Evaluation method and device based on cylinder sleeve cavitation erosion fault, electronic equipment and medium

Abstract

The invention provides an evaluation method and device based on a cylinder sleeve cavitation erosion fault, electronic equipment and a medium, and belongs to the technical field of engine fault detection, an engine transient working process calculation model is constructed, and thermal load distribution information of a cylinder sleeve wall surface and thermal load distribution information of a piston bowl and a top surface are obtained; constructing a piston calculation model, and calculating to obtain the wall surface temperature and the deformation state of the piston; a cylinder body and cylinder sleeve calculation model is constructed, and the wall surface temperature and the deformation state of the cylinder sleeve are obtained through calculation; constructing a calculation model to obtain the amplitude of the vibration speed of the surface of the cylinder sleeve; constructing a cooling system calculation model to obtain cooling liquid information; the surface pressure of the cylinder sleeve is calculated by using a Nokowski model, the saturated vapor pressure is obtained by comparing the absolute pressure with the surface pressure of the cylinder sleeve, and then the cavitation erosion fault state of the cylinder sleeve is evaluated. The method can predict the cavitation erosion fault of the cylinder sleeve with high precision, and has certain technical support for guiding the reliability design of an engine.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine fault detection, and in particular relates to an evaluation method, device, electronic equipment and medium based on cylinder liner cavitation fault. Background Art

[0002] In modern internal combustion engine design, cylinder liner cavitation is a common failure mode that poses a serious threat to engine performance, reliability and durability. Cylinder liner cavitation is mainly caused by the formation of tiny cavities on the inner wall of the cylinder liner under the influence of multiple factors such as high-frequency vibration, high temperature, high pressure and chemical corrosion of coolant, which gradually expand and eventually lead to fatigue damage of the cylinder liner material. This phenomenon not only affects the air tightness of the engine, but may also cause lubricating oil leakage, increase engine wear, shorten service life, and even cause serious mechanical failures.

[0003] At present, the prediction and evaluation of cylinder liner cavitation failure mainly rely on empirical formulas or laboratory test analysis. However, empirical formulas are often based on experimental results under specific conditions and are difficult to accurately reflect the complex and changeable actual working conditions.

[0004] Although laboratory testing can simulate some working conditions, it is costly, time-consuming, and difficult to fully cover all possible influencing factors. Summary of the invention

[0005] The present invention provides an evaluation method based on cylinder liner cavitation failure. The method evaluates the cylinder liner cavitation failure by comparing the saturated vapor pressure with the difference between the absolute pressure and the cylinder liner surface pressure calculated by using the Nokovsky model. The method can more accurately predict the temperature distribution and deformation state of the piston wall and the cylinder liner wall, and provide a reliable basis for cavitation evaluation.

[0006] Methods include:

[0007] S101: constructing a calculation model for the transient working process of the engine, configuring the design parameters and test parameters of the engine in the calculation model for the transient working process of the engine, and then obtaining the heat load distribution information of the cylinder liner wall and the heat load distribution information of the piston bowl and top surface by setting the spray model, the combustion model and the heat conduction model;

[0008] S102: construct a piston calculation model, and perform piston heat conduction analysis based on the heat load distribution information and test values ​​of the piston bowl and top surface to obtain the piston wall temperature and deformation state;

[0009] S103: constructing a calculation model of the cylinder block and the cylinder liner, and performing a heat conduction analysis of the cylinder block and the cylinder liner based on the heat load distribution information of the cylinder liner wall and the test value, and obtaining the temperature and deformation state of the cylinder liner wall;

[0010] S104: constructing a calculation model to obtain the amplitude of the vibration velocity of the cylinder liner surface according to the piston wall temperature and deformation state, the cylinder liner wall temperature and deformation state, the design parameters of the engine, and by setting the connection and membrane unit;

[0011] S105: constructing a cooling system calculation model, configuring cooling system design parameters in the cooling system calculation model, and obtaining coolant information by setting a cooling calculation equation;

[0012] S106: Based on the cylinder liner surface vibration velocity amplitude and coolant information, the cylinder liner surface pressure is calculated using the Nokovsky model. By comparing the absolute pressure with the cylinder liner surface pressure difference, the saturated vapor pressure is obtained, and then the cylinder liner cavitation fault state is evaluated.

[0013] It should be further explained that in step S101, the constructed calculation model of the transient working process of the engine includes the intake duct, the exhaust duct, the intake valve seat ring, the exhaust valve seat ring, the intake valve, the exhaust valve, the cylinder liner and the piston.

[0014] It should be further explained that in step S101, the heat conduction model is set to ’ Rourke and Amsden model implementation;

[0015] O ’ The Rourke and Amsden model is calculated using formula (1), formula (2) and formula (3):

[0016]

[0017] Where k is the thermal conductivity; T is the temperature; Pr m is the Prandtl number of chemical component m; T f is the fluid temperature; T w is the wall temperature; is the distance from the midpoint of the first layer of grid on the wall to the wall; c p is the specific heat; x is the spatial position; n is the normal phase of the unit surface; i is the number of the unit of interest;

[0018]

[0019] where κ is the Karman constant, which is 0.42; is the dimensionless distance from the midpoint of the first layer of the wall grid to the wall; Pr t is the turbulent Prandtl number; B is a constant;

[0020]

[0021] where ρ is the density; μ m is the turbulent viscosity of chemical component m; uτ is the shear rate.

