High-speed railway vehicle, low and medium frequency sound absorption apron board and design method of low and medium frequency sound absorption apron board

Abstract

The invention discloses a high-speed railway vehicle, a low and medium frequency sound absorption apron board and a design method thereof, and relates to the technical field of railway vehicles. The design method of the apron board comprises the steps that the target noise reduction amount, the total area and the radiation noise SWL of the inner surface of the apron board body and the sound absorption coefficient and the arrangement area S of the sound absorption panel are obtained; according to the total area of the inner surface of the apron board body, the sound absorption coefficient of the sound absorption panel and the arrangement area S, the sound absorption power A of the sound absorption panel is determined; according to the radiation noise SWL of the apron board body and the sound absorption power A of the sound absorption panel, the noise reduction amount NR of the sound absorption panel is determined; comparing the maximum value of the noise reduction amount NR of the sound absorption panel with a target noise reduction amount; if yes, the arrangement area S of the sound absorption panel meets the noise reduction requirement; and if the arrangement area S of the sound absorption panel does not meet the noise reduction requirement, the arrangement area S of the sound absorption panel is adjusted, and the design method can be used for manufacturing the low and medium frequency sound absorption apron board for reducing the low and medium frequency aerodynamic noise of the bogie.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail vehicles, and more particularly, to a high-speed rail vehicle, a middle-low frequency sound absorption skirt and a design method thereof. BACKGROUND

[0002] Rail transit is a main mode of transportation for passengers. During high-speed driving, the noise problem caused by the aerodynamics of the bogie gradually becomes one of the main factors affecting the surrounding residents and the environmental noise. Meanwhile, the aerodynamic noise of the bogie can be transmitted to the cabin through the vehicle body, causing the middle-low frequency noise problem in the cabin. In order to suppress the noise, the traditional bogie is usually provided with a skirt to locally straighten the bogie, thereby suppressing the aerodynamic noise of the bogie. The traditional skirt mainly has a straightening function and usually adopts a thin-walled structure, and its interior is typically supported by a mechanism. In the rail vehicle operating environment, the airflow pulsation caused by the rotation of the wheelset is reduced due to the straightening effect of the skirt, thereby effectively suppressing the noise. However, the aerodynamic noise caused by the rotation of the wheelset still exists. With the increase of the running speed of the high-speed rail vehicle, the middle-low frequency aerodynamic noise problem of the bogie is highlighted again.

[0003] In summary, how to reduce the middle-low frequency aerodynamic noise of the bogie is a problem to be solved by the technical personnel in the field. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a design method of a middle-low frequency sound absorption skirt, which can be used to manufacture a middle-low frequency sound absorption skirt capable of reducing the middle-low frequency aerodynamic noise of the bogie.

[0005] Another purpose of the present application is to provide a low frequency sound absorption skirt manufactured by using the above design method.

[0006] Still another purpose of the present application is to provide a high-speed rail vehicle comprising the above middle-low frequency sound absorption skirt.

[0007] In order to achieve the above purposes, the present application provides the following technical solutions:

[0008] A design method of a middle-low frequency sound absorption skirt, the middle-low frequency sound absorption skirt comprising a skirt body and a sound absorption panel, the sound absorption panel being laid on the inner surface of the skirt body;

[0009] The design method comprises:

[0010] obtaining a target noise reduction amount , the total area of the inner surface of the skirt body , the sound absorption coefficient of the sound absorption panel , the arrangement area S of the sound absorption panel, and the radiation noise SWL of the skirt body;

[0011] According to the sound absorption coefficient of the sound absorption panel , the total area of the inner surface of the apron body , the arrangement area S of the sound absorption panel, the sound absorption power A of the sound absorption panel is determined;

[0012] According to the radiation noise SWL of the apron body and the sound absorption power A of the sound absorption panel, the noise reduction amount NR of the sound absorption panel is determined;

[0013] The maximum value in the noise reduction amount NR of the sound absorption panel is compared with the target noise reduction amount ;

[0014] If , the arrangement area S of the sound absorption panel meets the noise reduction demand;

[0015] If , the arrangement area S of the sound absorption panel is adjusted, and the steps of determining the sound absorption power A of the sound absorption panel, determining the noise reduction amount NR of the sound absorption panel and comparing are repeated for the adjusted arrangement area S of the sound absorption panel until , or until the arrangement area S of the sound absorption panel is equal to the total area of the inner surface of the apron body .

[0016] Preferably, the target noise reduction amount is obtained , the total area of the inner surface of the apron body , the sound absorption coefficient of the sound absorption panel , the arrangement area S of the sound absorption panel, the radiation noise SWL of the apron body before

[0017] The configuration of the apron body is obtained;

[0018] The aerodynamic analysis is carried out for the configuration of the apron body, and the radiation noise SWL of the apron body and the target noise reduction amount of the sound absorption panel are determined according to the aerodynamic analysis result of the apron body ;

[0019] According to the aerodynamic analysis result of the apron body, the aerodynamic shape of the apron body is optimized, and the steps of determining the radiation noise SWL of the apron body, the target noise reduction amount of the sound absorption panel and optimizing the aerodynamic shape of the apron body are repeated for the optimized apron body, so that the radiation noise SWL of the apron body is reduced.

[0020] Preferably, the radiation noise SWL of the apron body is determined according to the aerodynamic analysis result of the apron body, comprising:

[0021] The curcle equation is obtained, and the sound source model of the apron body is determined according to the aerodynamic analysis result of the apron body and the curcle equation;

[0022] According to the sound source model of the apron body, an acoustic model of the apron body is determined to determine a radiation noise SWL of the apron body.

