A method for analyzing the sealing performance of aviation fuel pumps

Abstract

The present invention provides a method for analyzing the sealing performance of an aviation fuel pump, which involves obtaining the geometric parameters, material parameters and operating parameters of a seal, including the inner diameter of the seal, the sealing contact width, the thickness of the sealing lip, the Young's modulus of the sealing material, the Poisson's ratio, and the oil pressure and rotation speed. The elastic deformation of the sealing lip under pressure is calculated by finite element static analysis, and the oil film thickness distribution is determined based on this, and a dynamic lubrication model is established based on the fluid lubrication theory. Subsequently, the Reynolds equation is used to describe the oil film pressure distribution and its changing trend, and the Reynolds equation is discretized into multiple calculation grids by the finite difference method, and the oil film pressure and thickness distribution are obtained by numerically solving the equation using the successive super relaxation method. Based on these results, the reverse pumping rate of the seal is calculated to evaluate the sealing performance of the fuel pump. The method provided by the present invention can accurately analyze the sealing performance of the seal under different working conditions, and improve the design and reliability of the fuel pump sealing system.

Description

Technical Field

[0001] The invention relates to the technical field of fuel pump sealing performance analysis, and in particular to a method for analyzing the sealing performance of an aviation fuel pump. Background Art

[0002] In the prior art, the evaluation of aviation fuel pump sealing performance usually relies on empirical formulas and simplified calculation methods, which include estimating the pressure distribution and oil film thickness of the seal based on fluid mechanics theory. The conventional analysis process usually involves preliminary modeling of the material and geometric parameters of the seal, and then evaluating the performance of the seal under different working conditions through theoretical analysis and finite element simulation. These technologies are widely used in aviation and other high-demand sealing systems to ensure that fuel pumps can continue to operate efficiently under high pressure and high temperature environments.

[0003] However, existing technologies have limitations when dealing with complex sealing systems. First, traditional calculation methods rely on simplified assumptions and are difficult to accurately reflect the complex stress distribution and elastic deformation of seals under actual working conditions. Second, the oil film pressure distribution and oil film thickness calculations in the fluid dynamic lubrication model are usually based on idealized geometric shapes, ignoring the influence of the actual microscopic morphology of the sealing lip surface. In addition, the numerical solution efficiency in existing technologies is low, and when dealing with precise calculations under multiple working conditions, the calculation amount is huge and time-consuming.

[0004] Therefore, it is urgent to develop a more accurate aviation fuel pump sealing performance analysis method to improve the analysis accuracy and calculation efficiency of the sealing system. Summary of the invention

[0005] The present application provides an aviation fuel pump sealing performance analysis method to improve the analysis accuracy and calculation efficiency of the sealing system.

[0006] The present application provides a method for analyzing the sealing performance of an aviation fuel pump, comprising:

[0007] Acquire geometric parameters, material parameters and operating parameters of the seal of the aviation fuel pump, wherein the geometric parameters include the inner diameter of the seal, the seal contact width and the sealing lip thickness, the material parameters include the Young's modulus and Poisson's ratio of the sealing material, and the operating parameters include the oil pressure and the rotation speed;

[0008] Based on the geometric parameters, material parameters and working condition parameters, the elastic deformation of the sealing lip is calculated by finite element static analysis, wherein the elastic deformation reflects the deformation amplitude of the sealing lip under pressure;

[0009] Determine the oil film thickness distribution according to the calculated elastic deformation, wherein the oil film thickness distribution describes the spatial variation of the liquid film in the sealing area; establish a fluid dynamic lubrication model based on fluid lubrication theory using the oil film thickness distribution and operating condition parameters;

[0010] According to the fluid dynamic lubrication model, the Reynolds equation is used to describe the oil film pressure distribution and its change trend in the sealing area; the Reynolds equation is discretized by the finite difference method, and the sealing area is divided into a plurality of calculation grids, wherein the calculation grids are used to accurately solve the oil film pressure and thickness values ​​in each grid unit;

[0011] The discretized Reynolds equation is numerically solved using a successive over-relaxation method to obtain a first oil film pressure distribution and a first oil film thickness distribution; based on the obtained first oil film pressure distribution and the first oil film thickness distribution, a reverse pumping rate of the seal is calculated, wherein the reverse pumping rate reflects the volume flow rate from the air side to the oil side;

[0012] Evaluate aviation fuel pump seal performance based on calculated reverse pumping rates.

[0013] Furthermore, the elastic deformation is calculated using the following formula 1:

[0014]

[0015] in, Indicates the elastic deformation of the sealing lip; is the sealing pressure; is the contact pressure, obtained by finite element static analysis; is the sealing lip thickness; is Poisson's ratio; is the Young’s modulus of the sealing material.

[0016] Furthermore, the oil film thickness distribution is calculated using the following formula 2:

[0017]

[0018] in, is the oil film thickness distribution; is the average oil film thickness; is the reference value of oil film thickness; Indicates the elastic deformation of the sealing lip; is the sealing lip height distribution, which is determined by the following formula 3:

[0019]

[0020] in, and is a constant; is the characteristic length; and are the dimensionless axial and circumferential coordinates, respectively;

[0021] Furthermore, the oil film pressure distribution is determined by the dimensionless Reynolds equation, which uses the following formula 4:

[0022]

[0023] in; is the dimensionless oil film thickness; is the dimensionless oil film pressure; The coefficient is implemented using the following formula 5:

[0024]

[0025] in is the inner diameter of the seal, is the sealing contact width.

[0026] Furthermore, the discretized Reynolds equation is as follows:

[0027]

[0028] in, Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at

[0029] Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node The oil film thickness correlation coefficient at ; each coefficient is realized by the following formula 7:

[0030]

[0031] in, Representation Node The oil film thickness at Representation Node The oil film thickness at Representation Node The oil film thickness at Representation Node The oil film thickness at represents the interval between two discrete grid points in the axial direction; represents the interval between two discrete grid points in the circumferential direction; is the inner diameter of the seal, is the sealing contact width.

[0032] The beneficial effects of the technical solution provided by this application include:

[0033] (1) By obtaining the geometric parameters, material parameters and working condition parameters of the seal, and calculating the elastic deformation of the sealing lip based on finite element static analysis, this method can accurately reflect the deformation of the seal under actual working conditions, thereby providing a more accurate oil film thickness distribution and effectively improving the accuracy of the analysis. (2) By constructing a fluid dynamic lubrication model based on fluid lubrication theory and combining the Reynolds equation to describe the oil film pressure distribution, the present invention can truly reflect the pressure change trend of the liquid film in the sealing area, making the evaluation of the sealing performance more comprehensive and accurate. (3) This method uses the finite difference method to discretize the Reynolds equation and numerically solves it through the successive super relaxation method, which can effectively improve the calculation efficiency of complex sealing systems, especially under multiple working conditions, it can greatly reduce the calculation time and improve the calculation accuracy. (4) Based on the obtained oil film pressure distribution and oil film thickness distribution, this method can accurately calculate the reverse pumping rate of the seal, reflect the volume flow from the air side to the oil side, and further accurately evaluate the sealing performance of the seal under complex working conditions, providing an important basis for seal design. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of a method for analyzing the sealing performance of an aviation fuel pump provided in the first embodiment of the present application. DETAILED DESCRIPTION

[0035] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application, so the present application is not limited by the specific implementation disclosed below.

[0036] The first embodiment of the present application provides a method for analyzing the sealing performance of an aviation fuel pump. Figure 1, which is a schematic diagram of the first embodiment of the present application. Figure 1 A method for analyzing the sealing performance of an aviation fuel pump is described in detail in the first embodiment of the present application.

[0037] Step S101: Acquire geometric parameters, material parameters and operating parameters of the seal of the aviation fuel pump, wherein the geometric parameters include the inner diameter of the seal, the sealing contact width and the sealing lip thickness, the material parameters include the Young's modulus and Poisson's ratio of the sealing material, and the operating parameters include the oil pressure and the rotation speed.

[0038] In step S101, the geometric parameters, material parameters and operating parameters of the aviation fuel pump seal need to be obtained. In order to ensure the accuracy of the analysis, each parameter must be accurately defined and measured.

