank, and the other end is connected to the inner side of the oil tank, thus dividing the oil tank into several sub-areas. Water or oil is poured into the oil tank.

[0052] For two oil tank states—one with no baffles and the other with varying numbers of baffles—the processor controls a motor to drive a rotating shaft, gradually increasing its speed from 0 to a stable state. This causes the oil in the tank to vibrate violently. The processor records the rotor speed at the stable state and drives displacement and vibration sensors fixed to the shaft to record the shaft's displacement and vibration parameters in real time as the speed increases. It also drives a high-speed camera to capture real-time vibration images of the oil in the tank. The processor performs time-domain analysis on the displacement and vibration parameters, generating a vibration waveform. A Fourier transform is then used to obtain the corresponding spectrum. Analyzing the spectrum reveals the relevant frequency components and harmonic components of the vibration signal. If the rotor displacement increases sharply, the rotor system is considered unstable. Combining the rotor speed at the stable state with the oil vibration images, the processor analyzes the rotor stability and oil vibration patterns. If a modal transition occurs in the oil image, the rotor is considered unstable. Therefore, the high-speed instability range of the rotor oil is determined.

[0053] Regarding the structure of the experimental apparatus, the preferred option is [see below]. Figure 2 The frame consists of four square columns and parallel top and bottom plates. The two ends of the four columns are fixedly connected to the four corners of the upper and lower bottom plates, respectively. The top plate is a rectangular steel plate with a 20mm diameter hole in the center. There are a number of screw holes on one side of the hole. The top surface of the top plate has screw holes for connecting the motor, and the middle of the top plate has an opening for the shaft to pass through. There are screw holes in the middle of one side of the columns for connecting the stabilizing components.

[0054] The stabilizer is used to support the shelf on the four uprights of the steel frame. The stabilizer is a rectangular steel plate with a square hole in the center, the same size as the uprights of the frame. It has screw holes on its side, matching the screw holes on the sides of the uprights, for secure mounting to the uprights. The shelf is a rectangular steel plate with the same dimensions as the upper and lower base plates of the steel frame. It has a small circular hole (20mm in diameter) in the center and a pre-set number of screw holes in the center for fixing bearing seats. The shelf has four corner holes, the shape of which corresponds to the cross-section of the uprights of the frame. Each upright passes through these corner holes, allowing the shelf to be fitted and fixed between the top and bottom plates of the frame. The shelf has screw holes, the positions of which correspond to the screw holes on the stabilizer, allowing the shelf to be fixed to the stabilizer with screws. The pivot is a cylindrical steel column with threads at one end.

[0055] Figure 3 and Figure 4 This is a schematic diagram of the bearing housing and bearing used in this invention. The bearing housing is a device for connecting the bearing. Its base is a rectangular structure with screw holes at the four corners. The screw holes of the bearing housing base correspond to the screw holes of the device plate. The bearing housing and the device plate are fixedly connected by screws. The bearing is connected to the bearing housing and connected to the oil tank through a rotating shaft. When the rotor is driven by the motor, the oil tank rotates under the drive of the rotating shaft.

[0056] like Figure 5 As shown, the fuel tank is a cylindrical transparent disc with a groove in the middle. There are external threads on the outside of the fuel tank for connecting the top cover of the fuel tank. There is a cylindrical boss in the center of the disc. The top of the cylindrical boss is changed to a cuboid boss for installing and fixing various partitions. Each partition is made by cutting a hole in the middle of a square plate that fits the inner diameter of the fuel tank. The square hole is cut first and then the cylindrical groove is cut so that the partition can be assembled with the fuel tank.

[0057] like Figure 6 As shown, the top cover of the oil tank is a cylindrical disc with a central cylindrical groove and an inner spiral groove. It is threaded to the oil tank. A cylindrical through-hole is located in the center of the top cover disc, with internal threads on the inner wall corresponding to the threads of the rotating shaft. A raised section in the center of the oil tank is used to connect a baffle plate. The oil tank is designed to be detachable for easy placement and replacement of the baffle plate. The top cover has threaded holes for connection to the rotor; the thread direction should be opposite to the thread direction at the connection between the oil tank and the top cover.

[0058] The baffle has an opening in the center that corresponds to the central column of the fuel tank, and the baffle can be any piece connected center to center. Figure 7 This is a schematic diagram of a three-part partition; Figure 8 This is a schematic diagram of a six-partition system. In practical applications, other numbers of partitions can also be used, with holes left in the middle of the partitions for fixing to the fuel tank, facilitating installation and removal.

