Fluid-solid-acoustic coupling simulation method and device for automobile exhaust emission system and storage medium

Abstract

The application relates to the technical field of computational fluid dynamics and structural acoustic simulation, and particularly discloses a fluid-structure-acoustic coupling simulation method and device for an automobile exhaust emission system and a storage medium, which comprises the following steps: constructing a pipeline three-dimensional geometric model of the automobile exhaust emission system; performing finite element grid division on the pipeline three-dimensional geometric model; performing fluid dynamics simulation calculation on the pipeline finite element grid model; extracting flow field load of pipeline fluid characteristics; transferring pipeline flow field load data to a structure grid for fluid-structure coupling analysis according to heterogeneous grid data mapping; performing structural and acoustic coupling simulation analysis according to structural vibration response results; and realizing quantitative evaluation of the aerodynamic noise and structural vibration of the automobile exhaust emission system according to the structural vibration response results and the sound pressure distribution results of the internal sound field of the pipeline. The fluid-structure-acoustic coupling simulation method for the automobile exhaust emission system can realize collaborative analysis of the aerodynamic noise and structural vibration of the automobile exhaust emission system.

Description

Technical Field

[0001] This invention relates to the fields of computational fluid dynamics and structural acoustics simulation technology, and in particular to a fluid-structure-acoustic coupling simulation method, a fluid-structure-acoustic coupling simulation device, and a storage medium for an automotive exhaust emission system. Background Technology

[0002] The automotive exhaust emission system is a key component affecting vehicle power, economy, and NVH (noise, vibration, and harshness) performance. Under the influence of high temperature and high-speed pulsating airflow, it is prone to induce structural vibration and aerodynamic noise, which is one of the main sources of vehicle noise. Traditional simulation analysis methods usually analyze the three physical fields of fluid, structure, and sound field independently or sequentially, which makes it difficult to accurately characterize their inherent complex interaction mechanisms, resulting in significant deviations in the prediction of system vibration and noise levels.

[0003] Existing computational fluid dynamics (CFD) simulations can obtain flow field characteristics, but it is difficult to directly map the structural response; acoustic simulations are mostly based on simplified boundary conditions and do not consider the real-time excitation of the pipeline by fluid loads; data transfer between heterogeneous meshes lacks efficient mapping algorithms, which affects the simulation accuracy.

[0004] Therefore, how to achieve the coordinated analysis of aerodynamic noise and structural vibration of automotive exhaust emission systems has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a fluid-structure-acoustic coupling simulation method, a fluid-structure-acoustic coupling simulation device, and a storage medium for automotive exhaust emission systems, solving the problem in related technologies that cannot achieve coordinated analysis of aerodynamic noise and structural vibration in automotive exhaust emission systems.

[0006] As a first aspect of the present invention, a fluid-structure-acoustic coupling simulation method for an automotive exhaust emission system is provided, comprising:

[0007] Construct a three-dimensional geometric model of the pipeline of the automobile exhaust system;

[0008] The three-dimensional geometric model of the pipeline is meshed using the finite element method to obtain the finite element mesh model of the pipeline.

[0009] Fluid dynamics simulation calculations were performed on the finite element mesh model of the pipeline to obtain the pipeline fluid characteristics of the automobile exhaust emission system;

[0010] The flow field load is extracted from the fluid characteristics of the pipeline to obtain the pipeline flow field load data;

[0011] The pipeline flow field load data is transferred to the structural mesh based on the heterogeneous mesh data mapping to perform fluid-structure interaction analysis and obtain the structural vibration response results.

[0012] Based on the structural vibration response results, a structural-acoustic coupled simulation analysis was performed to obtain the sound pressure distribution results of the sound field inside the pipeline.

[0013] Based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, a quantitative assessment of the aerodynamic noise and structural vibration of the vehicle exhaust emission system can be achieved.

[0014] Furthermore, the pipeline flow field load data is transferred to the structural mesh for fluid-structure interaction analysis based on the heterogeneous mesh data mapping, including:

[0015] Import pipeline flow field load data;

[0016] Based on the load application location of the preset structural model, the pipeline flow field load data is mapped to the heterogeneous mesh coupling interface through a heterogeneous mesh data mapping algorithm.

[0017] Furthermore, based on the load application location of the preset structural model, the pipeline flow field load data is mapped to the heterogeneous mesh coupling interface using a heterogeneous mesh data mapping algorithm, including:

[0018] The load at each structural grid point is determined by calculating the grid area weight based on the pipeline flow field load data.