[0022] It should be further explained that the one-dimensional dynamic calculation model in step S104 includes: a cylinder liner, a piston, a piston pin, a connecting rod small end bearing, a connecting rod, a connecting rod big end bearing, and a crank.

[0023] It should be further explained that the coolant information in step S105 includes: the temperature, density, speed of sound, absolute pressure and saturated vapor pressure of the coolant.

[0024] It should be further explained that the cooling system calculation model in step S105 includes a water pump, an upper water jacket of a cylinder head, a lower water jacket of a cylinder head, a water jacket of an engine body, and a water outlet pipe.

[0025] It should be further explained that step S106 also includes:

[0026] The cylinder liner surface pressure is calculated by the following formula:

[0027] △P Joukowsky =ρ.cV Amplitude_liner (4)

[0028] Where ρ is density; c is the speed of sound; V Amplitude_liner is the vibration velocity amplitude of the cylinder liner surface;

[0029] Cylinder liner cavitation fault is realized by the following formula:

[0030] P stat -△P Joukowsky ≤P D (5)

[0031] Among them, P stat is the absolute pressure; P D is the saturated vapor pressure.

[0032] The present application also provides an evaluation system based on cylinder liner cavitation fault, the system comprising: a heat load distribution calculation module, a piston wall state analysis module, a cylinder liner wall state analysis module, a cylinder liner surface state analysis module, a coolant state analysis module and a cylinder liner cavitation fault evaluation module;

[0033] The heat load distribution calculation module is used to construct a calculation model of the engine's transient working process, configure the engine's design parameters and test parameters in the calculation model of the engine's transient working process, and then obtain the heat load distribution information of the cylinder liner wall and the heat load distribution information of the piston bowl and top surface by setting the spray model, combustion model and heat conduction model;

[0034] The piston wall state analysis module is used to build a piston calculation model and perform piston heat conduction analysis based on the heat load distribution information and test values ​​of the piston bowl and top surface to obtain the piston wall temperature and deformation state;

[0035] The cylinder liner wall state analysis module is used to build the cylinder block and cylinder liner calculation model, and based on the heat load distribution information and test values ​​of the cylinder liner wall, perform heat conduction analysis on the cylinder block and cylinder liner to obtain the cylinder liner wall temperature and deformation state;

[0036] The cylinder liner surface state analysis module is used to construct a calculation model to obtain the amplitude of the cylinder liner surface vibration velocity according to the piston wall temperature and deformation state, the cylinder liner wall temperature and deformation state, the engine design parameters, and by setting the connection and membrane unit;

[0037] The coolant state analysis module is used to build a cooling system calculation model, configure the cooling system design parameters in the cooling system calculation model, and obtain the coolant information by setting the cooling calculation equation;

[0038] The cylinder liner cavitation fault assessment module is used to calculate the cylinder liner surface pressure based on the cylinder liner surface vibration velocity amplitude and coolant information using the Nokovsky model, and obtain the saturated vapor pressure by comparing the absolute pressure with the cylinder liner surface pressure difference, thereby evaluating the cylinder liner cavitation fault status.

[0039] According to another embodiment of the present application, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the cylinder liner cavitation fault-based evaluation method when executing the program.

[0040] According to another embodiment of the present application, a storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the evaluation method based on cylinder liner cavitation fault are implemented.

[0041] It can be seen from the above technical solutions that the present invention has the following advantages:

[0042] The evaluation method provided in this application can more realistically simulate the actual working state of the engine by constructing an accurate calculation model of the engine's transient working process and configuring detailed design parameters and test parameters, thereby accurately obtaining the thermal load distribution information of the cylinder liner wall and the piston.

[0043] This application uses three-dimensional finite element analysis to simulate the heat conduction between the piston and the cylinder block / liner in detail, which can accurately predict the temperature distribution and deformation state of the piston wall and the cylinder liner wall, providing a reliable basis for cavitation evaluation. Moreover, the method not only considers the thermal load distribution of the engine, but also combines multiple factors such as the deformation state of the piston and cylinder liner, the performance of the cooling system, and the vibration characteristics of the cylinder liner to evaluate the cylinder liner cavitation failure.

[0044] This application calculates the cylinder liner surface pressure based on the Nokovsky model and evaluates the saturated vapor pressure by comparing the absolute pressure with the cylinder liner surface pressure difference, which can timely detect the potential risk of cylinder liner cavitation and avoid or reduce the impact of cylinder liner cavitation on engine performance and service life.