[0059] In the experiment, the device was first correctly connected. The platform was mounted in the middle of the frame using a stabilizer. One bearing seat was installed on the platform and another on the top of the frame. The motor was fixed to the top of the frame. The top cover of the oil tank was connected to the oil tank and then to the rotating shaft. The rotating shaft was connected to the motor via two bearing seats. A partition could be installed inside the oil tank. The oil tank was opened and filled with a certain amount of water or oil. The oil tank was then sealed and connected to the rotor. A photosensitive strip was fixed to the rotor, and displacement and vibration sensors were fixed to the device, with the other end connected to a computer to capture vibration amplitude and acceleration. A high-speed camera was fixed under the platform to capture the state of the oil in the tank at a certain moment. Then, the motor was turned on, and the rotor rotated. The rotation speed was gradually increased, and the liquid in the tank began to vibrate with the tank, vibrating violently at certain moments. Based on the changes in displacement and acceleration captured by the computer, time-domain analysis was performed, and the vibration state was plotted as a waveform. A Fourier transform was then used to generate a spectrum. The spectrum was then subjected to autocorrelation processing to simplify the results, and the frequency components and harmonic components of the vibration signal were analyzed. The component with the most prominent harmonic amplitude may be related to the fault. The forced vibration resonance state of the oil tank was captured using a high-speed camera, and experimental data was recorded for further analysis of the mechanism. Finally, the vibration state of the oil under different numbers of baffles was studied and analyzed.

[0060] This invention discloses an experimental method for studying the high-speed instability range of rotor oil based on the aforementioned experimental apparatus. The experimental method includes the following steps:

[0061] S1: Establish a rotor oil accumulation fault model based on the NS equation;

[0062] S2: Keep the fuel tank stationary and pour water or oil into the fuel tank without a baffle.

[0063] S3: The motor drives the rotor to rotate, increasing its speed from 0 to a preset stable state. The parameters of the rotor and oil are recorded during the increase, and the rotor speed at the stable state is recorded. The motor is then turned off.

[0064] S4: Based on the rotor speed under steady-state conditions and the rotor oil accumulation fault model, analyze rotor stability and record oil vibration parameters;

[0065] S5: Repeat steps S2-S4. If the analysis results of the rotor oil vibration law are the same in both steps, proceed to step S6; otherwise, repeat steps S2 to S4 until the same analysis result of the rotor oil vibration law as in step S4 is obtained.

[0066] S6, add multiple baffles to the oil tank, execute steps S3 to S4, and analyze the oil vibration law under different baffle conditions.

[0067] The method for establishing the theoretical model in step S1 is as follows:

[0068] Assuming the fluid motion is periodically disturbed by the small lateral deflection of the rotor, the values ​​characterizing the fluid oscillations in the circumferential and axial directions are proportional to an exponential function. For example, the disturbance pressure is:

[0069]

[0070] In the formula, the period T rθ It is the length of a radial-circular wave with a period T. z It is the length of a radial-axial wave.

[0071]

[0072] In the formula λ k This represents the arc length of the circular wave. Here, j is the number of nodes or crests moving in a circular motion along the rotating fluid within n chambers formed by n radial baffles (k = j in the case of missing baffles);

[0073]

[0074] Where l is the number of nodes or crests of the wave moving along the rotating fluid axis, and L is the distance between the two ends of the chamber. λ l This represents the distance between two nodes. Figure 9 The diagram shows a rotor chamber partially filled with fluid when there is no baffle (left figure) and with a baffle (right figure) under the condition of self-excitation of a first-order radial circular wave (j=1).

[0075] The Navier-Stokes and continuity equations that determine the natural motion of the fluid, rotating together with the rotor cylindrical coordinate system rθz, without considering the effects of body forces and surface forces, take the following form:

[0076]

[0077]

[0078] Where u, v, and w are the velocities of the fluid particles relative to the rotor, p is the pressure in the fluid, ρ is its density, and ω is the rotational speed.

[0079] The boundary conditions are supplemented as follows:

[0080]

[0081] This specifies the behavior of these equations on the fluid surface.

[0082] When r = R, u = 0 (on the outer wall of the cavity); when θ = mγ, w = 0, where m is an integer from 0 to n, and γ = 2π / n (on the n-th partition); when z = 0 or z = L, w = 0 (on the end face); When r = r, p = 0 (at the free surface of the fluid);

[0083] In a fluid, the disturbance velocities u, v, w are coupled with the disturbance pressure p, and are complementary to the stationary velocity p0, which is connected to the angular velocity ω. Similar to the hydrostatic pressure in a fluid column, in a given system, the acceleration is equal to ω. 2 (r+r) / 2, where the height equals rr. Therefore, in general, the pressure in the fluid is:

[0084] p = p0 + p(r,θ,z,t), p0 = ρω 2 (-r 2 ) / 2

[0085] Similarly, the free surface of the fluid can also be determined:

[0086] R = r + e(θ,z,t)

[0087] Where e is the disturbance displacement.

