CN114127840A

CN114127840A - Sound-absorbing stirring device

Info

Publication number: CN114127840A
Application number: CN202080052362.9A
Authority: CN
Inventors: 冨堂绫香; 秋松龙之介; 佐藤广之; 井手辰次
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2019-07-22
Filing date: 2020-07-03
Publication date: 2022-03-01
Also published as: JP2021018356A; WO2021014941A1

Abstract

The passage member (10) has a passage through which air flows. The microperforated plate (20) is a plate-like member having a plurality of fine through-holes (21) penetrating therethrough, and is disposed such that one surface faces the flow field (11) of air in the passage and the other surface faces the inner wall surface (13) of the passage member (10) with an air layer (12) of a constant thickness interposed therebetween, and the microperforated plate (20) exerts a viscosity attenuation action by the air passing through the through-holes (21). The plurality of through holes (21) are arranged linearly in a direction perpendicular to the Center Line (CL) of the passage.

Description

Sound-absorbing stirring device

Cross reference to related applications

The present application is based on japanese patent application No. 2019-134789 filed on 7/22/2019, the contents of which are incorporated herein by reference.

Technical Field

The present invention relates to a sound-absorbing stirring device that absorbs sound propagating through a fluid and stirs the fluid.

Background

Conventionally, a technique is known in which a sound absorbing effect is obtained by providing a perforated plate in front of a rigid wall with an air layer interposed therebetween. Patent document 1 discloses a structure in which a porous plate is provided on the inner wall of a cylindrical pipe with an air layer interposed therebetween, thereby absorbing sound propagating through the pipe.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-9483

However, the inventors have made intensive studies on a structure in which a fine perforated plate is provided on the inner wall of a passage member with an air layer interposed therebetween. Here, the Micro perforated plate is a plate-like member having a plurality of fine through holes penetrating therethrough, and is also referred to as MPP (Micro perforated plate). As a result, the inventors have found that, when air flows through the air flow field of the passage member, a state in which the air in the air layer is blown out to the flow field through the through holes of the fine perforated plate and a state in which the air flowing through the flow field enters the air layer through the through holes are repeated at a constant cycle.

The inventors have thus found that by providing a fine perforated plate on the inner wall of the passage member with a constant space therebetween, it is possible to reduce noise and to stir the fluid flowing through the passage member.

The structure described in patent document 1 does not consider the influence of air blown out from the holes of the porous plate or air entering the air layer from the flow field through the holes of the porous plate on air flowing in the pipe. The structure described in patent document 1 is intended only to reduce noise, and is not intended to stir air flowing in a pipe.

In the structure described in patent document 1, when the purpose is to reduce noise and stir a fluid, the porous plate does not have a large influence on the fluid, and a separate structure for stirring the fluid is required. In addition, when a structure for stirring a fluid is added to the structure described in patent document 1, noise is likely to be deteriorated.

Disclosure of Invention

The present invention aims to provide a sound-absorbing stirring device which absorbs sound propagating in air and stirs the air.

In accordance with one aspect of the present invention,

a sound-absorbing stirring device for absorbing sound propagating in air and stirring the air, comprising:

a passage member having a passage through which air flows; and

a micro-perforated plate which is a plate-like member having a plurality of fine through holes penetrating therethrough, and which is provided such that one surface faces a flow field of air in the passage and the other surface faces an inner wall surface of the passage member with an air layer having a constant thickness interposed therebetween, and which generates a viscosity attenuation effect by the air passing through the through holes,

the plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage.

Thus, as described above, when air flows at a constant flow rate in the flow field of air in the passage member, a state in which the air in the air layer is blown out toward the flow field through the through holes of the fine perforated plate and a state in which the air flowing in the flow field enters the air layer through the through holes are repeated. In this case, the micro perforated plate is disposed so as to face the inner wall surface of the passage member with an air layer of a constant thickness interposed therebetween, and the periods of air blowing from the plurality of through holes to the flow field are synchronized. The plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage, and thus the vortex of the plurality of air blown out from the plurality of through holes substantially simultaneously to the flow field forms a vortex core in the direction orthogonal to the center line of the passage. Therefore, in the vicinity of the fine perforated plate, the air turbulence becomes large, and the air flow disturbance is promoted. Therefore, the sound-absorbing stirring device can stir the air flowing through the passage member.

The micro-perforated plate is configured to generate a viscosity attenuation effect by air passing through the plurality of micro through holes. Therefore, the sound-absorbing stirring device can absorb sound transmitted in the air flowing through the passage member.

