A Solving Method for Oil Film Stiffness and Damping of Hydrodynamic Journal Bearings Based on Fluent

Abstract

This invention discloses a Fluent-based method for solving the oil film stiffness and damping of dynamic pressure sliding bearings. This method reduces the limitations of experimental equipment and experimental sites during the solution process, ensuring solution accuracy. Fluent is used to perform fluid calculations of the oil film flow field and a dynamic mesh method is used to update the oil film mesh model. Given the small radial dimensions of the oil film, high mesh quality is required during the fluid calculation process. Structured meshing and model block partitioning can be used to improve mesh quality and ensure calculation accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment evaluation, and more particularly to a Fluent-based method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing. Background Art

[0002] Hydrodynamic sliding bearings are commonly used in high-speed, high-precision rotating machinery, and their reliability directly impacts the accuracy, service life, and economic efficiency of the entire machine. The lubrication and load-bearing properties of hydrodynamic sliding bearings rely primarily on the lubricating oil film that fills the gap between the bearing journal and the bearing shell. Therefore, the stiffness and damping of the lubricating oil film, as key characteristic parameters of the sliding bearing, directly determine its operational stability and service life. Calculating the stiffness and damping of hydrodynamic sliding bearing oil films is often subject to numerous limitations, including experimental equipment and location, to ensure accurate calculations, due to the high speeds and thin oil film thickness of hydrodynamic sliding bearings.

[0003] Therefore, how to accurately solve the oil film stiffness and damping of the dynamic pressure sliding bearing is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a Fluent-based method for solving the oil film stiffness and damping of a hydrodynamic sliding bearing, which reduces the limitations of experimental equipment and experimental sites in the process of solving the lubricating oil film stiffness and damping of a hydrodynamic sliding bearing, and ensures its solution accuracy.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A Fluent-based method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing includes the following steps:

[0007] Step 1: Construct the oil film model in the gap between the bearing shell and the journal of the hydrodynamic sliding bearing;

[0008] Step 2: Perform structured meshing on the oil film model to obtain the bearing oil film mesh file;

[0009] Step 3: Import the oil film grid file described in step 2 into the Fluent software and set the initial stable position of the journal;

[0010] Step 4: Set the journal speed disturbance macro, journal oil film force monitoring macro, and axis trajectory monitoring macro in the Fluent software described in step 3, and set the control conditions corresponding to each macro;

[0011] Step 5: Set the flow field calculation control parameters, apply velocity disturbance to the journal using the journal velocity disturbance macro, and obtain the oil film force Fx along the X direction, the oil film force Fy along the Y direction, and the journal axis displacement S using the journal oil film force monitoring macro and axis trajectory monitoring macro set in step 4.

[0012] Step 6: Determine the calculation model and set the control parameters, and start iterative solution using the iterative solution model;

[0013] Step 7: Determine whether the iterative solution result in step 6 has converged based on the specific values of the parameters S, Fx, and Fy monitored in step 5. The convergence criterion is: if the ratio of the parameters Fx and Fy monitored in step 5 is less than the set convergence threshold, which can be 0.01, i.e., Fx / Fy < 0.01, and the value of the journal axis displacement S remains stable and is within the set displacement threshold, then the iterative solution result is determined to have converged, and the process proceeds to step 9. If it has not converged, the process proceeds to step 8.

[0014] Step 8: Start the mesh model and set the journal surface node displacement macro in Fluent software, adjust the journal stable position, and return to step 4;

[0015] Step 9: Collect oil film pressure monitoring data and axis trajectory monitoring data through the journal oil film force monitoring macro and axis trajectory monitoring macro set in step 4;

[0016] Step 10: Process the oil film pressure monitoring data and the axis trajectory monitoring data collected in step 9 to obtain the oil film stiffness and oil film damping;

[0017] Preferably, the oil film model includes three parts: an oil inlet, an oil tank and an oil film.

[0018] Preferably, step 2 is specifically as follows: a structured grid division method is selected according to the research object, and the oil film model is divided into pure hexahedral grids with the help of grid division software ICEM. The oil inlet, oil tank, and oil film block division method is adopted during the division. After the division is completed, the complete oil film grid model is obtained by grid assembly, and the bearing oil film grid file is derived based on the complete oil film grid model.