[0023] Preferably, the curcle equation is:

[0024] ;

[0025] In the formula, represents an equivalent quadrupole sound source;

[0026] represents an equivalent dipole sound source;

[0027] and is a partial derivative symbol;

[0028] is a surface tensor;

[0029] is a fluctuating pressure on the interface between the apron body and the gas;

[0030] is a normal direction of a unit grid;

[0031] is a distance between coordinate points.

[0032] Preferably, the radiation noise SWL is determined according to the following formula:

[0033] ;

[0034] ;

[0035] In the formula, K is a complex wave number, , w is an angular frequency, and c is a sound speed;

[0036] Ps is a sound pressure on the surface of the apron body;

[0037] is a gradient operator.

[0038] Preferably, the determination method of the aerodynamic analysis result is:

[0039] A model and a flow boundary of the apron body are obtained, and a computational fluid dynamics model of the apron body is determined according to the model and the flow boundary of the apron body;

[0040] An aerodynamic analysis result of the apron body is determined according to the computational fluid dynamics model of the apron body.

[0041] Preferably, the calculation method of the sound absorption power A of the sound absorption panel is:

[0042] ;

[0043] A is the sound absorption power of the sound absorption panel;

[0044] is the sound absorption coefficient of the sound absorption panel;

[0045] is the total area of the inner surface of the apron body;

[0046] S is the arrangement area of the sound absorption panel.

[0047] Preferably, the calculation method of the noise reduction amount NR of the sound absorption panel is:

[0048] ;

[0049] SWL is the radiation noise of the apron body;

[0050] A is the sound absorption power of the sound absorption panel.

[0051] Preferably, the optimization of the aerodynamic shape of the apron body comprises:

[0052] According to the aerodynamic analysis result of the apron body, the vortex separation serious position of the apron body is adjusted in shape to obtain the apron body after optimization;

[0053] and the steps of repeating the determination of the radiation noise SWL of the apron body, the target noise reduction amount NR of the sound absorption panel and the optimization of the aerodynamic shape of the apron body, comprising:

[0054] According to the aerodynamic analysis result of the apron body, it is determined whether the vortex of the apron body at the vortex separation serious position is weakened or enhanced;

[0055] If the vortex is weakened, the step of repeating the determination of the radiation noise SWL of the apron body is continued;

[0056] If the vortex is enhanced, the vortex separation serious position of the apron body is adjusted in shape again to optimize the configuration of the apron body, and then return to the optimization of the aerodynamic shape of the apron body.

[0057] A middle-low frequency sound absorption apron manufactured by the design method of any one of the above-mentioned middle-low frequency sound absorption aprons, the apron comprising:

[0058] an apron body;

[0059] a sound absorption panel, the sound absorption panel being laid on the inner surface of the apron body.

[0060] Preferably, the sound absorption panel comprises a plurality of sound absorption units, the plurality of sound absorption units are arranged in an array, and the sound absorption unit has a square frame structure, a sound absorption hole plate, and a throat pipe.

[0061] The square frame structure has a plurality of square resonant cavities arranged in an array.

[0062] The sound absorption hole plate is sealingly fitted to the first end of the square frame structure, and the sound absorption hole plate has a plurality of sound absorption holes arranged in an array.

[0063] A plurality of the throat pipes are sealingly fitted through the corresponding sound absorption holes, and a plurality of the throat pipes are inserted into the corresponding square resonant cavities, and the throat pipes communicate the external environment of the sound absorption unit and the corresponding square resonant cavities.

[0064] Preferably, 1 / 3 of the throat pipes in the sound absorption panel have a length of 38mm, and 2 / 3 of the throat pipes in the sound absorption panel have a length of 12mm.

[0065] The sound absorption panel has a thickness of 50mm at the second end of the square frame structure, the wall thickness of the square resonant cavity is 0.5mm, and the pipe diameter of the throat pipe is greater than or equal to 1.4mm.

[0066] Preferably, the square resonant cavities have rounded corners at the top corner positions, and in two adjacent rows of the square resonant cavities, the rounded corners of the square resonant cavities in one row are located at the middle positions of the side faces of the corresponding square resonant cavities in the other row.

[0067] Preferably, the apron comprises a plurality of sound absorption panels, and the gap between adjacent sound absorption panels ranges from 20mm to 50mm.

[0068] A high-speed rail vehicle comprises the low-frequency sound absorption apron according to any one of the above.

[0069] In this application, before the design, the target noise reduction amount is obtained by calling or externally inputting , the total area of the inner surface of the apron body , the sound absorption coefficient of the sound absorption panel , the arrangement area S of the sound absorption panel, the radiation noise SWL of the apron body, and other parameters, so as to prepare for the next step.

[0070] The total area of the inner surface of the apron body , the sound absorption coefficient of the sound absorption panel , and the arrangement area S of the sound absorption panel are used to calculate or simulate the sound absorption power A of the sound absorption panel, so as to prepare for the next step.

[0071] After the sound absorption power A of the sound absorption panel has been determined, where the sound absorption power A of the sound absorption panel refers to the portion of the radiated noise SWL of the skirt panel body that can be absorbed by the sound absorption panel, the noise reduction NR of the sound absorption panel that can be achieved by the current skirt panel design is determined by calculation using the two.

[0072] If the maximum noise reduction Does not meet the noise reduction requirements, that is When the sound absorption panel layout area is increased, the sound absorption power A of the sound absorption panel can be increased, and then the sound absorption power A of the sound absorption panel can be determined, and the process can be continued until the maximum noise reduction is compared. and target noise reduction amount The steps are then iterated and optimized until the layout area S of the sound absorbing panel meets the noise reduction requirements. In the process of increasing the layout area S of the sound absorbing panel, if Maximum noise reduction If the noise reduction requirements are still not met, the inner surface of the skirt body can be covered with sound-absorbing panels, or panels with different sound absorption coefficients can be replaced. sound-absorbing panels.

