A vehicle wind noise analysis method, system and storage medium

Abstract

The present invention relates to a vehicle wind noise analysis method, system and storage medium, wherein the wind noise analysis method includes: taking the part to be evaluated located on the outside of the vehicle as the excitation part, performing NTF analysis on the full interior body model to obtain the noise transfer function corresponding to the response point in the vehicle; performing transient external flow field analysis on the whole vehicle model, and extracting the flow field load function of the part to be evaluated; obtaining the in-vehicle noise prediction function according to the flow field load function and the noise transfer function that meets the transfer risk condition; judging whether the in-vehicle noise function meets the noise risk condition; if so, the part to be evaluated is evaluated as a high-risk noise part; otherwise, the part to be evaluated is evaluated as a low-risk noise part. Compared with the analysis by the SNGR method, it is applicable to the wind noise analysis of low-frequency noise, provides a wind noise analysis method with higher wind noise analysis accuracy in the low-frequency range, and can realize the simulation of wind noise analysis, reducing the cost of wind noise analysis.

Description

Technical Field

[0001] The present invention relates to the field of automobile engineering, and in particular to a vehicle wind noise analysis method, system and storage medium. Background Art

[0002] At present, in order to improve the driving comfort of the vehicle, the vehicle noise will be analyzed in detail so as to optimize the noise risk parts and reduce the noise inside the vehicle. Among them, wind noise is a source of vehicle noise, especially when the vehicle is driving at high speed, the wind noise of the vehicle is particularly prominent.

[0003] In related technologies, the SNGR (Stochastic Noise Generation And Radiation) method is often used to analyze vehicle wind noise. It uses the velocity and turbulent kinetic energy distribution characteristics of the time-averaged flow field calculated by Reynolds Average Navier-Stokes (RANS) and re-synthesizes the flow field data containing the time term by adding random perturbations, thereby identifying the Lighthill volume source from the RANS results.

[0004] However, SNGR has some missing information at low frequencies, making it difficult to accurately capture low-frequency results. The current SNGR method has low accuracy in wind noise analysis for low-frequency noise. Summary of the invention

[0005] The embodiments of the present invention provide a vehicle wind noise analysis method, system and storage medium to solve the problem of low accuracy of low-frequency wind noise analysis in the related art.

[0006] In a first aspect, a vehicle wind noise analysis method is provided, which includes: taking a part to be evaluated located on the outside of the vehicle as an excitation part, performing NTF analysis on a full interior body model to obtain a noise transfer function corresponding to a response point inside the vehicle; performing a transient external flow field analysis on the whole vehicle model, and extracting a flow field load function of the part to be evaluated; obtaining an in-vehicle noise prediction function based on the flow field load function and a noise transfer function that meets a transfer risk condition; judging whether the in-vehicle noise function meets a noise risk condition; if so, the part to be evaluated is evaluated as a high-risk noise part; otherwise, the part to be evaluated is evaluated as a low-risk noise part.

[0007] In some embodiments, before performing the transient external flow field analysis on the whole vehicle model, it also includes: determining whether there is at least one noise transfer function that satisfies the transfer risk condition; if not, the part to be evaluated is evaluated as a low-risk noise part; if so, continuing to perform the transient external flow field analysis on the whole vehicle model.

[0008] In some embodiments, the transmission risk condition is that an extreme value greater than a first sound intensity exists within a frequency range less than a first frequency.

[0009] In some embodiments, the part to be evaluated located on the outside of the vehicle is used as an excitation part, and an NTF analysis is performed on the full interior body model to obtain the noise transfer function, which includes: setting the excitation position in the stiffness weak area of ​​the part to be evaluated; setting the response point in a preset ear area; loading the excitation at the excitation position to perform NTF analysis on the full interior body model; and obtaining the noise transfer function corresponding to the preset ear area.

[0010] In some embodiments, the noise risk condition is that a difference between two adjacent extreme values ​​within a range less than the second frequency is greater than a first threshold.

[0011] In some embodiments, after the part to be evaluated is a high-risk noise part, the method further includes evaluating the noise risk frequency of the part to be evaluated as a frequency corresponding to a maximum value of two adjacent extreme values ​​of the extreme value difference that meet the noise risk condition.