[0019] Preferably, in step 4, the control conditions of each macro are set as follows: the journal speed disturbance macro, the journal oil film force monitoring macro and the axis trajectory monitoring macro are all set to run once per iterative calculation.

[0020] Preferably, in step 4, the axis trajectory monitoring macro can monitor the parameters including x, y, S, where x and y are the distances along the X and Y directions between the axis center position and the axis center stable position at any time, are the movement speed of the axis at any time, and S is the axis displacement of the journal.

[0021] Preferably, in step 4, the journal oil film force monitoring macro monitoring parameters set include F x 、F y 、F x0 、F y0 , where F x 、F y The oil film force on the journal along the X and Y directions, F x0 、F y0 The oil film forces acting on the journal along the X and Y directions are respectively when the journal is located at a stable axial position.

[0022] Preferably, in step 5, the flow field calculation control parameters are specifically set as: defining the physical properties of the lubricating oil, including the lubricating oil viscosity and the lubricating oil density, defining the oil film boundary conditions, wherein the lubricating oil inlet is a pressure inlet, the lubricating oil outlet is a pressure outlet, the journal surface is a rotating non-slip wall surface, and the bearing surface is a fixed wall surface.

[0023] Preferably, in step 5, the speed disturbance applied to the journal is two independent speed disturbances along the X direction and the Y direction, respectively. The speed disturbance can be expressed as:

[0024]

[0025] Where V represents the velocity disturbance; A represents the displacement amplitude of the velocity disturbance; ω represents the disturbance angular velocity; T represents the disturbance period; and t represents the disturbance time.

[0026] Preferably, in step 6, the selected calculation model is: the material model is the mixture model, the mass transfer mode is the total cavitation model, and the iterative solution model is the pressure-based separation solution model. The control parameters used in step 6 are set to: set the solution process to transient calculation, and the time step to 1e -5 , each time step is iterated 20 times, and the number of time steps is set to 10000.

[0027] Preferably, in step 8, the adjustment of the stable position of the journal is achieved by combining the two methods of starting the mesh model and setting the journal surface node displacement macro. This method can greatly reduce the degree of mesh deformation to ensure mesh quality.

[0028] Preferably, in step 10, the specific process of data processing is:

[0029] Step 101: When the journal of the hydrodynamic sliding bearing is subjected to velocity disturbance at a stable position, the relationship between the oil film force change and the disturbance displacement is nonlinear. When the disturbance displacement is small, the linear relationship between the oil film force and the disturbance is expressed as:

[0030]

[0031] Among them, the parameter F x 、F y 、F x0 、F y0 , x, y, From the monitoring data collected in step 9, K xx , K yy are direct stiffness coefficients, K xy , K yx are cross stiffness coefficients, C xx 、C yy are direct damping coefficients, C xy 、C yx are cross damping coefficients;

[0032] Step 102:

[0033] When the disturbance velocity is along the X direction, at T / 4: At T:

[0034] When the disturbance velocity is along the Y direction, at T / 4: At T:

[0035] Among them, A, ω, and T are the displacement amplitude, disturbance angular velocity, and disturbance period of the velocity disturbance applied in step 5, respectively. The oil film stiffness K of the hydrodynamic sliding bearing is xx , K yy , K xy , K yx and oil film damping C xx 、C yy 、C xy 、C yx Both can be obtained.