[0073] If the maximum noise reduction Meet the noise reduction requirements, that is When the current skirt design can fully meet the expected effect, the current sound absorption panel layout area S can be directly adopted. When the sound absorption panel is used, the layout area of ​​the sound absorption panel can be reduced, and the steps of determining the sound absorption power A of the sound absorption panel, determining the noise reduction amount NR of the sound absorption panel and comparing are repeated until . BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0075] Figure 1 A schematic diagram of a flow chart of a specific embodiment provided in this application;

[0076] Figure 2 This is a schematic diagram of the partial structure of the skirt board of the specific embodiment provided in this application;

[0077] Figure 3 This is a schematic structural diagram of the skirt body of a specific embodiment provided in this application;

[0078] Figure 4A longitudinal sectional view of the sound absorption panel of the specific embodiment provided in the present application;

[0079] Figure 5 A plan view of the sound absorption panel of the specific embodiment provided in the present application;

[0080] Figure 6 Another longitudinal sectional view of the sound absorption panel of the specific embodiment provided in the present application;

[0081] Figure 7 Another plan view of the sound absorption panel of the specific embodiment provided in the present application;

[0082] Figure 8 A lateral sectional view of the sound absorption panel of the specific embodiment provided in the present application.

[0083] Reference signs:

[0084] 1-skirt body; 11-clearance space; 2-sound absorption panel; 21-square frame structure; 211-square resonant cavity; 212-round corner; 22-sound absorption hole plate; 221-sound absorption hole; 23-throat. DETAILED DESCRIPTION

[0085] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0086] The core of the present application is to provide a design method of a middle-low frequency sound absorption skirt, using which a middle-low frequency sound absorption skirt reducing the middle-low frequency aerodynamic noise of a bogie can be manufactured. Another core of the present application is to provide a low frequency sound absorption skirt manufactured by using the above design method. Still another core of the present application is to provide a high-speed rail vehicle comprising the above middle-low frequency sound absorption skirt.

[0087] The present application provides a design method of a middle-low frequency sound absorption skirt, wherein the middle-low frequency sound absorption skirt comprises a skirt body 1 and a sound absorption panel 2, and the sound absorption panel 2 is laid on the inner surface of the skirt body 1.

[0088] Reference Figure 2 and Figure 3It is illustrated that the apron body 1 can be wrapped under the chassis, and a wheel set station is left to enable the wheel set arranged on the chassis to touch the rail, and the aerodynamic shape of the apron body 1 can be designed based on the whole vehicle structure; in order to further reduce the medium and low frequency noise, the sound absorption panel 2 is laid on the inner surface of the apron body 1, so that the aerodynamic noise generated by the wheel set is rectified through the apron body 1 to the greatest extent, and the sound absorption panel 2 is used to absorb the aerodynamic noise generated by the wheel set to reduce the transmission of the noise to the vehicle body, and the above design method is a comprehensive design method for designing the configuration of the apron body 1 and determining the laying scheme of the sound absorption panel 2, that is, a medium and low frequency sound absorption apron meeting the noise reduction amount requirement of the target frequency band noise is designed.

[0089] Reference Figure 1 It is illustrated that the design method includes the following steps:

[0090] Step S21: obtaining a target noise reduction amount , the total area of the inner surface of the apron body 1 , the sound absorption coefficient of the sound absorption panel 2 , the arrangement area S of the sound absorption panel 2, and the radiation noise SWL of the apron body 1;

[0091] It can be understood that the above parameters are obtained by calling or external input before design, so as to prepare for steps S22 and S23.

[0092] Step S22: determining the sound absorption power A of the sound absorption panel 2 according to the sound absorption coefficient of the sound absorption panel 2 , the total area of the inner surface of the apron body 1 , and the arrangement area S of the sound absorption panel 2;

[0093] It can be understood that the total area of the inner surface of the apron body 1 , the sound absorption coefficient of the sound absorption panel 2 , and the arrangement area S of the sound absorption panel 2 obtained in step S1 are used to calculate or simulate the sound absorption power A of the sound absorption panel 2 in a manner, and optionally, the calculation method of the sound absorption power A of the sound absorption panel 2 can adopt: , so as to prepare for step S3.

[0094] Step S23: determining the noise reduction amount NR of the sound absorption panel 2 according to the radiation noise SWL of the apron body 1 and the sound absorption power A of the sound absorption panel 2;

[0095] The maximum value of the noise reduction amount NR of the sound absorption panel 2 is compared with the target noise reduction amount ;

[0096] If The arrangement area S of the sound absorption panel 2 meets the noise reduction requirement;

[0097] If , the arrangement area S of the sound absorption panel 2 is adjusted, the steps of determining the sound absorption power A of the sound absorption panel 2, determining the noise reduction amount NR of the sound absorption panel 2 and comparison are repeated for the adjusted arrangement area S of the sound absorption panel 2, until , or until the arrangement area S of the sound absorption panel 2 is equal to the total area of the inner surface of the apron body 1 .

