Static pressure balance channel silencing device

Abstract

The utility model discloses a static pressure balance channel silencing device which comprises at least one connecting shell, and an installation opening communicated with the outside is formed in the outer end of the connecting shell. The first silencing assemblies are arranged in the mounting opening at intervals in the left-right direction, each first silencing assembly comprises a plurality of silencing units arranged at intervals in the height direction, each silencing unit comprises a silencing frame, the silencing frames are filled with sound absorption cotton, the peripheries of the silencing frames are provided with anti-overflow layers, and the anti-overflow layers are just sleeved with first mesh plates; the front end and the rear end of the first mesh plate are fixedly connected with flow guide covers correspondingly. The silencer is simple in structure, convenient to install and good in silencing performance.

Description

TECHNICAL FIELD

[0001] The utility model relates to anechoic chamber acoustic technical field, especially a static pressure balance passage anechoic device. BACKGROUND

[0002] The static pressure balance passage is one of indispensable parts of the anechoic chamber, and can quickly respond and adjust to adapt to possible pressure transients during the test process to ensure the continuous stability of the test conditions when performing dynamic testing.

[0003] Although the research on large anechoic chambers has made certain progress, the research mainly focuses on the structure of the indoor sound-absorbing wedge, the arrangement of the sound-absorbing wedge, and the selection of materials, and the research on the static pressure balance passage is quite scarce. SUMMARY

[0004] This section aims to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the utility model name to avoid obscuring the purpose of this section, the abstract of the specification and the utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0005] In view of the above and / or existing problems in the large anechoic chamber, the utility model is proposed.

[0006] Therefore, the purpose of the utility model is to provide a static pressure balance passage anechoic device, which fills the technical gap of the static pressure balance passage anechoic device and improves the anechoic performance.

[0007] To solve the above technical problems, the utility model provides the following technical scheme: a static pressure balance passage anechoic device, comprising,

[0008] At least one connecting shell, and an installation opening is formed in the outer end of the connecting shell and is in communication with the outside.

[0009] A plurality of first sound-absorbing assemblies are arranged in the installation opening and are spaced apart in the left-right direction, the first sound-absorbing assembly comprises a plurality of sound-absorbing units arranged in the height direction, the sound-absorbing unit comprises a sound-absorbing frame, the sound-absorbing frame is filled with sound-absorbing cotton, the sound-absorbing frame is provided with a spill-proof layer around the periphery, the spill-proof layer is exactly sleeved with a first mesh plate, and the front and rear ends of the first mesh plate are respectively fixedly connected with a flow guide cover.

[0010] As a preferred scheme of the static pressure balance passage anechoic device in the utility model, the upper and lower ends of the first sound-absorbing assembly are slidably connected in the connecting shell.

[0011] As a prior scheme of the static pressure balance passage silencing device in the utility model, wherein: the fairing is provided with a slot at one end of the sound attenuation frame, the sound attenuation assembly further comprises two connecting vertical plates, the fairing is inserted into the connecting vertical plates through the slot, the upper and lower ends of the connecting vertical plates are fixedly connected with sliding plates respectively, the sliding plates are slidingly connected to the inner walls at the upper and lower ends of the connecting shell, and the sliding plates are fixedly connected to the connecting shell after being slid to appropriate positions.

[0012] As a prior scheme of the static pressure balance passage silencing device in the utility model, wherein: the front end of the fairing is provided with a slot at one end of the sound attenuation frame, the sound attenuation assembly further comprises two connecting vertical plates, the fairing is inserted into the connecting vertical plates through the slot, the upper and lower ends of the connecting vertical plates are fixedly connected with sliding plates respectively, the sliding plates are slidingly connected to the inner walls at the upper and lower ends of the connecting shell, and the sliding plates are fixedly connected to the connecting shell after being slid to appropriate positions.

[0013] As a prior scheme of the static pressure balance passage silencing device in the utility model, wherein: the fairing is provided with a slot at one end of the sound attenuation frame, the sound attenuation assembly further comprises two connecting vertical plates, the fairing is inserted into the connecting vertical plates through the slot, the upper and lower ends of the connecting vertical plates are fixedly connected with sliding plates respectively, the sliding plates are slidingly connected to the inner walls at the upper and lower ends of the connecting shell, and the sliding plates are fixedly connected to the connecting shell after being slid to appropriate positions.