[0036] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method for solving the oil film stiffness and damping of a hydrodynamic sliding bearing based on Fluent, which reduces the limitations of experimental equipment and experimental sites in the process of solving the lubricating oil film stiffness and damping of a hydrodynamic sliding bearing, and ensures the accuracy of the solution. Taking into account the characteristics of the oil film having a very small radial dimension, the mesh quality is required to be high during the fluid calculation process, so the structured pure hexahedral mesh division and model block division are used to improve the mesh quality to ensure the calculation accuracy. By setting the journal velocity perturbation macro, independent velocity perturbations are applied to the journal in the X and Y directions respectively, and by setting the journal oil film force monitoring macro and the axis trajectory monitoring macro, each parameter is monitored. The fluid calculation software Fluent is used to iteratively calculate the oil film flow field, and the convergence is judged by the specific values of the monitoring parameters. After judging that the iterative solution results have converged, the collected oil film pressure monitoring data and axis trajectory monitoring data are processed to obtain the oil film stiffness and oil film damping; when using this method to solve the oil film stiffness and damping of the sliding bearing, the adjustment of the stable position of the journal is achieved by combining the start-up grid model with the setting of the journal surface node displacement macro. This method can greatly reduce the degree of grid deformation to ensure the grid quality, and prove the calculation accuracy and solution speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] 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 merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0038] Figure 1 A schematic diagram of the solution process provided by the present invention;

[0039] Figure 2 A schematic diagram of a dynamic grid update method provided by the present invention;

[0040] Figure 3 A grid model diagram of the oil inlet and oil tank provided by the present invention;

[0041] Figure 4 Schematic diagram of the oil film model provided by the present invention;

[0042] Figure 5 This is a schematic diagram of the oil film force monitoring data collected in step 9 provided by the present invention. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] The embodiment of the present invention discloses a method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing based on Fluent, comprising the following steps:

[0045] S1: Use SolidWorks software to establish the oil film model in the gap between the bearing pad and the journal of the hydrodynamic sliding bearing;

[0046] The oil film model consists of three parts: oil inlet, oil tank and oil film;

[0047] S2: Use the meshing software ICEM to perform structured meshing on the oil film model to obtain the bearing oil film mesh file;

[0048] According to the model characteristics of the research object, the structured grid division method is selected. With the help of the grid division software ICEM, the computational flow field of the oil film model is divided into a structured pure hexahedral grid. The oil inlet and oil inlet groove of the bearing oil film are separated from the oil film part. After the division is completed, the complete oil film grid model is assembled and the bearing oil film grid file is exported based on the complete oil film grid model.

[0049] S3: Import the oil film grid file into Fluent software and set the initial stable position of the journal;

[0050] S4: Set the journal speed disturbance macro, journal oil film force monitoring macro, and axis trajectory monitoring macro in the Fluent software, and set the control conditions corresponding to each macro;

[0051] Set the control conditions of axis trajectory monitoring macro, journal oil film force monitoring macro, and axis trajectory monitoring macro to run once for each iteration calculation, where the axis trajectory monitoring macro monitoring parameters include x, y, S, where x and y are the distances along the X and Y directions between the axis center position and the axis center stable position at any time, is the speed of the axis at any time, and S is the axis displacement of the journal. The parameters that can be monitored by the journal oil film force monitoring macro include F x 、F y 、F x0 、F y0 , where F x 、F y F is the oil film force on the journal along the X and Y directions, x0 、F y0When the journal is located at the stable position of the axis, the journal is subjected to the oil film force in the X and Y directions;

[0052] S5: Set the flow field calculation control parameters, apply velocity disturbance to the journal through the journal velocity disturbance macro, and monitor the oil film force Fx along the X direction and the oil film force Fy along the Y direction on the journal surface, as well as the journal axis displacement S, through the journal oil film force monitoring macro and the axis trajectory monitoring macro.

[0053] The velocity disturbance imposed on the journal is two independent velocity disturbances along the X and Y directions, respectively. The displacement amplitude of the velocity disturbance is A, the disturbance angular velocity is ω, the disturbance period is T, and the disturbance time is t. The velocity disturbance can be expressed as:

[0054]

[0055] S6: Select the calculation model and set the control parameters, and start iterative solution;

[0056] The selected calculation model is: the material model is the mixture model, the mass transfer mode is the full cavitation model, the iterative solution model is the pressure-based separation solution model, and the control parameters are set as follows: the solution process is set to transient calculation, and the time step is set to 1e -5 , each time step is iterated 20 times, and the number of time steps is set to 10000;

[0057] S7: Determine whether the iterative solution result converges based on the specific values of the monitored parameters S, Fx, and Fy. If the iterative solution result converges, proceed to S9; if not, proceed to S8.