In addition, the straight line in the present specification includes a state in which a plurality of through holes are slightly (specifically, about 1/2 of the hole diameter) shifted due to manufacturing tolerance or the like, in addition to a straight line.

In addition, from another point of view,

a passage member having a passage through which air flows; and

the plurality of through holes are arranged linearly in parallel with the center line of the passage.

Thus, as described above, when air flows at a constant flow rate in the flow field of air in the passage member, a state in which the air in the air layer is blown out toward the flow field through the through holes of the fine perforated plate and a state in which the air flowing in the flow field enters the air layer through the through holes are repeated. In this case, the micro perforated plate is disposed so as to face the inner wall surface of the passage member with an air layer of a constant thickness interposed therebetween, and the periods of air blowing from the plurality of through holes to the flow field are synchronized. Further, since the plurality of through holes are arranged linearly in parallel with the center line of the passage, the vortex of the air blown out from the through hole on the upstream side and the vortex of the air blown out from the through hole on the downstream side interfere with each other, and the vortices gradually increase from the upstream side toward the downstream side. Therefore, in the vicinity of the fine perforated plate, the air turbulence becomes large, and the air flow disturbance is promoted. Therefore, the sound-absorbing stirring device can stir the air flowing through the passage member.

Further, since the fine perforated plate produces a viscosity attenuation effect, the sound-absorbing stirring device can absorb sound propagated in the air flowing through the passage member.

The parenthesized reference numerals for each component and the like indicate an example of the correspondence between the component and the like and the specific component and the like described in the embodiment described later.

Drawings

Fig. 1 is a cross-sectional view parallel to the center line of the passage of the sound-absorbing stirring device according to the first embodiment.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a sectional view taken along line III-III of fig. 1.

Fig. 4 is a diagram for explaining a viscosity-attenuating effect by a fine perforated plate of the sound-absorbing stirring device.

Fig. 5A is a diagram illustrating a model of an experiment in the sound-absorbing stirring apparatus.

Fig. 5B is a view showing a state where air flows through the sound-absorbing stirring device.

Fig. 5C shows a state where air flows through the sound-absorbing stirring device, and is a view subsequent to fig. 5B.

Fig. 5D shows a state where air flows through the sound-absorbing stirring device, and is a view subsequent to fig. 5C.

Fig. 5E shows a state where air flows through the sound-absorbing stirring device, and is a view subsequent to fig. 5D.

Fig. 5F shows a state where air flows through the sound-absorbing stirring device, and is a view subsequent to fig. 5E.

Fig. 6A is a diagram for explaining a model of an experiment in the sound absorbing and stirring apparatus.

Fig. 6B is a view showing a state where air flows through the sound-absorbing stirring device.

Fig. 6C shows a state where air flows through the sound-absorbing stirring device, and is a view subsequent to fig. 6B.

Fig. 6D shows a state where air flows through the sound-absorbing stirring device, and is a view subsequent to fig. 6C.

Fig. 6E shows a state where air flows through the sound-absorbing stirring device, and is a view following fig. 6D.

Fig. 6F shows a state where air flows through the sound-absorbing stirring device, and is a view following fig. 6E.

Fig. 7 is a diagram for explaining the arrangement of through holes of the micro-perforated plate and the operation thereof in section VII of fig. 3.

Fig. 8 is a diagram for explaining the arrangement of through holes of the micro-perforated plate and the operation thereof in section VIII of fig. 1.

Fig. 9 is a diagram for explaining a positional shift amount of the through-hole of the fine perforated plate.

Fig. 10 is a diagram for explaining the pitch of through holes of the fine perforated plate.

Fig. 11 is a sectional view of an air conditioning unit provided with the sound-absorbing stirring device according to the second embodiment.

Fig. 12 is a view in the direction XII in fig. 11.

Fig. 13 is an enlarged view of XIII part of fig. 11.

Fig. 14 is a plan view of the sound-absorbing stirring device according to the third embodiment.

Fig. 15 is a plan view of the sound-absorbing stirring device according to the fourth embodiment.

Fig. 16 is a plan view of the sound-absorbing stirring device according to the fifth embodiment.

Fig. 17 is a plan view of the sound-absorbing stirring device according to the sixth embodiment.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same or equivalent portions are denoted by the same reference numerals and the description thereof is omitted.

(first embodiment)

The first embodiment is explained with reference to the drawings. The sound absorbing/stirring device according to the present embodiment is installed in, for example, a vehicle air conditioner or a blow duct, and absorbs sound propagating through the air to stir the air.