[0014] As a prior scheme of the static pressure balance passage silencing device in the utility model, wherein: the fairing is provided with a slot at one end of the sound attenuation frame, the sound attenuation assembly further comprises two connecting vertical plates, the fairing is inserted into the connecting vertical plates through the slot, the upper and lower ends of the connecting vertical plates are fixedly connected with sliding plates respectively, the sliding plates are slidingly connected to the inner walls at the upper and lower ends of the connecting shell, and the sliding plates are fixedly connected to the connecting shell after being slid to appropriate positions.

[0015] As a prior scheme of the static pressure balance passage silencing device in the utility model, wherein: the fairing is provided with a slot at one end of the sound attenuation frame, the sound attenuation assembly further comprises two connecting vertical plates, the fairing is inserted into the connecting vertical plates through the slot, the upper and lower ends of the connecting vertical plates are fixedly connected with sliding plates respectively, the sliding plates are slidingly connected to the inner walls at the upper and lower ends of the connecting shell, and the sliding plates are fixedly connected to the connecting shell after being slid to appropriate positions.

[0016] Compared with the prior art, the utility model has the following technical effects: simple structure, convenient installation, good silencing performance, and the technical vacancy of the static pressure balance passage silencing structure of the large silencing chamber is made up, and the problem of low silencing performance in the prior art is solved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the drawings needed in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating labor intensity. Among them:

[0018] Figure 1 The front view of the utility model is installed on the wall surface.

[0019] Figure 2 The three-dimensional structure of the utility model is installed on the wall surface Figure 1 .

[0020] Figure 3 The partial enlarged view of A in the utility model Figure 2 .

[0021] Figure 4 The three-dimensional structure of the utility model is installed on the wall surface Figure 2 .

[0022] Figure 5 The sectional view of one muffling unit in the utility model

[0023] Figure 6 The partial enlarged view of B in the utility model Figure 5 .

[0024] Figure 7 The sectional view of the muffling box body in the utility model

[0025] Figure 8 The partial enlarged view of C in the utility model Figure 7 .

[0026] Figure 9 The plan view of the utility model when the several connecting housings and the muffling box bodies on the right side of the hole are fixedly connected together

[0027] Figure 10 The view of D-D in the utility model Figure 9 .

[0028] Figure 11 The partial enlarged view of E in the utility model Figure 3 .

[0029] Figure 12 It is the schematic diagram of the calculation model simplification.

[0030] Figure 13 It is the schematic diagram of the grid division.

[0031] Figure 14 It is the full flow field pressure nephogram.

[0032] Figure 15 It is the pressure balance passage nephogram.

[0033] Figure 16 It is the internal nephogram of the pressure balance passage.

[0034] Figure 17 It is the narrow band spectrum in the range of 50Hz~200Hz.

[0035] In the figure: 100 wall, 200 first sound-absorbing assembly, 201 fixed plate, 202 fairing, 2021 flat top, 2022 slot, 2023 inclined surface, 203 first mesh plate, 204 connecting vertical plate, 205 anti-collapse rod, 206 transverse support rod, 207 sealing plate, 208 sound-absorbing frame, 209 first sound-absorbing cotton, 210 first anti-overflow layer, 211 sliding plate, 300 connecting shell, 301 mounting port, 400 sliding rail, 500 fixing frame, 600 sound-absorbing box, 601 mounting cavity, 700 grid frame, 800 second sound-absorbing cotton, 900 second anti-overflow layer, 1000 second mesh plate, 2000 second sound-absorbing assembly. DETAILED DESCRIPTION

[0036] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0037] In the following description, a lot of specific details are set forth in order to facilitate a full and complete understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited by the specific embodiments disclosed below.

[0038] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. In this specification, "in one embodiment" does not mean the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments.

[0039] Embodiment 1

[0040] Reference Figures 1-6 and Figure 11 For the first embodiment of the present application, the embodiment provides a static pressure balance channel sound-absorbing device, which has simple structure, convenient installation and good sound-absorbing performance.