[0045] Based on the evaluation results, this application can optimize the design of the engine, such as adjusting the cylinder liner material, wall thickness, cooling water channel layout, etc., to improve its anti-cavitation ability. A comprehensive and in-depth evaluation of cylinder liner cavitation failure not only improves the accuracy and reliability of the evaluation, but also provides technical support for engine design optimization and fault prevention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0047] Figure 1 The flow chart of the evaluation method based on cylinder liner cavitation failure;

[0048] Figure 2 The present invention is a flow chart of an embodiment of an evaluation method based on cylinder liner cavitation fault;

[0049] Figure 3 It is a schematic diagram of the analysis module of the transient working process in the engine cylinder;

[0050] Figure 4 This is a schematic diagram of the piston heat conduction analysis module;

[0051] Figure 5 It is a schematic diagram of the heat conduction analysis module of the cylinder block and cylinder liner;

[0052] Figure 6 It is a schematic diagram of the one-dimensional transient dynamics analysis module;

[0053] Figure 7 This is a schematic diagram of the cooling performance analysis module of the whole machine;

[0054] Figure 8 Schematic diagram of the module for evaluating cylinder liner cavitation fault;

[0055] Fig. 9 It is a schematic diagram of the calculation model of the engine transient working process;

[0056] Fig.10 This is a schematic diagram of the piston calculation model;

[0057] Fig.11 It is a schematic diagram of the one-dimensional dynamics calculation model;

[0058] Fig.12 It is the schematic diagram of the cooling system calculation model;

[0059] Fig.13 Schematic diagram of the hardware structure of the electronic device.

[0060] Explanation of the reference numerals in the accompanying drawings: 1. intake duct, 2. exhaust duct, 3. intake valve seat ring, 4. exhaust valve seat ring, 5. intake valve, 6. exhaust valve, 7. cylinder liner, 8. piston, 9. piston top surface, 10. piston bowl, 11. piston, 12. piston pin bearing, 13. piston pin, 14. connecting rod small end bearing, 15. connecting rod, 16. connecting rod big end bearing, 17. crank, 18. water pump, 19. cylinder head upper water jacket, 20. cylinder head lower water jacket, 21. engine body water jacket, 22. water outlet pipe. DETAILED DESCRIPTION

[0061] The specific steps of the evaluation method based on cylinder liner cavitation fault will be described in detail below. For the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are proposed to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details.

[0062] It should be understood that when used in the present specification, the term "includes" indicates the presence of the described features, integral bodies, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integral bodies, steps, operations, elements, components and / or their collections. The terms "include", "comprise", "have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0063] It should be understood that the "one or more" mentioned in this application refers to one, two or more than two, and the "multiple" mentioned in this application refers to two or more. In the description of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B. The "and / or" in this article is just a way to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0064] The phrases such as "one embodiment" or "some embodiments" described in the present application mean that the specific features, structures or characteristics described in the embodiment are included in one or more embodiments of the present application. Therefore, the phrases such as "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments" etc. that appear in different places in the present application do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0065] The following will describe in detail the cylinder liner cavitation fault assessment method of the present invention in conjunction with the accompanying drawings. The method can be applied to vehicle engine fault detection, for example. The present invention uses three-dimensional CFD flow field analysis, three-dimensional finite element heat load analysis and one-dimensional transient dynamics analysis, and uses comparative saturated vapor pressure values ​​to assess cylinder liner cavitation faults. The present invention can predict cylinder liner cavitation faults with high precision by assessing cylinder liner cavitation faults, which provides certain technical support for guiding engine reliability design and plays a positive role in improving engine design.

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] See also Figure 1 and Figure 2 FIG. 1 is a flow chart of a method for evaluating a cylinder liner cavitation fault in a specific embodiment, the method comprising:

[0068] S101: constructing a calculation model of the transient working process of the engine, and configuring the design parameters and test parameters of the engine in the calculation model of the transient working process of the engine, and then obtaining the heat load distribution information of the cylinder liner wall and the heat load distribution information of the piston bowl and top surface by setting the spray model, the combustion model and the heat conduction model.

[0069] In some embodiments, three-dimensional CFD software, such as ANSYS Fluent, STAR-CCM+, etc., can be used to simulate complex airflow, spray, combustion and other processes inside the engine.

[0070] In this embodiment, a geometric model can be established based on three-dimensional CFD software. According to the actual design of the engine, the geometric models of the engine's cylinder, piston, fuel injector and other components can be created using CAD software and imported into the CFD software.

[0071] Optionally, the geometry can be meshed to ensure that the mesh density in the spray region, combustion chamber, and cylinder liner walls is sufficient to capture subtle physical phenomena.

[0072] The design parameters and test parameters configured in this embodiment include, but are not limited to, engine speed, load, intake pressure, temperature, injection strategy, etc.

[0073] The spray model set in this embodiment can select a suitable spray KH-RT model to describe the injection, breakup and evaporation process of the fuel.

[0074] When setting the combustion model, you can choose a vortex breakup model or a premixed combustion model based on the diesel engine or gasoline engine.

[0075] The heat conduction model set in this embodiment can consider the heat exchange between components such as the cylinder wall, the piston, and the cooling water jacket, and set corresponding thermal boundary conditions.

[0076] For the operation simulation mode, the calculation model of the engine transient working process can be executed to obtain the thermal load distribution information of the cylinder liner wall, piston bowl and top surface.