[0012] In some embodiments, obtaining the in-vehicle noise prediction function based on the flow field load function and the noise transfer function that satisfies the transfer risk condition includes: multiplying the noise transfer function with the flow field load function to obtain a first function, and subtracting a calibration function from the first function to obtain the in-vehicle noise prediction function.

[0013] In some embodiments, before performing NTF analysis on the full interior vehicle body model, the wind noise analysis method further includes: selecting parts located on the outside of the vehicle and having a first-order local mode lower than a preset frequency as parts to be evaluated.

[0014] In a second aspect, a wind noise analysis system is provided, which includes: an NTF module, wherein the NTF module is used to perform NTF analysis on a full interior body model with a part to be evaluated located on the outside of the vehicle as an excitation part to obtain a noise transfer function; a flow field load module, wherein the flow field load module is used to perform a transient external flow field analysis on the whole vehicle model and extract the flow field load function of the part to be evaluated; an in-vehicle noise prediction module, wherein the in-vehicle noise prediction module is used to obtain an in-vehicle noise prediction function based on the flow field load function and a noise transfer function that meets a transfer risk condition; and a risk assessment module, wherein when the in-vehicle noise prediction function meets the noise risk condition, the risk assessment module outputs that the part to be evaluated is a high-risk noise part, otherwise, the risk assessment module outputs that the part to be evaluated is a low-risk noise part.

[0015] In some embodiments, the risk assessment module also includes a pre-assessment module, which is used to determine whether there is at least one noise transfer function that meets the transfer risk condition before the in-vehicle noise prediction module calculates the in-vehicle noise prediction function; if not, the pre-assessment module assesses the part to be assessed as a low-risk noise part; if so, the flow field load module continues to perform transient external flow field analysis on the whole vehicle model.

[0016] In some embodiments, the transmission risk condition is that an extreme value greater than a first sound intensity exists within a frequency range less than a first frequency.

[0017] In some embodiments, the NTF module performs NTF analysis on the full interior vehicle body model, including: setting the excitation position in the stiffness weak area of ​​the part to be evaluated; setting the response point in a preset ear area; loading excitation at the excitation position to perform NTF analysis on the full interior vehicle body model; and obtaining the noise transfer function corresponding to the preset ear area.

[0018] In some embodiments, the noise risk condition is that a difference between two adjacent extreme values ​​within a range less than the second frequency is greater than a first threshold.

[0019] In some embodiments, after the risk assessment module assesses that the part to be assessed is a high-risk noise part, the risk assessment module is further used to assess the noise risk frequency of the part to be assessed as the frequency corresponding to the maximum value of two adjacent extreme values ​​of the extreme value difference that meet the noise risk condition.

[0020] In some embodiments, the in-vehicle noise prediction module multiplies the noise transfer function by the flow field load function to obtain a first function, and subtracts a calibration function from the first function to obtain an in-vehicle noise prediction function.

[0021] In some embodiments, the wind noise analysis system further includes a screening module, wherein the screening module is used to screen parts located outside the vehicle and having a first-order local mode lower than a preset frequency as parts to be evaluated.

[0022] In a third aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the above-mentioned wind noise analysis method.

[0023] The beneficial effects brought about by the technical solution provided by the present invention include:

[0024] The embodiment of the present invention provides a vehicle wind noise analysis method, system and storage medium. Since the part to be evaluated located outside the vehicle is set as an excitation part, the noise transfer function with the excitation part as the wind pressure area is obtained by loading the excitation on the excitation part. When the noise transfer function has a transmission risk, the noise transfer function is combined with the flow field load to obtain the vehicle interior noise function under the excitation of the part to be evaluated, and the wind noise evaluation result of the part is judged based on the part to be evaluated with the transmission risk. Compared with the analysis by the SNGR method, it can be applied to the wind noise analysis of low-frequency noise, and because the current NTF (Noise Transfer Function) analysis and transient external flow field analysis have high accuracy in the low-frequency range, the noise prediction function obtained by combining the analysis results of the two also maintains high accuracy in the low-frequency range, and the noise analysis accuracy in the low-frequency range is higher than that of the SNGR analysis. And the analysis process of this method can be carried out in the design stage, and the cost of wind tunnel testing is reduced by simulation calculation. Therefore, a wind noise analysis method with higher accuracy of wind noise analysis in the low-frequency range is provided, and simulation of wind noise analysis can be realized, reducing the cost of wind noise analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A flow chart of a vehicle wind noise analysis method provided by an embodiment of the present invention;