[0019] The loads of each structural mesh point are added to the corresponding structural mesh according to the preset structural model load application location.

[0020] Further, based on the pipeline flow field load data, grid area weighting is performed to determine the load at each structural grid point, including:

[0021] Determine the area coordinates of the fluid grid cells based on the pipeline flow field load data;

[0022] The weights of the load structure grid points at each vertex of the fluid grid cell are determined based on the area coordinates of the fluid grid cell.

[0023] The load at each structural grid point is obtained based on the correspondence between fluid grid elements and structural grids.

[0024] Furthermore, based on the structural vibration response results, a structural-acoustic coupled simulation analysis is performed to obtain the sound pressure distribution results of the sound field inside the pipeline, including:

[0025] Based on the structural vibration response results, the vibration velocity of the structural surface is determined as the acoustic boundary condition.

[0026] The vibration velocity of the structure surface is mapped to the coupling interface of the acoustic mesh;

[0027] The sound pressure distribution inside the pipeline is obtained by solving the acoustic-structure interaction theory.

[0028] Furthermore, based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, a quantitative assessment of the aerodynamic noise and structural vibration of the vehicle exhaust emission system is achieved, including:

[0029] Based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, the aerodynamic noise and structural radiated noise of the pipeline are analyzed using acoustic harmonic response analysis.

[0030] Based on the results of the acoustic harmonic response analysis, a quantitative assessment of the aerodynamic noise and structural vibration of the vehicle exhaust emission system can be achieved.

[0031] Furthermore, flow field loads are extracted from the fluid characteristics of the pipeline to obtain pipeline flow field load data, including:

[0032] The pressure and velocity distribution of the flow field are obtained based on the fluid characteristics of the pipeline.

[0033] The pressure and velocity distribution of the flow field are exported as fluid mesh data in CGNS format and the corresponding result data;

[0034] Fluid mesh data in CGNS format and the corresponding result data are analyzed to obtain pipeline flow field load data.

[0035] Furthermore, this also includes steps performed prior to obtaining the pipeline flow field load data:

[0036] Fourier transform is performed on the analyzed CGNS format fluid mesh data and the corresponding result data to obtain the pipeline flow field load data in the frequency domain.

[0037] As another aspect of the present invention, a fluid-structure-acoustic coupling simulation device for an automotive exhaust emission system is provided, for implementing the fluid-structure-acoustic coupling simulation method for an automotive exhaust emission system described above, wherein the device includes:

[0038] The building module is used to construct a three-dimensional geometric model of the pipes in a car's exhaust system.

[0039] The finite element mesh generation module is used to perform finite element mesh generation on the three-dimensional geometric model of the pipeline to obtain the finite element mesh model of the pipeline.

[0040] The fluid dynamics simulation calculation module is used to perform fluid dynamics simulation calculations on the finite element mesh model of the pipeline to obtain the pipeline fluid characteristics of the automobile exhaust emission system.

[0041] The flow field load extraction module is used to extract the flow field load from the fluid characteristics of the pipeline to obtain the pipeline flow field load data.

[0042] The fluid-structure interaction analysis module is used to transfer the pipeline flow field load data to the structural mesh according to the heterogeneous mesh data mapping to perform fluid-structure interaction analysis and obtain the structural vibration response results.

[0043] The structural and acoustic coupling simulation analysis module is used to perform structural and acoustic coupling simulation analysis based on the structural vibration response results to obtain the sound pressure distribution results of the sound field inside the pipeline.

[0044] The quantitative assessment module is used to quantitatively assess the aerodynamic noise and structural vibration of the vehicle exhaust emission system based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline.

[0045] As another aspect of the present invention, a storage medium is provided for storing computer instructions that are loaded and executed by a processor to implement the fluid-structure-acoustic coupling simulation method for the automotive exhaust emission system described above.

[0046] The fluid-structure-acoustic coupling simulation method for automotive exhaust emission systems provided by this invention constructs a three-dimensional geometric model of the automotive exhaust emission system pipeline, performs finite element mesh generation and boundary condition setting, obtains flow field characteristics through computational fluid dynamics simulation, and utilizes a multi-physics fluid-structure-acoustic coupling simulation method to achieve fluid-structure-acoustic coupling analysis of the automotive exhaust emission system pipeline. This invention employs heterogeneous mesh data mapping and structural acoustic boundary condition mapping techniques to achieve collaborative analysis of aerodynamic noise and structural vibration in automotive exhaust emission systems. It solves the data transmission accuracy problem in multi-physics coupling simulation of fluid, structure, and sound fields, significantly improving the accuracy of noise prediction for automotive exhaust emission systems. Attached Figure Description

[0047] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof.