[0077] S102: Construct a piston calculation model, and perform a piston heat conduction analysis based on the heat load distribution information and test values ​​of the piston bowl and top surface to obtain the piston wall temperature and deformation state.

[0078] In some embodiments, for constructing a piston computational model, a three-dimensional finite element analysis software may be selected, optionally, ANSYS, Abaqus, etc. According to the design parameters of the engine, the geometric shape of the piston is extracted from the three-dimensional model of the CAD software, and a geometric model of the piston is established in the finite element software.

[0079] Optionally, the model may include but is not limited to key parts such as the top, land, ring area, skirt and bottom of the piston.

[0080] According to the material of the piston, the material can be aluminum alloy, steel, etc., and the corresponding thermal conductivity, specific heat capacity, density and other thermal physical parameters are defined in the finite element software.

[0081] As for the thermal load, in step S101, the heat load distribution information of the piston bowl and top surface can be obtained through the engine transient working process calculation model constructed by three-dimensional CFD software. Then the heat load data obtained in step S101 is loaded into the finite element model of the piston as a boundary condition. This includes the temperature or heat flux density values ​​of key areas such as the piston top, ring land, and piston ring area. At the same time, it is also necessary to consider the heat exchange between the piston and the cylinder wall, cooling water jacket and other components, and set the corresponding thermal boundary conditions.

[0082] In some embodiments, a transient solver can be set in the finite element software to perform heat conduction analysis. When performing heat conduction analysis, the software will calculate the temperature distribution and deformation state of the piston under the action of thermal load based on the input geometric model, material properties and boundary conditions. During the analysis process, the software will consider the influence of various heat transfer methods such as heat conduction, heat convection and thermal radiation. After the analysis is completed, you can view the temperature distribution cloud map, deformation map and other results of the piston. In this way, the thermal load state and deformation of the piston under different working conditions can be intuitively displayed.

[0083] In this embodiment, the analysis results can be used to evaluate whether the thermal load state of the piston meets the design requirements. If the temperature is too high or the deformation is too large, the performance and life of the piston may be adversely affected.

[0084] This embodiment can optimize the design of the piston according to the analysis results. For example, the material, structure or cooling method of the piston can be adjusted to reduce the heat load and reduce deformation.

[0085] It can be seen that the piston heat conduction analysis of this embodiment can provide an in-depth understanding of the thermal load state and deformation of the piston during engine operation, providing an important basis for cylinder liner cavitation fault assessment.

[0086] S103: constructing a calculation model of the cylinder block and the cylinder liner, and performing a heat conduction analysis of the cylinder block and the cylinder liner based on the heat load distribution information of the cylinder liner wall and the test value, and obtaining the temperature and deformation state of the cylinder liner wall.

[0087] In some embodiments, a cylinder block and cylinder liner calculation model is constructed, and a geometric model and material properties of the cylinder block and cylinder liner are established. The thermal load distribution information of the cylinder liner wall obtained in S101 is loaded onto the cylinder liner model. An analysis is run to obtain the temperature distribution and deformation state of the cylinder liner wall.

[0088] Specifically, according to the actual design of the engine, the geometric shapes of the cylinder block and cylinder liner are extracted using CAD software. In the finite element software, a detailed geometric model of the cylinder block and cylinder liner is established, including key parts such as the cylinder wall, cylinder liner, and water jacket. According to the materials of the cylinder block and cylinder liner, the corresponding thermal physical parameters such as thermal conductivity, specific heat capacity, and density are defined in the finite element software.

[0089] In some embodiments, heat load data is obtained. According to step S101, the heat load distribution information of the cylinder liner wall surface can be obtained by using the engine transient working process calculation model constructed by three-dimensional CFD software. Optionally, the heat load distribution information is usually given in the form of temperature field or heat flux density.

[0090] In some embodiments, the cylinder liner wall heat load data obtained in S101 is loaded into the finite element model of the cylinder block and cylinder liner as boundary conditions, which may include the temperature or heat flux values ​​of key areas such as the cylinder wall, the outer surface of the cylinder liner, and the inner surface in contact with the water jacket.

[0091] This embodiment may also consider the heat exchange between the cylinder block and the cylinder liner, and between the cylinder liner and the water jacket, and set corresponding thermal boundary conditions.

[0092] Set up appropriate solvers in the finite element software, such as steady-state or transient solvers, to perform heat transfer analysis. Select appropriate solution strategies and algorithms based on the needs of the analysis. Perform heat transfer analysis, and the software will calculate the temperature distribution and deformation state of the cylinder block and cylinder liner under thermal load based on the input geometric model, material properties, and boundary conditions.

[0093] This embodiment can view the temperature distribution cloud map, deformation map and other results of the cylinder block and cylinder liner based on the analysis data. The cylinder liner wall temperature and deformation state can intuitively display the thermal load state and deformation of the cylinder block and cylinder liner under different working conditions.

[0094] This embodiment evaluates whether the thermal load state of the cylinder block and the cylinder liner meets the design requirements based on the analysis results. If the temperature is too high or the deformation is too large, it may have an adverse effect on the performance and life of the engine. If it is found that it does not meet the design requirements, the design of the cylinder block and the cylinder liner can be optimized based on the analysis results.