[0041] The application discloses a kind of static pressure balance passage silencing device, including fixed on wall body 100 and respectively arranged in the left and right ends of wall body 100 hole fixed frame 500, fixed frame 500 is fixedly connected with at least one connecting shell 300, in the application, fixed frame 500 is fixedly connected with four connecting shell 300, and the outer end of connecting shell 300 is provided with installation port 301 communicated with outside;Installation port 301 is provided with a plurality of groups of first silencing assembly 200 spaced in left and right directions, and first silencing assembly 200 includes a plurality of sound-absorbing units spaced in height direction, and the sound-absorbing unit includes sound-absorbing frame 208, the front and rear ends of sound-absorbing frame 208 are respectively sleeved with sealing plate 207, sound-absorbing frame 208 is filled with first sound-absorbing cotton 209, and the outer periphery of sound-absorbing frame 208 is provided with first anti-overflow layer 210, first anti-overflow layer 210 is just sleeved with first mesh plate 203 for sound insulation, the front and rear ends of first mesh plate 203 are respectively fixedly connected with flow guide cover 202, flow guide cover 202 is sleeved on corresponding sealing plate 207, rivet is used to connect flow guide cover 202 and sealing plate 207 on first mesh plate 203 from top to bottom, and horizontal support rod 206 is arranged in the frame, and the two ends of horizontal support rod 206 are fixedly connected with one end of two sealing plates 207, vertically arranged anti-collapse rod 205 is fixedly connected in the frame, and anti-collapse rod 205 is fixedly connected with horizontal support rod 206, the center of the end of flow guide cover 202 away from first mesh plate 203 is flat top 2021, the inclined surface 2023 capable of reducing wind resistance is arranged around flat top 2021 towards the direction of first mesh plate 203, and the setting of flat top 2021 prevents dangerous collision when maintenance personnel works.

[0042] First mesh plate 203 is made of galvanized steel plate, first anti-overflow layer 210 is preferably polyester fiber felt, first anti-overflow layer 210 is wound around sound-absorbing frame 208, and first sound-absorbing cotton 209 is made of glass fiber felt as acoustic filler, and the filling density is 16-48kg / m³, and the collapse rate of the filler is not more than 5% within the service life.

[0043] Through the setting of first silencing assembly 200, the sound transmitted from the wall outside is absorbed.

[0044] Specifically, the upper and lower ends of the first muffling assembly 200 are slidingly connected in the connecting shell 300. Specifically, the fairing 202 is provided with a slot 2022 at one end relative to the muffling frame 208. The fairing 202 is inserted on the connecting vertical plate 204 through the slot 2022. The upper and lower ends of the connecting vertical plate 204 are fixedly connected with the sliding plate 211, respectively. The sliding plate 211 is slidingly connected on the inner wall of the upper and lower ends of the connecting shell 300. After the sliding plate 211 is slidingly positioned, the sliding plate 211 is fixedly connected on the connecting shell 300. The front side of the plurality of connecting vertical plates 204 at the front end and the rear side of the plurality of connecting vertical plates 204 at the rear end are fixedly connected with the fixed plate 201, respectively. The left and right sides of the fixed plate 201 are fixedly connected on the inner wall of the left and right ends of the connecting shell 300, respectively. The inner wall of the upper and lower ends of the connecting shell 300 is fixedly provided with the sliding rail 400 corresponding to the sliding plate 211, respectively. The upper sliding plate 211 has an upward sliding groove. The lower sliding plate 211 has a downward sliding groove. The sliding plate 211 is slidingly connected on the corresponding sliding rail 400 through the sliding groove.

[0045] The connecting vertical plate 204 is provided with a plurality of fixing holes. The connecting vertical plate 204 and the sealing plate 207 are screwed by using the fixing bolt. The connecting vertical plate 204 is fixedly connected on the sealing plate 207. The fairing 202 is inserted on the connecting vertical plate 204 through the slot 2022. The fairing 202 is sleeved on the sealing plate 207. The fairing 202 and the sealing plate 207 are fixedly connected on the first mesh plate 203 and the muffling frame 208 by using the rivet. Before the first muffling assembly 200 is installed, the two fixed plates 201 are fixed on the rear side of the plurality of connecting vertical plates 204 at the front end and the plurality of connecting vertical plates 204 at the rear end, respectively. When the first muffling assembly 200 is installed in the corresponding connecting shell 300, the sliding groove of the sliding plate 211 is aligned with the corresponding sliding rail 400. The upper and lower ends of the first muffling assembly 200 are slidingly inserted in the connecting shell 300 through the sliding rail 400. When the first muffling assembly 200 is pushed into the connecting shell 300 to the position, the left and right ends of the fixed plate 201 are fixedly connected in the connecting shell 300 by using the rivet and other fixing members, respectively. The installation of the first muffling assembly 200 and the connecting shell 300 is realized. The installation is convenient.

