Numerical analysis method for abrasive particle transport characteristics of engine transmission oil system fault

Abstract

The present disclosure relates to the technical field of aviation engine mechanical systems, and in particular to a numerical analysis method for abrasive transport characteristics of engine transmission lubricating oil system faults, comprising: S1, according to the structural characteristics of the engine transmission lubricating oil system; S2, according to the actual working conditions, setting the inlet and outlet boundary conditions and the physical property parameters of the lubricating oil for the three-dimensional fluid domain calculation model; S3, according to the SEM photos of the abrasive particles measured in the experiment, establishing a typical fault abrasive particle shape model, and using the superposition ball model calculation method to establish the DEM particle model of the abrasive particles; S4, using the CFD-DEM coupling calculation method, the CFD method calculates the flow field, and the DEM is used to calculate the motion force of the abrasive particle system to achieve coupling; analyzing the abrasive transport characteristics of the given lubricating oil inlet and outlet conditions, the lubricating oil and the physical properties of the abrasive particles; S5, checking the lubricating oil flow field and other information in the CFD calculation results, and counting the mass or quantity of the faulty abrasive particles captured by the chip sensor or oil filter at a given position.

Description

Technical Field

[0001] The present disclosure relates to the technical field of aviation engine mechanical systems, and in particular to a numerical analysis method for abrasive particle transport characteristics of engine transmission lubricating oil system failures. Background Art

[0002] The lubricating oil system is an important auxiliary system of aircraft engines. It is mainly used to lubricate and cool the main shaft bearings, gears and splines in the accessory gearbox, etc. of aircraft engines. It is an important guarantee for the operational reliability and stability of aircraft engines. The faulty abrasive particles generated by the friction pair during the failure process are also mainly carried away by the lubricating oil and enter the transmission lubricating oil system. The transport characteristics of faulty abrasive particles in the engine transmission lubricating oil system are unclear, resulting in the problem of limited improvement in the accuracy of faulty abrasive particle detection. Therefore, how to analyze the transport characteristics of engine abrasive particles is one of the important issues that need to be solved in this field. Summary of the invention

[0003] The present disclosure is proposed in view of the above problems. The present disclosure provides a numerical analysis method for the abrasive transport characteristics of engine transmission lubricating oil system faults, which can provide theoretical guidance for optimizing sensor layout, evaluating alarm value setting values, etc.

[0004] According to one aspect of the present disclosure, a numerical analysis method for abrasive transport characteristics of a faulty engine transmission lubricating oil system is provided, comprising the following steps:

[0005] S1, according to the structural characteristics of the engine transmission lubricating oil system, establish its three-dimensional solid model, and extract the three-dimensional fluid domain as the lubricating oil fluid model;

[0006] S2, according to the actual working conditions and the simulation analysis results of the transmission lubricating oil system, the inlet boundary conditions and outlet boundary conditions of the lubricating oil fluid model are given, and the physical property parameters of the lubricating oil are given;

[0007] S3, based on the SEM photos of the wear particles measured in the experiment, the shape parameters and fractal characteristics of the wear particles are determined through particle morphology analysis, a typical fault wear particle shape model is established, and the DEM particle model of the wear particles is established by using the superposition ball model calculation method;

[0008] S4, using CFD-DEM coupling calculation method, CFD method to calculate the lubricating oil flow field, the flow field information is converted into the fluid force acting on the abrasive particles in DEM (Digital Elevation Model) through the drag model and lift model, and the motion force of the abrasive particle system is calculated using DEM. The two transfer mass, momentum and energy to achieve coupled calculation; analyze the abrasive particle transport characteristics of the given lubricating oil inlet and outlet conditions, the physical properties of the lubricating oil and the abrasive particles, and store the calculation results according to the given data storage frequency;

[0009] S5, check the lubricating oil flow field information in the CFD calculation results; check the abrasive particle movement information and force information in the DEM calculation results; create a virtual sensor in the DEM according to the installation position of the chip sensor in the transmission lubricating oil system, count the total number or total mass of abrasive particles flowing through the sensor at different times, and set the minimum particle size of the abrasive particles measured by the sensor.

[0010] According to the method for analyzing the transport characteristics of engine wear particles proposed in one aspect of the present disclosure, the pre-established simulation model includes a three-dimensional solid model of fault wear particles, a discrete element model of fault wear particles, and a particle size distribution model of fault wear particles.