As shown in fig. 1 to 3, the sound-absorbing agitation apparatus includes a passage member 10, a micro perforated plate 20, and the like. The passage member 10 is formed in a rectangular shape in cross section, for example, and has a passage for air to flow inside thereof. The cross-sectional shape of the passage member 10 is not limited to a rectangular shape, and various shapes such as a circle, an ellipse, a polygon, or a combination thereof may be employed.

In fig. 1 and 3, the main flow direction of air flowing through the passage of the passage member 10 is indicated by hollow arrows. In the present embodiment, the main flow direction of the air flowing through the passage of the passage member 10 coincides with the direction of the center line CL of the passage. The center line CL of the passage member 10 is a virtual line that is the center of the opposing wall surfaces of the wall surfaces that form the flow field of air.

A micro perforated plate 20 is fixed to the inner wall of the passage member 10. The micro-perforated plate 20 is a plate-like member having a plurality of micro through holes 21. The Micro perforated plate 20 is called MPP (abbreviation of Micro perforated plate). Specifically, the diameter d of the through hole 21 is larger than 0 and 1mm or less. The micro perforated plate 20 is disposed such that one face faces the flow field 11 of air in the channel and the other face opposes the inner wall surface 13 of the channel member 10 via an air layer 12 of a constant thickness. The portion of the passage member 10 where the micro-perforated plate 20 is provided is not limited to one surface of the inner wall of the passage member 10, and may be a plurality of surfaces or all surfaces.

The micro-perforated plate 20 is configured to generate a viscosity attenuation effect by air passing through the plurality of through holes 21. Here, the viscosity attenuation action will be explained.

When the plurality of fine through holes 21 provided in the fine perforated plate 20 are considered as capillaries, whether or not the viscosity attenuation action is exerted is determined according to the action of the viscous boundary layer. Whether viscous damping is effective or not can be investigated by the reynolds number of the sound. Fig. 4 shows the diameter d of the through hole 21 and the thickness t of the viscous boundary layer. In fig. 4, the thickness t of the viscous boundary layer is indicated by hatching with a dotted line.

Density of air: rho [ kg/m ]³]；

Viscous heat: eta [ Pa · s ];

angular frequency: ω [ rad/s ], in this case, the reynolds number Rey of the sound is represented by the following formula 1.

[ numerical formula 1]

Then, if Rey <10, viscosity attenuation works. Accordingly, the micro perforated plate 20 generates a frictional force due to the viscosity of the air between the inner wall of the through hole 21 and the air in contact with the inner wall, and can absorb and attenuate the sound propagating through the air flowing through the flow field 11 of the passage member 10.

Further, the inventors have made extensive studies on a structure in which a micro perforated plate 20 is provided on the inner wall of the passage member 10 via an air layer 12 as in the sound-absorbing stirring apparatus of the present embodiment, and as a result, found the following. That is, the inventors found that if air flows at a constant flow rate through the air flow field 11 of the passage member 10, the first state and the second state, which will be described later, are repeated at a constant cycle. The first state is a state in which air in the air layer 12 is blown out to the flow field 11 through the through holes 21 of the micro perforated plate 20. The second state refers to a state in which air flowing in the flow field 11 enters the air layer 12 through the through holes 21.

Fig. 5A is a diagram for explaining a model used in an experiment of the sound-absorbing stirring apparatus. In fig. 5A, the main flow direction of air flowing through the flow field 11 of the passage member 10 is also indicated by hollow arrows. The main flow direction coincides with a center line CL of the passage member 10.

In this model, the plurality of through holes 21 penetrating the micro perforated plate 20 are linearly arranged in parallel with the center line CL of the passage. The through holes 21 used in the experiment had a diameter d of 1.0 mm. The distance P between the center of one through-hole 21 and the center of the other through-hole 21 adjacent to each other in the main flow direction is 3 mm.

In the model as shown in fig. 5A, air flows through the flow field 11 of the passage at a constant wind speed U. The wind speed U is 10 m/s.

Then, the fine particles are arranged in the air layer 12, and the state where the air in the visualized air layer 12 is blown out to the flow field 11 through the through holes 21 of the fine perforated plate 20 and the state where the air flowing in the flow field 11 enters the air layer 12 through the through holes 21 are visually evaluated. Fig. 5B to 5F are diagrams of images obtained by the experiment after binarization processing.

