WO2021014941A1 - Sound-absorption stirring device - Google Patents

Abstract

A passage member (10) has a passage through which air flows. A fine perforated plate (20) is a plate-like member in which a plurality of fine through holes (21) are perforated and is provided such that one surface of which faces an air flowing place (11) in the passage and the other surface of which is opposed to an inner wall surface (13) of the passage member (10) via an air layer (12) having a fixed thickness, thus causing a viscous damping action due to air passing through the through holes (21). The plurality of through holes (21) are arrayed in straight lines in directions perpendicular to the center line (CL) of the passage.

Description

Sound absorption agitator Cross-reference to related applications

This application is based on Japanese Patent Application No. 2019-134789 filed on July 22, 2019, the contents of which are incorporated herein by reference.

The present disclosure relates to a sound absorbing and stirring device that absorbs sound propagating in a fluid and agitates the fluid.

Conventionally, a technique for obtaining a sound absorbing effect by providing a perforated plate in front of a rigid wall via an air layer is known. Patent Document 1 discloses a configuration in which a perforated plate is provided on the inner wall of a cylindrical pipe via an air layer to absorb sound propagating in the pipe.

Japanese Unexamined Patent Publication No. 2005-9483

By the way, the inventors have conducted extensive research on the configuration in which the fine perforated plate is installed on the inner wall of the passage member via the air layer. Here, the micro perforated plate is a plate-shaped member in which a plurality of fine through holes are formed, and is called MPP (abbreviation of Micro perforated Panel). As a result, the inventors have stated that when air flows through the air flow field of the passage member, the air in the air layer is blown out into the flow field through the through hole of the fine perforated plate, and the air flowing through the flow field is air through the through hole. It was discovered that the state of entering the layer is repeated at regular intervals.
Therefore, the inventors can reduce noise and agitate the fluid flowing through the passage member by installing the fine perforated plate on the inner wall of the passage member through a certain space. I found that.

The configuration described in Patent Document 1 described above takes into consideration the influence of the air blown out from the holes of the perforated plate or the air entering the air layer from the flow field through the holes of the perforated plate with respect to the air flowing in the pipe. Absent. Further, the configuration described in Patent Document 1 is intended only for reducing noise, and is not intended for stirring air flowing in the pipe.
In the configuration described in Patent Document 1, if the purpose is to reduce noise and agitate the fluid, the perforated plate cannot have a great influence on the fluid, and a structure for agitating the fluid is required separately. .. Further, when a structure for stirring the fluid is separately added to the configuration described in Patent Document 1, there is a high possibility that noise will be aggravated.
It is an object of the present disclosure to provide a sound absorbing and stirring device that absorbs sound propagating in air and agitates air.

According to one aspect of the disclosure,
In a sound absorbing agitator that absorbs sound propagating in the air and agitates the air
A passage member having a passage through which air flows, and
A plate-shaped member with a plurality of fine through holes, one surface facing the air flow field in the passage, and the other surface with the inner wall surface of the passage member via an air layer having a constant thickness. It is provided with a fine perforated plate which is provided so as to face each other and generates a viscous damping action by air passing through the through hole.
The plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage.

According to this, as described above, when air flows through the air flow field of the passage member at a constant flow velocity, the air in the air layer is blown out to the flow field through the through hole of the fine perforated plate and flows through the flow field. The state in which air enters the air layer through the through hole is repeated. At that time, since the fine perforated plate is provided so as to face the inner wall surface of the passage member through the air layer having a constant thickness, the cycle in which air is blown from the plurality of through holes into the flow field is synchronized. Since the plurality of through holes are arranged linearly in the direction orthogonal to the center line of the passage, the plurality of air vortices blown from the plurality of through holes into the flow field at substantially the same time are located on the center line of the passage. A vortex core is formed in the direction orthogonal to the vortex core. Therefore, the vortex of air becomes large in the vicinity of the fine perforated plate, and the turbulence of the air flow is promoted. Therefore, this sound absorbing and stirring device can agitate the air flowing through the passage member.

