A method and device for simulating and analyzing a radial three-dimensional dynamic of a thin-wall oil film in a toroidal belt shape

Abstract

This invention provides a radial three-dimensional dynamic simulation analysis method for a circular annular thin-walled oil film. The method includes: Step 1: When the oil film is in equilibrium, based on the three-dimensional structure of the circular annular thin-walled oil film, key structural parameter information is obtained, and a three-dimensional mesh of the oil film is constructed; Step 2: When the oil film is in a stable state at a certain stable rotational speed, a force balance formula for the inner and outer walls of the oil film is constructed; Step 3: When the oil film changes from a stable state to an unstable state, the resultant force in the X and Y axes under the unstable state is set; Step 4: PID control parameters are set, and the control objective is set to make the resultant force in the X and Y axes under the unstable state tend to zero; Step 5: The above execution steps are converted into a script, so that each time step of the solution process is automatically read; Step 6: The script is executed and output; This invention can evaluate the internal state of the lubricating oil film between annular friction pairs, and the results are more intuitive and accurate.

Description

Technical Field

[0001] This invention belongs to the technical field of three-dimensional dynamic simulation analysis of annular thin-walled oil film in sliding bearings of aero-engine fuel control device, and relates to a method and device for radial three-dimensional dynamic simulation analysis of annular strip-shaped thin-walled oil film. Background Technology

[0002] The fuel control unit of an aircraft engine contains various booster pumps, such as gear pumps, centrifugal pumps, and piston pumps. Their basic principle is to pressurize the working fluid by performing work on it through rotational motion. To achieve higher pressures, higher rotational speeds are often required, which places higher demands on the lubrication of friction pairs such as sliding bearings and on related designs. However, current simulation evaluation methods for thin-walled oil films in annular belts like sliding bearings traditionally rely on the finite difference method. This involves constructing a fluid domain of uniform thickness using code programming to conduct one-dimensional or two-dimensional simulations. These simulations are steady-state and cannot consider multiphysics, nor can they accurately simulate the real changes in the thickness of the thin-walled oil film.

[0003] To address the aforementioned issues and gain a clearer understanding of the internal lubrication performance evaluation of annular thin-walled oil films, it is necessary to provide a method that can dynamically simulate changes in oil film thickness, reflect thickness non-uniformity, and consider the comprehensive performance evaluation of oil films under multi-physical field environments. Summary of the Invention

[0004] To address the shortcomings of existing technologies that rely on the finite difference method for one- or two-dimensional simulations of oil film fluid domains of uniform thickness, which are often steady-state simulations that cannot account for multiphysics and fail to accurately reflect the actual changes in thin-walled oil film thickness, this invention provides a radial three-dimensional dynamic simulation analysis method and apparatus for annular thin-walled oil films. This method can be used to evaluate the internal state of the lubricating oil film between annular friction pairs. The dynamic process of force balance within the oil film is realized through script code, and parameters of oil film non-uniformity distribution can be output. PID control parameters are introduced to automatically control the "force balance-imbalance-rebalancing" between the oil film friction pairs, making the simulation more closely resemble physical reality. Optimal PID parameters were obtained through multiple trials, and the results are more intuitive and accurate compared to previous methods.

[0005] The technical solution is as follows: Firstly, a radial three-dimensional dynamic simulation analysis method for a circular annular thin-walled oil film is provided. Based on PID control parameters, the oil film friction pairs are automatically controlled to achieve "force balance-imbalance-rebalancing". The dynamic process of force balance inside the oil film is realized through script code, and the oil film non-uniformity distribution parameters are output.

[0006] Optionally, the method includes: Step 1: The oil film is in equilibrium. Based on the three-dimensional structure of the annular thin-walled oil film, key structural parameter information is obtained, a three-dimensional mesh of the oil film is constructed, and the displacement value of the center coordinate of the inner wall of the oil film is set as a variable parameter. Step 2: When the bearing oil film is in a stable state at a certain stable speed, construct the formula for balancing the forces inside and outside the oil film; Step 3: The oil film changes from a stable state to an unstable state, and the resultant force in the X-axis and Y-axis directions in the unstable state is set; Step 4: Set the PID control parameters, set the control target to make the resultant force in the X and Y directions in the unsteady state tend to zero, and set the controlled object to the displacement value of the center coordinate of the inner wall of the oil film; Step 5: Convert the above execution steps into a script so that each time step of the solution process can be read automatically; Step 6: Execute the script and output the results.

[0007] Optionally, key structural parameter information includes the coordinates (x1, y1, z) of the center O1 of the outer wall of the oil film and its radius r1, the coordinates (x2, y2, z) of the center O2 of the inner wall of the oil film and its radius r2, and the gap between the inner and outer wall surfaces. The width of the oil film ring is given by setting the displacement value in the X-axis direction as 'a' and the displacement value in the Y-axis direction as 'b'. Based on physical constraints, we obtain: a = x2 - x1, b = y2 - y1. , .

