Method and system for analyzing transmission loss of air inlet system

Abstract

The invention relates to the technical field of vehicles, and discloses an air inlet system transmission loss analysis method and system, electronic equipment, a storage medium and a terminal.The air inlet system transmission loss analysis method includes the steps that a three-dimensional structure model of an air inlet system is constructed, the three-dimensional structure model comprises key components of the air inlet system, and the key components are determined based on actual simulation; performing vocal cavity extraction and corresponding simplification on the three-dimensional structure model to optimize the grid quality and improve the precision of the three-dimensional structure model; a finite element model is established, the finite element model uses a tetrahedral mesh for modeling, and different groups are established according to material attributes; and acoustic calculation is carried out based on the finite element model, a correspondingly calculated transmission loss value is obtained, and the transmission loss of the air inlet system is analyzed according to the transmission loss value. The precision of transmission loss analysis and calculation can be improved, so that the product development period is shortened, and the development cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to an intake system transmission loss analysis method, system, electronic equipment, storage medium and terminal. Background Art

[0002] At present, in the automotive field, as users' requirements for NVH become more and more stringent, the number of noise problems in the market has also increased, among which intake noise accounts for a large proportion. Therefore, it is very necessary to control the acoustic performance of intake air during the product development stage.

[0003] The noise evaluation indicators of the intake system usually include transmission loss, insertion loss, sound pressure level difference, sound pressure level, etc. When evaluating the silencing effect of a single silencer component or preliminarily evaluating the silencing performance of the system level, transmission loss is usually used. Transmission loss is also the simplest method to evaluate silencing performance. In the product development stage, the transmission loss of the intake system is analyzed and calculated by simulation, and the silencing performance of the intake system is mastered in advance, which greatly saves manpower and material resources to avoid intake noise problems.

[0004] The calculation and analysis methods in the prior art are quite different from the bench test results, which prolongs the product development time and increases the cost.

[0005] Therefore, the present application provides an intake system transmission loss analysis method to solve the above technical problems. Summary of the invention

[0006] The purpose of the present invention is to provide an intake system transmission loss analysis method, system, electronic device, storage medium and terminal to solve the technical problem in the prior art that the calculation analysis results are quite different from the bench test results, resulting in long development time and high cost.

[0007] In order to solve the above technical problems, the present invention provides an intake system transmission loss analysis method, comprising:

[0008] Constructing a three-dimensional structural model of the air intake system, wherein the three-dimensional structural model includes various key components of the air intake system, and each of the key components is determined based on actual simulation;

[0009] Performing acoustic cavity extraction and corresponding simplification on the three-dimensional structural model to optimize mesh quality and improve the accuracy of the three-dimensional structural model;

[0010] Establishing a finite element model, wherein the finite element model is modeled using a tetrahedral mesh, and different groups are established according to material properties;

[0011] Acoustic calculation is performed based on the finite element model to obtain a corresponding calculated transmission loss value, and the transmission loss of the intake system is analyzed according to the transmission loss value.

[0012] In some specific embodiments, a three-dimensional structural model of the intake system is constructed, wherein the three-dimensional structural model includes various key components of the intake system, and each of the key components is determined based on actual simulation, further comprising:

[0013] Acquire structural data of each of the key components of the air intake system, and record geometric dimensions and material properties of each of the key components;

[0014] Verifying the obtained geometric dimensions and material properties of the key components to ensure that each of the key components is consistent with the actual ones;

[0015] Determining the entire or partial structure of the intake system as a calculation model includes determining boundary conditions and connection relationships of the three-dimensional structural model, and simulating the airflow dynamics under actual working conditions so that the three-dimensional structural model can reflect the working state of the intake system.

[0016] In some specific embodiments, the three-dimensional structure model is subjected to acoustic cavity extraction and corresponding simplification to optimize mesh quality and improve the accuracy of the three-dimensional structure model, further comprising:

[0017] The surface formed by the air inside the intake system is retained, and the surface not involving the gas flow is deleted to ensure the accuracy and calculation efficiency of the three-dimensional structure model and reduce unnecessary calculation load;

[0018] Simplifying the three-dimensional structural model, including removing support plates or grid plates that do not hinder the gas flow direction;

[0019] Deleting structural features within a preset range that are smaller than the overall structural size of the three-dimensional structural model;

[0020] The structures that affect the mesh quality are removed or adjusted so that the three-dimensional structural model can reduce the computational complexity while maintaining the necessary physical properties.