[0046] Embodiment 2

[0047] With reference to Figures 7-10 The embodiment provides a static pressure balance channel muffling device. The static pressure balance channel muffling device is different from the embodiment 1. The static pressure balance channel muffling device can further improve the muffling performance.

[0048] Specifically, the inner end of the connecting shell 300 is fixedly connected with a sound-absorbing box body 600, the sound-absorbing box body 600 has a mounting cavity 601 communicating with the mounting port 301, and the second sound-absorbing assembly 2000 is mounted in the mounting cavity 601 of the sound-absorbing box body 600. The structure of the second sound-absorbing assembly 2000 is the same as that of the first sound-absorbing assembly 200, and the flow deflector 202 in the second sound-absorbing assembly 2000 faces the first mesh plate 203 in the first sound-absorbing assembly 200, that is, the arrangement direction of the second sound-absorbing assembly 2000 and the first sound-absorbing assembly 200 is perpendicular, as shown in Figure 10

[0049] Specifically, the sound-absorbing box body 600 is provided with a grid frame 700 attached to the inner wall of the sound-absorbing box body 600, the grid frame 700 is provided with second sound-absorbing cotton 800, the inner side of the second sound-absorbing cotton 800 is provided with a second anti-overflow layer 900 in the grid frame 700, the inner side of the second anti-overflow layer 900 is fixedly provided with a second mesh plate 1000, the structure of the second mesh plate 1000 is similar to that of the first mesh plate 203, the material of the second anti-overflow layer 900 is the same as that of the first anti-overflow layer 210, and the structure of the second sound-absorbing cotton 800 is the same as that of the first sound-absorbing cotton 209.

[0050] The sound entering the sound-absorbing box body 600 is further absorbed by the second sound-absorbing assembly 2000, and the structure of the second mesh plate 1000, the second anti-overflow layer 900 and the second sound-absorbing cotton 800 on the wall surface of the sound-absorbing box body 600 further absorbs the sound, thereby improving the sound-absorbing performance.

[0051] Embodiment 3

[0052] Referring to Figures 12-15 , the present embodiment provides a static pressure balance channel sound-absorbing device, which is different from that of embodiment 2 in that the technical effect of the present application is verified by scientific research verification means.

[0053] According to the simplified calculation model of the sound-absorbing device structure, the calculation model schematic diagram is as shown in Figure 12 , through the simplified model, the movable contraction section, the collector front section, the collector rear section, the windward surface acoustic treatment structure, the static pressure balance channel and the outer wall of the sound-absorbing chamber are reserved, the inlet of the movable contraction section in the model is set as a velocity inlet (Velocity Inlet), the outlet of the collector rear section is set as a pressure outlet, the fluid domain medium is ideal gas, and the gas parameters are standard atmospheric pressure (P0=101325Pa, T0=288.15K). By adjusting the inlet velocity, the stable wind speed of the test section is 90m / s.

[0054] The calculation domain is divided by using a non-structural grid division method, and the flow wall surface and the grid boundary are meshed.

[0055] ​Boundary layer mesh refinement was performed on the ductile surface. The first layer had a height of 0.1 mm, a growth rate of 1.2, and a total of 10 layers. The final mesh is shown below. Figure 13 As shown.

[0056] A density-based solver was used, which is well-adapted to different mesh qualities and produces results that are not significantly different from those obtained with a pressure-based solver. The SST k-omega model was chosen as the turbulence model, as it performs well for low Reynolds number flows.

[0057] The solution method employs an implicit scheme. Due to the subsonic flow, the Roe-FDS solver (an implicit solution method used in fluid mechanics) is selected. The pressure gradient is based on least-squares elements. In the spatial discretization, the flow is a second-order upwind scheme, while the rest are first-order. Simultaneously, the warped-face gradient correction and high-order term relaxation options are activated to improve computational accuracy and stability. The Courant number is set to 5, with the rest remaining at their default values.