Further, the fine perforated plate is configured to generate a viscous damping action by air passing through a plurality of fine through holes. Therefore, this sound absorbing / stirring device can absorb the sound propagating in the air flowing through the passage member.
In the present specification, the linear shape includes, in addition to the straight line, a state in which a plurality of through holes are slightly deviated (specifically, about 1/2 of the hole diameter) due to manufacturing tolerances and the like.

Also, from another point of view
In a sound absorbing agitator that absorbs sound propagating in the air and agitates the air
A passage member having a passage through which air flows, and
A plate-shaped member with a plurality of fine through holes, one surface facing the air flow field in the passage, and the other surface with the inner wall surface of the passage member via an air layer having a constant thickness. It is provided with a fine perforated plate which is provided so as to face each other and generates a viscous damping action by air passing through the through hole.
The plurality of through holes are arranged in a straight line parallel to the center line of the passage.

According to this, as described above, when air flows through the air flow field of the passage member at a constant flow velocity, the air in the air layer is blown out to the flow field through the through hole of the fine perforated plate and flows through the flow field. The state in which air enters the air layer through the through hole is repeated. At that time, since the fine perforated plate is provided so as to face the inner wall surface of the passage member through the air layer having a constant thickness, the cycle in which air is blown from the plurality of through holes into the flow field is synchronized. Since the plurality of through holes are arranged in a straight line parallel to the center line of the passage, the vortex of the air blown out from the through hole on the upstream side and the air blown out from the through hole on the downstream side thereof. The vortices interfere with each other, and the vortices gradually grow larger from the upstream side to the downstream side. Therefore, the vortex of air becomes large in the vicinity of the fine perforated plate, and the turbulence of the air flow is promoted. Therefore, this sound absorbing and stirring device can agitate the air flowing through the passage member.
Further, since the fine perforated plate generates a viscous damping action, this sound absorbing and stirring device can absorb the sound propagating in the air flowing through the passage member.

Note that the reference reference numerals in parentheses attached to each component or the like indicate an example of the correspondence between the component or the like and the specific component or the like described in the embodiment described later.

It is sectional drawing parallel to the center line of the passage of the sound absorption agitation apparatus which concerns on 1st Embodiment. It is sectional drawing of the line II-II of FIG. It is sectional drawing of the line III-III of FIG. It is a figure for demonstrating the viscous damping action by the fine perforation plate of a sound absorption agitation device. It is a figure for demonstrating the model of the experiment in the sound absorption agitation device. It is a figure which shows the state which the air is flowing through the sound absorption agitation device. It is a figure following FIG. 5B which shows the state which the air is flowing through the sound absorption agitation device. It is a figure following FIG. 5C which shows the state which the air is flowing through the sound absorption agitation device. It is a figure following FIG. 5D which shows the state which the air is flowing through the sound absorption agitation device. It is a figure following FIG. 5E which shows the state which the air is flowing through the sound absorption agitation device. It is a figure for demonstrating the model of the experiment in the sound absorption agitation device. It is a figure which shows the state which the air is flowing through the sound absorption agitation device. It is a figure following FIG. 6B which shows the state which the air is flowing through the sound absorption agitation device. It is a figure following FIG. 6C which shows the state which the air is flowing through the sound absorption agitation device. It is a figure following FIG. 6D which shows the state which the air is flowing through the sound absorption agitator. It is a figure following FIG. 6E which shows the state which the air is flowing through the sound absorption agitation device. It is a figure for demonstrating the arrangement of the through hole of the fine perforation plate and its action in the VII part of FIG. It is a figure for demonstrating the arrangement of the through hole of the fine perforation plate and its action in the VIII part of FIG. It is a figure for demonstrating the misalignment amount of the through hole of the fine perforation plate. It is a figure for demonstrating the pitch of the through hole of a fine perforation plate. It is sectional drawing of the air-conditioning unit which installs the sound absorption agitation device which concerns on 2nd Embodiment. FIG. 11 is an arrow view in the XII direction of FIG. It is an enlarged view of the XIII part of FIG. It is a top view of the sound absorption agitation device which concerns on 3rd Embodiment. It is a top view of the sound absorption agitation device which concerns on 4th Embodiment. It is a top view of the sound absorption agitation apparatus which concerns on 5th Embodiment. It is a top view of the sound absorption agitation apparatus which concerns on 6th Embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each of the following embodiments, the same or equal parts are designated by the same reference numerals, and the description thereof will be omitted.