[0048] Figure 1 The flowchart shows the fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems provided by this invention.

[0049] Figure 2 The flowchart for fluid-structure interaction analysis provided by this invention.

[0050] Figure 3 The flowchart provided by the present invention maps heterogeneous mesh data to a heterogeneous mesh coupling interface using a heterogeneous mesh data mapping algorithm.

[0051] Figure 4 The flowchart for the structural and acoustic coupling simulation analysis provided by this invention is shown.

[0052] Figure 5 This is a preview diagram of the heterogeneous mesh load mapping effect provided by the present invention.

[0053] Figure 6 A flowchart for flow field load extraction provided by the present invention.

[0054] Figure 7 This is a schematic diagram of the tree-like hierarchical structure of the CGNS file provided by the present invention.

[0055] Figure 8 This invention provides a flowchart for the quantitative assessment of aerodynamic noise and structural vibration of an automotive exhaust emission system.

[0056] Figure 9 The structural block diagram of the fluid-structure-acoustic coupling simulation device for automobile exhaust emission system provided by the present invention.

[0057] Figure 10 This is a structural block diagram of the electronic device provided by the present invention. Detailed Implementation

[0058] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0059] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0060] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0061] This embodiment provides a fluid-structure-acoustic coupling simulation method for automotive exhaust emission systems. Figure 1 This is a flowchart of a fluid-structure-acoustic coupling simulation method for an automotive exhaust emission system provided according to an embodiment of the present invention, such as... Figure 1 As shown, it includes:

[0062] S100. Construct a three-dimensional geometric model of the pipeline of the automobile exhaust system;

[0063] In this embodiment of the invention, a three-dimensional geometric model of the pipeline can be constructed based on the actual pipeline parameters of the vehicle exhaust emission system.

[0064] S200. Perform finite element mesh generation on the three-dimensional geometric model of the pipeline to obtain the finite element mesh model of the pipeline.

[0065] In this embodiment of the invention, the three-dimensional geometric model of the pipeline constructed above is divided into finite element meshes. Specifically, the finite element mesh can be used to discretize the calculation region, thereby setting the fluid inlet, outlet, and wall boundary conditions, etc.

[0066] Specifically, the meshing module of the finite element preprocessing software can be used to set appropriate global mesh size and curvature control parameters according to the pipeline geometry, and the model can be discretized to generate a volume mesh mainly composed of tetrahedrons or hexahedrons. After meshing, the boundary condition regions of the generated mesh model are defined: the inlet end face, outlet end face, and pipeline wall are selected and set as the fluid inlet boundary, fluid outlet boundary, and fluid-structure interaction wall boundary, respectively, providing a mesh foundation for subsequent computational fluid dynamics simulations.

[0067] S300. Perform fluid dynamics simulation calculations on the finite element mesh model of the pipeline to obtain the pipeline fluid characteristics of the automobile exhaust emission system.

[0068] Specifically, fluid dynamics simulation calculations are performed on the aforementioned finite element mesh model of the pipeline to obtain the pipeline fluid characteristics of the automobile exhaust emission system.

[0069] In this embodiment of the invention, the material properties of the fluid medium can be set, and a turbulence model suitable for exhaust gas flow can be selected. Velocity / pressure boundary conditions are applied at the inlet and outlet of the pipeline, and no-slip boundary conditions are applied at the wall. Iterative solutions are performed using a pressure-based solver and the SIMPLE algorithm until the residuals converge to the set criteria. The velocity field and pressure field inside the pipeline are extracted as the fluid characteristics of the pipeline.

[0070] S400. Extract flow field loads from the fluid characteristics of the pipeline to obtain pipeline flow field load data.

[0071] In this embodiment of the invention, flow field load data is extracted from the pipeline fluid characteristics obtained after fluid dynamics simulation calculations, which facilitates subsequent fluid-structure interaction analysis.

[0072] S500. Based on the heterogeneous mesh data mapping, the pipeline flow field load data is transferred to the structural mesh for fluid-structure interaction analysis to obtain the structural vibration response results.