[0021] In some specific embodiments, a finite element model is established, wherein the finite element model is modeled using a tetrahedral mesh, and different groups are established according to material properties, further comprising:

[0022] Use tetrahedral meshes for modeling, and adaptively select mesh density and type to reduce model complexity and balance computing resources;

[0023] Different groups are established according to material properties to simulate the influence of different materials on sound wave propagation, including density, elastic modulus and damping characteristics of different materials, so that the model can accurately reflect the influence of material properties on acoustic performance;

[0024] The grid has at least 6 units within the minimum wavelength range, that is, the side length of the largest unit is less than 1 / 6 of the shortest wavelength.

[0025] In some specific embodiments, it also includes:

[0026] The calculation accuracy is improved based on the following factors:

[0027] Wall characteristics of each key component, including wall thickness, material and surface treatment;

[0028] Air damping, including simulation based on actual airflow conditions;

[0029] Filter material properties, including resistivity and porosity;

[0030] The sound absorption properties of the material are defined to simulate actual or nearly actual situations, including the sound absorption coefficient of the wall and the damping characteristics of the material.

[0031] In some specific embodiments, performing acoustic calculation based on the finite element model to obtain a corresponding calculated transmission loss value, and analyzing the transmission loss of the intake system according to the transmission loss value further includes:

[0032] Performing finite element acoustic calculation on the finite element model based on Hypermesh / Virtua l Lab to obtain a transmission loss value;

[0033] The transmission loss values ​​are analyzed and the transmission loss values ​​at different frequencies are compared to evaluate the sound absorption performance of the structure.

[0034] Based on the same concept, the present invention also provides an intake system transmission loss analysis system, comprising:

[0035] A structural model building module, configured to build a three-dimensional structural model of the intake system, wherein the three-dimensional structural model includes various key components of the intake system, and each of the key components is determined based on actual simulation;

[0036] A structural model simplification module, configured to perform acoustic cavity extraction and corresponding simplification on the three-dimensional structural model to optimize mesh quality and improve the accuracy of the three-dimensional structural model;

[0037] A finite element model building module is configured to build a finite element model, wherein the finite element model is modeled using a tetrahedral mesh and different groups are established according to material properties;

[0038] The transmission loss analysis module is configured to perform acoustic calculation based on the finite element model to obtain a corresponding calculated transmission loss value, and analyze the transmission loss of the intake system according to the transmission loss value.

[0039] Based on the same concept, the present invention also provides an electronic device, comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the intake system transmission loss analysis method.

[0040] Based on the same concept, the present invention also provides a computer-readable storage medium storing a computer program executable by an electronic device. When the computer program runs on the electronic device, the electronic device executes the steps of the intake system transmission loss analysis method.

[0041] Based on the same concept, the present invention also provides an intake system transmission loss analysis terminal, wherein the terminal is provided with the intake system transmission loss analysis system as described above.

[0042] Compared with the prior art, the beneficial effects are:

[0043] The invention discloses an intake system transmission loss analysis method, system, electronic equipment, storage medium and terminal, which can improve the accuracy of transmission loss analysis calculation, thereby shortening the product development cycle and reducing development costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of an intake system transmission loss analysis method according to some specific embodiments of the present invention;

[0045] Figure 2 It is a schematic flow chart of an intake system transmission loss analysis method in some applications of the present invention;

[0046] Figure 3 It is a schematic diagram of simulation comparison of an intake system transmission loss analysis method of the present invention in some applications;

[0047] Figure 4 It is a schematic structural diagram of an intake system transmission loss analysis system in some specific embodiments of the present invention;

[0048] Figure 5 It is a schematic diagram of the structure of an electronic device in some specific embodiments of the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0050] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0051] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0052] It should be understood that although the terms first, second, third, etc. may be used to describe in the embodiments of the present application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, without departing from the scope of the embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0053] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0054] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0055] It should be particularly noted that any symbols and / or numbers in the specification that are not marked in the accompanying drawings are not drawing marks.

[0056] Reference Figure 1 , a method for analyzing transmission loss of an intake system, comprising:

[0057] S101, constructing a three-dimensional structural model of an intake system, wherein the three-dimensional structural model includes various key components of the intake system, and each of the key components is determined based on actual simulation;

[0058] It is understandable that the key component data of the intake system is first collected, including the structural dimensions and material properties of the intake duct, air filter, filter element, muffler, etc. A 3D model of each component is created based on the collected data. Each model reflects the geometry and size of the actual component. All individual component models are assembled into a complete intake system model. The accuracy of the model is verified by comparison with the actual intake system.

[0059] In some of these applications, a three-dimensional structural model of the intake system is constructed, including each key component of the intake system, and each key component is determined based on actual simulation, the structural data of each key component of the intake system is obtained, and the geometric dimensions and material properties of each key component are recorded; the obtained geometric dimensions and material properties of the key components are verified to ensure that each key component is consistent with the actual situation; the whole or part of the structure of the intake system is determined as a calculation model, including determining the boundary conditions and connection relationships of the three-dimensional structural model, and simulating the airflow dynamics under actual working conditions, so that the three-dimensional structural model can reflect the working state of the intake system.