(First Embodiment)
The first embodiment will be described with reference to the drawings. The sound absorbing and stirring device of the present embodiment is installed in, for example, a vehicle air conditioner or a blowout duct to absorb sound propagating in the air and agitate the air.

As shown in FIGS. 1 to 3, the sound absorbing and stirring device includes a passage member 10, a fine perforated plate 20, and the like. The passage member 10 has, for example, a rectangular cross section and has a passage through which air flows. The cross-sectional shape of the passage member 10 is not limited to a rectangular shape, and various shapes such as a circular shape, an elliptical shape, a polygonal shape, or a combination thereof can be adopted.

In FIGS. 1 and 3, the mainstream direction of air flowing through the passage of the passage member 10 is indicated by a white arrow. In the present embodiment, the mainstream direction of the air flowing through the passage of the passage member 10 and the direction of the center line CL of the passage coincide with each other. Further, the center line CL of the passage of the passage member 10 means a virtual line that is the center of the wall surfaces facing each other among the wall surfaces forming the air flow field.

A fine perforated plate 20 is fixed to the inner wall of the passage member 10. The fine perforated plate 20 is a plate-shaped member in which a plurality of fine through holes 21 are bored. The micro perforated plate 20 is called MPP (abbreviation for Micro perforated Panel). Specifically, the hole diameter d of the through hole 21 is larger than 0 and 1 mm or less. The fine perforated plate 20 is provided so that one surface faces the air flow field 11 in the passage and the other surface faces the inner wall surface 13 of the passage member 10 via an air layer 12 having a constant thickness. .. The location where the fine perforated plate 20 is provided on the passage member 10 is not limited to one surface of the inner wall of the passage member 10, but may be a plurality of surfaces or the entire surface.

The fine perforated plate 20 is configured to generate a viscous damping action by air passing through a plurality of through holes 21. Here, the viscous damping action will be described.
When a plurality of fine through holes 21 provided in the fine perforated plate 20 are considered as capillaries, the behavior of the viscous boundary layer determines whether or not the viscous damping action works. Whether or not the viscous damping action works can be examined by the acoustic Reynolds number. Note that 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 shown by hatching with a broken line.
Air density: ρ [kg / m3]
Viscosity coefficient: η [Pa · s]
Assuming that the angular frequency is ω [rad / s], the acoustic Reynolds number Rey is expressed by the following equation 1.

If Rey <10, the viscous damping action works. As a result, the fine 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 the sound propagates in the air flowing through the flow field 11 of the passage member 10. Can be absorbed and attenuated.

Furthermore, the inventors have found the following as a result of intensive research on the configuration in which the fine perforated plate 20 is installed on the inner wall of the passage member 10 such as the sound absorbing and stirring device of the present embodiment via the air layer 12. did. That is, the inventors have discovered that when air flows through the air flow field 11 of the passage member 10 at a constant flow velocity, the following first state and second state are repeated at a constant cycle. is there. The first state is a state in which the air in the air layer 12 is blown out to the flow field 11 through the through hole 21 of the fine perforated plate 20. The second state is a state in which the air flowing through the flow field 11 enters the air layer 12 through the through hole 21.

FIG. 5A is a diagram for explaining a model used in the experiment of the sound absorbing and stirring device. Also in FIG. 5A, the mainstream direction of the air flowing through the flow field 11 of the passage member 10 is indicated by a white arrow. The mainstream direction coincides with the center line CL of the passage of the passage member 10.
In this model, the plurality of through holes 21 formed in the fine perforated plate 20 are arranged in a straight line parallel to the center line CL of the passage. The hole diameter d of the plurality of through holes 21 used in the experiment is 1.0 mm. Further, the distance P between the center of one through hole 21 adjacent to each other in the mainstream direction and the center of the other through hole 21 is 3 mm.

In the model as shown in FIG. 5A, air was flowed through the flow field 11 of the passage at a constant wind speed U. The wind speed U is 10 m / s.
Then, fine particles are arranged in the air layer 12, and the air in the air layer 12 is blown out to the flow field 11 through the through hole 21 of the fine perforated plate 20, and the air flowing through the flow field 11 is air through the through hole 21. The state of entering the layer 12 was visualized and evaluated. 5B to 5F are binarized images obtained by the experiment.