[0073] In this embodiment of the invention, pipeline flow field load data is transferred to the structural mesh based on heterogeneous mesh data mapping technology, thereby realizing the vibration response analysis of fluid-structure interaction and obtaining the vibration velocity and displacement of the structural surface.

[0074] S600. Based on the structural vibration response results, perform structural and acoustic coupling simulation analysis to obtain the sound pressure distribution results of the sound field inside the pipeline.

[0075] In this embodiment of the invention, a structural and acoustic coupling simulation analysis is performed based on the structural vibration response results to obtain the sound pressure distribution of the sound field inside the pipeline.

[0076] S700. Based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, a quantitative assessment of the aerodynamic noise and structural vibration of the automobile exhaust emission system is achieved.

[0077] In this embodiment of the invention, the vibration and noise characteristics are quantitatively predicted based on the structural vibration response results and the sound pressure distribution results inside the pipeline, thereby improving the accuracy of noise prediction for automobile exhaust emission systems.

[0078] Therefore, the fluid-structure-acoustic coupling simulation method for automotive exhaust emission systems provided by this invention constructs a three-dimensional geometric model of the automotive exhaust emission system pipeline, performs finite element mesh generation and boundary condition setting, obtains flow field characteristics through computational fluid dynamics simulation, and utilizes a multi-physics fluid-structure-acoustic coupling simulation method to achieve fluid-structure-acoustic coupling analysis of the automotive exhaust emission system pipeline. This invention's fluid-structure-acoustic coupling simulation method for automotive exhaust emission systems employs heterogeneous mesh data mapping and structural acoustic boundary condition mapping techniques, achieving collaborative analysis of aerodynamic noise and structural vibration in automotive exhaust emission systems. It solves the data transmission accuracy problem in multi-physics coupling simulation of fluid, structure, and sound fields, significantly improving the accuracy of noise prediction for automotive exhaust emission systems.

[0079] In embodiments of the present invention, such as Figure 2 As shown, the pipeline flow field load data is transferred to the structural mesh for fluid-structure interaction analysis based on heterogeneous mesh data mapping, including:

[0080] S510, Import pipeline flow field load data;

[0081] S520. Based on the load application location of the preset structural model, the pipeline flow field load data is mapped to the heterogeneous mesh coupling interface through a heterogeneous mesh data mapping algorithm.

[0082] It should be understood that the preset structural model load application position can be the structural model load application position selected by the user as needed.

[0083] In this embodiment of the invention, the pipeline flow field load data is mapped to the heterogeneous mesh coupling interface according to the load application position of the preset structural model using a heterogeneous mesh data mapping algorithm, such as... Figure 3 As shown, it includes:

[0084] S521. Calculate the grid area weight based on the pipeline flow field load data to determine the load at each structural grid point;

[0085] In this embodiment of the invention, the load at each structural grid point is determined by calculating the grid area weight based on the pipeline flow field load data, including:

[0086] 1) Determine the area coordinates of the fluid grid cells based on the pipeline flow field load data;

[0087] Specifically, common surface mesh elements come in only two shapes: triangles and quadrilaterals. Quadrilaterals are also treated as two triangles. For each mesh point of the target mesh on the coupling interface, a corresponding source mesh triangular element can be uniquely identified. Projecting each mesh point of the target mesh onto the plane containing the triangular element yields the area coordinates of the point.

[0088] It should be noted that the information transfer problem between the coupling interface and coupling domain of heterogeneous meshes is handled by interpolation or weighting methods based on local information. For ease of distinction, these two sets of meshes can be referred to as the source mesh and the target mesh, respectively.

[0089] 2) Determine the weights of the load structure grid points at each vertex of the fluid grid cell based on the area coordinates of the fluid grid cell;

[0090] Specifically, the area coordinates of the fluid mesh triangular element are regarded as the weights of the load structure mesh points at each vertex of the triangular element, thereby calculating the loads at the structure mesh points.

[0091] 3) Obtain the load at each structural grid point based on the correspondence between fluid grid elements and structural grids.

[0092] It should be understood that by processing each structural grid point according to the area weighting method described above, the load mapping on the heterogeneous grid coupling interface can be completed.

[0093] It should be noted that the fluid in the embodiments of the present invention is specifically a gas, namely automobile exhaust.

[0094] S522. According to the preset structural model load application position, add the load of each structural mesh point to the corresponding structural mesh.