[0039] For geometric parameters, the inner diameter of the seal should be measured by precision measuring equipment (such as a vernier caliper or a three-dimensional coordinate measuring machine) to ensure accurate inner diameter data. The seal contact width refers to the actual contact area width between the seal and its contact surface, which can be obtained by optical scanning equipment or manual measuring tools. The sealing lip thickness refers to the actual thickness of the sealing lip part of the seal at the cross section, which should be measured with appropriate tools (such as a micrometer screw) and ensure multiple measurement points to obtain an accurate average value.

[0040] In terms of material parameters, it is necessary to obtain the Young's modulus and Poisson's ratio of the sealing material. Young's modulus can be obtained through laboratory testing, such as through a standard tensile test. The specific steps include fixing the sealing material sample on a tensile machine, applying gradually increasing axial tension, recording stress and strain data, and finally calculating the Young's modulus through the stress-strain curve. Poisson's ratio can be obtained through similar experiments, measuring the ratio of lateral strain to longitudinal strain. Usually, these material parameters can be obtained through the technical manual of the sealing material or the laboratory standard test report.

[0041] For operating parameters, oil pressure and speed are two key parameters. Oil pressure can be measured by the pump pressure sensor or online monitoring equipment, and speed can be obtained by the speed sensor installed in the pump system. Ensure that the oil pressure and speed are measured under the actual working conditions of the seal to reflect the actual working conditions. The acquisition of oil pressure and speed can be done through a real-time monitoring system or simulated operation in an experimental environment to ensure the accuracy of the parameters.

[0042] By obtaining the above-mentioned geometric parameters, material parameters and operating condition parameters, accurate input data can be provided for the subsequent sealing lip elastic deformation analysis and oil film thickness calculation, ensuring the accuracy and reliability of the entire sealing performance analysis.

[0043] Step S102: Based on the geometric parameters, material parameters and operating parameters, the elastic deformation of the sealing lip is calculated by finite element static analysis, wherein the elastic deformation reflects the deformation amplitude of the sealing lip under pressure.

[0044] In step S102, based on the geometric parameters, material parameters and working condition parameters of the aviation fuel pump seal obtained in step S101, the elastic deformation of the sealing lip is calculated. The calculation of the elastic deformation is based on the finite element static analysis method. This step requires special attention to the input of material properties and the setting of geometric boundary conditions to ensure that the simulation results can accurately reflect the actual deformation behavior of the seal under working pressure.

[0045] First, an accurate 3D geometric model needs to be built based on the seal geometry parameters obtained in the previous step. This model should include the exact shape of the seal lip, inner diameter, seal contact width, and seal lip thickness. This can be done using computer-aided design (CAD) software to ensure that the dimensions of the model are consistent with the actual seal.

[0046] Next, import the model into finite element analysis software, such as common finite element analysis tools such as ANSYS or ABAQUS. Then, the material parameters, including Young's modulus and Poisson's ratio, are accurately entered into the software. These parameters determine the stress-strain relationship of the material when subjected to external pressure. Young's modulus reflects the stiffness of the material, and Poisson's ratio describes the change in strain in the perpendicular direction when the material is compressed in one direction.

[0047] When setting the boundary conditions, make sure to define the fixed part of the seal lip (usually the area in contact with the shaft or housing) as a constrained boundary condition, restricting its movement in a specific direction. Next, enter the operating parameters, which are the oil pressure acting on the seal lip in the actual working environment. The oil pressure will be applied as an external load to a specific surface of the model, usually the part of the seal lip that is in contact with the oil side.

[0048] When performing static analysis, the finite element software will calculate the deformation of the sealing lip under these conditions based on the input of material properties, boundary conditions and external loads. Specifically, the elastic deformation of the sealing lip will be calculated through the stress-strain relationship, and the strain field and displacement field of the sealing lip under pressure will be generated. In the analysis results, the deformation amplitude of the sealing lip in the key contact areas should be focused on, which directly determines the thickness change of the oil film.

[0049] Finally, the analysis results will provide a displacement distribution diagram of the sealing lip at different stress positions, thereby determining the elastic deformation of the sealing lip under the working pressure. This elastic deformation will be used to calculate the oil film thickness distribution in the subsequent steps, so special attention needs to be paid to the accuracy of the calculation results. If stress concentration or unreasonable deformation occurs in the finite element analysis, it may be necessary to adjust the mesh density or redefine the boundary conditions to ensure the reliability of the results.

[0050] Through finite element static analysis, the elastic deformation of the sealing lip can be accurately calculated, laying the foundation for the subsequent calculation of oil film thickness distribution.

[0051] Furthermore, the elastic deformation is calculated using the following formula 1:

[0052]

[0053] in, Indicates the elastic deformation of the sealing lip; is the sealing pressure; is the contact pressure, obtained by finite element static analysis; is the sealing lip thickness; is Poisson's ratio; is the Young’s modulus of the sealing material.

[0054] Elastic deformation The calculation formula provides an analytical method based on material properties and operating conditions to determine the degree of deformation of the sealing lip under working pressure. The formula is as follows:

[0055]

[0056] Elastic deformation Represents the deformation of the sealing lip under the action of working pressure, especially the compression or extension of the sealing lip material after being subjected to force. It is a key parameter for evaluating how the seal responds to external pressure under actual working conditions. The calculation of this value helps to determine the spatial distribution of the oil film thickness in the subsequent steps.

[0057] Represents the sealing pressure applied to the seal surface, which is determined by the working conditions of the fuel pump. Usually in aviation fuel pumps, the sealing pressure is generated by the oil pressure inside the fuel pump, which can be measured in real time by a pressure sensor in the pump system or obtained from the design conditions. For example, you can obtain this value while the pump is running by monitoring the oil pressure in the pump.

[0058] Contact pressure It is the local contact pressure between the sealing lip and the shaft or housing. This pressure is usually obtained through finite element static analysis. When performing finite element static analysis, a three-dimensional model is first established based on the geometric parameters, material properties and working conditions of the seal, and external loads are applied to simulate the contact conditions. Through static analysis, the stress distribution in the contact area can be calculated, and finally the local pressure between the seal and the contact surface can be obtained. .

[0059] Sealing lip thickness It is one of the geometric parameters of the seal and indicates the actual thickness of the sealing lip. This value is usually measured by a precision measuring tool (such as a vernier caliper or a laser rangefinder) to ensure that its average value at multiple locations accurately reflects the size of the sealing lip. The thickness of the sealing lip has a direct impact on the amount of elastic deformation. A thicker sealing lip will produce less deformation under the same pressure.

[0060] Poisson's ratio It is an important parameter of sealing materials, which is used to describe the ratio of lateral strain to longitudinal strain when the material is under compression or tension. Poisson's ratio is usually between 0 and 0.5. A larger Poisson's ratio means that the material will produce a larger lateral deformation when subjected to force. The value of Poisson's ratio can be obtained through experimental measurement, usually from the technical specifications or test reports of the material. It has a direct impact on the deformation characteristics of the sealing lip. The larger the Poisson's ratio, the more significant the lateral deformation of the material.

[0061] Young's modulus It is an important parameter to measure the stiffness of a material. It describes the relationship between stress and strain of the material during the elastic deformation stage. The higher the Young's modulus, the stiffer the material and the less likely it is to deform. For sealing materials, the Young's modulus is usually obtained through a tensile test. The test sample is subjected to force on a tensile machine, and its stress-strain curve is recorded, and then the Young's modulus is calculated. The value of the Young's modulus directly affects the elastic deformation of the sealing lip. Materials with higher rigidity will deform less under the same pressure.

[0062] In the specific implementation process, first obtain the value of each parameter. Sealing pressure and contact pressure Usually it needs to be obtained through experiments or numerical simulations. Poisson's ratio and Young's modulus It is an inherent property of the seal material and can be determined through laboratory testing or from a material handbook. It is obtained through actual measurement.

[0063] After substituting these parameters into the formula, the elastic deformation of the sealing lip under specific working conditions can be calculated. This value represents the displacement amplitude of the sealing lip after being subjected to pressure, and is mainly used for the subsequent calculation of oil film thickness, which in turn affects the overall evaluation of sealing performance.