[0098] It can be understood that the sound absorption power A of the sound absorption panel 2 has been determined in step S22, wherein the sound absorption power A of the sound absorption panel 2 refers to the part of the radiation noise SWL of the apron body 1 that can be absorbed by the sound absorption panel 2. Then, the noise reduction amount NR of the sound absorption panel 2 that can be achieved by the current apron design scheme is determined after calculation using the two in this step. Optionally, the noise reduction amount NR of the sound absorption panel 2 can be obtained by the Sabine incident method, and the specific calculation process is as follows. The calculation method of the noise reduction amount NR of the sound absorption panel 2 is as follows:

[0099] ;

[0100] In the formula, is the total energy of the sound waves incident on the apron, and , W;

[0101] After simplification, the calculation method of the noise reduction amount NR of the sound absorption panel 2 is as follows:

[0102] .

[0103] Then, the maximum noise reduction amount in the noise reduction amount NR data set of the sound absorption panel 2 is selected and compared with the target noise reduction amount , that is, whether the current apron design scheme meets the standard can be measured.

[0104] If the maximum noise reduction amount does not meet the noise reduction requirement, that is, , the arrangement area S of the sound absorption panel 2 can be increased to improve the sound absorption power A of the sound absorption panel 2, and then return to step S22 and continue step S23, and then iterate and optimize until the arrangement area S of the sound absorption panel 2 meets the noise reduction requirement. During the process of increasing the arrangement area S of the sound absorption panel 2, if , the maximum noise reduction amount still does not meet the noise reduction requirement, the sound absorption panel 2 can be fully laid on the inner surface of the apron body 1, or the sound absorption panel 2 with a different sound absorption coefficient may also be replaced.

[0105] If the maximum noise reduction amount satisfies the noise reduction requirement, i.e. , the current apron design scheme can fully meet the expected effect, and the arrangement area S of the current sound absorption panel 2 can be directly used. Alternatively, when , the arrangement area of the sound absorption panel 2 can also be reduced, and the steps of determining the sound absorption power A of the sound absorption panel 2, determining the noise reduction amount NR of the sound absorption panel 2, and comparing are repeated until .

[0106] In some specific embodiments, in step S21, the arrangement area S of the sound absorption panel 2 is equal to the total area of the inner surface of the panel body 1 , which is beneficial to simplify the calculation process of step S23.

[0107] With reference to the description Figure 1 , on the basis of the above embodiment, the following steps are further included before step S21:

[0108] Step S11: Obtain the configuration of the initially designed apron body 1;

[0109] It can be understood that based on the overall vehicle structure, the aerodynamic shape of the apron body 1 is designed, and then the modeling is performed according to the designed aerodynamic shape.

[0110] Step S12: Perform aerodynamic analysis on the configuration of the apron body 1, and determine the radiation noise SWL of the apron body 1 and the target noise reduction amount NR of the sound absorption panel 2 according to the aerodynamic analysis result of the apron body 1 ;

[0111] It can be understood that based on the apron body 1 model created in step S11, aerodynamic analysis is performed. Alternatively, based on the apron body 1 model, the computational fluid dynamics model of the apron body 1 is obtained after the flow boundary is given, and the aerodynamic analysis is performed in the CFD analysis software using the computational fluid dynamics model. After the aerodynamic analysis, the fluctuating pressure on the outer surface of the apron body 1 can be obtained. It is explained that the computational fluid dynamics model is a model obtained by simulating aerodynamic noise based on the apron body 1 model, which is used for more efficient preliminary estimation of the apron body 1. Regarding the determination of the aerodynamic analysis result of the apron body 1, the CFD software is run and the aerodynamic analysis result is output, and the aerodynamic analysis result at least includes the surface fluctuating pressure of the airflow on the apron.

[0112] In some specific embodiments, the model of the apron body 1 is a partial structure of the vehicle body model; correspondingly, the step of performing aerodynamic analysis on the configuration of the apron body 1 also includes performing aerodynamic analysis on the wheelset and the car body; the step of determining the radiation noise SWL of the apron body 1 includes determining the radiation noise SWL of the apron body 1 according to the aerodynamic analysis results of the wheelset and the apron, such as the fluctuating pressure of the wheelset surface and the apron surface; the step of determining the computational fluid dynamics model of the apron body 1 according to the model of the apron body 1 and the flow boundary includes: defining the flow on the cross section of the vehicle body model to obtain the flow boundary, wherein the flow boundary includes the enlarged flow boundary of the cross sections at both ends of the car body model in the vehicle body model and the standard flow boundary of the remaining part of the vehicle body model, the calculation method of the standard flow boundary is the product of the vehicle running speed and the cross section area, and the enlarged flow boundary is 5 times the product of the vehicle running speed and the cross section area. In this way, the airflow has a certain turbulent effect into the apron and the wheelset, and the noise reduction effect of the low-frequency sound-absorbing apron manufactured by using this design method will be higher than the noise reduction demand.

[0113] Further, optionally, the fluctuating pressure on the outer surface of the apron body 1 is taken as an input quantity, and a curcle equation is used to simulate the apron aerodynamic noise source boundary, and the curcle equation is specifically:

[0114] ;

[0115] represents an equivalent quadrupole sound source, which is used to represent the sound source generated in the non-gas-solid combination surface of the airflow wake; it is explained that its contribution to the aerodynamic noise is low, and it can be omitted in aerodynamic analysis;

[0116] represents an equivalent dipole sound source, which is used to represent the fluctuation sound source on the gas-solid surface;

[0117] is a partial derivative symbol;

[0118] is a surface tensor, which can come from the aerodynamic analysis results in the CFD analysis software;

[0119] is the fluctuating pressure on the gas interface of the apron body 1, which comes from the aerodynamic analysis results in the CFD analysis software, specifically the fluctuating pressure on the gas interface of the apron body 1 extracted from the above aerodynamic analysis results;

[0120] is the normal direction of the unit grid;

[0121] ​​Next, in order to determine the radiation noise SWL of the apron body 1, based on the equivalent dipole sound source in the apron aerodynamic noise sound source boundary simulated by the curcle equation, the fluctuating pressure on the gas interface of the apron body 1 is simulated , that is, the apron acoustic model is built, so that the equivalent sound source cannot penetrate the surface of the apron body, the sound power of the radiation noise of the apron body 1 is captured, and then the sound power can be used to determine the radiation noise SWL of the apron body 1.