[0027] Figure 2 A flow chart of another vehicle wind noise analysis method provided by an embodiment of the present invention;

[0028] Figure 3 A flowchart of obtaining a noise transfer function through NTF analysis according to an embodiment of the present invention;

[0029] Figure 4 A structural block diagram of a vehicle wind noise analysis system provided by an embodiment of the present invention;

[0030] Figure 5 An example graph of a noise transfer function provided by an embodiment of the present invention;

[0031] Figure 6 An example graph of a flow field load function provided by an embodiment of the present invention;

[0032] Figure 7This is an example curve diagram of the in-vehicle noise prediction function provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The embodiments of the present invention provide a vehicle wind noise analysis method, system and storage medium, which can solve the problem of low accuracy of low-frequency wind noise analysis in related technologies.

[0035] In conjunction with the accompanying drawings, a vehicle wind noise analysis method, system and storage medium of the present application are described in detail below. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0036] See also Figure 1 As shown, a vehicle wind noise analysis method provided by an embodiment of the present invention includes the following steps: taking the part to be evaluated located on the outside of the vehicle as the excitation part, performing NTF analysis on the full interior body model to obtain the noise transfer function corresponding to the response point inside the vehicle; performing transient external flow field analysis on the whole vehicle model, and extracting the flow field load function of the part to be evaluated; obtaining the in-vehicle noise prediction function according to the flow field load function and the noise transfer function that meets the transfer risk condition; judging whether the in-vehicle noise function meets the noise risk condition; if so, the part to be evaluated is evaluated as a high-risk noise part; otherwise, the part to be evaluated is evaluated as a low-risk noise part.

[0037] In this embodiment, the full interior body model refers to the remaining part after removing the chassis and power system from the whole vehicle model. It is recommended to use Star cmm+ software for the transient external flow field analysis process. The main parameters of the steady-state flow field analysis are set as follows: grid setting, set 4mm encryption area in large glass and sheet metal areas such as the front windshield, side windows, ceiling, side door outer panels, etc.; K-Omega SST is used as the turbulence model; the number of iterations is 2000; the main parameters of the transient external flow field analysis are set as follows: analysis method: LES, K-Omega SST; physical time: 1 second; time step: e -5seconds; internal iteration: none; other: the first layer of the boundary layer is set to 0.006×surface mesh size, growth rate: 1.34, total number of layers: 16. After the calculation is completed, the transient flow field load of each grid node can be obtained, and the transient flow field load function of the part to be evaluated can be obtained by taking the distributed extraction and averaging method of the load extraction points of a single component.

[0038] Based on the more mature NTF analysis, the noise transfer function from the part to be evaluated to the response point inside the vehicle can be obtained, that is, the noise transfer function from the outside of the vehicle to the inside of the vehicle. Through the transient external flow field analysis, the flow field load that the part to be evaluated bears when the vehicle is driving at high speed can be obtained. The flow field load function is combined with the noise transfer function to obtain the noise prediction function of the part to be tested. Both the noise transfer function and the flow field load function are frequency-related functions. After combining the two, the in-vehicle noise prediction function with frequency as the independent variable can be obtained. The in-vehicle noise prediction function can be used to analyze how much noise the part to be tested will contribute to the vehicle during the driving process. Since the NTF analysis and transient external flow field analysis are relatively mature at present, high accuracy can be maintained in the low frequency range. The in-vehicle noise prediction function obtained based on NTF analysis and transient external flow field analysis can also maintain high simulation accuracy in the low frequency range. Compared with the SNGR analysis method, which has a large error within 200Hz, this method can have a higher accuracy within 200Hz. This method combines the acoustic transfer function and flow field excitation for comprehensive analysis, avoiding the situation where different evaluation conclusions are drawn from the acoustic transfer function alone or from the flow field excitation alone. At the same time, this solution is relatively simple, which simplifies the analysis process of low-frequency fluid-solid coupling problems. Compared with the current commercial analysis software with poor low-frequency accuracy, it provides a low-frequency wind noise analysis method with simple calculation and high accuracy.