[0064] Through this formula, the elastic deformation of the sealing lip can be accurately calculated, thus providing key input data for subsequent sealing performance analysis.

[0065] Step S103: determining the oil film thickness distribution according to the calculated elastic deformation, wherein the oil film thickness distribution describes the spatial variation of the liquid film in the sealing area; using the oil film thickness distribution and operating parameters, a fluid dynamic lubrication model is established based on fluid lubrication theory.

[0066] In step S103, the oil film thickness distribution is determined based on the elastic deformation of the sealing lip obtained by finite element static analysis. First, the elastic deformation of the sealing lip needs to be combined with the geometric shape of the sealing surface to determine the spatial variation of the oil film. The oil film thickness distribution is calculated based on the geometric shape of the seal and the deformation under the working pressure, which reflects how the thickness of the liquid film in the sealing area changes with position. Specifically, the oil film thickness distribution depends not only on the initial geometric shape of the sealing lip, but also on its elastic deformation under the working pressure.

[0067] In order to determine the oil film thickness distribution, the elastic deformation of the sealing lip is first superimposed on the initial geometric model. The elastic deformation is the displacement result obtained by finite element analysis, and these displacement data reflect the deformation amplitude of the sealing lip at different force positions. By superimposing these displacement data on the initial surface profile of the seal, the oil film thickness between the sealing lip and the shaft or other contact surface can be calculated. This thickness change can be accurately described in the entire sealing area, thus forming a spatially continuously changing oil film thickness distribution map.

[0068] Next, the oil film thickness distribution and related operating parameters are used to establish a hydrodynamic lubrication model based on fluid lubrication theory. The core of fluid lubrication theory is to describe the flow characteristics of a fluid (in this case, an oil film) under pressure. The oil film thickness distribution provides the geometric boundary conditions of the fluid lubrication model, while operating parameters such as oil pressure and speed provide boundary conditions and driving forces for the model. According to the hydrodynamic lubrication theory, the oil film thickness determines the flow resistance of the fluid between the sealing lip and the shaft, and further affects the sealing performance of the seal.

[0069] When establishing a fluid dynamic lubrication model, it is particularly important to note that changes in the oil film thickness distribution will affect the flow state of the fluid. For example, in some areas, a thinner oil film may lead to high pressure accumulation, while a thicker oil film may lead to lower pressure areas. These differences in fluid pressure will be reflected in the calculation of the oil film pressure distribution in subsequent steps. The establishment of the model can be completed through numerical simulation tools, usually using specialized software (such as ANSYS or ABAQUS) for fluid lubrication analysis. This model lays the foundation for subsequent sealing performance analysis.

[0070] By calculating the oil film thickness distribution in detail, the fluid characteristics of the seal under different working conditions can be accurately simulated, ensuring that accurate input data can be provided for subsequent oil film pressure distribution calculations.

[0071] Furthermore, the oil film thickness distribution is calculated using the following formula 2:

[0072]

[0073] in, is the oil film thickness distribution; is the average oil film thickness; is the reference value of oil film thickness; Indicates the elastic deformation of the sealing lip; is the sealing lip height distribution, which is determined by the following formula 3:

[0074]

[0075] in, and is a constant; is the characteristic length; and are the dimensionless axial and circumferential coordinates, respectively;

[0076] Oil film thickness distribution The calculation is done using Formula 2, which describes in detail how the oil film thickness in the sealing area changes with position. and This formula comprehensively considers the average oil film thickness, oil film thickness reference value, elastic deformation of the sealing lip and the distribution of sealing lip surface height, and can accurately simulate the oil film thickness of the seal under different working conditions.

[0077] Formula 2 has the following form:

[0078]

[0079] is the result of the target calculation, describing the oil film thickness at each location in the sealing area. The oil film thickness distribution is a random and The function of change, represents the axial coordinate, Represents the circumferential coordinate. By calculating , the spatial variation of the liquid film thickness in the sealing area can be obtained.

[0080] Average oil film thickness It is the base value of the oil film thickness when no pressure or deformation is applied. It represents the initial thickness of the liquid film between the sealing lip and the contact surface. This value can be measured experimentally, usually in the laboratory by measuring multiple positions with a liquid film thickness gauge and taking the average value.

[0081] It is a reference value, usually used to adjust the calculation of oil film thickness, representing the characteristic thickness of the oil film at a certain location. This reference value can be obtained by calculation or experimental measurement. It is related to the proportion of the oil film thickness distribution and is usually set at design time based on experience or through initial analysis of numerical simulation.

[0082] Represents the elastic deformation of the sealing lip under pressure, which is obtained through the finite element static analysis in the previous step or calculated based on formula 1. This parameter describes the displacement change of the sealing lip under external pressure and directly affects the thickness change of the oil film. Its calculation method has been explained in detail above.

[0083] Sealing lip height distribution Describes the microscopic geometry of the sealing lip surface. The sealing lip is not an ideal smooth surface, and there are usually tiny fluctuations or bumps on its surface. These tiny shape changes have a significant impact on the oil film thickness. It is calculated by formula 3, which describes the periodic fluctuations of the sealing lip surface through a sine function. These fluctuations are usually caused by errors in the manufacturing process or the result of surface treatment.

[0084]

[0085] constant and represents the amplitude of the sealing lip surface fluctuation, that is, the degree of fluctuation of the sealing lip surface height. They can be obtained by experimental measurement or by surface scanning equipment (such as 3D scanner or profilometer). In practical applications, constant and Usually determined according to the manufacturing process and surface roughness of the seal.

[0086] and Is the characteristic length, indicating the axial length of the sealing lip surface and circumferential The periodicity of the fluctuations in direction. Characteristic length and It indicates the period of the fluctuation in these two directions. These characteristic lengths can be obtained by surface morphology analysis of the seal or by measuring the surface profile with experimental equipment (such as atomic force microscope).

[0087] and is a characteristic length, but is related to a second set of wave parameters, describing the period of another set of surface waves. and Similarly, these values ​​can also be measured by surface scanning or profilometry.

[0088] and are dimensionless axial and circumferential coordinates, respectively. They are obtained by dividing the actual coordinates by a certain characteristic size and are used to standardize surface features at different scales. Dimensionless coordinates are convenient for uniformly describing the changes in surface features at different locations and are widely used in numerical solutions.

[0089] When calculating the oil film thickness distribution, the average oil film thickness must first be obtained. , Oil film thickness reference value , and the elastic deformation of the sealing lip These parameters are usually obtained through experimental measurement or previous finite element analysis steps. Next, the sealing lip surface height distribution is calculated using Formula 3 , you need to enter the surface fluctuation constant of the seal , , and the characteristic length of the fluctuation .

[0090] Once these values ​​are determined by measurement or calculation, substituting all parameters into Formula 2, the oil film thickness distribution in the sealing area can be obtained. This oil film thickness distribution is the basis for subsequent analysis and can be used to calculate the oil film pressure distribution and further evaluate the sealing performance.

[0091] Through this calculation, the oil film thickness distribution can be effectively calculated, thereby providing reliable data support for subsequent fluid dynamics analysis.

[0092] Step S104: According to the fluid dynamic lubrication model, the Reynolds equation is used to describe the oil film pressure distribution and its changing trend in the sealing area; the Reynolds equation is discretized by the finite difference method, and the sealing area is divided into multiple calculation grids, wherein the calculation grids are used to accurately solve the oil film pressure and thickness values ​​in each grid unit.

[0093] In step S104, the Reynolds equation is used to describe the oil film pressure distribution and its changing trend in the sealing area according to the established fluid dynamic lubrication model. The Reynolds equation is a basic equation used to describe the pressure distribution of a fluid flowing in a thin film. It is used in fluid dynamic lubrication to analyze the liquid film pressure between seals.

[0094] First, based on the theory of fluid dynamic lubrication, the form of the Reynolds equation needs to consider the thickness distribution of the oil film and the influence of operating parameters, such as seal speed and oil pressure. In this process, the oil film thickness distribution is determined by the previous step, so it will be used as an input condition to calculate the oil film pressure distribution. In the Reynolds equation, the oil film thickness It varies with position, which means that the flow characteristics of the fluid in the sealing area will change due to the difference in thickness, thus affecting the pressure distribution.