[0122] Optionally, in order to more accurately determine the radiation noise SWL of the apron body 1, the Neumann vibration velocity boundary is used to simulate the fluctuating pressure on the gas interface of the apron body 1 , when the equivalent dipole sound source cannot penetrate the outer surface of the apron body 1, the radiation noise sound power of the apron body 1 is accurately captured, and the specific conversion method is:

[0123] ;

[0124] ;

[0125] In the formula, K is a complex wave number, , and w is an angular frequency, and c is a sound speed;

[0126] Ps is the sound pressure on the surface of the apron body;

[0127] is a gradient operator.

[0128] Then, the radiation noise SWL of the apron body 1 is subtracted from the final noise reduction amount to calculate the target noise reduction amount , the target noise reduction amount refers to the part of the noise that needs to be absorbed by the sound absorption panel 2 to meet the noise reduction demand. It needs to be explained that it is usually difficult to meet the noise reduction demand in the medium and low frequency band through aerodynamic optimization of the apron body 1, and it is also difficult to effectively suppress the airflow pulsation in the transition area between the apron and the vehicle body, that is, it is usually In this application, the sound absorption panel 2 is laid on the inner surface of the apron body 1 to meet the noise reduction demand.

[0129] Step S13: According to the aerodynamic analysis result of the apron body 1, the aerodynamic shape of the apron body 1 is optimized, and the target noise reduction amount of the sound absorption panel 2 is determined for the optimized apron body 1 and the step of optimizing the aerodynamic shape of the apron body 1, so that the radiation noise SWL of the apron body 1 is reduced.

[0130] It can be understood that the aerodynamic shape of the initially designed apron body 1 is often difficult to achieve the optimal effect, and the shape of the apron body 1 is optimized in this step to optimize the aerodynamic characteristics of the apron body 1 to reduce the aerodynamic noise, which is embodied as reducing the radiation noise SWL of the apron body 1, and the target noise reduction amount Also reduced, so that the part of the noise that needs to be absorbed by the sound absorption panel 2 is effectively reduced, and in the process of repeatedly determining the radiation noise SWL of the apron body 1 and the target noise reduction amount of the sound absorption panel 2 The radiation noise SWL of the apron body 1 after optimization is determined, and then the target noise reduction amount of the sound absorption panel 2 after the optimization of the apron body 1 .

[0131] It should be noted that the number of times of optimizing the aerodynamic shape of the apron body 1 is not limited, as long as the effect of reducing the aerodynamic noise can be achieved.

[0132] On the basis of the above embodiment, the aerodynamic shape of the apron body 1 is optimized, which comprises:

[0133] According to the aerodynamic analysis result of the apron body 1, the vortex separation serious position of the apron body 1 is adjusted to obtain the apron body 1 after optimization;

[0134] It can be understood that the specific content of aerodynamic optimization is to adjust the shape according to the vortex separation serious position in the aerodynamic analysis result of the apron body 1, so that the radiation noise SWL of the apron body 1 is reduced.

[0135] And the steps of determining the radiation noise SWL of the apron body 1, the target noise reduction amount of the sound absorption panel 2 And optimizing the aerodynamic shape of the apron body 1, comprising:

[0136] According to the aerodynamic analysis result of the apron body 1, it is determined whether the vortex is weakened or enhanced at the vortex separation serious position of the apron body 1;

[0137] If the vortex is weakened, the step of repeatedly determining the radiation noise SWL of the apron body 1 is continued;

[0138] If the vortex is enhanced, the vortex separation serious position of the apron body 1 is adjusted to optimize the configuration of the apron body 1 again, and then the aerodynamic shape of the apron body 1 is returned.

[0139] It can be understood that in order to ensure that the radiation noise SWL of the skirt panel body 1 is reduced, after the aerodynamic analysis is performed on the optimized skirt panel body 1, the analysis is first performed to determine the severe vortex separation position of the skirt panel body 1 before optimization, and whether the vortex is enhanced or weakened after optimization. Then, when the vortex is weakened, the radiation noise SWL of the skirt panel body 1 can be continued to be determined, or, when the vortex is enhanced, the determination of the radiation noise SWL of the skirt panel body 1 is stopped, and the aerodynamic optimization of the skirt panel body 1 is re-performed, so as to analyze the severe vortex separation position after the optimization again to determine whether the vortex is enhanced or weakened after optimization.

[0140] It should be noted that due to the radiation noise SWL of the skirt body 1 and the sound absorption coefficient of the sound absorbing panel 2 It changes with frequency, that is, different frequencies have corresponding radiation noise values ​​of the skirt body 1 and the sound absorption coefficient of the sound absorption panel 2. The radiation noise SWL of the skirt body 1 is specifically the radiation noise SWL-frequency curve of the skirt body 1, and the sound absorption coefficient of the sound absorption panel 2 is Specifically, the sound absorption coefficient of the sound absorption panel 2 -frequency curve, the noise reduction NR of the sound-absorbing skirt is a data set or a noise reduction NR-frequency curve of the sound-absorbing skirt, wherein each data in the data set is calculated and determined using the radiation noise value of the skirt body 1 and the sound absorption coefficient value of the sound-absorbing panel 2 corresponding to the same frequency; the above maximum noise reduction It refers to the maximum value in the data set of the noise reduction amount NR or the maximum amplitude of the data curve in the target frequency band, such as 100-500Hz.