[0095] For example, the material, wall thickness, layout of cooling channels, etc. of the cylinder liner are adjusted to improve heat transfer efficiency and reduce heat load.

[0096] It can be seen that the heat conduction analysis of the cylinder block and the cylinder liner of this embodiment can understand the thermal load state and deformation of the cylinder block and the cylinder liner during the operation of the engine, and provide an important reference for the evaluation of cylinder liner cavitation failure.

[0097] S104: Construct a calculation model to obtain the amplitude of the vibration velocity of the cylinder liner surface according to the piston wall temperature and deformation state, the cylinder liner wall temperature and deformation state, the design parameters of the engine, and by setting the connection and membrane unit.

[0098] In some embodiments, the dynamic characteristics of the piston, cylinder liner and other relevant engine components can be integrated into the constructed computational model. The connection between the piston and the cylinder liner, the cylinder body and the cylinder liner can be simulated, and appropriate damping and stiffness can be set. Based on the dynamic response of the piston and the cylinder liner, the vibration velocity amplitude of the cylinder liner surface can be calculated.

[0099] S105: constructing a cooling system calculation model, configuring cooling system design parameters in the cooling system calculation model, and obtaining coolant information by setting a cooling calculation equation.

[0100] In this embodiment, the constructed cooling system calculation model may include components such as cooling water channels, water pumps, and radiators.

[0101] The configuration design parameters may include but are not limited to: coolant flow, temperature, water channel geometry, etc. The cooling calculation equation set may adopt the energy conservation equation, momentum conservation equation, etc.

[0102] S106: Based on the cylinder liner surface vibration velocity amplitude and coolant information, the cylinder liner surface pressure is calculated using the Nokovsky model. By comparing the absolute pressure with the cylinder liner surface pressure difference, the saturated vapor pressure is obtained, and then the cylinder liner cavitation fault state is evaluated.

[0103] In this embodiment, the cylinder liner surface vibration velocity amplitude and coolant information are used to calculate the cylinder liner surface pressure through the Nokovsky model. The saturated vapor pressure is obtained by comparing the absolute pressure with the cylinder liner surface pressure difference.

[0104] This embodiment can evaluate the cavitation risk or failure state of the cylinder liner based on the saturated vapor pressure and the cavitation resistance of the cylinder liner material.

[0105] This embodiment combines CFD, finite element analysis and physical models throughout the process to predict the thermal load, vibration and cooling system performance of the engine under transient working conditions, and then evaluate the cavitation risk of the cylinder liner.

[0106] Further, as a refinement and expansion of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process in this embodiment, the method for high-precision prediction of cylinder liner cavitation fault involved in this application includes transient working process analysis in the engine cylinder, cylinder body and cylinder liner heat conduction analysis, piston heat conduction analysis, whole machine cooling performance analysis, one-dimensional transient dynamics analysis and cavitation fault evaluation. Specific steps of the evaluation method based on cylinder liner cavitation fault are further provided. The method includes the following steps:

[0107] S201: Figure 3 As shown, a calculation model of the transient working process of the engine is constructed using three-dimensional CFD software. By inputting the design parameters and test parameters of the engine and setting the spray model, combustion model and heat conduction model, the heat load distribution on the cylinder liner wall and the heat load distribution on the piston bowl and top surface are obtained.

[0108] In some embodiments, Fig. 9 As shown, the calculation model of the transient working process of the engine includes: an intake port 1, an exhaust port 2, an intake valve seat ring 3, an exhaust valve seat ring 4, an intake valve 5, an exhaust valve 6, a cylinder liner 7 and a piston 8.

[0109] In some embodiments, the spray model is implemented by setting it to a KH-RT model. The KH model theory is that the unstable growth of the disturbance wave along the flow direction leads to breakup. The RT model theory is that the unstable growth of the disturbance wave along the windward direction of the droplet leads to breakup.

[0110] The KH-RT model theory is that the disruption is caused by the interaction of disturbance waves along the flow direction and disturbance waves along the windward direction of the droplets.

[0111] In this embodiment, the combustion model is implemented by setting it as a SAGE model. The SAGE model includes a detailed chemical kinetic model.

[0112] The heat conduction model of this embodiment is implemented by setting the O'Rourke and Amsden model.

[0113] It should be further explained that the O'Rourke and Amsden model is calculated by formula (1), formula (2) and formula (3):

[0114]

[0115] Where k is the thermal conductivity; T is the temperature; Pr m is the Prandtl number of chemical component m; T f is the fluid temperature; T w is the wall temperature; is the distance from the midpoint of the first layer of grid on the wall to the wall; c p is the specific heat; x is the spatial position; n is the normal phase of the unit face; i is the number of the unit of interest.

[0116]

[0117] Among them, κκ is the Karman constant, which is 0.42; is the dimensionless distance from the midpoint of the first layer of the wall grid to the wall; Pr t is the turbulent Prandtl number; B is a constant with a value of 5.5.

[0118]

[0119] where ρ is the density; μ m is the turbulent viscosity of chemical component m; u τ is the shear rate.