Fig. 5B shows a state in which the air in the air layer 12 starts to be blown out to the flow field 11 through the plurality of through holes 21 after the start of the experiment. As described above, the air blown from the air layer 12 to the flow field 11 through the plurality of through holes 21 is visualized by the fine particles disposed in the air layer 12. The air in the air layer 12 starts to be blown out from the plurality of through holes 21 to the flow field 11 at substantially the same time.

Fig. 5C shows a state following fig. 5B. At this time, the air blown out from the air layer 12 to the flow field 11 through the plurality of through holes 21 is substantially simultaneously swirled and moved to the downstream side by the wind flowing through the flow field 11.

Fig. 5D shows a state following fig. 5C. At this time, the air blown out from the air layer 12 to the flow field 11 through the plurality of through holes 21 interferes with the air blown out from the through holes 21 on the upstream side, and the air starts to grow.

Fig. 5E shows a state following fig. 5D. At this time, the swirl of the air blown out from the air layer 12 to the flow field 11 through the plurality of through holes 21 further increases from the upstream side toward the downstream side.

Fig. 5F shows a state following fig. 5E. At this time, the state in which the air is blown out from the air layer 12 to the flow field 11 through the plurality of through holes 21 is completed. After that, the air flowing through the flow field 11 enters the air layer 12 through the through-holes 21.

After a predetermined time has elapsed from the state of fig. 5F, the phenomena of fig. 5B to 5F described above are repeated again at a predetermined cycle. When the air flows through the flow field 11 of the passage member 10 at a constant flow rate in this way, the air in the air layer 12 is repeatedly blown out from the plurality of through holes 21 to the flow field 11 and blown into the air layer 12 from the flow field 11 through the through holes 21 at a constant cycle as if the air is breathing.

Fig. 6A is the same as fig. 5A. Fig. 6B to 6F show the same states as fig. 5B to 5F, and images obtained by the above-described experiment are shown in grayscale. However, although the gradation is binarized in the international application, it is described for the sake of understanding.

From the above experimental results, the inventors found that the sound-absorbing stirring device can reduce noise and stir air flowing through the passage member 10. When the sound-absorbing agitation apparatus of the present embodiment is installed in, for example, a vehicle air conditioner or an outlet duct, the temperature and humidity of the conditioned air blown out from an outlet provided in the vehicle interior can be made uniform while reducing noise, thereby improving the air conditioning performance.

In the present embodiment, as shown in fig. 7 and 8, the plurality of through holes 21 are arranged linearly in a direction orthogonal to the center line CL of the passage. The distance between the inner wall surface 13 of the passage member 10 and the microperforated plate 20 is set to be constant, and the air layer 12 formed between the inner wall surface 13 of the passage member 10 and the microperforated plate 20 is set to be constant in thickness.

Thus, by providing the micro perforated plate 20 with the air layer 12 having a constant thickness interposed therebetween, the periods of air blown from the plurality of through holes 21 to the flow field 11 are synchronized. Further, the plurality of through holes 21 are arranged linearly in the direction orthogonal to the center line CL of the passage, and thus, as shown by an arrow V in fig. 7, the vortex flow of the plurality of air blown out from the plurality of through holes 21 substantially simultaneously to the flow field 11 forms a vortex core in the direction orthogonal to the center line CL of the passage. Therefore, in the vicinity of the fine perforated plate 20, the air turbulence becomes large, and the air flow disturbance is promoted. Therefore, the sound-absorbing stirring device can stir the air flowing through the passage member 10.

In the present embodiment, the plurality of through holes 21 are arranged linearly in parallel with the center line CL of the passage. Therefore, as shown by the arrow V in fig. 8, the vortices of the plurality of air blown out from the plurality of through holes 21 toward the flow field 11 substantially simultaneously interfere with each other, and the vortices gradually grow from the upstream side toward the downstream side. Therefore, in the vicinity of the fine perforated plate 20, the air turbulence becomes large, and the air flow disturbance is promoted. Therefore, the sound-absorbing stirring device can stir the air flowing through the passage member 10.

As shown in fig. 9, in the present embodiment, the plurality of through holes 21 are not limited to being arranged in a completely straight line with respect to the direction parallel to the center line CL of the passage, and the through holes 21 may be arranged with a slight shift with respect to the direction parallel to the center line CL of the passage. Specifically, the eddy Vo generated from the plurality of through holes 21 is larger than the hole diameter d of the through holes 21. Therefore, the distance S between the center of the upstream through-hole 21 adjacent to the center of the downstream through-hole 21 in the main flow direction may be shifted in the direction perpendicular to the center line CL of the passage in the range of not more than 1/2 of the hole diameter d of the through-hole 21. Even when the plurality of through holes 21 are arranged in this manner, the vortices of the plurality of air blown out from the plurality of through holes 21 to the flow field 11 substantially simultaneously interfere with each other, and these vortices can gradually grow from the upstream side to the downstream side.