[0039] At the same time, since this wind noise analysis method is based on the relatively mature NTF analysis and transient external flow field analysis, the wind noise of the vehicle can be analyzed during the vehicle design stage. Wind noise risks can be identified during the design stage, reducing the number of subsequent wind tunnel tests and the number of part modifications. This reduces the development cost of parts and the test cost of the vehicle.

[0040] See also Figure 1 As shown, in some embodiments, before performing transient external flow field analysis on the whole vehicle model, it also includes: determining whether there is at least one noise transfer function that satisfies the transfer risk condition; if not, the part to be evaluated is evaluated as a low-risk noise part; if so, continuing to perform transient external flow field analysis on the whole vehicle model.

[0041] That is to say, the noise risk of the part to be evaluated is preliminarily judged through the noise transfer function. If the risk of the part to be evaluated is judged to be small through the noise transfer function, no further in-vehicle noise prediction is performed to improve the efficiency of wind noise analysis. The in-vehicle noise prediction function of the part to be evaluated is calculated only when the part to be evaluated has a transfer risk. The in-vehicle noise prediction function combined with the flow field load function can more accurately determine whether the part to be evaluated does have a noise risk. Avoid the situation where a part is judged to have a wind noise risk based on the noise transfer function, but the part itself does not have a large flow field load and the actual noise is small. It is more reliable than judging the risk of the part to be evaluated through the noise transfer function alone. Reference Figure 5 As shown, it is determined whether there is a peak value less than the first frequency 150Hz among the peak values ​​of the noise transfer function curve that exceeds the first sound intensity by 70dB. If so, it can be determined that the part to be evaluated has a transmission risk. From the curve, it can be seen that there are five peak values ​​exceeding the first sound intensity within the range less than the first frequency. That is, the part to be evaluated that generates this noise transfer function has a transmission risk.

[0042] See also Figure 1 as well as Figure 2 As shown, in some optional embodiments, the transfer risk condition is that there is an extreme value greater than the first sound intensity within the range of frequency less than the first frequency. That is to say, only when the frequency is less than the first frequency and the sound intensity is greater than the extreme value of the first sound intensity, the noise transfer function is considered to meet the transfer risk. In this embodiment, the first frequency is 150Hz and the first sound intensity is 70dB. This data is empirical data accumulated and determined by a large number of development models. Parts to be evaluated with risks can be screened out. In other embodiments, the first frequency and the first sound intensity can be adjusted accordingly according to the vehicle's requirements for noise.

[0043] In some embodiments, the parts to be evaluated that generate a peak value greater than 70 dB based on the noise transfer function of the front response point in the vehicle or the rear noise are also considered to meet the transfer risk.

[0044] See also Figures 1 to 3 As shown, in some optional embodiments, the part to be evaluated located on the outside of the vehicle is used as an excitation part, and an NTF analysis is performed on the full interior body model to obtain the noise transfer function, including: setting the excitation position in the stiffness weak area of ​​the part to be evaluated; setting the response point in a preset ear area; loading the excitation at the excitation position to perform NTF analysis on the full interior body model; and obtaining the noise transfer function corresponding to the preset ear area.

[0045] By setting the excitation position at the weak stiffness area of ​​the part to be evaluated, the noise transfer function closer to the wind noise generation area can be measured. In this embodiment, the weak stiffness area of ​​the part to be evaluated is determined based on experience. For example, for the front windshield, the weak stiffness area is at the geometric center of the front windshield and the center point of the upper edge of the front windshield. In other embodiments, the weak stiffness area of ​​the part to be evaluated can also be determined based on the stiffness simulation results.