[0095] In order to accurately solve the Reynolds equation, it must be discretized. The purpose of discretization is to convert the continuous partial differential equation into an algebraic equation that can be numerically calculated, which is usually achieved through the finite difference method. In this step, the sealing area needs to be divided into multiple small calculation grids, each grid represents a small area within the sealing area. The oil film thickness and pressure values ​​need to be solved at each grid node. The discretized Reynolds equation can be expressed as the relationship between the oil film thickness and oil film pressure at each grid node and the pressure of the surrounding nodes.

[0096] During the meshing process, the division of the sealing area should follow certain rules to ensure the calculation accuracy and efficiency. Set multiple mesh nodes in the X direction and Y direction respectively. Usually the X direction represents the axial direction and the Y direction represents the circumferential direction. The number of nodes should be adjusted according to the complexity of the sealing area and the calculation accuracy requirements. In general, more mesh nodes can improve the calculation accuracy, but it also increases the amount of calculation.

[0097] For each node, the partial derivative term in the Reynolds equation can be approximated by the finite difference method to obtain an algebraic equation about the oil film pressure and thickness of the node and its neighboring nodes. Through this treatment, the original continuous problem is transformed into a discrete set of algebraic equations. In each grid element, the Reynolds equation is expressed as the relationship between the oil film pressure and the oil film thickness. Therefore, the oil film pressure at each node can be obtained by numerically solving these algebraic equations.

[0098] Through this discretization and meshing method, the oil film pressure distribution in the entire sealing area can be gradually solved. This pressure distribution will provide the basis for the subsequent reverse pumping rate calculation, so the accuracy of the discretization and solution process must be ensured. After the calculation is completed, the oil film pressure distribution in the sealing area and its change trend will be clearly described.

[0099] Furthermore, the oil film pressure distribution is determined by the dimensionless Reynolds equation, which uses the following formula 4:

[0100]

[0101] in; is the dimensionless oil film thickness; is the dimensionless oil film pressure; The coefficient is implemented using the following formula 5:

[0102] ,

[0103] in is the inner diameter of the seal, is the sealing contact width.

[0104] The oil film pressure distribution is determined by the dimensionless Reynolds equation. The dimensionless Reynolds equation is an equation used to describe the flow of liquid in a thin film, and is particularly suitable for the analysis of fluid dynamic lubrication models. Here, the dimensionless form of the Reynolds equation simplifies the calculation and eliminates the influence of units, making it more general and easier to apply.

[0105] The dimensionless Reynolds equation has the form:

[0106]

[0107] Represents the dimensionless oil film thickness. Usually, the oil film thickness It is a physical quantity with units. By dimensionless processing, the influence of dimensions can be eliminated, making the model applicable to different system sizes or different unit systems. The oil film thickness is Divide by a characteristic length (usually the average thickness of the oil film This dimensionless treatment makes the calculation results independent of specific units and facilitates cross-system comparison.

[0108] is the dimensionless oil film pressure, which represents the oil film pressure distribution in the sealing area. Divide by a reference pressure value This reference pressure is usually determined by the system's operating pressure, fluid properties, or other key parameters, ensuring that the model can be applied to different systems. Dimensionless pressure makes the equations universal across different sizes and operating conditions.

[0109] is a coefficient related to geometric dimensions, which is used to adjust the relative influence of the circumferential component and the axial component in the equation. It determines the different responses of the oil film to the pressure distribution in the axial and circumferential directions. This coefficient is calculated by formula 5:

[0110]

[0111] Represents the inner diameter of the seal, usually the diameter of the inner cylindrical surface between the seal and the shaft. This value can be obtained by direct measurement, usually using a vernier caliper or laser rangefinder to accurately measure the inner diameter. The inner diameter of the seal determines the characteristics of the liquid film in the axial direction and has an important influence on the distribution of the oil film pressure.

[0112] Represents the contact width between the seal and the contact surface, usually refers to the width of the actual contact area between the seal lip and the shaft or other contact surface. This value can be measured experimentally or obtained from the seal design drawing. It is an important geometric parameter that affects the pressure distribution of the seal in the circumferential direction.

[0113] By using formula 5, the coefficient can be calculated , which is used to describe the mechanical properties of the oil film in the axial and circumferential directions. When the inner diameter of the seal is large and the contact width is small, The value will be larger, indicating that the flow and pressure changes of the oil film in the circumferential direction are more significant; and when the contact width When larger, The smaller the value of , the more important the effect of the oil film in the axial direction.

[0114] The dimensionless Reynolds equation (Formula 4) describes the change of the oil film pressure distribution in the dimensionless coordinate system. The two main sub-terms in the equation correspond to the oil film thickness and pressure In the axial and circumferential For each direction, the cube of the oil film thickness Multiplied by the pressure gradient to reflect the effect of oil film thickness on the resistance of fluid flow.

[0115] First, according to the oil film thickness distribution calculated in the previous step , and substitute it into the dimensionless Reynolds equation. Next, the equation is discretized using a numerical solution method (such as the finite difference method or the finite element method) to convert it into an algebraic equation suitable for numerical calculation. By iteratively solving the discretized Reynolds equation, the dimensionless oil film pressure can be obtained. Distribution over the entire sealing area.

[0116] The distribution of oil film pressure will directly affect the sealing performance of the seal. Under different working conditions, the oil film pressure distribution will show the flow trend of the liquid in the sealing area and the local pressure changes. This information is crucial for evaluating the sealing performance and can help designers determine whether the seal can effectively prevent liquid leakage under different working conditions.

[0117] Through this detailed calculation process, the oil film pressure distribution can be accurately calculated and the performance of the sealing system can be analyzed.

[0118] Step S105: Use the successive over-relaxation method to numerically solve the discretized Reynolds equation to obtain a first oil film pressure distribution and a first oil film thickness distribution; based on the obtained first oil film pressure distribution and the first oil film thickness distribution, calculate the reverse pumping rate of the seal, wherein the reverse pumping rate reflects the volume flow from the air side to the oil side.

[0119] In step S105, the discretized Reynolds equation is numerically solved using the successive over-relaxation method to obtain the first oil film pressure distribution and the first oil film thickness distribution. First, the successive over-relaxation method (SOR) is an iterative method for solving the discretized linear equations. This method has high efficiency in solving convergence and is particularly suitable for solving problems with large sparse matrices, such as the discretized Reynolds equation.

[0120] In the specific implementation, it is first necessary to ensure that the discretization of the Reynolds equation performed in step S104 has divided the entire sealing area into multiple grids, and the oil film pressure and oil film thickness values ​​at each grid point have been preliminarily defined as variables. In the successive super-relaxation method, the initial oil film pressure and oil film thickness can be set to a certain assumed value, which is usually an initial value obtained by estimation, such as a zero value or a reasonable initial value determined based on previous experience.

[0121] At the beginning of the iteration, for each grid node, the approximate value of the oil film pressure distribution is first calculated based on the discretized Reynolds equation. The successive super-relaxation method combines the solution of the current node with the previously calculated solution and uses the relaxation factor to accelerate convergence. The relaxation factor is usually a constant value greater than 1 and is used to adjust the update step size of each iteration. By adjusting the relaxation factor, the stability and speed of the iteration can be effectively controlled.

[0122] The specific process is that in each iteration, the oil film pressure and thickness values ​​of each node are updated. The updated values ​​are combined with the pressure values ​​of the surrounding nodes and re-substituted into the Reynolds equation for calculation, gradually approaching the final true solution. During the entire calculation process, the iteration will continue until the oil film pressure and thickness values ​​of all nodes meet the predetermined convergence criteria, that is, when the change between the pressure and thickness values ​​of two consecutive iterations is less than a certain set tolerance value, the iteration process can be stopped.

[0123] After the iteration is completed, the results will provide the first oil film pressure distribution and the first oil film thickness distribution. These distribution data reflect the spatial variation characteristics of the liquid film on the seal surface and the pressure variation of the liquid film in the sealing area under actual working conditions. The oil film pressure distribution and thickness distribution are important foundations for calculating the reverse pumping rate in the subsequent steps. Therefore, the accuracy and convergence of the numerical solution process must be ensured.