[0060] It is understandable that the key components of the intake system, including the structural data of the intake duct, air filter, filter element, muffler, etc., are collected. The geometric dimensions of each component are recorded, for example, the diameter of the intake duct is 100mm and the length is 500mm; the diameter of the air filter is 200mm and the height is 300mm; the diameter of the filter element is 180mm and the height is 250mm; the diameter of the muffler is 150mm and the length is 400mm. The material properties of each component are recorded, for example, the intake duct is made of aluminum alloy, the air filter and filter element are made of plastic and paper materials, and the muffler is made of stainless steel.

[0061] Verify the acquired geometry and material properties to ensure consistency with the actual air intake system. Measure and analyze the actual dimensions and materials of each component.

[0062] For example, the actual diameter and length of the intake duct were measured with a caliper to ensure that the measured values ​​were consistent with the recorded 100mm diameter and 500mm length; the stainless steel material composition of the muffler was confirmed with a spectrum analyzer.

[0063] Determine the entire or partial structure of the intake system as a computational model, including the intake duct, air filter, filter element, and muffler. Set the boundary conditions of the 3D structural model, for example, set pressure boundaries at the inlet and outlet of the intake duct to simulate the airflow dynamics under actual working conditions.

[0064] Determine the connection relationship of the model, such as the connection between the intake duct and the air filter, the connection between the air filter and the filter element, and the connection between the filter element and the muffler.

[0065] Simulate the airflow dynamics under actual working conditions. For example, set the airflow velocity to 60m / s and the temperature to 25°C, and simulate the process of airflow passing through the intake system in the simulation software.

[0066] S102, performing acoustic cavity extraction and corresponding simplification on the three-dimensional structure model to optimize mesh quality and improve the accuracy of the three-dimensional structure model;

[0067] It can be understood that this step is used to extract and simplify the acoustic cavity of the model to optimize the mesh quality and improve the accuracy of the model.

[0068] In some of these applications, the three-dimensional structural model is subjected to acoustic cavity extraction and corresponding simplification to optimize the mesh quality and improve the accuracy of the three-dimensional structural model. The surfaces formed by the air inside the intake system are retained, and the surfaces not involving the gas flow are deleted to ensure the accuracy and computational efficiency of the three-dimensional structural model and reduce unnecessary computational load. The three-dimensional structural model is simplified, including removing support plates or grids that do not hinder the gas flow direction; structural features that are smaller than the overall structural size of the three-dimensional structural model within a preset range are deleted; structures that affect the mesh quality are removed or adjusted so that the three-dimensional structural model can reduce computational complexity while maintaining the necessary physical properties.

[0069] It is understandable that the air cavities inside the intake system are identified and extracted. For external surfaces that do not participate in the propagation of sound waves, such as the housing of the intake system and non-functional covers, they are removed from the model to reduce the computational load. For support plates or grids that do not hinder the direction of gas flow, they are removed from the model. Set a threshold, for example, for a model with an overall size of several hundred millimeters, delete features smaller than 10mm. These features include small holes, small protrusions or grooves, and the impact on the acoustic performance can be ignored. For structures that affect the mesh quality, such as sharp edges or small gaps, adjustments are made. For example, increase the radius of sharp edges to 1mm to optimize the mesh quality.

[0070] Mesh the simplified model. Select tetrahedral mesh and control the cell size according to the requirements of acoustic simulation. For example, for a sound wave with a frequency of 500 Hz, the wavelength in 20°C air is about 6.67 mm, so the side length of the largest cell should be less than 1.11 mm (1 / 6 of the wavelength) to ensure calculation accuracy.

[0071] During the simplification process, make sure to retain all features that have a significant impact on the acoustic performance, such as the cross-sectional changes of the intake duct, the internal structure of the muffler, etc. Assign accurate material properties to each component in the model, including density, elastic modulus, damping ratio, etc., to simulate realistic acoustic behavior.

[0072] For example, the air intake system includes the following components:

[0073] Inlet pipe: diameter 100mm, length 500mm, material is 6061 aluminum alloy;

[0074] Air filter: diameter 200mm, height 300mm, material is polypropylene;

[0075] Filter element: diameter 180mm, height 250mm, material is cellulose;

[0076] Muffler: diameter 150mm, length 400mm, material is 304 stainless steel.

[0077] In the acoustic cavity extraction stage, the air cavities inside the intake duct and the muffler are identified and extracted. Solid surfaces that are in contact with the external environment, such as the outer wall of the intake duct, are deleted from the model.