[0095] In this embodiment of the invention, a structural-acoustic coupled simulation analysis is performed based on the structural vibration response results to obtain the sound pressure distribution results of the sound field inside the pipeline, such as... Figure 4 As shown, it includes:

[0096] S610. Determine the vibration velocity of the structural surface as the acoustic boundary condition based on the structural vibration response results.

[0097] S620. Map the vibration velocity of the structure surface to the coupling interface of the acoustic mesh;

[0098] Specifically, the vibration velocity of the structural surface can be mapped to the coupling interface of the acoustic mesh using Tie constraints. It should be understood that the acoustic mesh and the structural mesh are bound together at the boundary through the Tie connection. Figure 5 The image shown is a preview diagram of the load mapping effect of heterogeneous meshes.

[0099] It should be understood that, to ensure that the pressure load mapped from the fluid mesh to the structural mesh accurately reflects the original fluid pressure distribution characteristics, this invention verifies this through contour map distribution comparison. For example... Figure 5 The image shows a preview of the pressure load mapping effect. By outputting the original pressure cloud map of the fluid mesh surface and the pressure load cloud map of the mapped structural mesh surface respectively, and comparing the degree of agreement between the two in terms of peak position, distribution area, and numerical range, the consistency of the data distribution before and after mapping can be intuitively verified.

[0100] S630. Solve according to the acoustic-structure interaction theory to obtain the sound pressure distribution results of the sound field inside the pipeline.

[0101] In this embodiment of the invention, the specific process of solving the problem based on the acoustic-structure coupling theory includes:

[0102] In an acoustic-vibration coupling system, the sound field The boundary can be divided into velocity boundaries. Impedance Boundary Sound pressure boundary and acoustic-vibration coupling boundary At the coupled boundary, the vibration velocity in the normal direction of the structure is the same as the vibration velocity of the fluid, expressed as:

[0103] ,

[0104] sound field The sound pressure at any point inside can be expressed as:

[0105] ,

[0106] in, For the shape function of the unknown node, For unknown node sound pressure, The shape function is given by the nodal sound pressure level. The known nodal sound pressure levels are given.

[0107] For nodes in a sound field with unknown sound pressure, the following equation should be satisfied:

[0108] ,

[0109] in, Including known sound pressure, sound sources in the sound field, and vibration velocity boundaries. Its function.

[0110] For the structural model, the following equation is satisfied:

[0111] ,

[0112] in, , , Let these represent the stiffness matrix, damping matrix, and mass matrix of the unconstrained structural mesh, respectively. This includes the contribution of the structural constraint portion, the contribution of known loads, and the contribution of external acoustic pressure load p perpendicular to the structural surface.

[0113] The sound pressure load acting on the structure can be regarded as an additional normal load, then the dynamic equation of the structural model can be transformed into:

[0114] ,

[0115] in, Represents the coupling stiffness matrix. The excitation load is expressed as:

[0116] ,

[0117] .

[0118] At the boundary where the fluid and structure are coupled, the vibration velocity of the structure in the normal direction is the same as that of the fluid. Therefore, at this boundary, the vibration velocity of the structure can be regarded as an additional velocity input of sound. The equation that the node with unknown sound pressure in the sound field should satisfy changes as follows:

[0119] ,

[0120] in, Represents the coupling quality matrix. The excitation load is expressed as:

[0121] ,

[0122] ,

[0123] contrast and The expression can be obtained as follows:

[0124] ,

[0125] The dynamic equations of the structural model and the equations that the nodes with unknown sound pressure in the sound field should satisfy, after transformation, are written as matrix-form coupling equations:

[0126] .

[0127] In this embodiment of the invention, flow field loads are extracted from the fluid characteristics of the pipeline to obtain pipeline flow field load data, such as... Figure 6 As shown, it includes:

[0128] S410. Obtain the flow field pressure and velocity distribution based on the fluid characteristics of the pipeline;

[0129] It should be understood that the pressure and velocity distribution of the flow field are obtained through computational fluid dynamics simulation.

[0130] S420. Export the pressure and velocity distribution of the flow field as fluid mesh data in CGNS format and the corresponding result data;

[0131] S430: Analyze the fluid mesh data in CGNS format and the corresponding result data to obtain the pipeline flow field load data.

[0132] In this embodiment of the invention, the following steps are also performed before obtaining the pipeline flow field load data:

[0133] Fourier transform is performed on the analyzed CGNS format fluid mesh data and the corresponding result data to obtain the pipeline flow field load data in the frequency domain.