[0124] Next, based on the obtained oil film pressure distribution and oil film thickness distribution, the reverse pumping rate of the seal can be calculated. The reverse pumping rate is a key indicator for measuring sealing performance, which reflects the volume flow rate of liquid flowing from the air side to the oil side. Using the aforementioned pressure distribution and thickness data, combined with the fluid dynamics equation, the reverse pumping rate of the seal can be calculated, and the sealing performance can be further evaluated.

[0125] Furthermore, the discretized Reynolds equation is as follows:

[0126]

[0127] in, Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at

[0128] Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node The oil film thickness correlation coefficient at ; each coefficient is realized by the following formula 7:

[0129]

[0130] in, Representation Node The oil film thickness at Representation Node The oil film thickness at Representation Node The oil film thickness at Representation Node The oil film thickness at represents the interval between two discrete grid points in the axial direction; represents the interval between two discrete grid points in the circumferential direction; is the inner diameter of the seal, is the sealing contact width.

[0131] The purpose of discretization is to transform the continuous partial differential equation (Reynolds equation) into algebraic equations so that they can be solved numerically. The oil film pressure value at each discrete point (grid point) is calculated from these algebraic equations.

[0132] The discretized form of the Reynolds equation is as follows:

[0133]

[0134] This discretized equation is used at each grid node. It represents the relationship between the local oil film pressure and its adjacent nodes. Each item in the formula is explained in detail below.

[0135] Indicates the current node The oil film pressure at , , , They represent the oil film pressure at the adjacent nodes (in the axial or circumferential direction). By solving the pressure values ​​of these nodes, the oil film pressure distribution in the entire sealing area can be determined.

[0136] , , , , are the oil film thickness correlation coefficients. These coefficients are related to the oil film thickness and determine how the oil film at each node affects the oil film pressure at the adjacent nodes. Each coefficient corresponds to the cube of the oil film thickness in different directions. The specific calculation formula is as follows:

[0137]

[0138] These coefficients are related to the oil film thickness It is proportional to the cube of , which reflects the effect of oil film thickness on the conduction and diffusion of pressure. A thicker oil film produces a greater flow resistance, thus affecting the pressure gradient.

[0139] Representation Node and Similarly, other symbols such as , , Respectively represent the oil film thickness between the corresponding nodes. The oil film thickness is obtained by the previous steps (such as through the oil film thickness distribution calculation formula), which affects the oil film flow resistance and oil film pressure.

[0140] represents the interval between two adjacent discrete nodes in the axial direction, It represents the interval between two adjacent discrete nodes in the circumferential direction. These intervals determine the density of the grid. The denser the grid, the higher the calculation accuracy, but the calculation complexity will also increase. The grid interval is usually reasonably divided according to the geometric characteristics of the seal and the calculation requirements.

[0141] The inner diameter of the seal represents the diameter of the cylindrical surface between the sealing lip and the rotating shaft. This value can be obtained by direct measurement, usually using a precision measuring tool such as a vernier caliper. It has a direct impact on the distribution of oil film pressure.

[0142] The seal contact width indicates the width of the actual contact area between the seal and the contact surface. This value can also be obtained through precision measuring tools or from the seal design drawing. Determines the flow resistance and pressure change of the oil film in the circumferential direction.

[0143] is the driving force term in the equation, which is usually related to the externally applied working parameters. The oil film is affected by external forces or pressures, such as rotation speed or oil pressure. This may come from external working conditions, such as the rotation speed of the aviation fuel pump, the viscosity of the oil film, or the fluid pressure.

[0144] In practical applications, by discretizing the Reynolds equation, the entire sealing area is divided into multiple grid points, each of which has a corresponding oil film pressure By solving the discrete equations at these grid points point by point, the oil film pressure distribution in the entire sealing area can be finally obtained. The specific steps of the calculation include:

[0145] 1. First, define the mesh in the sealing area and calculate the oil film thickness coefficient between each node according to Equation 7.

[0146] 2. Substitute the initial pressure value (usually an estimated value) of each grid node into the discrete equation, and gradually solve the oil film pressure of each node through an iterative method (such as the successive over-relaxation method).

[0147] 3. Continue iterating until the pressure value converges to a stable value, that is, the pressure change between two adjacent iterations is less than the predetermined convergence standard.

[0148] In this way, the oil film pressure distribution in the entire sealing area can be solved step by step, ensuring that this method can be actually applied to the sealing performance analysis of aviation fuel pumps.

[0149] Furthermore, the reverse pumping rate is calculated by the following formula 8:

[0150]

[0151] in, is the first oil film thickness distribution; is the dynamic viscosity of the lubricating oil; is the first oil film pressure distribution; is the axial coordinate, is the circumferential coordinate.

[0152] Reverse pumping rate It is calculated by formula 8. The reverse pumping rate is an important parameter used to measure the flow of fluid from the air side to the oil side in the sealing area. The calculation of the reverse pumping rate is based on the distribution of oil film thickness and oil film pressure, which directly affect the flow behavior of the liquid.

[0153]

[0154] Indicates the oil film thickness in the sealing area, which varies with the spatial position and The calculation of the oil film thickness has been completed in the previous step. By considering the geometry of the sealing lip, the elastic deformation and the operating conditions, the distribution of the oil film thickness in the entire sealing area is obtained. Since the oil film thickness has a cubic effect on the reverse pumping rate, its accuracy is crucial.

[0155] Indicates the dynamic viscosity of lubricating oil, which is an important fluid property related to the oil film pressure distribution during the oil film flow process. Viscosity determines the resistance of the oil film when it flows in the sealing area. Dynamic viscosity Viscosity values ​​can be experimentally determined and are usually known material parameters. They may vary with temperature and may therefore need to be corrected in practice depending on the operating temperature of the seal.

[0156] Represents the first oil film pressure distribution, which is a function of the oil film pressure change in the sealing area, usually obtained by solving the Reynolds equation. With the location and The change reflects the local pressure in the sealing area. This pressure distribution is the result of solving the discrete Reynolds equation previously, so it is known. The gradient of the oil film pressure is It drives the flow of fluid.

[0157] is the axial coordinate, indicating the position along the axis of the seal. Oil film pressure gradient It is the rate of change of pressure along the axial direction, which is one of the core parameters for calculating the reverse pumping rate. This gradient represents the flow driving force of the oil film in the axial direction in the sealing area, which directly affects the flow direction and flow rate of the liquid.

[0158] is the circumferential coordinate, indicating the position along the circumference of the seal. Indicates that the integration is performed over the circumference of the entire seal, with the purpose of summing up the fluid flow conditions at different circumferential positions. The integration range usually covers the entire circumference of the sealing area.

[0159] Calculating the reverse pumping rate When and oil film pressure distribution Substitute the known data into formula 8. The integral in the formula represents the cumulative fluid flow rate in the entire circumferential direction, so the oil film pressure gradient needs to be calculated. Perform numerical solution.

[0160] The physical meaning of reverse pumping rate is the volume flow from the air side to the oil side, which describes the sealing performance of the seal under actual working conditions. If the reverse pumping rate is high, it means that the seal has a greater risk of liquid leakage in terms of sealing performance; while a low reverse pumping rate indicates that the sealing performance is good and can effectively prevent liquid leakage from one side to the other.

[0161] This calculation allows the reverse pumping capability of a seal to be accurately assessed and, if necessary, improved by adjusting the seal geometry or material properties.

[0162] Furthermore, the use of the successive super-relaxation method to numerically solve the discretized Reynolds equation, using an improved multi-grid algorithm, and accelerating it through parallel computing specifically includes the following steps:

[0163] In the meshing process, the computational domain is divided into coarse mesh and fine mesh. The coarse mesh is used to quickly converge large-scale solutions, and the fine mesh is used to finely solve local details.

[0164] At each grid level, parallel computing technology is used to distribute the computing tasks to multiple processor cores, processing the oil film thickness and pressure distribution of multiple grid points simultaneously;

[0165] Through the V-cycle strategy of the multi-grid algorithm, iterate back and forth between coarse and fine grids, and improve the calculation accuracy through local correction on the fine grid;

[0166] The successive over-relaxation method is used in each iteration to further improve the solution efficiency until convergence reaches a predetermined accuracy threshold.