[0078] In the model simplification stage, a support plate that does not hinder the gas flow is removed. The thickness of the support plate is 2mm, which is much smaller than the diameter of the intake pipe and has little effect on the propagation of sound waves. A small hole with a diameter of 5mm is also deleted. The small hole is smaller than the preset range (10mm) of the overall structural size of the model. In addition, a raised structure that affects the mesh quality is adjusted. The height of the raised structure is 15mm. By reducing its height to 10mm, the mesh quality is optimized while maintaining its influence on the acoustic performance.

[0079] When optimizing the mesh quality, ensure that there are at least 6 units within the minimum wavelength (assumed to be 6.67 mm, corresponding to the propagation of 500 Hz sound waves in the air), that is, the side length of the largest unit should be less than 1.11 mm to ensure the accuracy of the acoustic calculation.

[0080] S103, establishing a finite element model, wherein the finite element model is modeled using a tetrahedral mesh, and different groups are established according to material properties;

[0081] It can be understood that this step is used to establish a finite element model to prepare for the analysis and calculation of transmission loss.

[0082] In some of the applications, a finite element model is established, tetrahedral mesh is used for modeling, and different groups are established according to material properties, and tetrahedral mesh is used for modeling. The mesh density and type are adaptively selected to reduce the complexity of the model and balance the computing resources; different groups are established according to material properties to simulate the influence of different materials on sound wave propagation, including the density, elastic modulus and damping characteristics of different materials, so that the model can accurately reflect the influence of material properties on acoustic performance; the mesh has at least 6 units within the minimum wavelength range, that is, the side length of the largest unit is less than 1 / 6 of the shortest wavelength.

[0083] It can be understood that the three-dimensional structural model of the intake system after acoustic cavity extraction and simplification is imported. Select the appropriate mesh density and type to adaptively reduce the complexity of the model and balance the computing resources. For example, for the straight pipe part of the intake duct, a coarser mesh is selected, and for areas with complex acoustic characteristics such as air filters and mufflers, a finer mesh is selected. , create different groups for different material properties. For example, the intake duct of 6061 aluminum alloy, the air filter of polypropylene, the filter element of cellulose, and the muffler of 304 stainless steel are set to different groups respectively. Assign corresponding material properties to each group, including density, elastic modulus, and damping characteristics. For example, for 6061 aluminum alloy, set the density to 2700kg / m 3 , elastic modulus is 70 GPa, Poisson's ratio is 0.33; for polypropylene, the density is set to 900 kg / m 3 , the elastic modulus is 1.5 GPa, and the Poisson's ratio is 0.4.

[0084] According to the requirements of acoustic simulation, the mesh size is controlled. For example, for a sound wave with a frequency of 500 Hz, the wavelength in 20°C air is about 6.67 mm, so the side length of the largest unit should be less than 1.11 mm (1 / 6 of the wavelength) to ensure the calculation accuracy.

[0085] Set the mesh size parameters to ensure that there are at least 6 elements within the range of the minimum wavelength. For high-frequency areas, reduce the element size appropriately to improve calculation accuracy.

[0086] For example, the air intake system includes the following components:

[0087] Inlet pipe: diameter 100mm, length 500mm, material is 6061 aluminum alloy;

[0088] Air filter: diameter 200mm, height 300mm, material is polypropylene;

[0089] Filter element: diameter 180mm, height 250mm, material is cellulose;

[0090] Muffler: diameter 150mm, length 400mm, material is 304 stainless steel.

[0091] When building the finite element model, first import the 3D structural model of the intake system after acoustic cavity extraction and simplification. Then select a coarser mesh for the straight pipe part of the intake duct, and set the mesh size to 2mm. For areas with complex acoustic characteristics such as the air filter and muffler, select a finer mesh, and set the mesh size to 0.5mm.

[0092] For different material properties, different groups are created and the corresponding material properties are assigned. For example, for the intake duct of 6061 aluminum alloy, the density is set to 2700kg / m 3 , elastic modulus is 70GPa, Poisson's ratio is 0.33; for polypropylene air filter, the density is set to 900kg / m 3 , the elastic modulus is 1.5 GPa, and the Poisson's ratio is 0.4.

[0093] In terms of mesh size control, it is ensured that there are at least 6 units within the range of the minimum wavelength (assumed to be 6.67 mm, corresponding to the propagation of 500 Hz sound waves in the air), that is, the side length of the largest unit is less than 1.11 mm, to ensure the accuracy of acoustic calculations, especially in the high-frequency region, the unit size is appropriately reduced to improve the calculation accuracy.