[0134] It should be understood that parsing CGNS files through an interface and converting the time-domain results to frequency-domain results using Fourier transform: 1) Reading time-domain data from CGNS files through a standard interface. For example... Figure 7As shown, CGNS files organize data using a tree-like hierarchical structure, with the root node at the top and nodes below it including base, region, mesh coordinates, and flow field solutions. Simulation results can be systematically read through the mid-level application programming interface (API) provided by the CGNS library. 2) Fourier Transform. The frequency domain pressure data obtained after the transform (i.e., the pressure amplitude and phase corresponding to each frequency point) can be directly used as excitation conditions and input into the harmonic response analysis module of structural dynamics and acoustic simulation software. This makes it possible to efficiently and accurately calculate structural vibration and noise radiation in the frequency domain.

[0135] In this embodiment of the invention, a quantitative assessment of the aerodynamic noise and structural vibration of the vehicle exhaust emission system is achieved based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline. Figure 8 As shown, it includes:

[0136] S710. Based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, perform acoustic harmonic response analysis on the aerodynamic noise and structural radiated noise of the pipeline.

[0137] In this embodiment of the invention, a Tie constraint algorithm can be specifically used to map the vibration velocity data of the structural surface to the coupling interface nodes of the acoustic mesh; set the material properties, frequency range and solution step size of the acoustic analysis, and solve the acoustic-structure coupling system equations by frequency scanning; extract the sound pressure distribution cloud map of the sound field inside and outside the pipeline and the sound pressure level spectrum curve of the key monitoring point as the output result of the acoustic harmonic response analysis.

[0138] S720. Based on the results of the acoustic harmonic response analysis, a quantitative assessment of the aerodynamic noise and structural vibration of the automobile exhaust emission system is achieved.

[0139] In this embodiment of the invention, key physical quantities of the sound field inside the pipeline and the structural surface are extracted. By setting monitoring points in the fluid area of ​​the pipeline and the structural surface, the sound pressure level frequency response curve of each monitoring point in the analysis frequency band is obtained. Based on the frequency response curve, the characteristic frequencies of noise and vibration and their corresponding amplitudes are identified. By comparing the amplitude changes at the characteristic frequencies under different design schemes, or by quantifying the level of noise and vibration in the form of specific decibel values, a numerical evaluation of the aerodynamic noise and structural vibration characteristics is achieved.

[0140] In summary, the fluid-structure-acoustic coupling simulation method for automotive exhaust emission systems provided by this invention establishes a three-dimensional geometric model of the automotive exhaust emission system pipeline, performs finite element mesh generation and boundary condition setting, obtains flow field characteristics through computational fluid dynamics simulation, and utilizes a multi-physics fluid-structure-acoustic coupling simulation method to achieve fluid-structure-acoustic coupling analysis of the automotive exhaust emission system pipeline. This invention's fluid-structure-acoustic coupling simulation method for automotive exhaust emission systems employs heterogeneous mesh data mapping and structural acoustic boundary condition mapping techniques, solving the data transmission accuracy problem in multi-physics coupling simulation of fluid, structure, and sound field, and significantly improving the accuracy of noise prediction for automotive exhaust emission systems.

[0141] As another embodiment of the present invention, a fluid-structure-acoustic coupling simulation device 100 for an automobile exhaust emission system is provided, used to implement the fluid-structure-acoustic coupling simulation method for an automobile exhaust emission system described above, wherein, as Figure 9 As shown, it includes:

[0142] Module 110 is used to build a three-dimensional geometric model of the pipes of an automotive exhaust system;

[0143] The finite element mesh generation module 120 is used to perform finite element mesh generation on the three-dimensional geometric model of the pipeline to obtain the finite element mesh model of the pipeline.

[0144] The fluid dynamics simulation calculation module 130 is used to perform fluid dynamics simulation calculations on the finite element mesh model of the pipeline to obtain the pipeline fluid characteristics of the automobile exhaust emission system.

[0145] The flow field load extraction module 140 is used to extract the flow field load from the fluid characteristics of the pipeline to obtain the pipeline flow field load data.

[0146] The fluid-structure interaction analysis module 150 is used to transfer the pipeline flow field load data to the structural mesh according to the heterogeneous mesh data mapping to perform fluid-structure interaction analysis and obtain the structural vibration response results.