[0058] S8: Start the mesh model and set the journal surface node displacement macro, adjust the journal stable position, and return to S4;

[0059] S9: The oil film pressure monitoring data and the axis trajectory monitoring data are collected through the set journal oil film force monitoring macro and the axis trajectory monitoring macro. The oil film pressure monitoring data collected by the journal oil film force monitoring macro include: F x 、F y 、F x0 、F y0 , the axis trajectory monitoring data collected by the axis trajectory monitoring macro include: x, y,

[0060] S10: Processing the oil film pressure monitoring data and the axis trajectory monitoring data collected in step 9 to obtain the oil film stiffness and the oil film damping;

[0061] S101: When the journal of a hydrodynamic sliding bearing is subjected to velocity disturbances in a stable position, the relationship between the oil film force change and the disturbance displacement is nonlinear. When the disturbance displacement is small, the linear relationship between the oil film force and the disturbance is expressed as:

[0062]

[0063] Among them, the parameter F x 、F y 、F x0 、F y0 , x, y, From the monitoring data collected in step 9, K xx , K yy is the direct stiffness coefficient, K xy , K yx is the cross stiffness coefficient, C xx 、C yy is the direct damping coefficient, C xy 、C yx is the cross damping coefficient;

[0064] S102:

[0065] When the disturbance velocity is along the X direction, at T / 4: At T:

[0066] When the disturbance velocity is along the Y direction, at T / 4: At T:

[0067] Among them, A, ω, and T are the displacement amplitude, disturbance angular velocity, and disturbance period of the velocity disturbance applied in step 5. The oil film stiffness K of the hydrodynamic sliding bearing is xx , K yy , K xy , K yx and oil film damping C xx 、C yy 、C xy 、C yx Both can be obtained.

[0068] Example

[0069] In a specific embodiment, relevant parameters of the hydrodynamic sliding bearing are shown in Table 1 below.

[0070] Table 1 Physical properties of bearings, rotors and lubricating oil

[0071]

[0072]

[0073] When solving the bearing stiffness and damping, the main method is to apply independent custom speed disturbances to the journal along the X and Y directions through the journal speed disturbance macro, and monitor the parameters x, y, S, macro monitoring parameter F through the journal oil film force monitoring x 、F y 、F x0 、F y0 , the specific values of the monitored parameters S, Fx, and Fy are used to determine whether the iterative solution results have converged. After convergence, the journal oil film force monitoring macro and the axis trajectory monitoring macro collect the oil film pressure monitoring data and the axis trajectory monitoring data;

[0074] The oil film stiffness and oil film damping of the sliding bearing are finally obtained through data processing, which includes the following steps:

[0075] S1: Use SolidWorks software to establish the oil film model in the gap between the bearing bush and the journal of the hydrodynamic sliding bearing; the oil film model is as follows Figure 4 As shown;

[0076] The oil film model consists of three parts: oil inlet, oil tank and oil film; the network models of the oil inlet and oil tank are as follows: Figure 3 As shown;

[0077] S2: Use the meshing software ICEM to perform structured meshing on the oil film model to obtain the bearing oil film mesh file;

[0078] According to the model characteristics of the research object, a structured grid division method is selected. With the help of the grid division software ICEM, the computational flow field of the oil film model is divided into a structured pure hexahedral grid. The oil inlet and oil inlet groove of the bearing oil film are divided separately from the oil film part. After the division is completed, the complete oil film grid model is assembled and the bearing oil film grid file is derived based on the complete oil film grid model.

[0079] S3: Import the oil film grid file into Fluent software and set the initial stable position of the journal;

[0080] S4: Set the journal speed disturbance macro, journal oil film force monitoring macro, and axis trajectory monitoring macro in the Fluent software, and set the control conditions corresponding to each macro;

[0081] Set the control conditions of axis trajectory monitoring macro, journal oil film force monitoring macro, and axis trajectory monitoring macro to run once for each iteration calculation, where the axis trajectory monitoring macro monitoring parameters include x, y, S, where x and y are the distances along the X and Y directions between the axis center position and the axis center stable position at any time, is the speed of the axis at any time, and S is the axis displacement of the journal. The parameters that can be monitored by the journal oil film force monitoring macro include Fx 、F y 、F x0 、F y0 , where F x 、F y F is the oil film force on the journal along the X and Y directions, x0 、F y0 When the journal is located at the stable position of the axis, the journal is subjected to the oil film force in the X and Y directions;