[0094] In some of these applications, the following factors are used to improve the calculation accuracy: the wall characteristics of each key component, including the thickness, material and surface treatment of the wall; air damping, including simulation based on actual airflow conditions; filter element material characteristics, including flow resistivity and porosity; and simulation of actual or near-actual conditions by defining the sound absorption properties of the material, including the sound absorption coefficient of the wall and the damping characteristics of the material.

[0095] It is understandable that the key components of the intake system are measured with high precision, including the thickness, material and surface treatment of the wall. For example, the wall thickness of the intake duct is measured to be 1.05mm using a micron-level precision caliper, and the material is determined to be 6061 aluminum alloy using a spectrometer, the surface treatment is anodized, and the surface roughness is 0.8μm.

[0096] The wall thickness of the air filter was measured to be 2.5 mm, the material was polypropylene, the surface was smooth, and the surface roughness was 0.4 μm.

[0097] According to the actual airflow conditions, the influence of air damping on the propagation of sound waves is simulated. The airflow velocity is set to 60m / s and the temperature is set to 25℃. The process of airflow passing through the intake system is simulated in the simulation software, and the viscous resistance and turbulence effect of the airflow are considered.

[0098] The airflow velocity field and pressure field are simulated, and the air damping coefficient is calculated. For example, for a specific airflow condition, the air damping coefficient is set to 0.02 kg / m·s.

[0099] The flow resistance and porosity of the filter element are accurately measured. The flow resistance of the filter element measured by the flow resistance tester is 50kPa·s / m 2 , the porosity is 90%.

[0100] Define the sound absorption properties of the material, including the sound absorption coefficient of the wall and the damping characteristics of the material to simulate actual or nearly actual conditions.

[0101] For 6061 aluminum alloy, the sound absorption coefficient is set to 0.2 and the damping ratio is set to 0.05; for polypropylene, the sound absorption coefficient is set to 0.15 and the damping ratio is set to 0.03.

[0102] S104, performing acoustic calculation based on the finite element model to obtain a corresponding calculated transmission loss value, and analyzing the transmission loss of the intake system according to the transmission loss value.

[0103] It can be understood that this step performs acoustic calculations based on the finite element model and performs transmission loss analysis based on the calculation results.

[0104] In some of these applications, acoustic calculations are performed based on finite element models to obtain corresponding calculated transmission loss values. In the analysis of the transmission loss of the intake system, finite element acoustic calculations are performed on the finite element model based on Hypermesh / Virtua l Lab to obtain the transmission loss values. The transmission loss values ​​are analyzed and the transmission loss values ​​at different frequencies are compared to evaluate the sound absorption performance of the structure.

[0105] It is understandable that the Hypermesh software is started, and the 3D structural model of the intake system after acoustic cavity extraction and simplification is imported. Mesh division is performed in Hypermesh, tetrahedral mesh is selected, and the mesh size is set. For example, for the straight pipe part of the intake duct, the mesh size is set to 2mm; for areas with complex acoustic characteristics such as air filters and mufflers, the mesh size is set to 0.5mm.

[0106] Export the model to Virtual Lab software and set the acoustic analysis parameters. Define the frequency range of the sound wave as 100 Hz to 800 Hz, scan with a step of 10 Hz, set the sound source position at the entrance of the intake duct, and set the acoustic boundary condition to no reflection.

[0107] Run an acoustic calculation in Virtual Lab to obtain transmission loss values ​​at different frequencies. The transmission loss value indicates the degree of attenuation of sound waves when passing through the intake system, and the unit is decibel (dB).

[0108] For example, for sound waves of 100 Hz, 200 Hz, 400 Hz, and 800 Hz, the transmission loss values ​​are obtained respectively. After the calculation is completed, the transmission loss data at each frequency point is collected.

[0109] The obtained transmission loss value is analyzed to evaluate the noise reduction performance of the intake system. The larger the transmission loss value, the stronger the noise reduction performance of the structure.

[0110] For example, if the transmission loss value at 100 Hz is 15 dB, and the transmission loss value at 200 Hz is 25 dB, it means that the sound absorption performance of the structure is better at 200 Hz.

[0111] The transmission loss values ​​at different frequencies are compared to evaluate the sound absorption performance of the structure in different frequency ranges.

[0112] For example, if the transmission loss values ​​are low in the low-frequency range and high in the high-frequency range, this indicates that the structure is better at attenuating high-frequency sound waves.

[0113] Based on the analysis results of the transmission loss value, optimization suggestions are made. For example, if the low-frequency transmission loss value is low, the length of the muffler can be increased or its internal structure can be changed to improve the low-frequency muffler performance.