[0011] According to the method for analyzing the engine wear particle transport characteristics proposed in one aspect of the present disclosure, the method for constructing a simulation model includes:

[0012] S11, collecting fault abrasive particles of typical friction pair failures in the transmission oil system of an aircraft engine and obtaining the material information of the fault abrasive particles;

[0013] S12, screening multiple typical fault wear particle morphologies, constructing a three-dimensional solid model of the fault wear particles, and establishing a discrete element model of the fault wear particles;

[0014] S13, establishing a fault abrasive particle size distribution model, and setting the injection position, initial velocity and acceleration.

[0015] According to the method for analyzing the transport characteristics of engine abrasive particles proposed in one aspect of the present disclosure, the material information of the faulty abrasive particles includes the geometric dimensions, particle size distribution and composition of the faulty abrasive particles.

[0016] According to the method for analyzing the engine abrasive transport characteristics proposed in one aspect of the present disclosure, the method for obtaining the material information of the faulty abrasive is to measure the particle shape and particle size distribution of the faulty abrasive by SEM and to measure the component composition of the faulty abrasive by EDS.

[0017] According to the analysis method of the engine wear transport characteristics proposed in one aspect of the present disclosure, step S12 includes a method for establishing a discrete element model of fault wear particles, which is to calculate the shape index and fractal dimension through the three-dimensional solid model of the fault wear particles, and then use the superposition sphere model method to establish the discrete element model of the fault wear particles.

[0018] According to the method for analyzing the transport characteristics of engine abrasive particles proposed in one aspect of the present disclosure, in step S2, the contact force between the faulty abrasive particles and the inside of the pipeline is calculated using the Hertz-Mindlin model.

[0019] According to the method for analyzing the engine abrasive transport characteristics proposed in one aspect of the present disclosure, step S4 also includes establishing a particle factory in discrete element software, and setting the inflow position, initial velocity and particle size distribution of the faulty abrasive.

[0020] As described in detail below, according to the analysis method of the transport characteristics of engine wear particles in the embodiment of the present disclosure, a discrete element model of fault wear particles that is closer to the real form is realized by combining SEM measurement with the superposition ball model, and the motion behavior simulation of fault wear particles in lubricating oil is realized by coupling DEM with CFD, revealing the transport characteristics of engine fault wear particles, and providing theoretical support for optimizing sensor layout, evaluating alarm value setting values, and improving the detection accuracy of fault wear particles in transmission lubricating oil systems. This method has high universality and engineering applicability, and can optimize sensor layout, evaluate alarm value setting values, and improve the detection accuracy of fault wear particles in transmission lubricating oil systems.

[0021] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other purposes, features and advantages of the present disclosure will become more apparent by describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0023] The above and other purposes, features and advantages of the present disclosure will become more apparent by describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0024] Figure 1 is a flowchart of the steps of the method proposed in the present disclosure;

[0025] Figure 2 is the discrete element modeling step of the fault wear particles proposed in the present disclosure;

[0026] Figure 3 It is a schematic diagram of the structure of the abrasive particle transport experiment for a lubricating oil system failure proposed in the present disclosure;

[0027] Figure 4 It is a three-dimensional solid model of the lubricating oil pipeline proposed in the present disclosure;

[0028] Figure 5is the CFD calculation model proposed in the present disclosure;

[0029] Figure 6 is a schematic diagram of the wear particle DEM modeling proposed in the present disclosure;

[0030] Figure 7 is a schematic diagram of a lubricating oil velocity cloud diagram disclosed in the present invention;

[0031] Figure 8 is a schematic diagram of the motion characteristics of abrasive particles and a sensor proposed in the present disclosure;

[0032] Fig. 9 It is a DEM calculation model in a specific example proposed in this disclosure;

[0033] Fig.10 Schematic diagrams of three abrasive particle shapes used in a specific example proposed in the present disclosure;

[0034] Fig.11 It is the DEM calculation result in a specific example proposed in this disclosure. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present disclosure more obvious, the exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described here.

[0036] In order to make the purpose, technical solution and advantages of the present disclosure more obvious, the exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described here.

[0037] For the questions raised in the background technology, please refer to Figures 1 to 3 The present disclosure proposes a numerical analysis method for the abrasive transport characteristics of engine transmission lubricating oil system faults, specifically including steps S1 to S5.

