阅读说明：本技术 吸声系数测试系统、方法以及车辆 (Sound absorption coefficient testing system and method and vehicle ) 是由 吴健 高阳 陈士斌 郭伟强 于洋 于 2019-10-14 设计创作，主要内容包括：本申请涉及一种吸声系数测试系统、方法以及车辆。所述系统包括：传声装置,设置于测试管道内,用于将未被吸音材料吸收的声波转化成声信号,其中,所述吸音材料设置于所述测试管道的侧壁；风速检测装置,设置于所述测试管道内,用于检测所述测试管道内流体载荷的流速；处理装置,分别与所述传声装置和风速检测装置连接,用于接收所述传声装置传输的声信号和所述风速检测装置传输的流体载荷的流速,并对所述声信号进行快速傅里叶变换,以确定吸音材料在不同流速流体载荷作用下的吸声系数。上述系统能够提高测试精度、便捷以及降低成本。(The application relates to a sound absorption coefficient testing system, a sound absorption coefficient testing method and a vehicle. The system comprises: the sound transmission device is arranged in the test pipeline and used for converting sound waves which are not absorbed by a sound absorption material into sound signals, wherein the sound absorption material is arranged on the side wall of the test pipeline; the wind speed detection device is arranged in the test pipeline and used for detecting the flow velocity of the fluid load in the test pipeline; and the processing device is respectively connected with the sound transmission device and the wind speed detection device, is used for receiving the sound signals transmitted by the sound transmission device and the flow velocity of the fluid load transmitted by the wind speed detection device, and performs fast Fourier transform on the sound signals to determine the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow velocities. The system can improve the testing precision, is convenient and fast and reduces the cost.)

1. An acoustic absorption coefficient testing system, the system comprising:

the sound transmission device is arranged in the test pipeline and used for converting sound waves which are not absorbed by a sound absorption material into sound signals, wherein the sound absorption material is arranged on the side wall of the test pipeline;

the wind speed detection device is arranged in the test pipeline and used for detecting the flow velocity of the fluid load in the test pipeline;

and the processing device is respectively connected with the sound transmission device and the wind speed detection device, is used for receiving the sound signals transmitted by the sound transmission device and the flow velocity of the fluid load transmitted by the wind speed detection device, and performs fast Fourier transform on the sound signals to determine the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow velocities.

2. The system of claim 1, further comprising: and the sound wave transmitting device is arranged in the test pipeline and used for transmitting sound waves into the test pipeline.

3. The system of claim 2, wherein the acoustic emission device comprises a signal generator, a power amplifier, and a sound emitter,

the signal generator is used for emitting a single-frequency sine wave signal;

the power amplifier is connected with the signal generator and is used for amplifying the power of the single-frequency sine wave signal;

and the sounding body is arranged in the test pipeline and emits sound waves based on the single-frequency sine wave signals after power amplification.

4. The system of claim 1, further comprising: and the airflow source device is connected with the inlet of the test pipeline and is used for providing fluid loads with different flow rates into the test pipeline.

5. The system of claim 1, wherein the airflow source device comprises

The air supply module is used for providing fluid loads with different flow rates;

and the first silencing module is connected with the air supply module and used for eliminating the noise of the air supply module and transmitting the fluid loads with different flow rates to the test pipeline.

6. The system of claim 5, wherein the air supply module comprises at least a variable speed control unit.

7. The system of claim 5, wherein the first sound attenuation module includes at least a sound attenuator.

8. The system of claim 1, further comprising:

and the second silencing module is connected with the outlet of the test pipeline and used for eliminating the sound waves transmitted from the outlet of the test pipeline.

9. A method of sound absorption coefficient testing, the method comprising:

acquiring acoustic signals and flow rates of the fluid load;

carrying out fast Fourier transform on the acoustic signal to obtain the relative acoustic resistance and the relative acoustic reactance of the sound-absorbing material;

and determining the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow rates according to the flow rate, the relative acoustic resistance and the relative acoustic reactance of the fluid loads.