[0120] S202: Figure 4 As shown, a piston calculation model is constructed using three-dimensional finite element software, and a piston heat conduction analysis is performed based on the heat load distribution of the piston bowl and top surface obtained in step S201 and the experimental or empirical values ​​to obtain the piston wall temperature and deformation.

[0121] The piston calculation model of this embodiment is as follows Fig.10 shown. Fig.10 It includes: a piston top surface 9, a piston bowl 10 and a piston 11.

[0122] The heat load distribution of the piston bowl and top surface is obtained by mapping the results of the transient working process of the engine in step S201 using CFD software.

[0123] S203: Figure 5 As shown, a calculation model of the cylinder block and cylinder liner is constructed using three-dimensional finite element software, and a heat conduction analysis of the cylinder block and cylinder liner is performed based on the heat load distribution on the cylinder liner wall obtained in step S201 and experimental or empirical values ​​to obtain the cylinder liner wall temperature and deformation.

[0124] The cylinder block and cylinder liner calculation model of this embodiment includes the cylinder block and the cylinder liner. The thermal load distribution of the cylinder liner is obtained by mapping the result of the transient working process of the engine in step S201 through CFD software.

[0125] S204: Figure 6 As shown, a calculation model is constructed using one-dimensional dynamics software, and the amplitude of the cylinder liner surface vibration velocity is obtained by inputting the design parameters of the engine, setting the connection and membrane unit, etc. through the piston wall temperature and deformation obtained in step S202 and the cylinder liner wall temperature and deformation obtained in step S203.

[0126] like Fig.11 As shown, the one-dimensional dynamic calculation model of this embodiment includes: a piston 11, a piston pin bearing 12, a piston pin 13, a connecting rod small end bearing 14, a connecting rod 15, a connecting rod big end bearing 16 and a crank 17.

[0127] The piston wall temperature and deformation of this embodiment are obtained by extracting the piston heat conduction calculation results in step S202 using finite element software. The cylinder liner wall temperature and deformation are obtained by extracting the cylinder body and cylinder liner heat conduction calculation results in step S203 using finite element software.

[0128] S205: Figure 7 As shown, a three-dimensional CFD software is used to build a cooling system calculation model. By inputting design parameters and setting the continuity equation, momentum equation and energy equation, the temperature, density, sound velocity, absolute pressure and saturated vapor pressure of the coolant are obtained.

[0129] In this embodiment, Fig.12 As shown, the cooling system calculation model includes a water pump 18 , a cylinder head upper water jacket 19 , a cylinder head lower water jacket 20 , a body water jacket 21 and a water outlet pipe 22 .

[0130] This embodiment uses the well-known continuity equation, momentum equation, energy equation, etc. built into the CFD software for calculation and solution.

[0131] S206: Figure 8 As shown, the vibration velocity amplitude of the cylinder liner surface obtained by step S204, the temperature, density, speed of sound, absolute pressure and saturated vapor pressure of the coolant are obtained by 5), the cylinder liner surface pressure is calculated using the Nokovsky model, and the cylinder liner cavitation fault is evaluated by comparing the saturated vapor pressure with the absolute pressure and the cylinder liner surface pressure difference.

[0132] The cylinder liner surface vibration velocity amplitude of this embodiment is obtained by extracting the one-dimensional dynamics calculation result in step S204.

[0133] The temperature, density, speed of sound, absolute pressure and saturated vapor pressure of the coolant in this embodiment are obtained by extracting the calculation results of the cooling system in step S205.

[0134] The cylinder liner surface pressure of this embodiment is achieved by formula (4).

[0135] △P Joukowsky =ρ.cV Amplitude_liner (4)

[0136] Where ρ is density; c is the speed of sound; V Amplitude_liner is the vibration velocity amplitude of the cylinder liner surface.

[0137] The cylinder liner cavitation fault is realized by the following formula (5).

[0138] P stat -△P Joukowsky ≤P D (5)

[0139] Among them, P stat is the absolute pressure; P D is the saturated vapor pressure.

[0140] According to the embodiment of the present application, by comprehensively using 3D CFD software and 3D finite element software, the working process, heat conduction characteristics and cooling system of the engine are comprehensively and carefully simulated and analyzed, which can improve the reliability of cylinder liner cavitation fault assessment. By constructing an accurate calculation model of the engine transient working process and configuring detailed design parameters and test parameters, the actual working state of the engine can be simulated more realistically, thereby more accurately obtaining the thermal load distribution information of the cylinder liner wall and the piston.

[0141] The following is an embodiment of an evaluation system based on cylinder liner cavitation fault provided by an embodiment of the present disclosure. The system and the evaluation method based on cylinder liner cavitation fault of the above-mentioned embodiments belong to the same inventive concept. For details not described in detail in the embodiment of the evaluation system based on cylinder liner cavitation fault, reference can be made to the embodiment of the evaluation method based on cylinder liner cavitation fault.