[0141] In addition to the above-mentioned design method for the medium and low frequency sound absorbing skirt panel, the present application also provides a medium and low frequency sound absorbing skirt panel manufactured using the design method disclosed in the above-mentioned embodiment. The medium and low frequency sound absorbing skirt panel includes a skirt panel body 1 and a sound absorbing panel 2. The sound absorbing panel 2 is laid on the inner surface of the skirt panel body 1. The aerodynamic noise generated during operation can be efficiently absorbed to reduce the transmission of noise to the interior of the vehicle body.

[0142] It should be noted that the type of the sound absorbing panel 2 is not limited, as long as it meets the noise reduction requirements, for example, Figure 6 and Figure 7 The sound absorbing panel 2 shown has a sound absorbing perforated plate 22 on the front, periodically arranged resonance cavities inside, and the sound absorbing holes 221 of the perforated plate are connected to the corresponding resonance cavities, or, Figure 4 and Figure 5 The sound absorbing panel 2 shown has a sound absorbing perforated plate 22 , a throat 23 inserted in the sound absorbing holes 221 of the sound absorbing perforated plate 22 , and periodically arranged square resonance cavities 211 inside.

[0143] It should also be noted that the structure of the skirt body 1 can adopt the structure of a traditional skirt, preferably, asFigure 3 As shown, the apron body 1 adopts a U-shaped semi-enclosed structure, and the apron body 1 is enclosed at the bottom structure of the bogie. The bottom plate of the apron body 1 has at least two accommodation spaces 11. In use, the wheels are movably arranged in the accommodation spaces 11. In this way, the overall pulsating pressure of the airflow in the transition area between the wheel set, the vehicle body and the apron is effectively reduced, thereby suppressing the noise.

[0144] On the basis of the above embodiment, the sound absorption panel 2 comprises a plurality of sound absorption units, the plurality of sound absorption units are arranged in an array, and the sound absorption unit has a square frame structure 21, a sound absorption hole plate 22 and a throat pipe 23.

[0145] The square frame structure 21 has a plurality of square resonant cavities 211 arranged in an array.

[0146] The sound absorption hole plate 22 is sealingly fitted to the first end of the square frame structure 21. The sound absorption hole plate 22 has a plurality of sound absorption holes 221 arranged in an array.

[0147] The plurality of throat pipes 23 sealingly pass through the corresponding sound absorption holes 221, and the plurality of throat pipes 23 are inserted into the corresponding square resonant cavities 211. The throat pipe 23 communicates the external environment of the sound absorption unit and the corresponding square resonant cavity 211.

[0148] Reference Figure 4 and Figure 5 As described above, the sound absorption unit comprises a hollow square frame structure 21. Specifically, a mesh barrier plate is further embedded in the inner cavity of the square frame structure 21 to separate a plurality of square resonant cavities 211 from each other. The plurality of square resonant cavities 211 can be arranged in an array of 4x4 or 5x5 or 6x6 type. The sound absorption unit further comprises a sound absorption hole plate 22 having a plurality of sound absorption holes 221. The square resonant cavities 211 extend along the thickness direction of the square frame structure 21. The sound absorption hole plate 22 is sealingly fitted to the first end of the square frame structure 21, i.e. the sound absorption hole plate 22 closes the open end of all the square resonant cavities 211. The sound absorption holes 221 correspond to the square resonant cavities 211 one by one. A plurality of throat pipes 23 are inserted into the corresponding sound absorption holes 221 and square resonant cavities 211. The sound absorption unit can absorb noise in a target frequency band. The sound absorption panel 2 has a plurality of sound absorption units arranged in an array, so as to effectively absorb the noise of the target apron. The back end of the sound absorption panel 2 abuts and is fixedly connected to the apron body 1. In use, the noise propagates into the square resonant cavities 211 through the throat pipes 23, so as to be absorbed by the resonance principle.

[0149] In some embodiments, the sound absorption panel 2 has a back plate which is sealingly fitted to the second end of the square frame structure 21, and in use, the back plate is bonded to the skirt body 1, so that the production is facilitated; or in some embodiments, the second end of the sound absorption panel 2 is open, i.e. without the back plate, and the back end of the skirt body 1 is sealingly fitted to the skirt body 1, so as to ensure the sealing performance of the square resonant cavity 211, thereby achieving noise reduction.

[0150] In addition, a manufacturing method of the low-frequency sound absorption skirt can be realized, and the manufacturing method comprises the following steps:

[0151] Bonding the skirt body 1 and the sound absorption panel 2 at one end of the skirt body 1 and / or the square frame structure 21;

[0152] Applying epoxy glue to the square frame structure 21 and / or the sound absorption hole plate 22, and bonding the sound absorption hole plate 22 to the other end of the square frame structure 21;

[0153] Applying epoxy glue to the inner wall of the sound absorption hole 221 of the sound absorption hole plate 22 and / or the outer circumferential surface of the throat pipe 23, and inserting the throat pipe 23 into the corresponding sound absorption hole 221;

[0154] Performing heat curing to integrally form the low-frequency sound absorption skirt.

[0155] Further, preferably, the skirt body 1 and the sound absorption panel 2 are both carbon fiber structures, or glass fiber structures.