[0147] The structural and acoustic coupling simulation analysis module 160 is used to perform structural and acoustic coupling simulation analysis based on the structural vibration response results to obtain the sound pressure distribution results of the sound field inside the pipeline.

[0148] The quantitative assessment module 170 is used to quantitatively assess the aerodynamic noise and structural vibration of the vehicle exhaust emission system based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline.

[0149] The fluid-structure-acoustic coupling simulation device for automotive exhaust emission systems provided by this invention constructs a three-dimensional geometric model of the automotive exhaust emission system pipeline, performs finite element mesh generation and boundary condition setting, obtains flow field characteristics through computational fluid dynamics simulation, and utilizes a multi-physics fluid-structure-acoustic coupling simulation method to achieve fluid-structure-acoustic coupling analysis of the automotive exhaust emission system pipeline. This invention employs heterogeneous mesh data mapping and structural acoustic boundary condition mapping techniques to achieve collaborative analysis of aerodynamic noise and structural vibration in automotive exhaust emission systems. It solves the data transmission accuracy problem in multi-physics coupling simulation of fluid, structure, and sound fields, significantly improving the accuracy of noise prediction for automotive exhaust emission systems.

[0150] The specific working principle of the fluid-structure-acoustic coupling simulation device for automobile exhaust emission systems provided by this invention can be referred to the description of the fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems above, and will not be repeated here.

[0151] As another embodiment of the present invention, a storage medium is provided, wherein computer instructions are stored, which are loaded and executed by a processor to implement the fluid-structure-acoustic coupling simulation method for the automobile exhaust emission system described above.

[0152] In this embodiment of the invention, a non-transitory computer-readable storage medium is provided. The computer-readable storage medium stores computer-executable instructions that can execute the fluid-structure-acoustic coupling simulation method for the automotive exhaust emission system in any of the above method embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium may also include combinations of the above types of memory.

[0153] As another embodiment of the present invention, an electronic device is provided, comprising a memory and a processor, wherein the processor is communicatively connected to the memory, the memory is used to store a computer program, and the processor is used to load and execute the computer program to implement the fluid-structure-acoustic coupling simulation method for the automobile exhaust emission system described above.

[0154] like Figure 10As shown, the electronic device 10 may include: at least one processor 11, such as a CPU (Central Processing Unit), at least one communication interface 13, a memory 14, and at least one communication bus 12. The communication bus 12 is used to enable communication between these components. The communication interface 13 may include a display screen or a keyboard; optionally, the communication interface 13 may also include a standard wired interface or a wireless interface. The memory 14 may be high-speed RAM (Random Access Memory) or non-volatile memory, such as at least one disk drive. Optionally, the memory 14 may also be at least one storage device located remotely from the aforementioned processor 11. The memory 14 stores application programs, and the processor 11 calls the program code stored in the memory 14 to execute any of the aforementioned method steps.

[0155] The communication bus 12 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The communication bus 12 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 10 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0156] The memory 14 may include volatile memory, such as random-access memory (RAM); the memory may also include non-volatile memory, such as flash memory, hard disk drive (HDD) or solid-state drive (SSD); the memory 14 may also include a combination of the above types of memory.

[0157] The processor 11 can be a central processing unit (CPU), a network processor (NP), or a combination of CPU and NP.

[0158] The processor 11 may further include a hardware chip. This hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0159] Optionally, memory 14 is also used to store program instructions. Processor 11 can invoke program instructions to implement the present invention. Figure 1 The embodiment shows a fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems.

[0160] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems, characterized in that, include: Construct a three-dimensional geometric model of the pipeline of the automobile exhaust system; The three-dimensional geometric model of the pipeline is meshed using the finite element method to obtain the finite element mesh model of the pipeline. Fluid dynamics simulation calculations were performed on the finite element mesh model of the pipeline to obtain the pipeline fluid characteristics of the automobile exhaust emission system; The flow field load is extracted from the fluid characteristics of the pipeline to obtain the pipeline flow field load data; The pipeline flow field load data is transferred to the structural mesh based on the heterogeneous mesh data mapping to perform fluid-structure interaction analysis and obtain the structural vibration response results. Based on the structural vibration response results, a structural-acoustic coupled simulation analysis was performed to obtain the sound pressure distribution results of the sound field inside the pipeline. Based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, a quantitative assessment of the aerodynamic noise and structural vibration of the vehicle exhaust emission system can be achieved.