[0167] First, during the numerical solution process, the computational domain is divided into grids of different levels. This process divides the entire computational domain into coarse grids and fine grids. Coarse grids are used to process large-scale solutions, that is, to solve the global nature of the problem, ensuring a faster convergence speed. Fine grids are used to capture fine details in local areas and solve local complex flow characteristics. This grid division method not only ensures the global convergence speed of the solution, but also ensures the calculation accuracy in local areas.

[0168] Parallel computing technology plays an important role in this step. Since the Reynolds equation involves solving a large number of nodes, and the oil film thickness and pressure distribution of each node need to be calculated independently, parallel computing can assign the calculation task of each grid point to multiple processor cores to perform simultaneously. This method greatly speeds up the calculation process, especially in complex three-dimensional calculation areas, where parallel computing technology can significantly improve calculation speed and efficiency.

[0169] At each grid level, the oil film thickness and pressure distribution are processed separately. The large-scale solution on the coarse grid obtains a preliminary solution through rapid convergence, and then transfers it to the fine grid. On the fine grid, the preliminary solution is used to make local fine corrections to obtain a more accurate solution. The calculations at each grid level are accelerated by parallel technology, which significantly reduces the overall calculation time.

[0170] The multigrid algorithm uses the V-cycle strategy. In the V-cycle strategy, the calculation process alternates between coarse and fine grids. First, a rough solution is obtained from the coarse grid, and the solution is transferred to the fine grid for local correction before entering the fine grid. Then, the solution of the fine grid is returned to the coarse grid for global correction and iterated again. In this way, the multigrid algorithm can effectively combine local details with the global solution and gradually improve the accuracy of the solution.

[0171] In each iteration of the V-cycle, the successive super-relaxation method is used to further improve the computational efficiency. The successive super-relaxation method is an iterative technique that accelerates convergence. It introduces a relaxation factor , the solution after each iteration is adjusted to reduce the number of iterations and speed up the convergence. The solution in each iteration is continuously adjusted to gradually approach the final exact solution.

[0172] The key to the successive super-relaxation method is to choose an appropriate relaxation factor Typically, the relaxation factor The choice of depends on the specific characteristics of the problem and is usually determined by experiment or a priori analysis. This factor can effectively balance the correction step size of the solution so that each iteration can move towards the direction of global convergence.

[0173] In each iteration, the solution is modified by successive super-relaxation until the solution of the entire system meets the predetermined convergence condition. The convergence condition is usually based on the calculated residual, that is, the difference between the current solution and the true solution. If the residual is less than a predetermined threshold, the calculation is considered to have reached sufficient accuracy and the iteration is stopped.

[0174] In order to ensure the accuracy of the solution, a predetermined accuracy threshold is usually set. This threshold can be adjusted according to specific application requirements. For example, in the analysis of sealing performance, if the solution errors of oil film pressure distribution and oil film thickness are within the engineering allowable range, the calculation can be considered to have converged. Otherwise, continue to iterate until the accuracy of the solution meets the requirements.

[0175] This numerical solution method that combines multi-grid algorithm, successive super-relaxation method and parallel computing can significantly improve the computational efficiency while ensuring accuracy. The use of coarse grids reduces the convergence time of the global solution, while fine grids ensure a fine solution in the local area. Parallel computing technology maximizes the use of computing resources, allowing complex problems to be solved in a shorter time.

[0176] Step S106: Evaluate the sealing performance of the aviation fuel pump based on the calculated reverse pumping rate.

[0177] In step S106, the sealing performance of the aviation fuel pump is evaluated based on the reverse pumping rate calculated in the previous step. The reverse pumping rate is a key indicator that reflects the volume flow rate of liquid from the air side to the oil side during the operation of the seal. In order to evaluate the sealing performance, it is necessary to compare with the predetermined performance standards and combine the specific working conditions of the pump to determine whether the sealing system can effectively prevent liquid leakage.

[0178] First, the expected range of the reverse pumping rate needs to be determined. This can be based on the design requirements and industry standards of the aviation fuel pump. In practical applications, the reverse pumping rate of the seal should be controlled in a very low range to ensure that there will be no obvious leakage during the operation of the pump. If the calculated reverse pumping rate is too high, it may indicate that there is a design flaw or improper material selection in the sealing system, and adjustments need to be made.

[0179] Next, the effect of the reverse pumping rate on the sealing performance is analyzed in combination with the operating parameters (such as oil pressure, speed, etc.). High oil pressure and high-speed rotation may cause the stability of the oil film in the sealing area to deteriorate, thereby increasing the reverse pumping rate. In this case, the evaluation should consider the performance of the seal under high pressure and high speed conditions, especially the load-bearing capacity of the liquid film under these conditions. If the reverse pumping rate remains at a low level under extreme conditions, the sealing performance can be considered to be excellent. Otherwise, it is necessary to consider replacing the material or optimizing the design.

[0180] The evaluation of sealing performance should also be combined with the oil film pressure distribution and the trend of oil film thickness. In areas with low oil film thickness or high pressure, there may be a risk of local leakage. The evaluation should focus on analyzing the distribution of reverse pumping rates in these areas to ensure that the sealing system can provide sufficient sealing performance in all parts. Ultimately, a comprehensive evaluation of sealing performance will help determine whether the fuel pump seal can maintain the required sealing effect under working conditions.

[0181] By comprehensively analyzing the relationship between reverse pumping rate and sealing performance, the overall performance of the sealing system of the aviation fuel pump can be effectively evaluated.

[0182] Furthermore, the aviation fuel pump sealing performance analysis method further includes adjusting the Young's modulus and viscosity of the sealing material according to the elastic deformation of the sealing lip and the oil film thickness distribution, specifically including the following steps:

[0183] Real-time measurement of the change in oil film thickness at the sealing lip during the analysis process;

[0184] Using a feedback control system, the Young's modulus is dynamically adjusted according to the measured oil film thickness changes and dynamic viscosity , so that the oil film thickness is maintained within the preset threshold range;

[0185] Adjustments for Young's modulus and viscosity are made using the following equations 9 and 10:

[0186]

[0187]

[0188] in, is the adjusted Young’s modulus; is the adjusted viscosity; and are the initial Young’s modulus and viscosity, respectively; and is the adjustment factor; is the deviation of oil film thickness.

[0189] This embodiment proposes a strategy for dynamically adjusting the performance of sealing materials to optimize the sealing performance of aviation fuel pumps. This method monitors the changes in the oil film thickness of the sealing lip in real time and dynamically adjusts the Young's modulus and viscosity of the material in combination with a feedback control system to ensure that the oil film thickness is maintained within a preset threshold range, thereby ensuring the stability and effectiveness of the seal during operation.

[0190] During the operation of the fuel pump, the thickness of the oil film between the sealing lip and the contact surface may fluctuate as the operating conditions change. In order to prevent the oil film thickness from being too thin to cause sealing failure or too thick to cause sealing performance degradation, this embodiment proposes a feedback control system that measures the oil film thickness in real time and dynamically adjusts the Young's modulus and viscosity of the sealing material according to the deviation between the actual measured oil film thickness and the preset threshold, thereby automatically optimizing the sealing performance.

[0191] First, the oil film thickness changes are measured in real time. The changes in oil film thickness can be detected at the sealing lip by precision sensors that monitor the thickness of the oil film in real time while the seal is operating. This measurement data provides instant feedback on the seal performance, especially when the fuel pump is under high pressure or high speed, the fluctuation of oil film thickness is particularly obvious.

[0192] The Young's modulus and dynamic viscosity are then dynamically adjusted using a feedback control system that compares the film thickness measured in real time with the and preset oil film thickness threshold , calculate the deviation of oil film thickness Based on this deviation, the system dynamically adjusts the Young's modulus and viscosity of the sealing material using the following formula:

[0193]

[0194]

[0195] Indicates the dynamically adjusted Young's modulus, which is the elastic modulus of the material adjusted to maintain the stability of the oil film thickness after measuring the change in oil film thickness in real time. By adjusting the Young's modulus, the stiffness of the sealing material can be changed, causing it to produce different deformation amounts when the pressure changes, thereby controlling the oil film thickness.