[0038] S1, according to the structural characteristics of the engine transmission lubricating oil system, construct its three-dimensional solid model, and extract the three-dimensional fluid domain as the lubricating oil CFD (Computational Fluid Dynamics) calculation model; please refer to Figure 4 and Figure 5 In a specific implementation, the method for constructing a three-dimensional solid model includes: S11, establishing a three-dimensional solid model of a pipeline and a CFD calculation model of lubricating oil according to the structural characteristics of the aircraft engine transmission lubricating oil system.

[0039] S12, collect faulty abrasive particles of typical friction pair failure in the transmission oil system of an aircraft engine, and obtain the shape information, material information, and particle size distribution information of the faulty abrasive particles; use the particle morphology analysis method to calculate the shape parameters and fractal characteristics of the abrasive particles, and on this basis screen out the typical faulty abrasive particle morphology, and use the superposition sphere model calculation method to establish a discrete element model of the faulty abrasive particles; in the specific implementation, the material information of the faulty abrasive particles includes the geometric size, particle size distribution, and composition of the faulty abrasive particles. The method for obtaining the material information of the faulty abrasive particles is to measure the particle shape and particle size distribution of the faulty abrasive particles by a scanning electron microscope (SEM), and to measure the composition of the faulty abrasive particles by an energy dispersive spectrometer (EDS).

[0040] S13, based on the particle size distribution information obtained in S12, a discrete element model of the abrasive system is established, and the position, speed, and acceleration of the faulty abrasive entering the lubricating oil are set. According to the analysis method of engine abrasive transport characteristics proposed in one aspect of the present disclosure, the faulty abrasive material information includes the geometric size, particle size distribution, and faulty abrasive composition of the faulty abrasive. Specifically, the shape and size of the abrasive particles are measured by SEM, and the shape parameters are calculated through particle morphology analysis to obtain the particle size distribution curve. For abrasive particles of a certain shape, by scaling the radius size, abrasive particles with similar shapes but different masses can be generated. For example, the mass proportion of abrasive particles with a diameter of 100um is 50%; the mass proportion of abrasive particles with a diameter of 500um is 30%; the mass proportion of abrasive particles with a diameter of 1000um is 20%; if the total mass of the given abrasive system is 100g, the total mass of abrasive particles with a particle size of 100um is 50g, the total mass of abrasive particles with a particle size of 500um is 30g, and the total mass of abrasive particles with a particle size of 1000um is 20g. The number of particles generated is then inferred based on the mass, and then a discrete element model of the abrasive system is generated.

[0041] S2, according to the actual working conditions and the simulation analysis results of the transmission lubricating oil system, the lubricating oil CFD calculation model parameters are given, including but not limited to: inlet boundary, outlet boundary, lubricating oil density and viscosity. For example, the lubricating oil attribute parameters are set to: density 890kg / m 3 , viscosity is 45mPas; the mass flow rate inlet is 1.2kg / s, and the pressure outlet is atmospheric pressure.

[0042] S3, according to the SEM photos of the wear particles measured in the experiment, the shape parameters and fractal characteristics of the wear particles are determined through particle morphology analysis. On this basis, a typical fault wear particle shape model is established, and the DEM particle model of the wear particles is established by using the superposition ball model calculation method, such as Figure 6For example, for the long strip abrasive particles, the superposition ball model method is used to establish the abrasive particle DEM calculation model.

[0043] S4, using CFD-DEM coupling calculation method, CFD method calculates the lubricating oil flow field, converts the flow field information into the fluid force acting on the abrasive particles in DEM through the drag model and lift model, and uses DEM to calculate the motion force of the abrasive system. The two transfer mass, momentum, and energy to achieve coupled calculation; analyze the abrasive transport characteristics of the given lubricating oil inlet and outlet conditions, the physical properties of the lubricating oil and the abrasive particles, and store the calculation results according to the given data preservation frequency. In this step, the Hertz-Mindlin model is used to calculate the contact force between the faulty abrasive particles and the faulty abrasive particles and the inner wall of the pipe, and the motion information of the abrasive particles is calculated by Newton's second law. The calculation formula is as follows:

[0044]

[0045]

[0046] Where: is the translational velocity of abrasive particle i; is the rotation speed of abrasive particle i; is the contact force of abrasive particle i; is the contact torque of abrasive particle i; is the non-contact force of abrasive particle i; is the gravity of abrasive particle i; is the fluid rotation resistance torque.