[0008] Optionally, in step 2, the force F1 on the inner wall of the oil film has the X-axis component F1x and the Y-axis component F1y, and so on. The force F2 on the outer wall of the oil film has the X-axis and Y-axis components F2x and F2y respectively, resulting in: F1x=F2x, F1y=F2y.

[0009] Optionally, in step 3, the oil film changes from a stable state to an unstable state. At this time, the force F1' on the inner wall of the oil film has the component F1'x on the X-axis and F1'y on the Y-axis. Similarly, the force F2' on the outer wall of the oil film has the components F2'x and F2'y on the X-axis and Y-axis, respectively. Since it is an unstable state, the resultant force must not be 0. The coordinates of the inner wall center change to O2'. Parameters Px and Py are introduced. Px and Py are the resultant forces in the X-axis and Y-axis directions in the unstable state, Px=F1x+F2x, Py=F1y+F2y.

[0010] Optionally, in step 4, the PID control parameters are set as follows: Kp = 0.1, Ti = 1, and Td = 0, so that Px and Py are the resultant force parameters of the oil film in the X and Y axes, respectively; the control objective is set to make the results of Px and Py approach zero, and the controlled object is set to the displacement values ​​a and b of the center coordinates of the inner wall of the oil film, with the values ​​of a and b changing at different times.

[0011] Optionally, in step 5, a time step is set for every 1° rotation of the inner wall.

[0012] Secondly, a radial three-dimensional dynamic simulation analysis device for annular thin-walled oil film is provided, comprising: The first construction module is used to obtain key structural parameter information, construct a three-dimensional mesh of the oil film based on the three-dimensional structure of the annular thin-walled oil film when the oil film is in equilibrium, and set the displacement value of the inner wall center coordinates of the oil film as a variable parameter. The second construction module is used to construct the oil film inner and outer wall force balance formula when the oil film is in a stable state at a certain stable speed; The first setting module is used to set the resultant force in the X-axis and Y-axis directions in the unstable state when the oil film changes from a stable state to an unstable state. The second setting module is used to set PID control parameters, set the control target as the resultant force in the X and Y directions tending to zero in the unsteady state, and set the controlled object as the displacement value of the center coordinate of the inner wall of the oil film. The conversion module is used to convert the above execution steps into a script, so that each time step of the solution process can be automatically read. The output module is used to execute scripts and output the results.

[0013] In a second aspect, a radial three-dimensional dynamic simulation analysis device for a circular annular thin-walled oil film is provided, comprising a processor and a memory, wherein the processor is configured to execute instructions stored in the memory, and the processor implements the radial three-dimensional dynamic simulation analysis method for a circular annular thin-walled oil film as described in any of the first aspects by executing the instructions.

[0014] Thirdly, a computer-readable storage medium is provided, wherein instructions are stored therein, which, when executed on a processing component of a computer, cause the processing component to perform the radial three-dimensional dynamic simulation analysis method for annular thin-walled oil film as described in any of the first aspects.

[0015] Fourthly, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to execute the radial three-dimensional dynamic simulation analysis method for annular thin-walled oil film as described in any of the first aspects.