[0082] S5: Set the flow field calculation control parameters, apply velocity disturbance to the journal through the journal velocity disturbance macro, and monitor the oil film force Fx along the X direction and the oil film force Fy along the Y direction on the journal surface, as well as the journal axis displacement S, through the journal oil film force monitoring macro and the axis trajectory monitoring macro.

[0083] The velocity disturbance imposed on the journal is two independent velocity disturbances along the X and Y directions, respectively. The displacement amplitude of the velocity disturbance is A, the disturbance angular velocity is ω, the disturbance period is T, and the disturbance time is t. The velocity disturbance can be expressed as:

[0084]

[0085] S6: Select the calculation model and set the control parameters, and start the iterative solution;

[0086] The selected calculation model is: the material model is the mixture model, the mass transfer mode is the full cavitation model, the iterative solution model is the pressure-based separation solution model, and the control parameters are set as follows: the solution process is set to transient calculation, and the time step is set to 1e -5 , each time step is iterated 20 times, and the number of time steps is set to 10000;

[0087] S7: Determine whether the iterative solution result converges based on the specific values of the monitored parameters S, Fx, and Fy. If the iterative solution result converges, proceed to S9; if not, proceed to S8.

[0088] S8: Start the mesh model and set the journal surface node displacement macro, adjust the journal stable position, and return to S4; the dynamic mesh update method is as follows Figure 2 As shown;

[0089] S9: The oil film pressure monitoring data and the axis trajectory monitoring data are collected through the set journal oil film force monitoring macro and the axis trajectory monitoring macro. The oil film pressure monitoring data collected by the journal oil film force monitoring macro include: F x 、F y 、F x0 、F y0 , the axis trajectory monitoring data collected by the axis trajectory monitoring macro include: x, y, The monitoring data obtained are as follows: Figure 5 As shown;

[0090] S10: Processing the oil film pressure monitoring data and the axis trajectory monitoring data collected in step 9 to obtain the oil film stiffness and the oil film damping;

[0091] S101: When the journal of a hydrodynamic sliding bearing is subjected to velocity disturbances in a stable position, the relationship between the oil film force change and the disturbance displacement is nonlinear. When the disturbance displacement is small, the linear relationship between the oil film force and the disturbance is expressed as:

[0092]

[0093] Among them, the parameter F x 、F y 、F x0 、F y0 , x, y, From the monitoring data collected in step 9, K xx , K yy is the direct stiffness coefficient, K xy , K yx is the cross stiffness coefficient, C xx 、C yy is the direct damping coefficient, C xy 、C yx is the cross damping coefficient;

[0094] S102:

[0095] When the disturbance velocity is along the X direction, at T / 4: At T:

[0096] When the disturbance velocity is along the Y direction, at T / 4: At T:

[0097] Among them, A, ω, and T are the displacement amplitude, disturbance angular velocity, and disturbance period of the velocity disturbance applied in step 5. The oil film stiffness K of the hydrodynamic sliding bearing is xx , K yy , K xy , K yx and oil film damping C xx 、C yy 、C xy 、C yx Both can be obtained.