[0114] For example, the air intake system includes the following components:

[0115] Inlet pipe: diameter 100mm, length 500mm;

[0116] Air filter: diameter 200mm, height 300mm;

[0117] Filter element: diameter 180mm, height 250mm;

[0118] Muffler: diameter 150mm, length 400mm.

[0119] When performing acoustic calculations, the model was first meshed in Hypermesh, and a mesh size of 1 mm was selected to ensure the accuracy of the model and the efficiency of the calculation. In Virtua Lab, the frequency range of the sound wave was set to 100 Hz to 800 Hz, the sound source position was set at the entrance of the intake duct, and the acoustic boundary condition was set to no reflection.

[0120] After running the acoustic calculation, obtain the transmission loss values ​​at different frequencies. For example, the following results are obtained:

[0121] The transmission loss value at 100Hz is 15dB;

[0122] The transmission loss value at 200Hz is 25dB;

[0123] The transmission loss value at 400Hz is 30dB;

[0124] The transmission loss value at 800Hz is 35dB.

[0125] The noise reduction performance of the intake system is evaluated by analyzing the transmission loss value. As the frequency increases, the transmission loss value also increases, indicating that the structure has a better noise reduction effect on high-frequency sound waves. In particular, at 800Hz, the transmission loss value reaches 35dB, indicating that the structure has good noise reduction performance at high frequencies.

[0126] By comparing the transmission loss values ​​at different frequencies, the noise reduction performance of the structure in different frequency ranges can be evaluated, and the design optimization can be carried out accordingly to improve the overall acoustic performance of the intake system. For example, if the transmission loss value is found to be low in the low-frequency range, the length of the muffler can be increased or its internal structure can be changed, such as adding baffles or adjusting the baffle angle, to improve the low-frequency noise reduction performance.

[0127] Combine the following Figure 2 and Figure 3 The following describes an embodiment of an intake system transmission loss analysis method of the present invention in some applications:

[0128] like Figure 2 As shown, this application can use Hypermesh / Virtua l Lab software to complete simulation modeling, solving and post-processing.

[0129] First, obtain the three-dimensional model of the intake system to prepare for simulation analysis. The collected data includes: intake pipe, air filter and filter element, clean pipe, muffler and other structures. Check the above data to ensure its accuracy.

[0130] Secondly, the intake system acoustic cavity extraction and model simplification. The specific principles are as follows:

[0131] 1. Support plates or grids that do not hinder the gas flow direction can be removed when simplifying the model;

[0132] 2. Structural features that are too small relative to the overall structure of the model can be deleted;

[0133] 3. Blind holes and blind tubes in the structure can be removed when their length is too small or their total volume is too small;

[0134] 4. Protrusions in the structure should be removed unless the total volume is too large;

[0135] 5. The structure that affects the quality of the grid should be removed or adjusted. In addition, in the air intake system, the filter material has a certain noise reduction effect in the medium and high frequencies, so it cannot be ignored. When processing the model, the filter model area needs to be pre-divided;

[0136] Next, a finite element model is established. In this application, the finite element model can accurately simulate the actual sound propagation process. Modeling is done using tetrahedral meshes, and different groups are established according to material properties. The unit size is limited by the analysis frequency. The specific requirement for the mesh size during acoustic simulation is that there must be at least 6 units within the minimum wavelength range, that is, the side length of the largest unit must be less than 1 / 6 of the shortest wavelength, that is, the unit length L should satisfy

[0137]

[0138] In the formula,

[0139] c is the fluid sound velocity;

[0140] f max is the highest frequency calculated.

[0141] This application explains the key factors that affect transmission loss accuracy:

[0142] 1. This application aims to solve the problem of insufficient simulation accuracy of transmission loss when the intake system is large in size and complex in structure. It proposes that the air damping inside the acoustic cavity should be considered during calculation. Different air damping needs to be set for structures of different sizes.

[0143] 2. This application is aimed at calculating the sound absorption performance of air filter elements, and requires the establishment of material properties to simulate the actual sound absorption situation. There are two main parameters, one is the flow resistivity, which needs to be obtained by actual testing or simulation calculation, and the other is the porosity. The porosity of different structures is also different. The porosity of air filter elements is basically above 90%.

[0144] like Figure 3As shown in the figure, through the comparison of actual cases, the influence of air damping inside the sound cavity and the sound absorption performance of the air filter element on the simulation accuracy is explained. The peak frequency of the loss result of the intake system measured in the experiment is 596Hz, corresponding to an amplitude of 43.4dB. Considering the above two factors, simulation calculations are carried out in turn.

[0145] 1. When both factors are not considered, the simulation results are very different from the test results. The peak frequency is bifurcated, the amplitude reaches 75.2dB, and the simulation deviation is 42.3%.