As shown in fig. 10, the distance P between the center of the upstream through hole 21 and the center of the downstream through hole 21 adjacent to each other in the main flow direction is set to a distance at which the vortex generated from the upstream through hole 21 reaches the vortex generated from the downstream through hole 21 and the vortices can interfere with each other. The distance P can be set as appropriate by an experiment or the like.

(second embodiment)

A second embodiment will be explained. The second embodiment describes an embodiment in which a sound-absorbing agitation apparatus is provided in an air conditioning unit of a vehicle air conditioning apparatus.

As shown in fig. 11, an air conditioning unit 1 of an air conditioning device for a vehicle includes an air conditioning casing 2, an evaporator 4, a heater core 5, an air mix door 6, an outlet opening door 7, and the like.

The air conditioning casing 2 is a member corresponding to the passage member 10 of the sound-absorbing agitation apparatus. The air conditioning casing 2 is formed of a resin (e.g., polypropylene) having a certain degree of elasticity and excellent strength. The air conditioning case 2 forms an outer shell of the air conditioning unit 1. A passage (i.e., an air flow field 11) through which air blown into the vehicle interior flows is formed inside the air conditioning casing 2. In fig. 11, the flow direction of air in the passage is indicated by an open arrow.

The air conditioning casing 2 further includes a plurality of outlet openings 8 for blowing air toward a predetermined area in the vehicle interior on the downstream side in the air flow direction of the passage.

Inside the air conditioning casing 2, an evaporator 4, a heater core 5, an air mix door 6, a blow-out opening door 7, and the like are provided.

The evaporator 4 is a heat exchanger for cooling air flowing through the passage. The evaporator 4 constitutes a part of a refrigeration cycle not shown. The evaporator 4 exchanges heat between the low-pressure refrigerant flowing therein and the air passing through the evaporator 4, evaporates the refrigerant, and cools the air.

The heater core 5 is a heat exchanger for heating air flowing through the passage. The heater core 5 exchanges heat between the engine cooling water or the high-pressure refrigerant flowing therein and the air passing through the heater core 5, and heats the air by using the heat of the engine cooling water or the high-pressure refrigerant.

The passage in the air conditioning casing 2 has a bypass passage 51 outside the heater core 5, through which air flows so as to bypass the heater core 5.

In the passage of the air conditioning unit 1, an air mix door 6 is provided between the evaporator 4 and the heater core 5. The air mix door 6 adjusts the air volume ratio of the air flowing through the evaporator 4 and bypassing the heater core 5 (i.e., the air flowing through the bypass passage 51) to the air flowing through the heater core 5 after passing through the evaporator 4.

The outlet opening door 7 is provided in one first outlet opening 81 of the plurality of outlet openings 8, and adjusts the opening area of the first outlet opening 81. In fig. 11, the outlet opening door provided in the second outlet opening 82 of the other of the plurality of outlet openings 8 is not shown, but an outlet opening door may be provided in the second outlet opening 82 in the same manner as in the first outlet opening 81.

The micro perforated plate 20 included in the sound-absorbing and stirring device according to the second embodiment is provided inside the air-conditioning casing 2 in order to absorb sound propagating through the air-conditioning casing 2 and stir air flowing through the air-conditioning casing 2. In fig. 11, a portion where the micro perforated plate 20 is provided in the air-conditioning casing 2 is illustrated by a broken line. However, the location where the micro perforated plate 20 is provided is not limited to the location shown in fig. 11, and may be any location on the inner wall of the air-conditioning casing 2. Thus, the sound-absorbing/agitating device can improve air conditioning performance by making uniform the temperature and humidity of the conditioned air blown out from the air outlet provided in the vehicle interior while reducing the noise emitted from the air conditioning device into the vehicle interior.

As shown in fig. 12 and 13, the sound-absorbing stirring device of the second embodiment includes a partition plate 30 that partitions an air layer 12. In fig. 12, the microperforated panel 20 is viewed from the flow field 11 of the air in the air-conditioning casing 2, but for the sake of easy viewing of the drawing, the microperforated panel 20 is seen in perspective and the partition plate 30 disposed on the passage member 10 side with respect to the microperforated panel 20 is shown by solid lines. In fig. 12 and 13, the main flow direction of the air flow in the passage is also indicated by an open arrow. This is also the same in fig. 14 to 17 referred to in the third to sixth embodiments described later.