FIG. 5B shows a state in which the air in the air layer 12 begins to blow out into the flow field 11 through the plurality of through holes 21 after the experiment is started. 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 fine particles arranged in the air layer 12. The air in the air layer 12 begins to blow 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 at substantially the same time becomes vortices, and is 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 from the air layer 12 to the flow field 11 through the plurality of through holes 21 is the vortex of the air blown out from the through holes 21 on the upstream side and the air blown out from the through holes 21 on the downstream side thereof. The vortex interferes with each other and begins to grow.
FIG. 5E shows a state following FIG. 5D. At this time, the vortex of air blown out from the air layer 12 to the flow field 11 through the plurality of through holes 21 gradually grows larger from the upstream side to the downstream side.

FIG. 5F shows a state following FIG. 5E. At this time, the state in which air is blown 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 hole 21.
After a certain period of time has passed from the state of FIG. 5F, the above-mentioned phenomenon of FIGS. 5B to 5F is repeated at a constant cycle. In this way, when air flows through the flow field 11 of the passage member 10 at a constant flow velocity, the air in the air layer 12 is blown out from the plurality of through holes 21 into the flow field 11 so as to breathe, and the flow field. The state of entering the air layer 12 from 11 through the through hole 21 is repeated at a constant cycle.

Note that FIG. 6A is the same diagram as FIG. 5A. 6B to 6F show the same state as FIGS. 5B to 5F, and the images obtained by the above experiment are shown in gray scale. However, in the international application, the gray scale is binarized, but it is described for the sake of understanding.

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

Therefore, in the present embodiment, as shown in FIGS. 7 and 8, a plurality of through holes 21 are arranged linearly in a direction orthogonal to the center line CL of the passage. Further, the distance between the inner wall surface 13 of the passage member 10 and the fine perforated plate 20 is constant, and the air layer 12 formed between the inner wall surface 13 of the passage member 10 and the fine perforated plate 20 has a constant thickness.
As a result, since the fine perforated plate 20 is provided via the air layer 12 having a constant thickness, the cycle in which air is blown from the plurality of through holes 21 to the flow field 11 is synchronized. Since the plurality of through holes 21 are arranged linearly in the direction orthogonal to the center line CL of the passage, as shown by the arrow V in FIG. 7, the plurality of through holes 21 are substantially connected to the flow field 11. A plurality of vortices of air blown out at the same time form a vortex core in a direction orthogonal to the center line CL of the passage. Therefore, the vortex of air becomes large in the vicinity of the fine perforated plate 20, and the turbulence of the air flow is promoted. Therefore, this sound absorbing and stirring device can agitate the air flowing through the passage member 10.

Further, 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 plurality of air vortices blown from the plurality of through holes 21 into the flow field 11 at substantially the same time interfere with each other, and the vortices gradually grow larger from the upstream side to the downstream side. To do. Therefore, the vortex of air becomes large in the vicinity of the fine perforated plate 20, and the turbulence of the air flow is promoted. Therefore, this sound absorbing and stirring device can agitate 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 perfect straight line with respect to the direction parallel to the center line CL of the passage, and are parallel to the center line CL of the passage. It is also possible to arrange the through holes 21 slightly offset from each other. Specifically, the vortex 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 through hole 21 on the upstream side adjacent to the mainstream direction and the center of the through hole 21 on the downstream side is within a range of 1/2 or less of the hole diameter d of the through hole 21 and is the center of the passage. It may be deviated in the direction perpendicular to the line CL. Even when the plurality of through holes 21 are arranged in this way, the vortices of the plurality of air blown from the plurality of through holes 21 into the flow field 11 at substantially the same time interfere with each other, and the vortices gradually interfere with each other from the upstream side to the downstream side. It is possible to grow big.

Further, as shown in FIG. 10, the distance P between the center of the through hole 21 on the upstream side adjacent to the mainstream direction and the center of the through hole 21 on the downstream side thereof is such that the vortex generated from the through hole 21 on the upstream side is downstream. The distance is set so that the vortices generated from the through holes 21 on the side can reach each other and interfere with each other. Then, the distance P can be appropriately set by an experiment or the like.