[0156] On the basis of the above-mentioned embodiments, the length h of the 1 / 3 throat pipe 23 in the sound absorption panel 2 is 38mm, and the length h of the 2 / 3 throat pipe 23 in the sound absorption panel 2 is 12mm;

[0157] The thickness of the sound absorption panel 2 with the open second end of the square frame structure 21 is 50mm, the wall thickness of the square resonant cavity 211 is 0.5mm, and the pipe diameter of the throat pipe 23 is greater than or equal to 1.4mm, so as to be able to absorb the low-frequency noise of 100-500Hz, and effectively prevent clogging from occurring after long-term use.

[0158] On the basis of the above-mentioned embodiments, the square resonant cavity 211 has a rounded corner 212 at the top corner position, and among the two adjacent rows of square resonant cavities 211, the rounded corner 212 of the square resonant cavity 211 in one row is located at the middle position of the side surface of the corresponding square resonant cavity 211 in the other row.

[0159] As Figure 8As shown, the four corners of the square resonant cavity 211 are machined with a fillet 212, and the square resonant cavities 211 in the adjacent two rows are staggered, specifically, one row of square resonant cavities 211 is located in the middle position between the two adjacent square resonant cavities 211 in the other row, and the top corner position of the square resonant cavity 211 in one row close to the other row is located in the middle position of the width of the two adjacent square resonant cavities 211 in the other row. Therefore, the sound absorption panel 2 can not only meet the noise reduction demand, but also avoid the saddle effect, which is conducive to prolonging the service life of the square local resonant wideband sound absorption panel 2 manufactured by the design method, and is conducive to meeting the space surface modeling demand of the sound absorption panel 2.

[0160] On the basis of the above-mentioned embodiments, the apron includes a plurality of sound absorption panels 2, and the gap between the adjacent sound absorption panels 2 is 20-50 mm, that is, a plurality of sound absorption panels 2 are laid on the inner surface of the apron body 1, and the gap between the sound absorption panels 2 is 20-50 mm, so as to facilitate laying.

[0161] In addition to the above-mentioned low-frequency sound absorption apron and the design method thereof, the application also provides a high-speed rail vehicle including the low-frequency sound absorption apron disclosed in the above-mentioned embodiments. The structures of other parts of the high-speed rail vehicle refer to the prior art, and will not be described here.

[0162] It should be noted that the relationship terms such as "first" and "second" described above are only used to distinguish one entity from other entities, and do not necessarily require or imply any actual relationship or order between the entities; the "upper surface, lower surface, top, bottom" described above and the orientation words "up, down, left, right" are defined based on the drawings.

[0163] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0164] The high-speed rail vehicle, the low-frequency sound absorption apron and the design method thereof provided by the application are described in detail above. The principles and implementation modes of the application are described by applying specific examples. The above description of the embodiments is only used to help understand the method of the application and its core idea. It should be noted that those skilled in the art can make some improvements and modifications to the application without departing from the principles of the application, and these improvements and modifications also fall within the protection scope of the application.

Claims

1. A design method for a mid- and low-frequency sound-absorbing skirt, characterized in that: The medium and low frequency sound absorbing skirt comprises a skirt body (1) and a sound absorbing panel (2), wherein the sound absorbing panel (2) is laid on the inner surface of the skirt body (1); The design method includes: Get the target noise reduction amount , the total inner surface area of ​​the skirt body (1) , Sound absorption coefficient of sound absorbing panel (2) , the layout area S of the sound absorbing panel (2), and the radiation noise SWL of the skirt body (1); According to the sound absorption coefficient of the sound absorbing panel (2) , the total inner surface area of ​​the skirt body (1) , the layout area S of the sound absorbing panel (2), and determining the sound absorption power A of the sound absorbing panel (2); Determine the noise reduction NR of the sound absorbing panel (2) based on the radiation noise SWL of the skirt body (1) and the sound absorption power A of the sound absorbing panel (2); The maximum value of the noise reduction NR of the sound absorbing panel (2) Target noise reduction amount Make comparisons; if , then the layout area S of the sound-absorbing panel (2) meets the noise reduction requirement; if , then adjust the layout area S of the sound absorbing panel (2), and repeat the steps of determining the sound absorption power A of the sound absorbing panel (2), determining the noise reduction amount NR of the sound absorbing panel (2), and comparing with respect to the layout area S of the sound absorbing panel (2) after adjustment, until , or, until the layout area S of the sound absorbing panel (2) is equal to the total inner surface area of ​​the skirt body (1) .

2. The design method of the mid- and low-frequency sound-absorbing skirt according to claim 1, characterized in that: Obtaining the target noise reduction amount , the total inner surface area of ​​the skirt body (1) , Sound absorption coefficient of sound absorbing panel (2) , the layout area S of the sound absorbing panel (2), the radiation noise SWL of the skirt body (1), and also include: Obtaining the configuration of the initial design skirt body (1); An aerodynamic analysis is performed on the configuration of the skirt body (1), and the radiation noise SWL of the skirt body (1) and the target noise reduction amount of the sound absorbing panel (2) are determined based on the aerodynamic analysis results of the skirt body (1). ; According to the aerodynamic analysis results of the skirt body (1), the aerodynamic shape of the skirt body (1) is optimized, and for the optimized skirt body (1), the radiation noise SWL of the skirt body (1) and the target noise reduction amount of the sound absorbing panel (2) are determined cyclically. And the steps of optimizing the aerodynamic shape of the skirt body (1) reduce the radiation noise SWL of the skirt body (1).