[0046] The response point is set in the preset ear area to obtain the noise transfer function from the excitation position to the ear area. The ear area is determined based on the vehicle seat position and the human body model. In this embodiment, it is necessary to set multiple response points for the same part to be evaluated, including the outer ear position of the driver, the inner ear position, the inner ear position of the co-driver, the outer ear position of the left rear seat passenger, and the outer ear position of the right rear seat passenger. Each response point will correspond to a noise transfer function. By setting the response point in the preset ear area, the actual sound transmission route can be simulated to obtain a more accurate noise transfer function. The position and number of the response points can be adjusted according to the number of seats and the seat position of the vehicle. So as to evaluate the vehicle more closely.

[0047] In some optional embodiments, the noise risk condition is that the difference between two adjacent extreme values ​​within a range less than the second frequency is greater than the first threshold. By calculating the difference between adjacent extreme values, the change value of the predicted noise can be determined when the frequency changes in a small range. Compared with the simple noise value, the human body is more sensitive to the change of noise. The judgment based on the extreme value difference is more in line with the human body's tolerance for noise. In this embodiment, when the extreme value difference between two adjacent extreme values ​​reaches 500, it is judged that the human body can obviously identify the noise. In other embodiments, the first threshold can be adjusted according to the vehicle's requirements for noise. Since the in-vehicle noise prediction function in this application is obtained based on the noise transfer function and the flow field load, its main part is the wind noise of the vehicle. The vehicle not only has wind noise, but also generates noise under road excitation. The frequency of the road excitation is a high-frequency band excitation, and the main noise source of the vehicle in the low-frequency band is wind noise. By limiting the evaluation of the wind noise risk of the vehicle within the second frequency range, a higher accuracy can be guaranteed, and other methods can be used to evaluate the wind noise greater than the second frequency range.

[0048] See also Figure 7 It can be seen that the in-vehicle noise prediction function can generate an in-vehicle noise prediction curve, and the visualized curve can be used to intuitively analyze whether there is an extreme value difference that meets the noise risk. Figure 7 The curve shown in has a case where the extreme value difference between adjacent extreme values ​​is greater than 500, that is, the part to be evaluated corresponding to the curve is a high-risk wind noise part.

[0049] In some optional embodiments, after the part to be evaluated is a high-risk noise part, the method further includes evaluating the noise risk frequency of the part to be evaluated as the frequency corresponding to the maximum value of two adjacent extreme values ​​of the extreme value difference that meet the noise risk condition. Figure 7 It can be seen that the circled area is the maximum value of two adjacent extreme values ​​that meet the extreme value difference, which indicates that at this frequency, it will produce noise that is more obvious than the difference between adjacent frequencies, that is, this frequency is the noise risk frequency where noise risk occurs. In this embodiment, the noise risk frequency is 67.5Hz. Obtaining the noise risk frequency of the part to be evaluated can be used to guide the improved design of the part to better avoid noise risks.

[0050] In some optional embodiments, the step of obtaining the in-vehicle noise prediction function according to the flow field load function and the noise transfer function satisfying the transfer risk condition comprises: multiplying the noise transfer function with the flow field load function to obtain a first function, and subtracting a calibration function from the first function to obtain the in-vehicle noise prediction function. The theoretical wind noise generated by the part in a wind field environment can be obtained by multiplying the noise transfer function with the flow field load function. The first function is calibrated in combination with the calibration function to reduce the error between the theoretical calculation and the actual wind noise.

[0051] The specific formula of the in-vehicle noise prediction function is:

[0052] Y result =x load ×NTF correct -10×factor A ;

[0053] where Y result is the prediction function of the noise inside the car;

[0054] x load is the flow field load function;

[0055] NTF correct is the correction function of the noise transfer function;

[0056] 10×factor A is the calibration function.