(Second Embodiment)
The second embodiment will be described. The second embodiment describes a mode in which a sound absorbing / stirring device is installed in an air conditioning unit of a vehicle air conditioner.

As shown in FIG. 11, the air conditioning unit 1 of the vehicle air conditioner includes an air conditioning case 2, an evaporator 4, a heater core 5, an air mix door 6, an outlet opening door 7, and the like.
The air conditioning case 2 is a member corresponding to the passage member 10 of the sound absorbing and stirring device. The air conditioning case 2 is made of a resin (for example, polypropylene) having a certain degree of elasticity and excellent strength. The air conditioning case 2 forms the outer shell of the air conditioning unit 1. Inside the air conditioning case 2, a passage (that is, an air flow field 11) through which the air blown into the vehicle interior flows is formed. In FIG. 11, the flow direction of air in the passage is indicated by a white arrow.
Further, the air conditioning case 2 has a plurality of outlet openings 8 for blowing air into a predetermined area in the vehicle interior on the downstream side in the air flow direction of the passage.

Inside the air conditioning case 2, an evaporator 4, a heater core 5, an air mix door 6, a blowout opening door 7, and the like are provided.

The evaporator 4 is a heat exchanger for cooling the 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 inside the evaporator 4 and the air passing through the evaporator 4, evaporating the refrigerant and cooling the air.
The heater core 5 is a heat exchanger for heating the air flowing through the passage. The heater core 5 exchanges heat between the engine cooling water or high-pressure refrigerant flowing inside the heater core 5 and the air passing through the heater core 5, and heats the air with the heat of the engine cooling water or high-pressure refrigerant.

Further, the passage in the air conditioning case 2 includes a bypass passage 51 that bypasses the heater core 5 and allows air to flow outside the heater core 5.
An air mix door 6 is provided between the evaporator 4 and the heater core 5 in the passage of the air conditioning unit 1. The air mix door 6 adjusts the air volume ratio between the wind that passes through the evaporator 4 and bypasses the heater core 5 (that is, the wind that flows through the bypass passage 51) and the wind that passes through the evaporator 4 and then passes through the heater core 5. To do.

The blowout opening door 7 is provided in the first blowout opening 81 of one of the plurality of blowout openings 8, and adjusts the opening area of the first blowout opening 81. Although the blowout opening door provided in the second blowout opening 82 of the other of the plurality of blowout openings 8 is omitted in FIG. 11, the first blowout is also shown in the second blowout opening 82. A blowout opening door may be provided in the same manner as the opening 81.

The fine perforated plate 20 included in the sound absorbing and stirring device of the second embodiment is provided inside the air conditioning case 2 in order to absorb the sound propagating in the air conditioning case 2 and to stir the air flowing in the air conditioning case 2. ing. In FIG. 11, a portion where the fine perforated plate 20 is installed in the air conditioning case 2 is shown by an example of a broken line. However, the place where the fine perforated plate 20 is installed is not limited to the place shown in FIG. 11, and may be any place among the inner walls of the air conditioning case 2. As a result, the sound absorbing and stirring device improves the air conditioning performance by reducing the noise emitted from the air conditioner into the vehicle interior and making the temperature and humidity of the air conditioning air blown out from the air outlet provided in the vehicle interior uniform. Can be enhanced.

As shown in FIGS. 12 and 13, the sound absorbing and stirring device of the second embodiment includes a partition plate 30 for partitioning the air layer 12. In FIG. 12, the fine perforated plate 20 is viewed from the air flow field 11 of the air conditioning case 2, but in order to make the figure easier to see, a partition arranged on the passage member 10 side with respect to the fine perforated plate 20. The plate 30 is shown by a solid line through the fine perforated plate 20. Further, also in FIGS. 12 and 13, the mainstream direction of the air flow in the passage is indicated by a white arrow. This also applies to FIGS. 14 to 17 referred to in the third to sixth embodiments described later.