[0047] The specific implementation steps of this step are as follows:

[0048] (1) Using Fluent software, import the lubricating oil CFD grid model, export the boundary grid model, and then use EDEM software to import the boundary grid model and build a DEM calculation model of the abrasive system, including but not limited to: abrasive material property parameters, abrasive shape model, abrasive particle size distribution model, particle factory settings, time step, data saving frequency, etc.; finally, open the CFD-DEM coupling server and wait for Fluent to connect;

[0049] (2) In the Fluent software, set the lubricating oil property parameters, boundary conditions, and solution methods, and realize CFD-DEM coupling by loading the UDF interface file; then, select the pressure model, lift model, etc.; finally, set the CFD time step, data saving frequency, total simulation time, etc., and submit the calculation.

[0050] (3) After the simulation is completed, view the oil velocity cloud map and other information in Fluent post-processing; please refer to Figure 7 and Figure 8, the abrasive motion information and force information can be viewed in EDEM, and virtual sensors can be set to capture the number and mass of abrasive particles flowing through the sensor at different times.

[0051] S5, check the lubricating oil flow field information in the CFD calculation results; check the abrasive particle movement information and force information in the DEM calculation results; create a virtual sensor in the DEM according to the installation position of the chip sensor in the transmission lubricating oil system, count the total number or total mass of abrasive particles flowing through the sensor at different times, and set the minimum particle size of the abrasive particles measured by the sensor.

[0052] The following example illustrates this: Figure 4 As shown in the figure, a three-dimensional solid model of some pipelines of the engine transmission lubricating oil system is established; then, the lubricating oil CFD calculation model is extracted using Space Claim software, as shown in the figure. Figure 5 As shown; Finally, the CFD mesh model is divided using Meshing software. This example is only used to illustrate the implementation method and effect of the present disclosure. The lubricating oil and abrasive particle parameters and pipeline structure model adopted are only schematic models. When the present disclosure is actually used to carry out abrasive particle transport characteristic analysis, it is necessary to re-establish the fluid domain model and abrasive particle discrete element model based on the physical and mechanical properties of the lubricating oil, the abrasive particle material and shape and particle size, the abrasive particle injection speed, the inlet and outlet boundary conditions, etc., so as to ensure the validity of the analysis results.

[0053] Please refer to Figures 9 to 11 In this example, Pegasus II lubricant is used, with a density of 890 kg / m 3 , dynamic viscosity 45mPas; abrasive and pipeline materials are bearing steel, density 7800kg / m 3 , Young's modulus 210GPa, Poisson's ratio 0.3; friction coefficient between abrasive particles 0.5, friction coefficient between abrasive particles and the inside of the pipe 0.15, recovery coefficient 0.5, rolling friction coefficient 0.01; lubricating oil inlet mass flow rate 1.2kg / s, outlet pressure atmospheric pressure. The abrasive injection method is: through the particle factory of EDEM software, the total number of injected abrasive particles is set to 1000, the initial speed (red surface normal direction, -Z axis) 10m / s, the equivalent diameter range of abrasive particles 0.1mm~1.8mm, and the particle shape includes three types, long strips, corn flakes, and blocks, such as Fig.10 shown.

[0054] like Fig.11 As shown in the figure, after the abrasive particles are injected into the pipeline from the particle factory at an initial velocity of 10m / s, some small abrasive particles move toward the outlet and pass through the sensor under the coupling of contact force, gravity and lift. After the simulation time of 0.1s, the total mass of abrasive particles passing through the sensor is 9.895mg, and the total number is 8.

[0055] According to the analysis method of the engine abrasive transport characteristics of the embodiment of the present disclosure, a discrete element model of fault abrasive particles that is closer to the real form is realized by combining SEM measurement with the superposition ball model, and the motion behavior simulation of fault abrasive particles in lubricating oil is realized by coupling DEM with CFD, revealing the transport characteristics of engine fault abrasive particles, and providing theoretical support for optimizing sensor layout, evaluating alarm value setting values, and improving the detection accuracy of fault abrasive particles in transmission lubricating oil systems. This method has high universality and engineering applicability, and can optimize sensor layout, evaluate alarm value setting values, and improve the detection accuracy of fault abrasive particles in transmission lubricating oil systems.