[0146] 2. When considering air damping, the simulation peak frequency is 590 Hz, the simulation deviation is 1.01%, the amplitude is 48.4 dB, and the simulation deviation is 10.33%;

[0147] 3. When considering air damping and air filter element, the simulation peak frequency is 584 Hz, the simulation deviation is 2.05%, the amplitude is 42.5 dB, and the simulation deviation is 2.12%.

[0148] Finally, submit the calculation and result analysis. Considering that the intake noise is mainly concentrated in the low and medium frequency range, the analysis frequency range can be set to 10-800Hz. For the frequency band of key concern, the frequency interval can be set to 2Hz, and the frequency interval of non-key frequency bands can be set separately. The calculation results include transmission loss, sound pressure level at each frequency, etc. When the transmission loss value is ≥20dB, the structure has good noise reduction performance.

[0149] For the method steps disclosed in the above embodiments, the method steps are described as a series of action combinations for the purpose of simple description, but those skilled in the art should know that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0150] like Figure 4 As shown, the present invention also provides an intake system transmission loss analysis system, comprising:

[0151] A structural model building module 201 is configured to build a three-dimensional structural model of the intake system, wherein the three-dimensional structural model includes various key components of the intake system, and each of the key components is determined based on actual simulation;

[0152] A structural model simplification module 202, configured to perform acoustic cavity extraction and corresponding simplification on the three-dimensional structural model to optimize mesh quality and improve the accuracy of the three-dimensional structural model;

[0153] A finite element model building module 203 is configured to build a finite element model, wherein the finite element model is modeled using a tetrahedral mesh and different groups are established according to material properties;

[0154] The transmission loss analysis module 204 is configured to perform acoustic calculation based on the finite element model to obtain a corresponding calculated transmission loss value, and analyze the transmission loss of the intake system according to the transmission loss value.

[0155] It is worth noting that although only some basic functional modules are disclosed in the embodiments of the present invention, it does not mean that the composition of the present system is limited to the above basic functional modules. On the contrary, what the present embodiment wants to express is that on the basis of the above basic functional modules, those skilled in the art can arbitrarily add one or more functional modules in combination with the prior art to form an infinite number of embodiments or technical solutions. In other words, the present system is open rather than closed. Just because the present embodiment only discloses individual basic functional modules, it cannot be considered that the protection scope of the claims of the present invention is limited to the disclosed basic functional modules. At the same time, for the convenience of description, the above devices are described in terms of functions and are described separately in various units and modules. Of course, when implementing the present invention, the functions of each unit and module can be implemented in the same or one or more software and / or hardware.

[0156] like Figure 5 As shown, the present invention also provides an electronic device, comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the intake system transmission loss analysis method.

[0157] Figure 5 Schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Figure 5 The electronic device provided in the embodiment of the present invention includes: one or more processors 710 and a storage device 720; the processor 710 in the electronic device may be one or more, Figure 5 A processor 710 is taken as an example; the storage device 720 is used to store one or more programs; the one or more programs are executed by the one or more processors 710, so that the one or more processors 710 implement the intake system transmission loss analysis method as described in any one of the embodiments of the present invention.

[0158] The electronic device may further include: an input device 730 and an output device 740 .

[0159] The processor 710, storage device 720, input device 730 and output device 740 in the electronic device can be connected via a bus or other means. Figure 5 The example of connecting through bus is taken in the following.

[0160] The storage device 720 in the electronic device is a computer-readable storage medium that can be used to store one or more programs, which can be software programs, computer executable programs and modules, such as program instructions / modules corresponding to the air intake system transmission loss analysis method provided in the embodiment of the present invention. The processor 710 executes various functional applications and data processing of the electronic device by running the software programs, instructions and modules stored in the storage device 720, that is, the air intake system transmission loss analysis method in the above method embodiment is implemented.

[0161] The storage device 720 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the electronic device, etc. In addition, the storage device 720 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the storage device 720 may further include a memory remotely arranged relative to the processor 710, and these remote memories may be connected to the device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0162] The input device 730 may be used to receive input digital or character information and generate key signal input related to user settings and function control of the electronic device. The output device 740 may include a display device such as a display screen.

[0163] The present invention also provides a computer-readable storage medium storing a computer program executable by an electronic device. When the computer program runs on the electronic device, the electronic device executes the steps of the intake system transmission loss analysis method.

[0164] Specifically, the computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer 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. In the present embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0165] The present invention also provides an air intake system transmission loss analysis terminal, wherein the terminal is provided with the air intake system transmission loss analysis system as described above.