The partition plate 30 is a plate-shaped member that connects the inner wall surface of the passage member 10 (that is, the air conditioning case 2) and the fine perforated plate 20. Among the partition plates 30, those extending in the direction orthogonal to the center line CL of the passage are referred to as the first partition plate 31. The first partition plate 31 is provided so as to be arranged in a direction orthogonal to the center line CL of the passage. As a result, it is possible to more reliably synchronize the period in which air is blown out from the plurality of through holes 21 arranged linearly in the direction orthogonal to the center line CL of the passage to the flow field 11.
Further, among the partition plates 30, those extending parallel to the center line CL of the passage are referred to as the second partition plate 32. The second partition plate 32 is provided so as to be arranged parallel to the center line CL of the passage.

In the second embodiment, a plurality of sections are formed by the inner wall surface 13, the fine perforated plate 20, and the partition plate 30 of the passage member 10. The number of through holes 21 provided in each section is the same for the plurality of sections. Further, in the plurality of sections, the ratio of the number of through holes 21 provided in each section to the volume of the section is the same. In addition, in the present specification, the same includes the range of manufacturing tolerance in addition to the exact same.

As a result, since the pressure fluctuations in the plurality of sections are all synchronized, it is possible to synchronize the cycle in which the air is blown from the air layer 12 to the air flow field 11 in the air conditioning case 2 through the plurality of through holes 21. Therefore, this sound absorbing and stirring device can further exert the air stirring effect by making the air vortex larger in the vicinity of the fine perforated plate 20 and promoting the turbulence of the air flow.

(Third to sixth embodiments)
The third to sixth embodiments will be described. The third to sixth embodiments are different from the first and second embodiments in the configuration of the partition plate 30, and the other parts are the same as those of the first and second embodiments. Only the part different from the second embodiment will be described.

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

Also in the third embodiment, the number of through holes 21 provided in each of the plurality of sections formed by the inner wall surface 13, the fine perforated plate 20, and the partition plate 30 of the passage member 10 is the same. In addition, the volume of each of the plurality of compartments is the same. Therefore, also in the third embodiment, it is possible to synchronize the cycle of air blowing from the plurality of through holes 21 to the flow field 11.

(Fourth Embodiment)
As shown in FIG. 15, in the fourth embodiment, among the partition plates 30, the first partition plate 31 extending in the direction orthogonal to the center line CL of the passage is provided. On the other hand, in the fourth embodiment, of the partition plates 30, the second partition plate 32 extending parallel to the center line CL of the passage is not provided.

Also in the fourth embodiment, the number of through holes 21 provided for each section is the same. In addition, the volume of each of the plurality of compartments is the same. Therefore, also in the fourth embodiment, it is possible to synchronize the period in which air is blown from the plurality of through holes 21 to the flow field 11.

(Fifth Embodiment)
As shown in FIG. 16, in the fifth embodiment, among the partition plates 30, the first partition plate 31 extending in a direction orthogonal to the center line CL of the passage and the second partition extending parallel to the center line CL of the passage. Both plates 32 are provided.

In FIG. 16, the square of the alternate long and short dash line indicated by the symbol α indicates the volume of the air layer 12 assigned to one through hole 21.
In the fifth embodiment, the number of through holes 21 provided in each section is not the same. In addition, the volumes of the plurality of compartments are not the same for each compartment. However, the volume of the air layer 12 assigned to one through hole 21 is the same in the plurality of compartments. Therefore, in the plurality of sections, the ratio of the number of through holes 21 provided in each section to the volume of the section is the same. Therefore, also in the fifth embodiment, it is possible to synchronize the cycle of air blowing from the plurality of through holes 21 to the flow field 11.

(Sixth Embodiment)
As shown in FIG. 17, in the sixth embodiment, the first partition plate 31 is formed in a predetermined wave shape, and a plurality of waves constituting the wave shape are arranged in a direction orthogonal to the center line CL of the passage. It is provided as follows. Further, the second partition plate 32 is also formed in a predetermined wave shape, and is provided so that a plurality of waves forming the wave 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 for each section is the same. Further, the plurality of compartments have the same volume for each compartment. The ratio of the number of through holes 21 provided in each section to the volume of the section is the same in the plurality of sections. Therefore, also in the sixth embodiment, it is possible to synchronize the cycle of air blowing from the plurality of through holes 21 to the flow field 11.