[0098] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0099] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A Fluent-based method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing, characterized in that: The following steps are involved: Step 1: Construct the oil film model in the gap between the bearing shell and the journal of the hydrodynamic sliding bearing; Step 2: Perform structured meshing on the oil film model to obtain the bearing oil film mesh file; Step 3: Import the oil film grid file described in step 2 into the Fluent software and set the initial stable position of the journal; Step 4: Set the journal speed disturbance macro, journal oil film force monitoring macro, and axis trajectory monitoring macro in the Fluent software described in step 3, and set the control conditions for each macro; Step 5: Set the flow field calculation control parameters, apply velocity disturbance to the journal using the journal velocity disturbance macro, and obtain the oil film force along the X direction and Y direction of the oil film on the journal surface and the journal axis displacement through the journal oil film force monitoring macro and the axis trajectory monitoring macro respectively. Step 6: Determine the calculation model and set the control parameters, and start iterative solution using the iterative solution model; Step 7: If the ratio of the oil film force on the journal surface in the X direction to the oil film force on the journal surface in the Y direction is less than the set convergence threshold, and the journal axis displacement S is within the set displacement threshold, it is determined to be converged and the process proceeds to Step 9; otherwise, it is determined to be non-convergent and the process proceeds to Step 8; Step 8: Start the mesh model and set the journal surface node displacement macro in Fluent software, adjust the journal position, and return to step 4; Step 9: Collect oil film pressure monitoring data and axis trajectory monitoring data through the journal oil film force monitoring macro and the axis trajectory monitoring macro; Step 10: Calculate the oil film stiffness and oil film damping of the sliding bearing based on the oil film pressure monitoring data and the axis trajectory monitoring data; The specific process of data processing in step 10 is as follows: Step 101: When the journal of the hydrodynamic sliding bearing is subjected to velocity disturbance at a stable position, the relationship between the oil film force change and the disturbance displacement is nonlinear. When the disturbance displacement is small, the linear relationship between the oil film force and the disturbance is expressed as: Among them, F x 、F y The oil film forces acting on the journal along the X and Y directions are respectively; F x0 、F y0 are the oil film forces acting on the journal along the X and Y directions when the journal is at the stable axis position; x and y are the distances along the X and Y directions between the axis position and the stable axis position at any moment; are the movement speed of the axis at any time; K xx , K yy Both are direct stiffness coefficients; K xy , K yx are cross stiffness coefficients; C xx 、C yy are direct damping coefficients; C xy 、C yx are cross damping coefficients; Step 102: When the disturbance velocity is along the X direction, at T / 4: At T: When the disturbance velocity is along the Y direction, at T / 4: At T: Where A is the displacement amplitude of the applied velocity disturbance; ω is the angular velocity of the applied velocity disturbance; T is the disturbance period of the applied velocity disturbance, and the oil film stiffness K of the hydrodynamic sliding bearing is obtained by solving xx , K yy , K xy , K yx and oil film damping C xx 、C yy 、C xy 、C yx .

2. A method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing based on Fluent according to claim 1, characterized in that: The oil film model in step 1 includes an oil inlet, an oil tank and an oil film.

3. The method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing based on Fluent according to claim 1, characterized in that: In step 2, the oil film model is divided into structured grids by dividing the oil inlet, oil tank, and oil film blocks. After the division is completed, grid assembly is used to obtain a complete oil film grid model, and the bearing oil film grid file is derived based on the complete oil film grid model.

4. The method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing based on Fluent according to claim 1, characterized in that: The monitoring data collected by the axis trajectory monitoring macro include the distance between the axis position and the axis stable position along the X and Y directions at any time, the movement speed of the axis at any time, and the axis displacement of the journal.

5. The method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing based on Fluent according to claim 1, characterized in that: The monitoring data collected by the journal oil film force monitoring macro includes the oil film force applied to the journal in the X and Y directions, as well as the oil film force applied to the journal in the X and Y directions when the journal is located at a stable axis position.

6. The method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing based on Fluent according to claim 1, characterized in that: The speed disturbance applied to the journal in step 5 is two independent speed disturbances along the X direction and the Y direction respectively. The speed disturbance is expressed as: Where V represents the velocity disturbance; A represents the displacement amplitude of the velocity disturbance; ω represents the disturbance angular velocity; T represents the disturbance period; and t represents the disturbance time.

7. The method for solving the oil film stiffness and damping of a dynamic pressure sliding bearing based on Fluent according to claim 1, characterized in that: The calculation model selected in step 6 is: the material model selects the mixture model, the mass transfer mode selects the full cavitation model, and the iterative solution model selects the pressure-based separation solution model; the control parameters in step 6 are set to: set the solution process to transient calculation, and the time step to 1e -5 , each time step is iterated 20 times, and the number of time steps is set to 10000.

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