The partition plate 30 is a plate-like member that connects the inner wall surface of the passage member 10 (i.e., the air conditioning casing 2) and the micro perforated plate 20. Of the partition plates 30, the partition plate extending in the direction orthogonal to the center line CL of the passage is referred to as a first partition plate 31. The first partition plates 31 are arranged to be aligned in a direction orthogonal to the center line CL of the passage. This makes it possible to more reliably synchronize the periods in which air is blown out to the flow field 11 from the plurality of through holes 21 arranged linearly in the direction orthogonal to the center line CL of the passage.

The partition plate 30 extending parallel to the center line CL of the passage is referred to as a second partition plate 32. The second partition plate 32 is provided to be aligned in parallel with the center line CL of the passage.

In the second embodiment, a plurality of partitions are formed by the inner wall surface 13 of the passage member 10, the microperforated panel 20, and the partition plate 30. In addition, the number of through holes 21 provided in each of the plurality of partitions is the same. The ratio of the number of holes of the through hole 21 provided in each of the plurality of partitions to the volume of the partition is set to be the same. In the present specification, the same means that the manufacturing tolerances are also within the same range, except for the exact same.

Accordingly, since the pressure fluctuations in the plurality of zones are synchronized, the period in which air is blown from the air layer 12 through the plurality of through holes 21 to the flow field 11 of air in the air-conditioning casing 2 can be synchronized. Therefore, the sound-absorbing stirring device further increases the eddy current of the air in the vicinity of the micro perforated plate 20, and promotes the turbulence of the air flow, thereby further exhibiting the stirring effect of the air.

(third to sixth embodiments)

The third to sixth embodiments will be explained. The third to sixth embodiments are embodiments in which the configuration of the partition plate 30 is changed from the first and second embodiments, and the other embodiments are the same as the first and second embodiments, and therefore only the portions different from the first and second embodiments will be described.

(third embodiment)

As shown in fig. 14, in the third embodiment, a second partition plate 32 extending parallel to the center line CL of the passage is provided in the partition plate 30. On the other hand, in the third embodiment, the first partition plate 31 extending in the direction orthogonal to the center line CL of the passage in the partition plate 30 is not provided.

In the third embodiment, the number of through holes 21 provided in each of the plurality of partitions formed by the inner wall surface 13 of the passage member 10, the micro perforated plate 20, and the partition plate 30 is also set to be the same. Further, the volume of each of the plurality of partitions is set to be the same. Therefore, in the third embodiment, the periods in which the air is blown out from the plurality of through holes 21 to the flow field 11 can be synchronized.

(fourth embodiment)

As shown in fig. 15, in the fourth embodiment, a first partition plate 31 extending in a direction orthogonal to the center line CL of the passage is provided in the partition plate 30. On the other hand, in the fourth embodiment, the second partition plate 32 extending in parallel with the center line CL of the passage in the partition plate 30 is not provided.

In the fourth embodiment, the number of through holes 21 provided in each partition is also set to be the same. Further, the volume of each of the plurality of partitions is set to be the same. Therefore, in the fourth embodiment, the periods in which the air is blown out from the plurality of through holes 21 to the flow field 11 can also be synchronized.

(fifth embodiment)

As shown in fig. 16, in the fifth embodiment, both of the first partition plate 31 extending in the direction orthogonal to the center line CL of the passage and the second partition plate 32 extending in parallel to the center line CL of the passage in the partition plate 30 are provided.

In fig. 16, the square of the one-dot chain line indicated by the symbol α indicates the volume of the air layer 12 allocated to one through-hole 21.

In the fifth embodiment, the number of through holes 21 provided in each partition is not set to be the same. Further, in the plurality of partitions, the volume of each partition is not set to be the same. However, in the plurality of partitions, the volume of the air layer 12 assigned to one through hole 21 is set to be the same. Therefore, in the plurality of partitions, the ratio of the number of through holes 21 provided in each partition to the volume of the partition is the same. Therefore, in the fifth embodiment, the periods in which the air is blown out from the plurality of through holes 21 to the flow field 11 can also be synchronized.