[0088] If the perturbation method is used, when each variable is represented in a single row according to the small deflection e of the rotor shaft, then

[0089] p = p0 + εp1 + ε 2 p2+…

[0090] u=εu1+ε 2 u2+…,v=εv1+ε 2 v2+…,w=0#(2)

[0091] Since in the first approximation, by substituting equation (2) into equation (1) and deleting the viscosity and second- and higher-order terms, we obtain the following equation:

[0092]

[0093]

[0094] By expressing R = r + e(θ,z,t) without considering the quadratic effect, and satisfying the following kinematic and dynamic boundary conditions for the chamber sidewalls and the free fluid surface, we now seek periodic solutions for u1, ν1, and p1:

[0095] u_1 = 0, r = R

[0096]

[0097] If we use the wave problem solution that is generally accepted in fluid dynamics, then

[0098] e1(θ,t)=expi(kθ-Ω k t)

[0099] u1(r,θ,t)=U(r)expi(kθ-Ω k t)

[0100] v1(r,θ,t)=V(r)expi(kθ-Ω k t)#(5)

[0101] p1(r,θ,t)=P(r)expi(kθ-Ω k t)

[0102] Among them, Ω k It is the angular velocity (2πr) of the radial-circular wave along the entire free surface of the fluid.

[0103] By substituting into equation (5) and dividing by the universal function expi(kθ-Ω) k t), Equation (3) can be simplified to the following form:

[0104] -iΩ_k U-2ωV=-1 / ρdP / dr

[0105]

[0106] r dU / dr+U+ikV=0

[0107] The solutions to the first two equations are:

[0108]

[0109] Substituting these relationships into the third equation (continuity), we obtain the simplest form of the Bessel equation.

[0110] r 2 P″+rP′-k 2 P=0

[0111] Using general solutions

[0112] P(r) = C1rk +C2r -k #(7)

[0113] C1 and C2 are determined by boundary condition (4), or as a result of an alternative form of equation (5).

[0114] U(R)=0, U(r)=-iΩ k P(r)=-ρω 2 r

[0115] Therefore, to determine C1 and C2, we only need to return to the relation obtained for U and substitute P and P′.

[0116]

[0117] Starting from the condition U(R) = 0

[0118]

[0119] From U(r)=-iΩ k Taking this coefficient (8) into account

[0120]

[0121] expression C1r k +C2r -k =-ρω 2 Since equations (8) and (9) give the frequency equation for radial circular (two-dimensional) surface waves.

[0122]

[0123] Under normal circumstances (when w≠0), axial circular (three-dimensional) surface waves will appear. The cyclic characteristic frequency of a two-dimensional surface wave is (in a rotating reference frame).

[0124]

[0125] Therefore, the real solutions obtained from equations (2) and (5)-(9) are as follows:

[0126]

[0127] Therefore, the velocity on the fluid free surface and the pressure on the rotor wall are equal:

[0128]

[0129] Figure 10 This diagram illustrates the cyclic frequencies of a basic radial circular surface wave (single node) with and without baffles (Ω1), with three baffles (Ω3), and with six baffles (Ω6). It represents the positive eddy frequency of the fluid. This represents the reverse eddy current of a fluid. Among them, Figure 10 In the figure, (a) represents the forward and reverse vortex frequencies of different radial fluids; Figure 10 In the figure, (b) represents the forward and reverse eddy frequencies of the fluid at different frequencies, and the point where instability occurs is where it intersects with the critical instability line.

[0130] Based on the forward and reverse eddy frequencies of the fluid at different frequencies obtained in step S1, the intersection of the forward and reverse eddy frequencies with the critical instability line is considered as instability, thus obtaining the theoretical instability range. After obtaining the rotor instability range from the spectrum diagram, it is compared with the theoretical instability range to determine whether the experimental instability range is consistent with the calculated instability range, thereby achieving mutual verification between theory and practice.