[0016] This invention provides a radial three-dimensional dynamic simulation analysis method for a circular annular thin-walled oil film. Based on PID control parameters, it automatically controls the "force balance-imbalance-rebalancing" between oil film friction pairs. The dynamic process of force balance inside the oil film is realized through script code, and the oil film non-uniformity distribution parameters are output. It can clearly evaluate the internal lubrication performance of the circular annular thin-walled oil film, and the results are more intuitive and accurate compared with previous methods. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the simulation analysis method of the present invention; Figure 2 Define the parameters for step S1; Figure 3 Define the parameters for step S1; Figure 4 This is a schematic diagram of force balance in step S2; Figure 5 This is a schematic diagram of the force imbalance in step S3; Figure 6 This is a schematic diagram of force non-equilibrium at a certain moment in step S4; Figure 7 This is a schematic diagram of an oil film mesh. Figure 8 This is a schematic diagram of the oil film pressure distribution. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0021] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited from each other.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] See Figure 1 An embodiment of the present invention provides a radial three-dimensional dynamic simulation analysis method for a circular annular thin-walled oil film, specifically including the following steps: Step S1: As Figure 2 , Figure 3 As shown, when the oil film is in equilibrium at a certain moment, key structural parameter information is obtained based on the three-dimensional structure of the annular thin-walled oil film, such as the coordinates (x1, y1, z) of the center O1 of the outer wall of the oil film and its radius r1, the coordinates (x2, y2, z) of the center O2 of the inner wall of the oil film and its radius r2, and the gap between the inner and outer wall surfaces. (Radial direction, the gap is the oil film filling space), oil film annular width c, these parameters are used to construct a three-dimensional mesh of the oil film, and the displacement value of the center coordinate of the inner wall of the oil film is set as a variable parameter, the displacement value in the X-axis direction is set as a, and the displacement value in the Y-axis direction is set as b. Based on physical constraints, the following formula can be obtained: a = x2 - x1 (1) b = y2 - y1 (2) (3) (4) Step S2: As Figure 4 As shown, when the oil film is in a stable state at a certain stable speed, the force balance formula between the inner and outer walls of the oil film is constructed. The force F1 on the inner wall of the oil film has the X-axis component F1x and the Y-axis component F1y, and so on. The force F2 on the outer wall of the oil film has the X-axis and Y-axis components F2x and F2y, respectively, which can be used to obtain the following formula: F1x=F2x(5) F1y=F2y(6) Step S3: As Figure 5 As shown, at a certain moment, the oil film changes from a stable state to an unstable state. At this time, the force F1' on the inner wall of the oil film has the X-axis component F1'x and the Y-axis component F1'y. Similarly, the force F2' on the outer wall of the oil film has the X-axis and Y-axis components F2'x and F2'y, respectively. Since it is an unstable state, the resultant force must not be 0. The coordinates of the inner wall center change to O2'. Introducing parameters Px and Py, as shown in formulas (7) and (8), Px and Py are the resultant forces in the X-axis and Y-axis directions in the unstable state. Px = F1x + F2x (7) Py = F1y + F2y (8) Step S4: As Figure 6 As shown, in this state, the PID control parameters are set so that Kp is 0.1, Ti is 1, and Td is 0, and Px and Py are the resultant force parameters of the oil film in the X and Y axes, respectively, as shown in formulas (7) and (8); the control target is set so that the results of Px and Py tend to be equal to zero, and the controlled object is set as the displacement values ​​a and b of the center coordinates of the inner wall of the oil film. The values ​​of a and b are changing at different times.

[0024] Step S5: Convert the logical relationships of the above steps into a script so that each time step in the solution process is automatically read. Generally, it is assumed that a time step is set for every 1° rotation of the inner wall. The main logical relationship of the relevant script is as follows: For each time step, obtain the X-axis and Y-axis force components of the inner wall and the X-axis and Y-axis force components of the outer wall. Let Px be the resultant force along the X-axis of the inner and outer walls, and Py be the resultant force along the Y-axis of the inner and outer walls. Set the control objectives as Px=0, Py=0 When specifying the values ​​of Px and Py, the range of values ​​that can be considered convergent can be defined. Set the range of values ​​for the inner wall center coordinate displacements a and b, and simultaneously set them as control output parameters. Set the maximum change value for a single time step a and b. Based on the obtained a and b values, the oil film mesh is regenerated, and the coordinates of the inner wall center are updated. Determine whether the values ​​of Px and Py converge. If the values ​​of Px and Py do not converge, then continue the calculation and solution based on the newly generated mesh at the new time step. If convergence is achieved, the computation ends and the final result is saved. end Step S6: Output the results through a customized script, such as the X-axis and Y-axis displacement of the inner wall of the oil film, the resultant force angle, etc., to complete the final post-processing. The relevant script logic is as follows. "for each time step" After solving the problem at each time step, output the values ​​of a and b for that step. After solving at each time step, output the Px and Py values ​​obtained at that step. After solving at each time step, output the angle between the position of the thinnest oil film and the Y-axis force direction. After solving at each time step, output the thinnest oil film thickness value. After solving at each time step, the oil film eccentricity is output. end.

[0025] In one embodiment, the process is mainly based on flow field analysis software. During the modeling process in stages S1-S4, after clearly defining the center coordinates of the inner and outer walls of the oil film, it is necessary to set the motion form of the mesh to radial motion, that is, to constrain the displacement of the oil film in the Z direction, and at the same time, set the mesh to be regenerated at each time step; it is necessary to clearly name the inner and outer walls of the oil film in advance, and define them according to formulas (1)-(8), where the pressure on the X-axis is in the format of " (Wall naming)", the pressure format in the Y-axis direction is " (Wall surface naming). See oil film mesh. Figure 7 ; In the S5 stage, two PID functional modules are constructed to control the displacement in the X and Y axes respectively, and the relevant PID values ​​can be set consistently. The entire simulation script must ensure that a minimum oil film thickness is set; a recommended value is 10. -7 m, the execution logic of the relevant sub-process script is as follows: "For each time step, obtain the thinnest oil film thickness value at that time step." If the thickness value is greater than or equal to 10 -7 m, output the thickness value Else reassigns the thickness value to 10. -7 m end Once the thinnest oil film thickness result is output as 10 -7 If m remains stable, it can be determined that the inner and outer walls have already experienced contact wear.