10. A vehicle, characterized in that it comprises at least an acoustic absorption coefficient testing system according to claims 1-8.

Technical Field

The application relates to the technical field of testing, in particular to a sound absorption coefficient testing system and method and a vehicle.

Background

China is the country with the fastest development speed and the largest scale of high-speed railways in the world, the operation speed of high-speed railways in China is mostly between 250km/h and 350km/h, and 400km/h high-speed trains are researched and manufactured at present. While rail transit is rapidly developed, along with improvement of living standard of people, enhancement of environmental awareness and forced implementation of relevant laws and regulations of noise prevention and control, noise problems of rail transit train vehicles are increasingly prominent and are widely concerned in society. The rail transit train noise problem generally comprises two major parts of an outside train noise problem and an inside train noise problem. Vehicle external noise, also known as traffic noise, is one of the main sources of noise pollution in urban areas. The high-intensity and continuous passenger room noise brings fatigue and oppression to the bodies of drivers and passengers, so that the spleen and the breath of people are violent, the emotion is fluctuated, even the hearing can be damaged in serious cases, the riding comfort of the passengers is seriously influenced, and the method is an important aspect of vehicle noise control.

In the process that the noise of the rail transit vehicle is generated and transmitted in the air, the noise reduction mode by adopting the sound absorption material can effectively attenuate the pollution generated by the noise and reduce the influence of the noise on the surrounding environment. And the sound absorption coefficient is the most important parameter for evaluating the sound absorption performance of the material. When sound waves are incident on the surface of the material, part of incident sound energy is reflected, part of the incident sound energy is absorbed by the material, and the ratio of the absorbed sound energy to the incident sound energy is the sound absorption coefficient. Sound absorbing materials are laid in the areas of the underframe, the apron board and the like of the bogie area of the train, so that the radiation of wheel track noise to the surrounding environment can be effectively reduced, and the noise level outside the train is reduced.

At present, a reverberation chamber method and a standing wave tube method are adopted in a material sound absorption coefficient test method, the working principle of the standing wave tube method is that sound waves are emitted through a sound source system consisting of an audio signal generator, a power amplifier and a loudspeaker, the sound waves are transmitted in the standing wave tube, and when the sound waves vertically enter the surface of a test material and are reflected, standing waves are formed in the tube. After the ratio of the maximum sound pressure to the minimum sound pressure, namely the standing-wave ratio, is measured by a microphone on the wall of the standing-wave pipe, the sound absorption coefficient of the material is obtained through calculation. The sound absorption coefficient is tested by a sound room method in a reverberation room with the volume larger than 200m3, the change of the sound absorption quantity in the reverberation room before and after the placement of the material in the reverberation room is tested, namely the sound absorption quantity of the material to be tested is calculated by a Sabin formula, and the sound absorption coefficient of the material to be tested can be calculated by the sound absorption quantity of the material to be tested and the test area.

However, the conventional method has problems of low precision, resource waste and the like.

Disclosure of Invention

In view of the above, there is a need to provide a sound absorption coefficient testing system, a sound absorption coefficient testing method and a vehicle, which can improve testing accuracy, facilitate testing and reduce cost.

An acoustic absorption coefficient testing system, the system comprising:

the sound transmission device is arranged in the test pipeline and used for converting sound waves which are not absorbed by a sound absorption material into sound signals, wherein the sound absorption material is arranged on the side wall of the test pipeline;

the wind speed detection device is arranged in the test pipeline and used for detecting the flow velocity of the fluid load in the test pipeline;

and the processing device is respectively connected with the sound transmission device and the wind speed detection device, is used for receiving the sound signals transmitted by the sound transmission device and the flow velocity of the fluid load transmitted by the wind speed detection device, and performs fast Fourier transform on the sound signals to determine the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow velocities.

In one embodiment, the system further comprises: and the sound wave transmitting device is arranged in the test pipeline and used for transmitting sound waves into the test pipeline.