[0142] A mobile terminal implementing various embodiments of the present invention will now be described with reference to the accompanying drawings. In the subsequent description, suffixes such as "module", "component" or "unit" used to represent elements are used only to facilitate the description of the embodiments of the present invention and have no specific meaning in themselves. Therefore, "module" and "component" can be used interchangeably.

[0143] The system includes: a heat load distribution calculation module, a piston wall state analysis module, a cylinder liner wall state analysis module, a cylinder liner surface state analysis module, a coolant state analysis module and a cylinder liner cavitation fault assessment module.

[0144] The heat load distribution calculation module is used to construct a calculation model of the engine's transient working process, and configure the engine's design parameters and test parameters in the calculation model of the engine's transient working process. Then, by setting the spray model, combustion model and heat conduction model, the heat load distribution information of the cylinder liner wall and the heat load distribution information of the piston bowl and top surface are obtained.

[0145] The piston wall state analysis module is used to build a piston calculation model and perform piston heat conduction analysis based on the heat load distribution information and test values ​​of the piston bowl and top surface to obtain the piston wall temperature and deformation state.

[0146] The cylinder liner wall state analysis module is used to construct the calculation model of the cylinder block and cylinder liner, and based on the heat load distribution information and experimental values ​​of the cylinder liner wall, perform heat conduction analysis on the cylinder block and cylinder liner to obtain the cylinder liner wall temperature and deformation state.

[0147] The cylinder liner surface state analysis module is used to construct a calculation model to obtain the amplitude of the cylinder liner surface vibration velocity according to the piston wall temperature and deformation state, the cylinder liner wall temperature and deformation state, the engine design parameters, and by setting the connection and membrane units.

[0148] The coolant state analysis module is used to build a cooling system calculation model, configure cooling system design parameters in the cooling system calculation model, and obtain coolant information by setting the cooling calculation equation.

[0149] The cylinder liner cavitation fault assessment module is used to calculate the cylinder liner surface pressure based on the cylinder liner surface vibration velocity amplitude and coolant information using the Nokovsky model, and obtain the saturated vapor pressure by comparing the absolute pressure with the cylinder liner surface pressure difference, thereby evaluating the cylinder liner cavitation fault status.

[0150] The evaluation method based on cylinder liner cavitation fault involved in this embodiment can be applied to electronic equipment. Fig.13 A schematic diagram of the hardware structure of an electronic device for implementing various embodiments of the present invention.

[0151] In embodiments of the present invention, electronic devices include, but are not limited to, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processing and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the embodiments of the present application described and / or required herein.

[0152] The electronic device 500 includes, but is not limited to, components such as a processor 501, a network module 502, an audio output unit 503, an input unit 504, a display unit 506, a user input unit 507, an interface unit 508, a memory 509, and a power module 511. Those skilled in the art will appreciate that the electronic device structure involved in the embodiments of the present invention does not constitute a limitation on the electronic device, and the electronic device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0153] In the embodiment of the present application, the processor 501 can be implemented by using at least one of an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microcontroller, a microprocessor, and an electronic unit designed to perform the functions described herein. In some cases, such an implementation can be implemented in a controller.

[0154] The audio output unit 503 may provide audio output related to a specific function executed by the processor 501. The audio output unit 503 includes a speaker, a buzzer, a receiver, and the like.

[0155] The input unit 504 is used to receive audio or video signals. The input unit 504 may include a graphics processing unit (GPU) and a microphone, and the graphics processor processes image data of a static picture or video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode.

[0156] The display unit 506 is used to display information input by the user or information provided to the user.

[0157] The user input unit 507 includes a touch screen and other input devices.

[0158] The electronic device 500 includes some functional modules not shown, which will not be described in detail here.

[0159] The electronic device 500 based on the cylinder liner cavitation fault assessment method involved in the present application is a combination of the units and algorithm steps of each example described in the embodiments disclosed herein, and can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0160] In the storage medium involved in the application, a program product capable of implementing the above method of this specification is stored. In some possible implementations, various aspects of the present disclosure can also be implemented in the form of a program product, which includes a program code. When the program product is run on a terminal device, the program code is used to enable the terminal device to execute the steps according to various exemplary implementations of the present disclosure described in the above "Exemplary Method" section of this specification.

[0161] The storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0162] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for evaluating cylinder liner cavitation failure, characterized in that: Methods include: S101: constructing a calculation model for the transient working process of the engine, configuring the design parameters and test parameters of the engine in the calculation model for the transient working process of the engine, and then obtaining the heat load distribution information of the cylinder liner wall and the heat load distribution information of the piston bowl and top surface by setting the spray model, the combustion model and the heat conduction model; S102: construct a piston calculation model, and perform piston heat conduction analysis based on the heat load distribution information and test values ​​of the piston bowl and top surface to obtain the piston wall temperature and deformation state; S103: constructing a calculation model of the cylinder block and the cylinder liner, and performing a heat conduction analysis of the cylinder block and the cylinder liner based on the heat load distribution information of the cylinder liner wall and the test value, and obtaining the temperature and deformation state of the cylinder liner wall; S104: constructing a calculation model to obtain the amplitude of the vibration velocity of the cylinder liner surface according to the piston wall temperature and deformation state, the cylinder liner wall temperature and deformation state, the design parameters of the engine, and by setting the connection and membrane unit; S105: constructing a cooling system calculation model, configuring cooling system design parameters in the cooling system calculation model, and obtaining coolant information by setting a cooling calculation equation; S106: Based on the cylinder liner surface vibration velocity amplitude and coolant information, the cylinder liner surface pressure is calculated using the Nokovsky model. By comparing the absolute pressure with the cylinder liner surface pressure difference, the saturated vapor pressure is obtained, and then the cylinder liner cavitation fault state is evaluated.