[0057] Among them, NTF correct =(NTF m-2 +NTF m-1 +NTF m +NTF m+1 +NTF m+2 ) / 5;

[0058] NTF here m-2 、NTF m-1 、NTF m 、NTFm+1 、NTF m+2 For the noise transfer functions corresponding to different response points, since in this embodiment, each part to be evaluated has five response points of noise transfer functions, the noise transfer functions of multiple response points are added and then divided by five to obtain the average. The correction function of the noise transfer function of the part to be evaluated is obtained by taking the average of the noise transfer functions of all response points. In other embodiments, if the noise transfer functions of different numbers of response points are collected, the correction function of the noise transfer function of the part to be evaluated can be obtained by taking the average.

[0059] factor A The characteristic points can be seen in the following table:

[0060] Frequency Hz 18.0 22.5 27.0 31.5 36.0 40.5 45.0 49.5 54.0 58.5 63.0 67.5 factorA 37.9 36.7 35.5 34.4 33.2 32.0 30.8 29.7 28.5 27.3 26.1 25.0

[0061] The factor can be obtained by using the difference calculation of the above feature points A The functional form of , and then multiply it by ten to get the calibration function.

[0062] The calibration function in this embodiment is a calibration function obtained by summarizing the current data, and the calibration function can be further supplemented with calibration data to improve the calibration accuracy of the calibration function.

[0063] In some optional embodiments, before the NTF analysis of the full interior body model, the wind noise analysis method further includes: screening the parts located on the outside of the vehicle and whose first-order local modes are lower than the preset frequency as parts to be evaluated. Since the present application mainly analyzes wind noise in the low-frequency range, when the mode of the part is low-frequency, it is more likely to resonate under the action of low-frequency excitation, and the risk of generating low-frequency wind noise is greater. By screening the parts to be evaluated by the first-order local mode, the number of parts to be analyzed can be reduced and the efficiency of wind noise analysis can be improved. In this embodiment, the preset frequency is 200Hz.

[0064] In this embodiment, the first-order local mode of the part is analyzed by CAE simulation. In other embodiments, if the part is an existing production part with an inspection report, the first-order local mode of the part can also be directly obtained based on the inspection report. When the same part has multiple first-order local modes that are all less than the preset frequency, each area of ​​the part that meets the requirements is divided into a separate analysis unit. For example, after analysis, it is found that the first-order local modes of the upper, middle and lower parts of the front windshield are all less than the preset frequency. The upper part of the front windshield is treated as a part to be evaluated for subsequent wind noise analysis. Similarly, the middle and lower parts of the front windshield are also analyzed as independent parts to be evaluated.

[0065] See also Figure 4As shown, a wind noise analysis system provided by an embodiment of the present invention includes: an NTF module, wherein the NTF module is used to perform NTF analysis on a full interior vehicle body model with a part to be evaluated located on the outside of the vehicle as an excitation part to obtain a noise transfer function; a flow field load module, wherein the flow field load module is used to perform transient external flow field analysis on the whole vehicle model and extract the flow field load function of the part to be evaluated; an in-vehicle noise prediction module, wherein the in-vehicle noise prediction module is used to obtain an in-vehicle noise prediction function according to the flow field load function and a noise transfer function that meets the transfer risk condition; and a risk assessment module, wherein when the in-vehicle noise prediction function meets the noise risk condition, the risk assessment module outputs that the part to be evaluated is a high-risk noise part, otherwise, the risk assessment module outputs that the part to be evaluated is a low-risk noise part.

[0066] Based on the more mature NTF analysis, the noise transfer function from the part to be evaluated to the response point inside the vehicle can be obtained, that is, the noise transfer function from the outside of the vehicle to the inside of the vehicle. Through the transient external flow field analysis, the flow field load that the part to be evaluated bears when the vehicle is driving at high speed can be obtained. The flow field load function is combined with the noise transfer function to obtain the noise prediction function of the part to be tested. Both the noise transfer function and the flow field load function are frequency-related functions. After combining the two, the in-vehicle noise prediction function with frequency as the independent variable can be obtained. The in-vehicle noise prediction function can be used to analyze how much noise the part to be tested will contribute to the vehicle during the driving process. Since the NTF analysis and transient external flow field analysis are relatively mature at present, high accuracy can also be maintained in the low frequency range. The noise prediction function obtained based on NTF analysis and transient external flow field analysis can also maintain high simulation accuracy in the low frequency range. Compared with the SNGR analysis method, which has a large error within 200Hz, this method can have a higher accuracy within 200Hz. This method combines the acoustic transfer function and flow field excitation for comprehensive analysis, avoiding the situation where different evaluation conclusions are drawn from the acoustic transfer function alone or from the flow field excitation alone. This solution is relatively simple, which simplifies the analysis process of low-frequency fluid-solid coupling problems. Compared with the current commercial analysis software with poor low-frequency accuracy, it provides a low-frequency wind noise analysis method with simple calculation and high accuracy.