[0166] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for analyzing transmission loss of an intake system, characterized in that: include: Constructing a three-dimensional structural model of the air intake system, wherein the three-dimensional structural model includes various key components of the air intake system, and each of the key components is determined based on actual simulation; Performing acoustic cavity extraction and corresponding simplification on the three-dimensional structural model to optimize mesh quality and improve the accuracy of the three-dimensional structural model; Establishing a finite element model, wherein the finite element model is modeled using a tetrahedral mesh, and different groups are established according to material properties; Acoustic calculation is performed based on the finite element model to obtain a corresponding calculated transmission loss value, and the transmission loss of the intake system is analyzed according to the transmission loss value.

2. The air intake system transmission loss analysis method according to claim 1, characterized in that: Constructing a three-dimensional structural model of the air intake system, wherein the three-dimensional structural model includes various key components of the air intake system, and each of the key components is determined based on actual simulation, further comprising: Acquire structural data of each of the key components of the air intake system, and record geometric dimensions and material properties of each of the key components; Verifying the obtained geometric dimensions and material properties of the key components to ensure that each of the key components is consistent with the actual ones; Determining the entire or partial structure of the intake system as a calculation model includes determining boundary conditions and connection relationships of the three-dimensional structural model, and simulating the airflow dynamics under actual working conditions so that the three-dimensional structural model can reflect the working state of the intake system.

3. The air intake system transmission loss analysis method according to claim 1, characterized in that: Extracting the acoustic cavity and simplifying the three-dimensional structure model accordingly to optimize the mesh quality and improve the accuracy of the three-dimensional structure model further includes: The surface formed by the air inside the intake system is retained, and the surface not involving the gas flow is deleted to ensure the accuracy and calculation efficiency of the three-dimensional structure model and reduce unnecessary calculation load; Simplifying the three-dimensional structural model, including removing support plates or grid plates that do not hinder the gas flow direction; Deleting structural features within a preset range that are smaller than the overall structural size of the three-dimensional structural model; The structures that affect the mesh quality are removed or adjusted so that the three-dimensional structural model can reduce the computational complexity while maintaining the necessary physical properties.

4. The air intake system transmission loss analysis method according to claim 1, characterized in that: Establishing a finite element model, wherein the finite element model is modeled using a tetrahedral mesh, and different groups are established according to material properties, further comprising: Use tetrahedral meshes for modeling, and adaptively select mesh density and type to reduce model complexity and balance computing resources; Different groups are established according to material properties to simulate the influence of different materials on sound wave propagation, including density, elastic modulus and damping characteristics of different materials, so that the model can accurately reflect the influence of material properties on acoustic performance; The grid has at least 6 units within the minimum wavelength range, that is, the side length of the largest unit is less than 1 / 6 of the shortest wavelength.

5. The air intake system transmission loss analysis method according to claim 4, characterized in that: Also includes: The calculation accuracy is improved based on the following factors: Wall characteristics of each key component, including wall thickness, material and surface treatment; Air damping, including simulation based on actual airflow conditions; Filter material properties, including resistivity and porosity; The sound absorption properties of the material are defined to simulate actual or nearly actual situations, including the sound absorption coefficient of the wall and the damping characteristics of the material.

6. The air intake system transmission loss analysis method according to claim 1, characterized in that: Performing acoustic calculation based on the finite element model to obtain a corresponding calculated transmission loss value, and analyzing the transmission loss of the intake system according to the transmission loss value, further includes: Performing finite element acoustic calculation on the finite element model based on Hypermesh / Virtual Lab to obtain a transmission loss value; The transmission loss values ​​are analyzed and the transmission loss values ​​at different frequencies are compared to evaluate the sound absorption performance of the structure.

7. An intake system transmission loss analysis system, characterized in that: include: A structural model building module, configured to build a three-dimensional structural model of the intake system, wherein the three-dimensional structural model includes various key components of the intake system, and each of the key components is determined based on actual simulation; A structural model simplification module, configured to perform acoustic cavity extraction and corresponding simplification on the three-dimensional structural model to optimize mesh quality and improve the accuracy of the three-dimensional structural model; A finite element model building module is configured to build a finite element model, wherein the finite element model is modeled using a tetrahedral mesh and different groups are established according to material properties; The transmission loss analysis module is configured to perform acoustic calculation based on the finite element model to obtain a corresponding calculated transmission loss value, and analyze the transmission loss of the intake system according to the transmission loss value.

8. An electronic device, characterized in that: include: A processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the method described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: It stores a computer program executable by an electronic device, and when the computer program runs on the electronic device, the electronic device executes the steps of the method described in any one of claims 1 to 6.

10. An intake system transmission loss analysis terminal, characterized in that: The terminal is provided with the intake system transmission loss analysis system as claimed in claim 7.

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