In one embodiment, the sound wave transmitting device comprises a signal generator, a power amplifier and a sounding body,

the signal generator is used for emitting a single-frequency sine wave signal;

the power amplifier is connected with the signal generator and is used for amplifying the power of the single-frequency sine wave signal;

and the sounding body is arranged in the test pipeline and emits sound waves based on the single-frequency sine wave signals after power amplification.

In one embodiment, the system further comprises: and the airflow source device is connected with the inlet of the test pipeline and is used for providing fluid loads with different flow rates into the test pipeline.

In one embodiment, the airflow source device comprises

The air supply module is used for providing fluid loads with different flow rates;

and the silencing module is connected with the air supply module and used for eliminating the noise of the air supply module and transmitting the fluid loads with different flow rates to the test pipeline.

In one embodiment, the air supply module comprises at least a variable speed control unit.

In one embodiment, the sound attenuation module comprises at least a sound attenuator.

In one embodiment, the system further comprises:

and the second silencing module is connected with the outlet of the test pipeline and used for eliminating the sound waves transmitted from the outlet of the test pipeline.

A method of sound absorption coefficient testing, the method comprising:

acquiring acoustic signals and flow rates of the fluid load;

carrying out fast Fourier transform on the acoustic signal to obtain the relative acoustic resistance and the relative acoustic reactance of the sound-absorbing material;

and determining the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow rates according to the flow rate, the relative acoustic resistance and the relative acoustic reactance of the fluid loads.

A vehicle comprising at least an acoustic absorption coefficient testing system as described above.

The sound absorption coefficient test system, the sound absorption coefficient test method and the vehicle comprise the following steps: the sound transmission device is arranged in the test pipeline and used for converting sound waves which are not absorbed by a sound absorption material into sound signals, wherein the sound absorption material is arranged on the side wall of the test pipeline; the wind speed detection device is arranged in the test pipeline and used for detecting the flow velocity of the fluid load in the test pipeline; and the processing device is respectively connected with the sound transmission device and the wind speed detection device, is used for receiving the sound signals transmitted by the sound transmission device and the flow velocity of the fluid load transmitted by the wind speed detection device, and performs fast Fourier transform on the sound signals to determine the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow velocities. The system can apply fluid loads with different flow rates to the surface of the material, test the sound absorption coefficient of the sound absorption material under the action of the fluid loads, fully consider the influence of the fluid loads with different flow rates on the sound absorption coefficient of the material, and provide real and effective data support for the acoustic design of a vehicle.

Drawings

FIG. 1 is a block diagram of an acoustic absorption coefficient testing system in one embodiment;

FIG. 2 is a schematic flow chart of a method for testing sound absorption coefficient in one embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Referring to fig. 1, an acoustic absorption coefficient testing system, the system comprising:

the sound transmission device 1 is arranged in the test pipeline and used for converting sound waves which are not absorbed by a sound absorption material into sound signals, wherein the sound absorption material is arranged on the side wall of the test pipeline;

the wind speed detection device 2 is arranged in the test pipeline and used for detecting the flow speed of fluid load in the test pipeline;

and the processing device 3 is respectively connected with the sound transmission device 1 and the wind speed detection device 2, is used for receiving the sound signals transmitted by the sound transmission device 1 and the flow rate of the fluid load transmitted by the wind speed detection device 2, and performs fast Fourier transform on the sound signals to determine the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow rates.

In one embodiment, the system further comprises: and the sound wave transmitting device 4 is arranged in the test pipeline and is used for transmitting sound waves into the test pipeline.

In one embodiment, the acoustic wave emission device 4 includes a signal generator 41, a power amplifier 42 and a sounding body 43,

the signal generating unit 41 is used for emitting a single-frequency sine wave signal;

a power amplifier 42 connected to the signal generator 41 for amplifying the power of the single-frequency sine wave signal;

and the sounding body 43 is arranged in the test pipeline and used for sending sound waves based on the single-frequency sine wave signals after power amplification.