[0131] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An experimental apparatus for studying the high-speed instability range of rotor oil, characterized in that, The experimental apparatus includes a frame, a rotating shaft, an oil tank, a first bearing, a second bearing, a storage plate, multiple partitions, and a processor. The frame consists of four square columns and a top plate and a bottom plate that are parallel to each other; the shelf is installed in the middle of the frame; the first bearing and the second bearing are respectively installed on the shelf and the top plate of the frame through the first bearing seat and the second bearing seat. A circular hole is provided between the top plate and the shelf. The first bearing and the second bearing are installed in the circular hole of the shelf and the top plate of the frame through the first bearing seat and the second bearing seat, respectively. The rotating shaft passes vertically from top to bottom through the first bearing and the second bearing and is connected to the oil tank located between the shelf and the bottom plate. Under the action of the motor, it carries the oil tank to rotate horizontally. The multiple partitions are detachably and evenly distributed inside the oil tank. One end of each partition is connected to a column located in the center of the oil tank, and the other end is connected to the inner side of the oil tank, thus dividing the oil tank into several sub-areas. Water or oil is poured into the oil tank. For two oil tank states—one with no baffles and the other with varying numbers of baffles—the processor controls a motor to drive a rotating shaft, gradually increasing its speed from 0 to a steady state. This causes the oil in the tank to vibrate violently. The processor records the rotor speed at the steady state and drives displacement and vibration sensors fixed to the shaft to record the shaft's displacement and vibration parameters in real time as the speed increases. It also drives a high-speed camera to capture real-time images of the oil vibration within the tank. The processor performs time-domain analysis on the displacement and vibration parameters, generating a vibration waveform. A Fourier transform is then used to obtain the corresponding spectrum. Analyzing the spectrum reveals the relevant frequency components and harmonic components of the vibration signal. If the rotor displacement increases sharply, the rotor system is considered unstable. Combining the rotor speed at the steady state with the oil vibration images, the processor analyzes the rotor stability and oil vibration patterns. If a modal transition occurs in the oil image, the rotor is considered unstable, thus determining the high-speed instability range of the rotor oil.

2. The experimental apparatus for studying the high-speed instability range of rotor oil according to claim 1, characterized in that, The shelf is installed in the middle of the frame by a stabilizer; the stabilizer is a rectangular steel plate with a square hole in the middle. The size of the stabilizer is consistent with the outer dimensions of the frame, and there are screw holes on the side that correspond to the screw holes on the side of the square column of the frame.

3. The experimental apparatus for studying the high-speed instability range of rotor oil according to claim 1, characterized in that, A 20mm diameter circular hole is provided between the top plate and the shelf.

4. The experimental apparatus for studying the high-speed instability range of rotor oil according to claim 1, characterized in that, The shaft is a cylindrical steel column with threads at one end; The oil tank is equipped with an oil tank top cover, the inner diameter of which is the same as the outer diameter of the oil tank, and a screw hole corresponding to the thread of the rotating shaft is provided in the center of the oil tank top cover.

5. The experimental apparatus for studying the high-speed instability range of rotor oil according to claim 1, characterized in that, The fuel tank is a transparent disc with a central slot. A column is fixed to the bottom of the fuel tank at the center. The bottom of the column is cylindrical, and the top of the column is a square column. The diagonal length of the square column is less than the diameter of the cylindrical column.

6. The experimental apparatus for studying the high-speed instability range of rotor oil according to claim 1, characterized in that, The oil tank is equipped with three or six partitions evenly installed inside.

7. An experimental method for studying the high-speed instability range of rotor oil based on the experimental apparatus described in any one of claims 1-6, characterized in that, The experimental method includes the following steps: S1: Establish a rotor oil accumulation fault model based on the NS equation; S2: Keep the fuel tank stationary and pour water or oil into the fuel tank without a baffle. S3: The motor drives the rotor to rotate, increasing its speed from 0 to a preset stable state. The parameters of the rotor and oil are recorded during the increase, and the rotor speed at the stable state is recorded. The motor is then turned off. S4: Based on the rotor speed under steady-state conditions and the rotor oil accumulation fault model, analyze rotor stability and record oil vibration parameters; S5: Repeat steps S2-S4. If the analysis results of the rotor oil vibration law are the same in both steps, proceed to step S6; otherwise, repeat steps S2 to S4 until the same analysis result of the rotor oil vibration law as in step S4 is obtained. S6, add multiple baffles to the oil tank, execute steps S3 to S4, analyze the oil vibration law under different baffle conditions, and obtain the high-speed instability range of the rotor oil.

8. The experimental method for studying the high-speed instability range of rotor oil according to claim 7, characterized in that, Step S1 further includes the following steps: List the frequency equation for radial circular surface waves: When w≠0, an axial circular surface wave appears; the cyclic characteristic frequency of the two-dimensional surface wave is: in It represents the positive eddy frequency of the fluid. The frequency of the reverse eddy current in the fluid is represented by R, where R is the radius of the tank and r is the radial coordinate.

9. The experimental method for studying the high-speed instability range of rotor oil according to claim 8, characterized in that, The experimental method also includes the following steps: Based on the forward and reverse eddy frequencies of the fluid at different frequencies obtained in step S1, the intersection of the forward and reverse eddy frequencies and the critical instability line is regarded as instability, and the theoretical instability range is obtained. The rotor instability range obtained from the spectrum diagram in step S6 is compared with the theoretical instability range to determine whether the experimental instability range is consistent with the calculated instability range.

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