2. The cylinder liner cavitation fault assessment method according to claim 1, characterized in that: In step S101, the constructed calculation model of the transient working process of the engine includes an intake duct, an exhaust duct, an intake valve seat ring, an exhaust valve seat ring, an intake valve, an exhaust valve, a cylinder liner and a piston.

3. The cylinder liner cavitation fault assessment method according to claim 1, characterized in that: In step S101, the heat conduction model is set by ’ Rourke and Amsden model implementation; O ’ The Rourke and Amsden model is calculated using formula (1), formula (2) and formula (3): Where k is the thermal conductivity; T is the temperature; Pr m is the Prandtl number of chemical component m; T f is the fluid temperature; T w is the wall temperature; y is the distance from the midpoint of the first layer of the wall grid to the wall; c p is the specific heat; x is the spatial position; n is the normal phase of the unit surface; i is the number of the unit of interest; where κ is the Karman constant, which is 0.42; y + is the dimensionless distance from the midpoint of the first layer of the wall grid to the wall; Pr i is the turbulent Prandtl number; B is a constant; where ρ is the density; μ m is the turbulent viscosity of chemical component m; u τ is the shear rate.

4. The cylinder liner cavitation fault assessment method according to claim 1, characterized in that: The one-dimensional dynamics calculation model in step S104 includes: a cylinder liner, a piston, a piston pin, a connecting rod small end bearing, a connecting rod, a connecting rod big end bearing, and a crank.

5. The cylinder liner cavitation fault assessment method according to claim 1, characterized in that: The coolant information in step S105 includes: the temperature, density, speed of sound, absolute pressure and saturated vapor pressure of the coolant.

6. The cylinder liner cavitation fault assessment method according to claim 1, characterized in that: The cooling system calculation model in step S105 includes a water pump, a cylinder head upper water jacket, a cylinder head lower water jacket, a body water jacket and a water outlet pipe.

7. The cylinder liner cavitation fault assessment method according to claim 1, characterized in that: Step S106 also includes: The cylinder liner surface pressure is calculated by the following formula: △P Joukowsky =ρ.cV Amplitude_liner (4) Where ρ is the density; c is the speed of sound; V Amplitude_liner is the vibration velocity amplitude of the cylinder liner surface; Cylinder liner cavitation fault is realized by the following formula: P stat -△P Joukowsky ≤P D (5) Among them, P stat is the absolute pressure; P D is the saturated vapor pressure.

8. An evaluation system based on cylinder liner cavitation fault, characterized in that: The system is used to implement the evaluation method based on cylinder liner cavitation fault according to any one of claims 1 to 7; The system includes: a heat load distribution calculation module, a piston wall state analysis module, a cylinder liner wall state analysis module, a cylinder liner surface state analysis module, a coolant state analysis module and a cylinder liner cavitation fault assessment module; The heat load distribution calculation module is used to construct a calculation model of the engine's transient working process, configure the engine's design parameters and test parameters in the calculation model of the engine's transient working process, and then obtain the heat load distribution information of the cylinder liner wall and the heat load distribution information of the piston bowl and top surface by setting the spray model, combustion model and heat conduction model; The piston wall state analysis module is used to build a piston calculation model and perform piston heat conduction analysis based on the heat load distribution information and test values ​​of the piston bowl and top surface to obtain the piston wall temperature and deformation state; The cylinder liner wall state analysis module is used to build the cylinder block and cylinder liner calculation model, and based on the heat load distribution information and test values ​​of the cylinder liner wall, perform heat conduction analysis on the cylinder block and cylinder liner to obtain the cylinder liner wall temperature and deformation state; The cylinder liner surface state analysis module is used to construct a calculation model to obtain the amplitude of the cylinder liner surface vibration velocity according to the piston wall temperature and deformation state, the cylinder liner wall temperature and deformation state, the engine design parameters, and by setting the connection and membrane unit; The coolant state analysis module is used to build a cooling system calculation model, configure the cooling system design parameters in the cooling system calculation model, and obtain the coolant information by setting the cooling calculation equation; The cylinder liner cavitation fault assessment module is used to calculate the cylinder liner surface pressure based on the cylinder liner surface vibration velocity amplitude and coolant information using the Nokovsky model, and obtain the saturated vapor pressure by comparing the absolute pressure with the cylinder liner surface pressure difference, thereby evaluating the cylinder liner cavitation fault status.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the cylinder liner cavitation fault evaluation method according to any one of claims 1 to 7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the cylinder liner cavitation fault assessment method according to any one of claims 1 to 7 are implemented.

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