As described above, also in the third to sixth embodiments, it is possible to synchronize the cycle of air blowing from the plurality of through holes 21 to the flow field 11. Further, 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 arranged linearly in parallel with the center line CL of the passage. Therefore, the sound absorbing and stirring devices of the third to sixth embodiments can also exert the air stirring effect by making the air vortex larger in the vicinity of the fine perforated plate 20 and promoting the turbulence of the air flow. ..

(Other embodiments)
The present disclosure is not limited to the above-described embodiment, and can be changed as appropriate. Further, the above-described embodiments are not unrelated to each other, and can be appropriately combined unless the combination is clearly impossible. Further, in each of the above embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential except when it is clearly stated that they are essential and when they are clearly considered to be essential in principle. No. Further, in each of the above embodiments, when numerical values such as the number, numerical values, amounts, and ranges of the constituent elements of the embodiment are mentioned, when it is clearly stated that they are particularly essential, and in principle, the number is clearly limited to a specific number. It is not limited to the specific number except when it is done. In addition, in each of the above embodiments, when referring to the shape, positional relationship, etc. of a component or the like, the shape, unless otherwise specified or limited in principle to a specific shape, positional relationship, etc. It is not limited to the positional relationship.

(1) In each of the above embodiments, the plurality of through holes 21 are arranged linearly in a direction orthogonal to the center line CL of the passage, but the present invention is not limited to this. The plurality of through holes 21 may exceptionally include those arranged at positions deviated from the direction orthogonal to the center line CL of the passage.

(2) In each of the above embodiments, the plurality of through holes 21 are arranged linearly in a direction parallel to the center line CL of the passage, but the present invention is not limited to this. The plurality of through holes 21 may exceptionally include those arranged at positions deviated from the direction parallel to the center line CL of the passage.

(3) In each of the above embodiments, the number of through holes 21 provided in each section is the same, but the number is not limited to this. A part of the through holes 21 provided in the section having different numbers of holes may be exceptionally included.

(4) In each of the above embodiments, the volume of each section is the same, but the volume is not limited to this. A part having a different volume of the compartment may be exceptionally included.

(5) In each of the above embodiments, the ratio of the number of through holes 21 provided in each section to the volume of the section is the same, but the present invention is not limited to this. A part having a different ratio between the number of through holes 21 provided for each section and the volume of the section may be exceptionally included.

(Summary)
According to the first aspect shown in part or all of the above embodiments, the sound absorbing and stirring device that absorbs the sound propagating in the air and agitates the air includes a passage member and a fine perforated plate. The passage member has a passage through which air flows. The fine perforated plate is a plate-shaped member having a plurality of fine through holes, one surface of which faces the air flow field of the passage, and the other surface of the passage through an air layer having a constant thickness. It is provided so as to face the inner wall surface of the member, and a viscous damping action is generated by the air passing through the through hole. The plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage.

According to the second viewpoint, the sound absorbing / stirring device that absorbs the sound propagating in the air and agitates the air includes a passage member and a fine perforated plate. The passage member has a passage through which air flows. The fine perforated plate is a plate-shaped member having a plurality of fine through holes, one surface of which faces the air flow field of the passage, and the other surface of the passage through an air layer having a constant thickness. It is provided so as to face the inner wall surface of the member, and a viscous damping action is generated by the air passing through the through hole. The plurality of through holes are arranged in a straight line parallel to the center line of the passage.

According to the third aspect, the plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage, and are arranged linearly parallel to the center line of the passage.
According to this, since the plurality of through holes are arranged linearly in the direction orthogonal to the center line of the passage, the plurality of air vortices blown from the plurality of through holes into the flow field at substantially the same time are generated in the passage. The vortex core is formed in the direction orthogonal to the center line. Furthermore, since the plurality of through holes are arranged in a straight line parallel to the center line of the passage, the vortex of the air blown out from the through hole on the upstream side and the air blown out from the through hole on the downstream side thereof. The vortices interfere with each other, and the vortices gradually grow larger from the upstream side to the downstream side. Therefore, this sound absorbing and stirring device can exert the air stirring effect by making the air vortex larger in the vicinity of the fine perforated plate and promoting the turbulence of the air flow.