[0056] The basic principles of the present disclosure are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present disclosure. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, and are not limitations. The above details do not limit the present disclosure to the necessity of adopting the above specific details to be implemented.

[0057] The block diagrams of the devices, apparatuses, equipment, and systems involved in this disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including," "comprising," "having," and the like are open words, referring to "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or," and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0058] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not mean that the example described is preferred or better than other examples.

[0059] It should also be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.

[0060] Various changes, substitutions, and modifications of the techniques described herein may be made without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of the present disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and actions described above. Currently existing or later to be developed processes, machines, manufactures, compositions of events, means, methods, or actions that perform substantially the same functions or achieve substantially the same results as the corresponding aspects described herein may be utilized. Thus, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or actions within their scope.

[0061] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0062] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for analyzing engine wear transport characteristics, characterized in that: The following steps are involved: S1, according to the structural characteristics of the engine transmission lubricating oil system, establish its three-dimensional solid model, and extract the three-dimensional fluid domain as the lubricating oil fluid model; S2, according to the actual working conditions and the simulation analysis results of the transmission lubricating oil system, the inlet boundary conditions and outlet boundary conditions of the lubricating oil fluid model are given, and the physical property parameters of the lubricating oil are given; S3, based on the SEM photos of the wear particles measured in the experiment, the shape parameters and fractal characteristics of the wear particles are determined through particle morphology analysis, a typical fault wear particle shape model is established, and the DEM particle model of the wear particles is established by using the superposition ball model calculation method; S4, using CFD-DEM coupling calculation method, CFD method to calculate the oil flow field, the flow field information is converted into the fluid force acting on the abrasive particles in DEM through the drag model and lift model, and the DEM is used to calculate the motion force of the abrasive system. The two transfer mass, momentum and energy to achieve coupled calculation; analyze the abrasive transport characteristics of the given oil inlet and outlet conditions, the physical properties of the oil and the abrasive particles, and store the calculation results according to the given data storage frequency; S5, check the lubricating oil flow field information in the CFD calculation results; Check the motion and force information of abrasive particles in the DEM calculation results; create a virtual sensor in DEM according to the installation position of the chip sensor in the transmission oil system, count the total number or total mass of abrasive particles flowing through the sensor at different times, and set the minimum particle size of abrasive particles measured by the sensor.

2. The method for analyzing engine wear particle transport characteristics according to claim 1, characterized in that: The pre-established simulation models include a three-dimensional solid model of faulty wear particles, a discrete element model of faulty wear particles, and a particle size distribution model of faulty wear particles.

3. The method for analyzing engine wear particle transport characteristics according to claim 2, characterized in that: Methods for building simulation models include: S11, collecting fault abrasive particles of typical friction pair failures in the transmission oil system of an aircraft engine and obtaining the material information of the fault abrasive particles; S12, screening multiple typical fault wear particle morphologies, constructing a three-dimensional solid model of the fault wear particles, and establishing a discrete element model of the fault wear particles; S13, establishing a fault abrasive particle size distribution model, and setting the injection position, initial velocity and acceleration.

4. The method for analyzing engine wear transport characteristics according to claim 3, characterized in that: The material information of the faulty abrasive particles includes the geometric size, particle size distribution and composition of the faulty abrasive particles.

5. The method for analyzing engine wear particle transport characteristics according to claim 3, characterized in that: The method for obtaining the material information of the faulty abrasive particles is to measure the particle shape and particle size distribution of the faulty abrasive particles by SEM and to measure the component composition of the faulty abrasive particles by EDS.

6. The method for analyzing engine wear particle transport characteristics according to claim 3, characterized in that: Step S12 includes: a method for establishing a discrete element model of the faulty wear particles is to calculate a shape index and a fractal dimension through a three-dimensional solid model of the faulty wear particles, and then establish the discrete element model of the faulty wear particles by using a superposition sphere model method.

7. The method for analyzing engine wear particle transport characteristics according to claim 6, characterized in that: In step S2, the contact force between the faulty abrasive particles and the interior of the pipe is calculated using the Hertz-Mindlin model.

8. The method for analyzing the engine wear transport characteristics according to any one of claims 1 to 7, characterized in that: Step S4 also includes establishing a particle factory in the discrete element software, and setting the inflow position, initial velocity and particle size distribution of the faulty abrasive particles.

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