[0026] In the S6 stage, develop the output script and analyze the results, paying attention to the following requirements: First, the simulation results of the initial 360 time steps are not considered when analyzing the results; Second, even if Px and Py converge, if the values ​​of a and b at this step size fluctuate, and the ratio of the difference between the maximum and minimum values ​​to the difference within the set fluctuation range exceeds 5%, the time step needs to be adjusted and recalculated until the requirements are met. Third, if the difference in surface roughness of the actual friction pair is greater than the thinnest thickness of the oil film, it can also be considered that the friction pair has experienced contact wear.

[0027] The results of oil film pressure distribution are shown below. Figure 8 .

[0028] It should be noted that the above process operations can be combined to varying degrees. For the sake of simplicity, the implementation methods of various combinations will not be elaborated further. Those skilled in the art can flexibly adjust or combine the order of the steps of the above method (or the position of the product components) according to the actual situation.

[0029] The above description merely illustrates the embodiments of this application, and while it is quite specific and detailed, it should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Furthermore, any parts not detailed in this application are conventional techniques.

Claims

1. A radial three-dimensional dynamic simulation analysis method for a circular annular thin-walled oil film, characterized in that, The system automatically balances, debalances, and rebalances the oil film friction pairs based on PID control parameters. The dynamic process of force balance within the oil film is realized through script code, and the oil film non-uniformity distribution parameters are output.

2. The method according to claim 1, characterized in that, The method includes: Step 1: The oil film is in equilibrium. Based on the three-dimensional structure of the annular thin-walled oil film, key structural parameter information is obtained, a three-dimensional mesh of the oil film is constructed, and the displacement value of the center coordinate of the inner wall of the oil film is set as a variable parameter. Step 2: When the bearing oil film is in a stable state at a certain stable speed, construct the formula for balancing the forces inside and outside the oil film; Step 3: The oil film changes from a stable state to an unstable state, and the resultant force in the X-axis and Y-axis directions is set in the unstable state; Step 4: Set the PID control parameters, set the control target to make the resultant force in the X and Y directions in the unsteady state tend to zero, and set the controlled object to the displacement value of the center coordinate of the inner wall of the oil film; Step 5: Convert the above execution steps into a script so that each time step of the solution process can be read automatically; Step 6: Execute the script and output the results.

3. The method according to claim 2, characterized in that, Key structural parameters include the coordinates (x1, y1, z) of the center O1 of the outer wall of the oil film and its radius r1, the coordinates (x2, y2, z) of the center O2 of the inner wall of the oil film and its radius r2, and the gap between the inner and outer wall surfaces. The width of the oil film ring is given by setting the displacement value in the X-axis direction as 'a' and the displacement value in the Y-axis direction as 'b'. Based on physical constraints, we obtain: a = x2 - x1, b = y2 - y1. , .

4. The method according to claim 3, characterized in that, In step 2, the force F1 on the inner wall of the oil film has the component F1x on the X-axis and F1y on the Y-axis. Similarly, the force F2 on the outer wall of the oil film has the components F2x and F2y on the X-axis and Y-axis, respectively, so we get: F1x=F2x, F1y=F2y.

5. The method according to claim 4, characterized in that, In step 3, the oil film changes from a stable state to an unstable state. At this time, the force F1' on the inner wall of the oil film has the X-axis component F1'x and the Y-axis component F1'y. Similarly, the force F2' on the outer wall of the oil film has the X-axis and Y-axis components F2'x and F2'y, respectively. Since it is an unstable state, the resultant force must not be 0. The coordinates of the inner wall center change to O2'. Introduce parameters Px and Py, which are the resultant forces in the X-axis and Y-axis directions in the unstable state. Px = F1x + F2x, Py = F1y + F2y.

6. The method according to claim 5, characterized in that, In step 4, the PID control parameters are set as follows: Kp = 0.1, Ti = 1, and Td = 0, so that Px and Py are the resultant force parameters of the oil film in the X and Y axes, respectively. The control objective is set to make the results of Px and Py approach zero. The controlled object is set as the displacement values ​​a and b of the center coordinates of the inner wall of the oil film. The values ​​of a and b are changing at different times.

7. The method according to claim 2, characterized in that, In step 5, a time step is set for every 1° rotation of the inner wall.

8. A radial three-dimensional dynamic simulation analysis device for a circular strip-shaped thin-walled oil film, characterized in that, The method includes a processor and a memory, the processor being configured to execute instructions stored in the memory, the processor implementing the radial three-dimensional dynamic simulation analysis method for annular thin-walled oil film as described in any one of claims 1 to 7 by executing the instructions.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer's processing component, cause the processing component to perform the radial three-dimensional dynamic simulation analysis method for annular thin-walled oil films as described in any one of claims 1 to 7.

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