[0058] The initialization method is mixed initialization.

[0059] Calculation results:

[0060] The anechoic chamber in this application is only a part of the overall wind tunnel project, which also includes a fan section, etc. The fan section provides a continuous airflow to the entire flow field. The airflow is blown out from the fan section, flows into the anechoic chamber through the contraction section, and flows out from the collector outlet. Assuming a stable flow velocity of 90 m / s in the test section, the calculation results are as follows: Figure 14 As shown in the figure, the airflow in the test section creates a high-pressure zone around the collector due to the influence of the airflow in the anechoic chamber.

[0061] from Figure 15 and Figure 16 As can be seen from the pressure balance channel cloud diagram, the channel outlet pressure is positive, indicating that the channel is in the intake state at this time.

[0062] Table 1. Mass flow balance in the static pressure balance channel

[0063]

[0064] From table 1, it can be seen that the inflow flow of the contraction section is not equal to the outflow flow of the collector, in order to ensure the pressure balance inside and outside the sound attenuation chamber, the static pressure balance channel supplements the flow shortage in time, and after the flow field is stable, it can be seen that the difference between the inlet and outlet flow of the whole flow field is 0.01%, the static pressure balance channel can quickly respond and adjust, can adapt to the pressure transients that may occur during the test, ensure the continuous stability of the test conditions, and make up the technical gap of the sound attenuation structure of the static pressure balance channel of the large sound attenuation chamber.

[0065] Sound insulation amount calculation:

[0066] The port in the comsol software is used to calculate the transmission loss, and the calculation result is shown in the table 1. Figure 17 As shown in table 1, the sound insulation amount at all frequency points in the range of 50Hz~200Hz is greater than 20dB, the minimum point is 50Hz, and the corresponding sound insulation amount is 21.63dB.

[0067] In the present application, the direction is referred to the front view, the direction perpendicular to the paper surface is the front-back direction, the horizontal direction parallel to the paper surface is the left-right direction, and the vertical direction parallel to the paper surface is the height direction.

[0068] It should be noted that the above examples are only used to illustrate the technical solutions of the present application, but not limit the present application, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A hydrostatically balanced passage silencing device, characterized by: The utility model relates to a sound-absorbing device for vehicle engine, which comprises a connecting shell, a plurality of first sound-absorbing assemblies arranged in the left-right direction and a second sound-absorbing assembly. The upper and lower ends of the first sound-absorbing assembly are slidably connected in the connecting shell. One end of the fairing is provided with a slot relative to the sound-absorbing frame, and the sound-absorbing assembly further comprises two connecting vertical plates.

2. The static pressure balanced passage silencing device of claim 1, wherein: The fairing is inserted into the connecting vertical plate through the slot.

3. The static pressure balanced passage silencing device of claim 2, wherein: The upper and lower ends of the connecting vertical plate are respectively fixedly connected with sliding plates.

4. The static pressure balanced passage silencing device of claim 3, wherein: The left and right sides of the fixed plate are respectively fixedly connected to the inner walls of the left and right ends of the connecting shell.

5. The static pressure balanced passage silencing device of claim 3, wherein: The inner walls of the upper and lower ends of the connecting shell are respectively fixed with sliding tracks corresponding to the sliding plates.

6. A static pressure balancing passage silencing device according to claim 4 or 5, characterized in that: The upper sliding plate has an upward sliding groove, and the lower sliding plate has a downward sliding groove.

7. The static pressure balanced passage silencing device of claim 6, wherein: The connecting shell is fixedly connected with a sound-absorbing box body at the inner end. The sound-absorbing box body has a mounting cavity communicating with the mounting port. The second sound-absorbing assembly is installed in the mounting cavity of the sound-absorbing box body. The structure of the second sound-absorbing assembly is the same as that of the first sound-absorbing assembly. The fairing of the second sound-absorbing assembly faces the first mesh plate of the first sound-absorbing assembly. The sound-absorbing box body is provided with a grid frame attached to the inner walls of the sound-absorbing box body. The grid frame is provided with sound-absorbing cotton. The inner side of the sound-absorbing cotton is provided with an anti-overflow layer. The inner side of the anti-overflow layer is fixedly connected with a second mesh plate.

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