(sixth embodiment)

As shown in fig. 17, in the sixth embodiment, the first partition plate 31 is formed in a prescribed corrugated shape, and a plurality of corrugations constituting the corrugated shape are arranged in a direction orthogonal to the center line CL of the passage. The second partition plate 32 is also formed in a predetermined corrugated shape, and a plurality of corrugations constituting the corrugated shape are arranged in a direction orthogonal to the center line CL of the passage.

In the sixth embodiment, the number of through holes 21 provided in each partition is the same. Further, each of the plurality of partitions has the same volume. In the plurality of partitions, the ratio of the number of through holes 21 provided in each partition to the volume of the partition is the same. Therefore, in the sixth embodiment, the periods in which the air is blown out from the plurality of through holes 21 to the flow field 11 can also be synchronized.

As described above, in the third to sixth embodiments, the periods in which the air is blown out from the plurality of through holes 21 to the flow field 11 can be synchronized. The plurality of through holes 21 are arranged linearly in a direction orthogonal to the center line CL of the passage. Further, the plurality of through holes 21 are linearly arranged in parallel with the center line CL of the passage. Therefore, the sound-absorbing stirring devices according to the third to sixth embodiments can exhibit the air stirring effect by further increasing the air vortex near the micro perforated plate 20 and promoting the turbulence of the air flow.

(other embodiments)

The present invention is not limited to the above-described embodiments, and can be modified as appropriate. The above embodiments are not independent of each other, and may be appropriately combined unless they are obviously not combined. In the above embodiments, it goes without saying that elements constituting the embodiments are not necessarily essential, except for cases where they are explicitly indicated as being particularly essential and where they are considered to be obviously essential in principle. In the above embodiments, the number of components of the embodiments is not limited to a specific number except for the case where the number, the numerical value, the number, the range, and other numerical values of the components of the embodiments are mentioned, particularly the case where the components are clearly indicated as necessary, and the case where the components are clearly limited to a specific number in principle. In the above embodiments, when referring to the shape, positional relationship, and the like of the constituent elements and the like, the shape, positional relationship, and the like are not limited to those unless explicitly stated otherwise or limited to a specific shape, positional relationship, and the like in principle.

(1) In each of the above embodiments, the plurality of through holes 21 are all arranged linearly in a direction orthogonal to the center line CL of the passage, but the present invention is not limited thereto. A part of the plurality of through holes 21 may be disposed at a position shifted from a direction orthogonal to the center line CL of the passage.

(2) In each of the above embodiments, the plurality of through holes 21 are all arranged linearly in a direction parallel to the center line CL of the passage, but the present invention is not limited thereto. A part of the plurality of through holes 21 may be disposed at a position shifted from a direction parallel to the center line CL of the passage.

(3) In the above embodiments, the number of through holes 21 provided in each partition is the same, but the present invention is not limited thereto, and some of the through holes 21 provided in the partitions may be exceptionally different.

(4) In the above embodiments, the volumes of the respective partitions are set to be the same, but the present invention is not limited thereto, and a part of the partitions may be an exception including a portion having a different volume.

(5) In the above embodiments, the ratio of the number of through holes 21 provided in each partition to the volume of the partition is set to be the same, but the present invention is not limited thereto, and a part of the present invention may include a portion having a different ratio of the number of through holes 21 provided in each partition to the volume of the partition.

(conclusion)

According to a first aspect shown in part or all of the above embodiments, a sound-absorbing stirring device that absorbs sound propagating through air and stirs the air includes a passage member and a fine perforated plate. The passage member has a passage through which air flows. The microperforated plate is a plate-like member having a plurality of fine through holes penetrating therethrough, and is provided such that one surface faces a flow field of air in the passage and the other surface faces an inner wall surface of the passage member with an air layer of a constant thickness interposed therebetween. The plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage.

According to a second aspect, a sound-absorbing stirring device for absorbing sound propagating through air and stirring the air includes a passage member and a fine perforated plate. The passage member has a passage through which air flows. The microperforated plate is a plate-like member having a plurality of fine through holes penetrating therethrough, and is provided such that one surface faces a flow field of air in the passage and the other surface faces an inner wall surface of the passage member with an air layer of a constant thickness interposed therebetween. The plurality of through holes are arranged linearly in parallel with the center line of the passage.

According to a third aspect, the plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage and linearly in parallel with the center line of the passage.