According to the fourth viewpoint, the sound absorbing and stirring device further includes a partition plate for partitioning the air layer. The partition plate connects the inner wall surface of the passage member and the fine perforated plate. According to this, it is possible to more reliably synchronize the cycle of air blowing out from the plurality of through holes into the flow field. Therefore, this sound absorbing and stirring device can exert the air stirring effect by making the air vortex larger in the vicinity of the fine perforated plate and promoting the turbulence of the air flow.

According to the fifth viewpoint, the partition plates are arranged in a direction orthogonal to the center line of the passage. According to this, it is possible to more reliably synchronize the cycle of air blowing out from the plurality of through holes into the flow field.

According to the sixth viewpoint, the partition plates are lined up parallel to the center line of the passage. According to this, it is possible to more reliably synchronize the cycle of air blowing out from the plurality of through holes into the flow field.

According to the seventh viewpoint, the plurality of sections formed by the inner wall surface of the passage member, the fine perforated plate, and the partition plate have the same number of through holes provided for each section. According to this, it is possible to synchronize the period in which air is blown out from a plurality of through holes into the flow field.

According to the eighth viewpoint, the volume of each of the plurality of compartments formed by the inner wall surface of the passage member, the fine perforated plate and the partition plate is the same. According to this, it is possible to synchronize the period in which air is blown out from a plurality of through holes into the flow field.

According to the ninth aspect, in the plurality of compartments formed by the inner wall surface of the passage member, the fine perforated plate and the partition plate, the ratio of the number of through holes provided in each compartment to the volume of the compartment is the same. Is. According to this, it is possible to synchronize the period in which air is blown out from a plurality of through holes into the flow field. Therefore, this sound absorbing and stirring device can further exert the air stirring effect by making the vortex of air larger in the vicinity of the fine perforated plate and promoting the turbulence of the air flow.

Claims (9)

1. In a sound absorbing agitator that absorbs sound propagating in the air and agitates the air
   A passage member (10) having a passage through which air flows,
   A plate-shaped member having a plurality of fine through holes (21), one surface facing the air flow field (11) in the passage, and the other surface having an air layer (12) having a constant thickness. ), Which is provided so as to face the inner wall surface (13) of the passage member, and includes a fine perforated plate (20) that causes a viscous damping action by air passing through the through hole.
   A sound absorbing and stirring device in which the plurality of through holes are linearly arranged in a direction orthogonal to the center line (CL) of the passage.
2. In a sound absorbing agitator that absorbs sound propagating in the air and agitates the air
   A passage member (10) having a passage through which air flows,
   A plate-shaped member having a plurality of fine through holes (21), one surface facing the air flow field (11) in the passage, and the other surface having an air layer (12) having a constant thickness. ), Which is provided so as to face the inner wall surface (13) of the passage member, and includes a fine perforated plate (20) that causes a viscous damping action by air passing through the through hole.
   A sound absorbing and stirring device in which the plurality of through holes are linearly arranged in parallel with the center line (CL) of the passage.
3. The first or second aspect of claim 1 or 2, wherein the plurality of through holes are arranged linearly in a direction orthogonal to the center line of the passage, and are arranged linearly parallel to the center line of the passage. Sound absorbing and stirring device.
4. The sound absorbing and stirring device according to any one of claims 1 to 3, further comprising a partition plate (30) for connecting the inner wall surface of the passage member and the fine perforated plate and partitioning the air layer.
5. The sound absorbing and stirring device according to claim 4, wherein the partition plates are arranged in a direction orthogonal to the center line of the passage.
6. The sound absorbing and stirring device according to claim 4 or 5, wherein the partition plate is lined up in parallel with the center line of the passage.
7. Any of claims 4 to 6, wherein the inner wall surface of the passage member, the fine perforated plate, and the plurality of compartments formed by the partition plate have the same number of through holes provided for each compartment. The sound absorbing and stirring device according to one.
8. The sound absorbing stirring according to any one of claims 4 to 7, wherein the inner wall surface of the passage member, the fine perforated plate, and the plurality of compartments formed by the partition plate have the same volume for each compartment. apparatus.
9. The inner wall surface of the passage member, the fine perforated plate, and the plurality of compartments formed by the partition plate have the same ratio of the number of holes of the through holes provided for each compartment to the volume of the compartment. , The sound absorbing and stirring device according to any one of claims 4 to 8.

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