[0196] Indicates the adjusted viscosity, which is a real-time viscosity adjustment based on the change in oil film thickness during feedback control. The viscosity of the lubricating oil directly affects the oil film thickness and the fluid lubrication state of the seal.

[0197] and are the initial Young's modulus and initial lubricant viscosity, respectively. These initial values ​​can be determined by material properties or obtained from the design data of the seal.

[0198] and is the adjustment coefficient, which indicates the deviation of Young's modulus and viscosity with oil film thickness The values ​​of these two coefficients are determined through experimental calibration to ensure that the changes in oil film thickness can be adjusted promptly and effectively under different working conditions.

[0199] is the deviation of the oil film thickness, which indicates the difference between the real-time measured oil film thickness and the preset threshold. is positive, indicating that the oil film is too thick; if If it is negative, it means the oil film is too thin. The feedback control system automatically adjusts Young's modulus and viscosity to keep the oil film thickness within the ideal range.

[0200] Through this dynamic adjustment method, the present embodiment can optimize the performance of the sealing material in real time during the operation of the fuel pump, ensuring that the oil film thickness is always maintained within the preset ideal range. This can not only improve the sealing performance and prevent leakage, but also reduce the performance degradation caused by material deformation or unstable fluid pressure. In addition, the dynamic adjustment process is automatic and can respond to the changes in the oil film under different working conditions, making the entire sealing system more stable and reliable.

[0201] Furthermore, the aviation fuel pump sealing performance analysis method further includes real-time monitoring of the temperature distribution on the surface of the seal by an infrared sensor, and real-time adjustment of the oil film thickness according to the temperature distribution, specifically including the following steps:

[0202] Arrange multiple infrared temperature sensors on the surface of the seal to record the surface temperature at different positions;

[0203] According to the following formula 11, calculate the change in oil film thickness corresponding to different temperatures :

[0204]

[0205] in, is the reference temperature; is the coefficient of variation of temperature-oil film thickness; is the temperature distribution curve;

[0206] Adjust the oil film thickness of the sealing lip to match the calculated Maintain consistency to ensure even distribution of oil film pressure.

[0207] This embodiment proposes a method for adjusting the oil film thickness in real time based on temperature distribution, by arranging an infrared sensor on the surface of the seal to monitor the temperature distribution, and dynamically adjusting the oil film thickness by using the temperature change. This method ensures the uniform distribution of the oil film thickness in the sealing area through the relationship between temperature and oil film thickness, thereby improving the sealing performance.

[0208] First, multiple infrared temperature sensors are arranged on the surface of the seal. These sensors are distributed at key locations in the sealing area and can record the surface temperature at each location in real time. The layout of the temperature sensors should be designed according to the geometry and working conditions of the seal to ensure that the sealing area can be fully covered. The temperature data detected by the infrared sensor can help understand the working status of the seal at different locations, especially under high load or high temperature conditions, the temperature distribution can reflect the force and friction of the seal.

[0209] Next, the temperature data recorded by the infrared temperature sensor is used for calculation. By recording the temperature at different locations on the seal surface and compare it with the preset reference temperature By comparison, the temperature deviation at different locations can be obtained. Temperature changes will affect the oil film thickness, because the viscosity of the oil film and the elasticity of the sealing material are directly related to the temperature. It is the ideal temperature of the oil film under standard operating conditions, which is usually determined by experiments or theoretical analysis.

[0210] Next, the change in oil film thickness \( ​​\Delta h_T \) is calculated using formula 11:

[0211]

[0212] Indicates the amount of deviation in oil film thickness due to temperature change. An increase or decrease in temperature will cause a change in oil film thickness, for example, an increase in temperature may cause the oil film to become thinner, while a decrease in temperature may cause the oil film to become thicker.

[0213] It is the coefficient of variation between temperature and oil film thickness, which indicates the degree of influence of temperature change on oil film thickness. This coefficient is obtained through experimental measurement or material property analysis, and reflects the characteristics of the sealing material under temperature change. Usually, this coefficient is a parameter related to the properties of the sealing material and the lubricating oil.

[0214] It is the reference temperature, which indicates the ideal temperature value of the oil film under normal working conditions. When the temperature of the seal reaches the reference temperature, the oil film thickness remains at the designed ideal value.

[0215] It is the temperature distribution recorded by the infrared sensor, describing the temperature change at each location on the seal surface. This distribution curve reflects the temperature gradient of different areas on the seal surface and can be obtained through real-time data monitoring.

[0216] Through the above calculation, the change of oil film thickness under different temperature conditions can be obtained. , which provides a basis for the subsequent adjustment of oil film thickness.

[0217] Finally, adjust the oil film thickness of the sealing lip. Once the change in oil film thickness is obtained, The oil film thickness of the sealing lip is adjusted in real time through the control system. This adjustment process can be achieved by changing the pressure distribution of the seal, dynamically adjusting the elastic deformation of the sealing lip, or changing the oil supply of the oil film. The ultimate goal is to adjust the oil film thickness in accordance with the calculated This ensures uniform distribution of oil film pressure over the entire sealing area.

[0218] Through this method of temperature monitoring and real-time adjustment of oil film thickness, this embodiment can effectively deal with the problem of uneven oil film thickness of the seal under high temperature and high pressure conditions. The uneven distribution of seal surface temperature may cause the oil film in some areas to be too thin or too thick, thereby affecting the sealing performance. By real-time monitoring and dynamic adjustment of the oil film thickness, it can be ensured that the oil film thickness is always kept within the ideal range under different working conditions, thereby improving the overall performance of the seal, reducing the risk of oil leakage, and extending the service life of the seal.

[0219] Furthermore, the aviation fuel pump sealing performance analysis method further includes high-precision modeling of the actual surface morphology of the seal by three-dimensional optical scanning technology to improve the geometric parameter input of the sealing lip surface, specifically including the following steps:

[0220] Use high-precision three-dimensional optical scanning equipment to scan the entire surface of the sealing lip to obtain the microscopic morphology data of the sealing lip;

[0221] Convert the 3D data obtained by scanning into a digital model to analyze the microscopic features of the sealing lip surface, including roughness and unevenness;

[0222] According to the obtained surface geometry model, the geometric parameters input into the finite element analysis are adjusted to ensure that the surface parameters can truly reflect the actual state of the sealing lip.

[0223] This embodiment proposes a process of high-precision modeling of the seal surface by three-dimensional optical scanning technology, which is used to improve the geometric parameter input of the sealing lip surface, thereby improving the accuracy of subsequent finite element analysis. By high-precision scanning of the actual surface morphology of the sealing lip, its true geometric characteristics can be more accurately reflected, ensuring that the subsequent analysis results are more consistent with the actual working conditions.

[0224] First, use a high-precision 3D optical scanning device to scan the sealing lip surface. 3D optical scanning technology can accurately capture the microscopic morphology of the sealing lip surface and generate detailed data including surface roughness, unevenness, microscopic texture, etc. This type of scanning equipment usually uses laser or structured light as the scanning source, which can obtain the full surface data of the sealing lip without contact, avoiding deformation or damage to the sealing lip surface caused by contact measurement.

[0225] The 3D optical scanning equipment has high resolution and high precision, and can capture micron-level surface details. This fine data acquisition is the basis for ensuring the accuracy of subsequent finite element analysis. In actual operation, the scanning process needs to be carried out from multiple angles to ensure that all key features of the sealing lip surface are captured.

[0226] Next, the 3D data obtained by scanning is converted into a digital model. These 3D data are usually stored in the form of point clouds, representing countless coordinate points on the surface of the sealing lip. Through 3D modeling software (such as CAD software), these point cloud data can be converted into a complete geometric model. The digital model can accurately describe the actual surface morphology of the sealing lip, including features such as tiny bumps and surface roughness.

[0227] After the digital model is generated, the microscopic features of the sealing lip surface need to be analyzed. Surface roughness is a key parameter for sealing performance, which affects the formation and stability of the oil film. In this step, by measuring and calculating the surface roughness, we can better understand how the sealing lip surface interacts with the rotating shaft or other contact surfaces under working conditions. By analyzing the local concave and convex features on the surface, we can evaluate their influence on the oil film thickness and pressure distribution.