In one embodiment, the system further comprises: and the air flow source device 5 is connected with the inlet of the test pipeline and is used for providing fluid loads with different flow rates into the test pipeline.

In one embodiment, the airflow source device 5 includes: a wind supply module 51 for providing fluid loads of different flow rates; the air supply module 51 at least comprises a variable speed control unit 511, and also comprises a fan, a roots machine or an air compressor for supplying air, wherein the variable speed control unit 511 can control the flow rate of fluid load supplied by the fan, the roots machine or the air compressor;

the first noise elimination module 52 is connected with the air supply module 51 and is used for eliminating noise of the air supply module 51 and transmitting the fluid loads with different flow rates to the test pipeline; the first muffling module 52 at least comprises a muffler 521, which can eliminate noise in the frequency range of 100Hz-5000 Hz.

The air flow source device 5 is arranged in a closed structure with good sound insulation performance, and the outlet of the air flow source device is connected with the test pipeline through a flexible connecting pipe.

The outlet of the test pipeline is also connected with a second silencing module 6, and the second silencing module 6 prevents noise in the test system from being discharged to the surrounding environment to deteriorate the acoustic environment where the attraction coefficient test system is located. The passage section of the second sound-damping module 6 should slowly increase with distance. The frequency parameter over the outlet cross section should have a sufficiently large value in the frequency range tested. The inner wall of the channel of the second silencing module 6 is subjected to sound absorption treatment, so that sound waves transmitted along the channel are effectively attenuated within a test range. The normal sound admittance of the sound-absorbing inner wall of the channel of the second sound-damping module 6 should increase slowly with distance and should not have a significant sudden change.

In one embodiment, a membrane is arranged at the outlet of the test pipeline, so that the fluid load can be ensured to smoothly flow through the outlet of the test pipeline, the unstable fluid load and the aerodynamic noise caused by vortex generation in the wind tunnel are avoided, and meanwhile, the sound attenuation is minimum.

The above-mentioned sound absorption coefficient test system, the system includes: the sound transmission device is arranged in the test pipeline and used for converting sound waves which are not absorbed by a sound absorption material into sound signals, wherein the sound absorption material is arranged on the side wall of the test pipeline; the wind speed detection device is arranged in the test pipeline and used for detecting the flow velocity of the fluid load in the test pipeline; and the processing device is respectively connected with the sound transmission device and the wind speed detection device, is used for receiving the sound signals transmitted by the sound transmission device and the flow velocity of the fluid load transmitted by the wind speed detection device, and performs fast Fourier transform on the sound signals to determine the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow velocities. The system can apply fluid loads with different flow rates to the surface of the material, test the sound absorption coefficient of the sound absorption material under the action of the fluid loads, fully consider the influence of the fluid loads with different flow rates on the sound absorption coefficient of the material, and provide real and effective data support for the acoustic design of a vehicle.

In one embodiment, as shown in FIG. 2, there is provided a sound absorption coefficient testing method comprising the steps of:

step S1: acquiring acoustic signals and flow rates of the fluid load;

step S2: carrying out fast Fourier transform on the acoustic signal to obtain the relative acoustic resistance and the relative acoustic reactance of the sound-absorbing material;

step S3: and determining the sound absorption coefficient of the sound absorption material under the action of the fluid loads at different flow rates according to the flow rate, the relative acoustic resistance and the relative acoustic reactance of the fluid loads.

In steps S1-S3, the relative acoustic resistance (R) and the relative acoustic reactance (x) of the attraction material are measured, and the measured data are substituted into equation (1) to obtain a test measurement of the acoustic impedance of the perforated plate, as follows:

wherein R is relative acoustic resistance, and X is relative acoustic reactance.

It should be understood that, although the steps in the flowchart of fig. 2 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 2 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

In one embodiment, a vehicle is also provided that includes at least the sound absorption coefficient testing system described above.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.