3. The design method of the mid- and low-frequency sound-absorbing skirt according to claim 2, characterized in that: The step of determining the radiation noise SWL of the skirt plate body (1) based on the aerodynamic analysis results of the skirt plate body (1) comprises: Obtaining a curcle equation, and determining a sound source model of the skirt body (1) based on an aerodynamic analysis result of the skirt body (1) and the curcle equation; According to the sound source model of the skirt plate body (1), the acoustic model of the skirt plate body (1) is determined to determine the radiation noise SWL of the skirt plate body (1).

4. The design method of the mid- and low-frequency sound-absorbing skirt according to claim 3 is characterized in that: The curcle equation is: ； Where, represents an equivalent quadrupole sound source; represents an equivalent dipole sound source; and is the symbol of partial derivative; is the surface tensor; is the pulsating pressure on the interface between the skirt body (1) and the gas; is the normal direction of the unit grid; is the distance between the coordinate points.

5. The design method of the mid- and low-frequency sound-absorbing skirt according to claim 4, characterized in that: The radiation noise SWL is determined according to the following formula: ； ； Where K is the complex wave number, , and w is the angular frequency, c is the speed of sound; Ps is the sound pressure on the skirt body surface; is the gradient operator.

6. The design method of the mid- and low-frequency sound-absorbing skirt according to claim 2, characterized in that: The method for determining the aerodynamic analysis result is: Obtaining a model and a flow boundary of the skirt plate body (1), and determining a computational fluid dynamics model of the skirt plate body (1) based on the model and the flow boundary of the skirt plate body (1); According to the computational fluid dynamics model of the skirt plate body (1), an aerodynamic analysis result of the skirt plate body (1) is determined.

7. The design method of the low- and medium-frequency sound-absorbing skirt according to claim 1, characterized in that: The calculation method of the sound absorption power A of the sound absorption panel (2) is: ； Where A is the sound absorption power of the sound absorption panel (2); is the sound absorption coefficient of the sound absorption panel (2); is the total inner surface area of ​​the skirt body (1); S is the layout area of ​​the sound absorbing panel (2).

8. The design method of the mid- and low-frequency sound-absorbing skirt according to claim 7, characterized in that: The calculation method of the noise reduction amount NR of the sound absorbing panel (2) is: ； Where SWL is the radiation noise of the skirt body (1); A is the sound absorption power of the sound absorption panel (2).

9. The design method of the mid- and low-frequency sound-absorbing skirt according to claim 2, characterized in that: The aerodynamic shape of the optimized skirt body (1) comprises: According to the aerodynamic analysis results of the skirt plate body (1), the shape of the skirt plate body (1) at the location where vortex separation is severe is adjusted to obtain an optimized skirt plate body (1); The cycle is performed to determine the radiation noise SWL of the skirt body (1) and the target noise reduction amount of the sound absorbing panel (2). and the steps of optimizing the aerodynamic shape of the skirt body (1), comprising: According to the aerodynamic analysis results of the skirt plate body (1), it is determined whether the skirt plate body (1) achieves vortex reduction or enhancement at the location where vortex separation is serious; If the vortex weakens, continue to repeat the step of determining the radiation noise SWL of the skirt body (1); If the vortex is enhanced, the shape of the skirt body (1) where the vortex separation is serious is re-adjusted to optimize the configuration of the skirt body (1) again, and then the aerodynamic shape of the optimized skirt body (1) is returned to.

10. A mid-low frequency sound absorbing skirt, characterized in that: The mid- and low-frequency sound-absorbing skirt panel is manufactured using the design method of any one of claims 1 to 9, wherein the skirt panel comprises: Skirt body (1); A sound absorbing panel (2), the sound absorbing panel (2) being laid on the inner surface of the skirt board body (1).

11. The mid- and low-frequency sound-absorbing skirt according to claim 10, characterized in that: The sound absorbing panel (2) comprises a plurality of sound absorbing units, the plurality of sound absorbing units are arranged in an array, and the sound absorbing units have a square frame structure (21), a sound absorbing perforated plate (22) and a throat (23); The square frame structure (21) has a plurality of square resonance cavities (211) arranged in an array; The sound absorbing perforated plate (22) is sealed and fitted to the first end of the square frame structure (21), and the sound absorbing perforated plate (22) has a plurality of sound absorbing holes (221) arranged in an array. A plurality of the throats (23) are sealed and fitted through the corresponding sound absorption holes (221), and a plurality of the throats (23) are inserted into the corresponding square resonance cavities (211). The throats (23) communicate with the external environment of the sound absorption unit and the corresponding square resonance cavities (211).

12. The mid- and low-frequency sound-absorbing skirt according to claim 11, characterized in that: The length of the throat (23) in 1 / 3 of the sound absorbing panel (2) is 38 mm, and the length of the throat (23) in 2 / 3 of the sound absorbing panel (2) is 12 mm; The sound-absorbing panel (2) with the second end of the square frame structure (21) open has a thickness of 50 mm, the wall thickness of the square resonance cavity (211) is 0.5 mm, and the pipe diameter of the throat (23) is greater than or equal to 1.4 mm.

13. The mid- and low-frequency sound-absorbing skirt according to claim 11, characterized in that: The top corners of the square resonant cavities (211) have rounded corners (212), and in two adjacent rows of the square resonant cavities (211), the rounded corners (212) of the square resonant cavities (211) in one row are located in the middle of the side faces of the corresponding square resonant cavities (211) in the other row.

14. The mid- and low-frequency sound-absorbing skirt according to claim 10, characterized in that: The skirt board comprises a plurality of sound-absorbing panels (2), and the gap between adjacent sound-absorbing panels (2) ranges from 20 to 50 mm.

15. A high-speed rail vehicle, characterized in that: The invention comprises the mid- and low-frequency sound-absorbing skirt panel as described in any one of claims 10 to 14.

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