[0067] At the same time, since this wind noise analysis method is based on the relatively mature NTF analysis and transient external flow field analysis, the wind noise of the vehicle can be analyzed during the vehicle design stage. Wind noise risks can be identified during the design stage, reducing the number of subsequent wind tunnel tests and the number of part modifications. This reduces the development cost of parts and the test cost of the vehicle.

[0068] In some embodiments, the risk assessment module also includes a pre-assessment module, which is used to determine whether there is at least one noise transfer function that meets the transfer risk condition before the in-vehicle noise prediction module calculates the in-vehicle noise prediction function; if not, the pre-assessment module assesses the part to be assessed as a low-risk noise part; if so, the flow field load module continues to perform transient external flow field analysis on the whole vehicle model. In other words, the noise risk of the part to be assessed is first preliminarily judged by the noise transfer function. If the risk of the part to be assessed is judged to be small through the noise transfer function, no further subsequent in-vehicle noise prediction is performed, thereby improving the efficiency of wind noise analysis. The in-vehicle noise prediction function of the part to be assessed is calculated only when the part to be assessed has a transfer risk. The in-vehicle noise prediction function combined with the flow field load function can more accurately determine whether the part to be assessed does have a noise risk. Avoid the situation where the actual noise is small because the part is judged to have a wind noise risk based on the noise transfer function, but the part itself does not have a large flow field load. It is more reliable than judging the risk of the part to be assessed by the noise transfer function alone. Reference Figure 5 As shown, it is determined whether there is a peak value less than the first frequency 150Hz among the peak values ​​of the noise transfer function curve that exceeds the first sound intensity by 70dB. If so, it can be determined that the part to be evaluated has a transmission risk. From the curve, it can be seen that there are five peak values ​​exceeding the first sound intensity within the range less than the first frequency. That is, the part to be evaluated that generates this noise transfer function has a transmission risk.

[0069] In some embodiments, the transmission risk condition is that an extreme value greater than a first sound intensity exists within a frequency range less than a first frequency.

[0070] In some embodiments, the NTF module performs NTF analysis on the full interior vehicle body model, including: setting the excitation position in the stiffness weak area of ​​the part to be evaluated; setting the response point in a preset ear area; loading excitation at the excitation position to perform NTF analysis on the full interior vehicle body model; and obtaining the noise transfer function corresponding to the preset ear area.

[0071] In some embodiments, the noise risk condition is that a difference between two adjacent extreme values ​​within a range less than the second frequency is greater than a first threshold.

[0072] In some embodiments, after the risk assessment module assesses that the part to be assessed is a high-risk noise part, the risk assessment module is further used to assess the noise risk frequency of the part to be assessed as the frequency corresponding to the maximum value of two adjacent extreme values ​​of the extreme value difference that meet the noise risk condition.

[0073] In some embodiments, the in-vehicle noise prediction module multiplies the noise transfer function by the flow field load function to obtain a first function, and subtracts a calibration function from the first function to obtain an in-vehicle noise prediction function.

[0074] In some embodiments, the wind noise analysis system further includes a screening module, wherein the screening module is used to screen parts located outside the vehicle and having a first-order local mode lower than a preset frequency as parts to be evaluated.