As a result, the plurality of through holes are arranged linearly in the direction orthogonal to the center line of the passage, and the vortex of the plurality of air blown out from the plurality of through holes substantially simultaneously to the flow field forms a vortex core in the direction orthogonal to the center line of the passage. Further, since the plurality of through holes are arranged linearly in parallel with the center line of the passage, the vortex of the air blown out from the through hole on the upstream side and the vortex of the air blown out from the through hole on the downstream side interfere with each other, and the vortices grow gradually from the upstream side toward the downstream side. Therefore, the sound-absorbing stirring device further increases the eddy current of the air in the vicinity of the fine perforated plate, and promotes the turbulence of the air flow, thereby exhibiting the stirring effect of the air.

According to a fourth aspect, the sound-absorbing stirring device further includes a partition plate that partitions the air layer. The partition plate connects the inner wall surface of the passage member and the microperforated sheet. This makes it possible to more reliably synchronize the periods of air blown out from the plurality of through holes to the flow field. Therefore, the sound-absorbing stirring device further increases the eddy current of the air in the vicinity of the fine perforated plate, and promotes the turbulence of the air flow, thereby exhibiting the stirring effect of the air.

According to a fifth aspect, the partition plates are aligned in a direction orthogonal to the center line of the passage. This makes it possible to more reliably synchronize the periods of air blown out from the plurality of through holes to the flow field.

According to a sixth aspect, the partition plate is aligned parallel to the center line of the passage. This makes it possible to more reliably synchronize the periods of air blown out from the plurality of through holes to the flow field.

According to the seventh aspect, the number of through holes provided in each partition is the same in the plurality of partitions formed by the inner wall surface of the passage member, the micro perforated plate, and the partition plate. This makes it possible to synchronize the periods of air blown out from the plurality of through holes to the flow field.

According to an eighth aspect, the volume of each of the plurality of partitions formed by the inner wall surface of the passage member, the microperforated plate, and the partition plate is the same. This makes it possible to synchronize the periods of air blown out from the plurality of through holes to the flow field.

According to a ninth aspect, in the plurality of partitions formed by the inner wall surface of the passage member, the micro perforated plate, and the partition plate, the ratio of the number of holes of the through-holes provided in each partition to the volume of the partition is the same. This makes it possible to synchronize the periods of air blown out from the plurality of through holes to the flow field. Therefore, the sound-absorbing stirring device further increases the eddy current of the air in the vicinity of the fine perforated plate, and promotes the turbulence of the air flow, thereby further exhibiting the stirring effect of the air.

Claims

1. A sound-absorbing stirring device that absorbs sound propagating through air and stirs the air, the sound-absorbing stirring device comprising:

a passage member (10) having a passage through which air flows; and

a micro-perforated plate (20) which is a plate-like member having a plurality of micro through holes (21) penetrating therethrough, and which is provided so that one surface faces a flow field (11) of air in the passage and the other surface faces an inner wall surface (13) of the passage member with an air layer (12) having a constant thickness interposed therebetween, and which generates a viscosity attenuation effect by the air passing through the through holes,

the plurality of through holes are arranged linearly in a direction orthogonal to a Center Line (CL) of the passage.

2. A sound-absorbing stirring device that absorbs sound propagating through air and stirs the air, the sound-absorbing stirring device comprising:

a passage member (10) having a passage through which air flows; and

the plurality of through holes are arranged linearly in parallel with a Center Line (CL) of the passage.

3. The sound-absorbing stirring apparatus of claim 1 or 2,

the plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage and linearly parallel to the center line of the passage.

4. The sound-absorbing stirring apparatus of any one of claims 1 to 3,

and a partition plate (30) that connects the inner wall surface of the passage member and the microperforated sheet and partitions the air layer.

5. The sound-absorbing stirring apparatus of claim 4,

the partition plates are arranged in a direction orthogonal to a center line of the passage.

6. The sound-absorbing stirring apparatus of claim 4 or 5,

the partition plates are aligned in parallel with the center line of the passage.

7. The sound-absorbing stirring apparatus of any one of claims 4 to 6,

in the plurality of partitions formed by the inner wall surface of the passage member, the microperforated plate, and the partition plate, the number of holes of the through-hole provided in each of the partitions is the same.

8. The sound-absorbing stirring apparatus of any one of claims 4 to 7,

in a plurality of partitions formed by the inner wall surface of the passage member, the microperforated plate, and the partition plate, the volume of each of the partitions is the same.

9. The sound-absorbing stirring apparatus of any one of claims 4 to 8,

in the plurality of partitions formed by the inner wall surface of the passage member, the micro perforated plate, and the partition plate, the ratio of the number of holes of the through-hole provided in each of the partitions to the volume of the partition is the same.