[0228] According to the surface geometry model obtained, the geometric parameters of the sealing lip can be adjusted. The geometric parameters used in finite element analysis (FEA) usually rely on ideal geometric assumptions, but these assumptions often cannot accurately reflect the actual state of the sealing lip. By introducing the real geometric data obtained by 3D scanning, it can be ensured that the geometric parameters input into the finite element analysis can more realistically describe the actual surface morphology of the seal.

[0229] Specifically, the adjustment of geometric parameters includes but is not limited to the thickness of the sealing lip, contact width, surface roughness, etc. For microscopic features such as surface roughness, accurate modeling can be performed based on the scanning results, which helps to simulate the actual working conditions during the oil film formation process. By optimizing these geometric parameters, the accuracy of finite element analysis will be significantly improved, and the deformation, oil film thickness and pressure distribution of the sealing lip under different working conditions can be more accurately predicted.

[0230] By introducing high-precision 3D optical scanning technology, the actual morphology of the sealing lip surface can be effectively captured, overcoming the limitations of idealized assumptions in traditional geometric parameter modeling. With the help of scanning technology, the surface geometric features of the seal can be input into the finite element analysis with higher accuracy, thus significantly improving the accuracy and reliability of subsequent analysis.

[0231] This method ensures that the influence of the surface characteristics of the sealing lip on the sealing performance can be accurately simulated under actual working conditions. It has important application value, especially in the study of the relationship between microscopic surface roughness and oil film thickness.

[0232] A second embodiment of the present application provides an electronic device, the electronic device comprising:

[0233] processor;

[0234] The memory is used to store a program, and when the program is read and executed by the processor, the method for analyzing the sealing performance of an aviation fuel pump provided in the first embodiment of the present application is executed.

[0235] The third embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for analyzing the sealing performance of an aviation fuel pump provided in the first embodiment of the present application is executed.

[0236] Although the present application is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present application. Any technical personnel in this field may make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

Claims

1. A method for analyzing the sealing performance of an aviation fuel pump, characterized in that: include: Acquire geometric parameters, material parameters and operating parameters of the seal of the aviation fuel pump, wherein the geometric parameters include the inner diameter of the seal, the seal contact width and the sealing lip thickness, the material parameters include the Young's modulus and Poisson's ratio of the sealing material, and the operating parameters include the oil pressure and the rotation speed; Based on the geometric parameters, material parameters and working condition parameters, the elastic deformation of the sealing lip is calculated by finite element static analysis, wherein the elastic deformation reflects the deformation amplitude of the sealing lip under pressure; Determine the oil film thickness distribution according to the calculated elastic deformation, wherein the oil film thickness distribution describes the spatial variation of the liquid film in the sealing area; establish a fluid dynamic lubrication model based on fluid lubrication theory using the oil film thickness distribution and operating condition parameters; According to the fluid dynamic lubrication model, the Reynolds equation is used to describe the oil film pressure distribution and its change trend in the sealing area; the Reynolds equation is discretized by the finite difference method, and the sealing area is divided into a plurality of calculation grids, wherein the calculation grids are used to accurately solve the oil film pressure and thickness values ​​in each grid unit; The discretized Reynolds equation is numerically solved using a successive over-relaxation method to obtain a first oil film pressure distribution and a first oil film thickness distribution; based on the obtained first oil film pressure distribution and the first oil film thickness distribution, a reverse pumping rate of the seal is calculated, wherein the reverse pumping rate reflects the volume flow rate from the air side to the oil side; Evaluate the sealing performance of aviation fuel pumps based on the calculated reverse pumping rate; The elastic deformation is calculated using the following formula 1: in, Indicates the elastic deformation of the sealing lip; is the sealing pressure; is the contact pressure, obtained by finite element static analysis; is the sealing lip thickness; is Poisson's ratio; is the Young's modulus of the sealing material; The oil film thickness distribution is calculated using the following formula 2: in, is the oil film thickness distribution; is the average oil film thickness; is the reference value of oil film thickness; Indicates the elastic deformation of the sealing lip; is the sealing lip height distribution, which is determined by the following formula 3: in, and is a constant; is the characteristic length; and are the dimensionless axial and circumferential coordinates, respectively; The oil film pressure distribution is determined by the dimensionless Reynolds equation, which adopts the following formula 4: in; is the dimensionless oil film thickness; is the dimensionless oil film pressure; The coefficient is implemented using the following formula 5: in is the inner diameter of the seal, is the sealing contact width; The discretized Reynolds equation is the following formula 6: in, Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Oil film pressure at Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node Correlation coefficient of oil film thickness at ; Representation Node The oil film thickness correlation coefficient at ; each coefficient is realized by the following formula 7: in, Representation Node The oil film thickness at Representation Node The oil film thickness at Representation Node The oil film thickness at Representation Node The oil film thickness at represents the interval between two discrete grid points in the axial direction; represents the interval between two discrete grid points in the circumferential direction; is the inner diameter of the seal, is the sealing contact width.

2. The method for analyzing the sealing performance of an aviation fuel pump according to claim 1, characterized in that: The reverse pumping rate is calculated by the following formula 8: in, is the first oil film thickness distribution; is the dynamic viscosity of the lubricating oil; is the first oil film pressure distribution; is the axial coordinate, is the circumferential coordinate.

3. The method for analyzing the sealing performance of an aviation fuel pump according to claim 1, characterized in that: It also includes adjusting the Young's modulus of the sealing material according to the elastic deformation of the sealing lip and the oil film thickness distribution. and viscosity, specifically comprising the following steps: Real-time measurement of the change in oil film thickness at the sealing lip during the analysis process; Using a feedback control system, the Young's modulus and dynamic viscosity are dynamically adjusted according to the measured change in oil film thickness, so that the oil film thickness is maintained within a preset threshold range; Adjustments for Young's modulus and viscosity are made using the following equations 9 and 10: in, is the adjusted Young’s modulus; is the adjusted viscosity; and are the initial Young’s modulus and viscosity, respectively; and is the adjustment factor; is the deviation of oil film thickness.

4. The method for analyzing the sealing performance of an aviation fuel pump according to claim 1, characterized in that: It also includes real-time monitoring of the temperature distribution on the surface of the seal by an infrared sensor, and real-time adjustment of the oil film thickness according to the temperature distribution, which specifically includes the following steps: Arrange multiple infrared temperature sensors on the surface of the seal to record the surface temperature at different positions; According to the following formula 11, calculate the change in oil film thickness corresponding to different temperatures : in, is the reference temperature; is the coefficient of variation of temperature-oil film thickness; is the temperature distribution curve; Adjust the oil film thickness of the sealing lip to match the calculated Maintain consistency to ensure even distribution of oil film pressure.

5. The method for analyzing the sealing performance of an aviation fuel pump according to claim 1, characterized in that: The method of numerically solving the discretized Reynolds equation by using the successive super-relaxation method, adopting an improved multi-grid algorithm, and accelerating it by parallel computing specifically includes the following steps: In the meshing process, the computational domain is divided into coarse mesh and fine mesh. The coarse mesh is used to quickly converge large-scale solutions, and the fine mesh is used to finely solve local details. At each grid level, parallel computing technology is used to distribute the computing tasks to multiple processor cores, processing the oil film thickness and pressure distribution of multiple grid points simultaneously; Through the V-cycle strategy of the multi-grid algorithm, iterate back and forth between coarse and fine grids, and improve the calculation accuracy through local correction on the fine grid; The successive over-relaxation method is used in each iteration to further improve the solution efficiency until convergence reaches a predetermined accuracy threshold.

6. The method for analyzing the sealing performance of an aviation fuel pump according to claim 1, characterized in that: It also includes high-precision modeling of the actual surface morphology of the seal through 3D optical scanning technology to improve the geometric parameter input of the sealing lip surface, which specifically includes the following steps: Use high-precision three-dimensional optical scanning equipment to scan the entire surface of the sealing lip to obtain the microscopic morphology data of the sealing lip; Convert the 3D data obtained by scanning into a digital model to analyze the microscopic features of the sealing lip surface, including roughness and unevenness; According to the obtained surface geometry model, the geometric parameters input into the finite element analysis are adjusted to ensure that the surface parameters can truly reflect the actual state of the sealing lip.

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