[0075] In this embodiment, the wind noise analysis system is presented in the form of a module. The "module" here may refer to an application-specific integrated circuit (ASIC), a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions. The system disclosed above can be implemented in other ways. For example, the division of the unit is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The mutual coupling, direct coupling, or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0076] The embodiment of the present invention further provides a computer-readable storage medium, the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to perform the above-mentioned wind noise analysis method. Optionally, in this embodiment, the above-mentioned storage medium may be located in at least one network server among multiple network servers of a computer network. Optionally, in this embodiment, the above-mentioned storage medium may include but is not limited to: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0077] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0078] It should be noted that, in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article 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 process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0079] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for analyzing wind noise of a vehicle, characterized in that: It includes: Taking the part to be evaluated located on the outside of the vehicle as the excitation part, NTF analysis is performed on the full interior body model to obtain the noise transfer function corresponding to the response point inside the vehicle; Performing transient external flow field analysis on the vehicle model and extracting the flow field load function of the part to be evaluated; Obtaining a vehicle interior noise prediction function according to the flow field load function and a noise transfer function that satisfies a transfer risk condition; Determining whether the vehicle interior noise prediction function satisfies a noise risk condition, wherein the noise risk condition is that a difference between two adjacent extreme values ​​within a range less than a second frequency is greater than a first threshold; If yes, the part to be evaluated is evaluated as a high-risk noise part; Otherwise, the part to be evaluated is evaluated as a low-risk noise part; Wherein, obtaining the in-vehicle noise prediction function according to the flow field load function and the noise transfer function satisfying the transfer risk condition comprises: The noise transfer function is multiplied by the flow field load function to obtain a first function, and a calibration function is subtracted from the first function to obtain an in-vehicle noise prediction function.

2. The wind noise analysis method according to claim 1, characterized in that: Before the transient external flow field analysis is performed on the whole vehicle model, the method further includes: Determining whether there is at least one of the noise transfer functions that satisfies the transfer risk condition; If not, the part to be evaluated is evaluated as a low-risk noise part; If so, continue to perform transient external flow field analysis on the entire vehicle model.

3. The wind noise analysis method according to claim 1, characterized in that: The transmission risk condition is that an extreme value greater than a first sound intensity exists within a frequency range less than a first frequency.

4. The wind noise analysis method according to claim 1, characterized in that: The NTF analysis is performed on the full interior body model by taking the part to be evaluated located outside the vehicle as the excitation part to obtain the noise transfer function, which includes: Setting the excitation position at the stiffness weak area of ​​the part to be evaluated; Set the response point in the preset ear area; Loading excitation at the excitation position to perform NTF analysis on the full interior vehicle body model; A noise transfer function corresponding to a preset ear area is obtained.

5. The wind noise analysis method according to claim 1, characterized in that: After the part to be evaluated is a high-risk noise part, the method further includes evaluating the noise risk frequency of the part to be evaluated as a frequency corresponding to a maximum value of two adjacent extreme values ​​of an extreme value difference that satisfies a noise risk condition.

6. The wind noise analysis method according to claim 1, characterized in that: Before performing NTF analysis on the full interior vehicle body model, the wind noise analysis method further includes: Parts located outside the vehicle and with a first-order local mode below a preset frequency are screened as parts to be evaluated.

7. A wind noise analysis system, characterized in that: It includes: An NTF module, wherein the NTF module is used to perform NTF analysis on the full interior body model using the part to be evaluated located outside the vehicle as an excitation part to obtain a noise transfer function; A flow field load module, which is used to perform transient external flow field analysis on the vehicle model and extract the flow field load function of the part to be evaluated; An in-vehicle noise prediction module, the in-vehicle noise prediction module is used to obtain an in-vehicle noise prediction function according to the flow field load function and a noise transfer function that satisfies a transfer risk condition; a risk assessment module, wherein when the in-vehicle noise prediction function satisfies a noise risk condition, the risk assessment module outputs that the part to be assessed is a high-risk noise part; otherwise, the risk assessment module outputs that the part to be assessed is a low-risk noise part, and the noise risk condition is that a difference between two adjacent extreme values ​​within a range less than the second frequency is greater than a first threshold; The in-vehicle noise prediction module is further used for: The noise transfer function is multiplied by the flow field load function to obtain a first function, and a calibration function is subtracted from the first function to obtain an in-vehicle noise prediction function.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the wind noise analysis method according to any one of claims 1 to 6.

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