2. The fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems according to claim 1, characterized in that, The pipeline flow field load data is transferred to the structural mesh based on the heterogeneous mesh data mapping for fluid-structure interaction analysis, including: Import pipeline flow field load data; Based on the load application location of the preset structural model, the pipeline flow field load data is mapped to the heterogeneous mesh coupling interface through a heterogeneous mesh data mapping algorithm.

3. The fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems according to claim 2, characterized in that, Based on the load application location of the preset structural model, the pipeline flow field load data is mapped to the heterogeneous mesh coupling interface using a heterogeneous mesh data mapping algorithm, including: The load at each structural grid point is determined by calculating the grid area weight based on the pipeline flow field load data. The loads of each structural mesh point are added to the corresponding structural mesh according to the preset structural model load application location.

4. The fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems according to claim 3, characterized in that, The load at each structural grid point is determined by calculating the grid area weight based on the pipeline flow field load data, including: Determine the area coordinates of the fluid grid cells based on the pipeline flow field load data; The weights of the load structure grid points at each vertex of the fluid grid cell are determined based on the area coordinates of the fluid grid cell. The load at each structural grid point is obtained based on the correspondence between fluid grid elements and structural grids.

5. The fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems according to claim 1, characterized in that, Based on the structural vibration response results, a coupled structural and acoustic simulation analysis is performed to obtain the sound pressure distribution results of the sound field inside the pipeline, including: Based on the structural vibration response results, the vibration velocity of the structural surface is determined as the acoustic boundary condition. The vibration velocity of the structure surface is mapped to the coupling interface of the acoustic mesh; The sound pressure distribution inside the pipeline is obtained by solving the acoustic-structure interaction theory.

6. The fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems according to claim 1, characterized in that, A quantitative assessment of the aerodynamic noise and structural vibration of the vehicle exhaust emission system is achieved based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, including: Based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline, the aerodynamic noise and structural radiated noise of the pipeline are analyzed using acoustic harmonic response analysis. Based on the results of the acoustic harmonic response analysis, a quantitative assessment of the aerodynamic noise and structural vibration of the vehicle exhaust emission system can be achieved.

7. The fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems according to claim 1, characterized in that, The flow field load is extracted from the fluid characteristics of the pipeline to obtain pipeline flow field load data, including: The pressure and velocity distribution of the flow field are obtained based on the fluid characteristics of the pipeline. The pressure and velocity distribution of the flow field are exported as fluid mesh data in CGNS format and the corresponding result data; Fluid mesh data in CGNS format and the corresponding result data are analyzed to obtain pipeline flow field load data.

8. The fluid-structure-acoustic coupling simulation method for automobile exhaust emission systems according to claim 7, characterized in that, This also includes steps performed before obtaining pipeline flow field load data: Fourier transform is performed on the analyzed CGNS format fluid mesh data and the corresponding result data to obtain the pipeline flow field load data in the frequency domain.

9. A fluid-structure-acoustic coupling simulation device for an automotive exhaust emission system, used to implement the fluid-structure-acoustic coupling simulation method for an automotive exhaust emission system as described in any one of claims 1 to 8, characterized in that, include: The building module is used to construct a three-dimensional geometric model of the pipes in a car's exhaust system. The finite element mesh generation module is used to perform finite element mesh generation on the three-dimensional geometric model of the pipeline to obtain the finite element mesh model of the pipeline. The fluid dynamics simulation calculation module is used to perform fluid dynamics simulation calculations on the finite element mesh model of the pipeline to obtain the pipeline fluid characteristics of the automobile exhaust emission system. The flow field load extraction module is used to extract the flow field load from the fluid characteristics of the pipeline to obtain the pipeline flow field load data. The fluid-structure interaction analysis module is used to transfer the pipeline flow field load data to the structural mesh according to the heterogeneous mesh data mapping to perform fluid-structure interaction analysis and obtain the structural vibration response results. The structural and acoustic coupling simulation analysis module is used to perform structural and acoustic coupling simulation analysis based on the structural vibration response results to obtain the sound pressure distribution results of the sound field inside the pipeline. The quantitative assessment module is used to quantitatively assess the aerodynamic noise and structural vibration of the vehicle exhaust emission system based on the structural vibration response results and the sound pressure distribution results of the sound field inside the pipeline.

10. A storage medium, characterized in that, Used to store computer instructions, which are loaded and executed by a processor to implement the fluid-structure-acoustic coupling simulation method for an automotive exhaust emission system as described in any one of claims 1 to 8.

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