JPH09257823A - Sheetlike-fine-particle generation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheetlike-fine particle generation apparatus which can discharge sheetlike fine particle whose density is constant and steady and whose thickness is thin. SOLUTION: An air intake part 6 is formed at one end part 8a in the length direction of a duct 8, and an opening part 4 which comprises a plurality of through holes is formed along the length direction. A fine-particle supply device 5 is installed between the air intake part 6 and the opening part 4, and fine particle are supplied into the duct 8. The duct 8 is covered with a streamlined member 9 which has a streamlined hollow shape, and a fine-particle discharge port 7 which discharges the fine particles is formed over the whole width of the streamlined member 9 at the rear edge 9a or the side face of the streamlined member 9. The fine particles whose density is made constant by the air introduced from the air intake part 6 are discharged into a main stream as sheetlike fine particles from the fine-particle discharge port 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-shaped particle generating device for flowing particles into a sheet in an air stream.

[0002]

2. Description of the Related Art A wind tunnel test is generally carried out in order to investigate the force exerted by air on an object moving in the air. In order to measure the flow velocity distribution in such a wind tunnel test, fine particles are floated in the air flow flowing through the measurement part of the wind tunnel and flowed to the PIV.
(Particle Image Velocimetry) or LDV (Laser D
In some cases, a method of measuring the flow velocity distribution by measuring the velocity of fine particles using oppler velocimetry) is used. The fine particles used for such PIV and LDV need to be supplied in a sheet form at a uniform thin concentration.

Further, in order to visualize the flow, it may be necessary to supply the fine particles in a sheet in a uniform thin concentration in a sheet form.

Conventionally, as a device for supplying fine particles into an air flow, the fine particle generator directly discharges the fine particles into the main stream, or the fine particles are discharged through a slit, or a hose or the like is directly connected to the fine particle generator. However, a method of discharging fine particles from the tip of this hose is adopted.

[0005]

The fine particles generated from such a conventional fine particle generating apparatus have uneven concentration,
Problems such as non-uniform sheet shape tend to occur. Also,
If you do not connect the particle generator to the particle outlet with an appropriate method, liquefaction and precipitation of particles are likely to occur in the middle of the route, so even if you increase the generation amount of particles, the amount of particles required by liquefaction or precipitation Is not supplied. In addition, the presence of the particle generator itself disturbs the airflow in the wind tunnel, which causes a problem that the quality of data is impaired.

Therefore, an object of the present invention is to provide a sheet-like particle generating apparatus capable of generating a sheet-like particle having a constant and constant concentration and a thin thickness without disturbing an air flow.

[0007]

DISCLOSURE OF THE INVENTION According to the present invention, there is provided a duct which is arranged in a direction substantially perpendicular to a blowing direction and has an opening along a wall surface in a longitudinal direction, and a fine particle supply for supplying fine particles into the duct. A sheet-shaped particle generation device comprising: a means; and an air intake part for supplying air to the inside of the duct. According to the present invention, the air that has flowed in from the air intake portion is effectively mixed with the fine particles from the fine particle supply means so as to be evenly filled in the duct, and is constantly discharged from the opening portion at a constant concentration. Since the opening is formed along the longitudinal direction, the fine particles are discharged in the form of a thin sheet. Since the fine particles supplied from the fine particle supply means are positively discharged from the opening by the air flowing in from the air intake part, the fine particle density in the duct becomes excessive even if the supply amount of the fine particles increases. Therefore, it is possible to prevent the fine particles from being liquefied in the duct. Further, the air blowing may be a method of taking in the air flow in the wind tunnel as it is, or a fan or the like may be attached to the end of the air taking-in portion or the duct to forcibly supply the air. Further, the air intake section may be of a type provided outside the wind tunnel.

Further, according to the present invention, there is formed a streamlined hollow shape along the air blowing direction, a fine particle discharging port for discharging fine particles is formed at a trailing edge on the downstream side in the air blowing direction, and the fine particle discharging port is arranged so as to cover the duct. A streamlined member is included. According to the present invention, since the duct is covered with the streamlined member having the airfoil-shaped hollow shape, it is possible to prevent the airflow due to the blown air from being disturbed by the device itself. Further, since the particle discharge port is formed at the trailing edge of the streamlined member, the particle discharged from the opening of the duct is discharged from the particle discharge port of the streamlined member in a uniform sheet shape.

Further, the present invention is characterized in that a back pressure lowering member for lowering an air pressure around the particulate discharge port is provided near the particulate discharge port of the streamlined member. According to the present invention, the back pressure reducing member reduces the pressure in the vicinity of the particulate discharge port, so that the pressure difference between the air intake portion and the particulate discharge port becomes large. Therefore, the fine particles supplied from the fine particle supply means are positively discharged to the outside from the fine particle outlet through the air flow generated inside the apparatus due to the pressure difference, and the fine particles are liquefied or settled in the streamlined member. Can be prevented, and the fine particles can be efficiently discharged in a sheet form.

Further, the present invention is characterized in that it includes a streamlined member which forms a part of an airfoil hollow shape along the air blowing direction and which is arranged in proximity to one of the side wall surfaces of the duct. According to the present invention, since the streamlined member is provided on the side wall surface of the duct, it is possible to prevent the airflow due to the blown air from being disturbed by the device itself. The fine particles discharged from the opening of the duct are guided along the streamlined member and discharged from the trailing edge of the streamlined member in the form of a thin sheet having a constant and constant concentration.

Further, according to the present invention, a side surface fine particle outlet having a blade-shaped hollow shape along the air blowing direction is arranged so as to cover the duct and is connected to the opening of the duct in the vicinity of the maximum blade thickness. It is characterized by including a streamlined member. According to the present invention, the air flowing in from the air intake section is mixed with the fine particles supplied from the fine particle supply means and uniformly fills the duct. Since the streamlined member has the airfoil hollow shape, it is possible to prevent the airflow from being disturbed. Since the side surface particulate discharge port is formed near the maximum blade thickness, the pressure of the air flow outside the apparatus is the lowest near the side surface particulate discharge port due to the blowing. Therefore, the particles in the duct are quickly guided to the side surface particle discharge port by the air flow generated inside the device due to the pressure difference between the air intake part of the device and the side surface particle discharge port, and pass through the side surface particle discharge port of the device. It is discharged to the outside and guided on the streamlined member according to the air flow due to the air blow,
From the trailing edge, sheet-like fine particles having a constant and constant concentration and a thin thickness are discharged into the air stream.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing a sheet-shaped fine particle generator 1 according to a first embodiment of the present invention.
FIG. 2 is a horizontal sectional view schematically showing the sheet-shaped fine particle generator 1. The sheet-shaped fine particle generator 1 is provided, for example, in a wind tunnel, and an air blower for blowing air or a high-pressure tank is provided on the upstream side of the sheet-shaped fine particle generator 1 in the blowing direction A to blow air.

The sheet-shaped fine particle generator 1 has a blowing direction A.
Is arranged so as to be substantially vertical to the rear wall surface 10 on the downstream side in the blowing direction A, with both longitudinal end faces 2 and 3 sealed.
A duct 8 having an opening 4 along the longitudinal direction, and a particle supply device 5 for supplying particles into the duct 8.
And an air intake section 6 for supplying air to the inside of the duct 8,
A streamlined member 9 having a blade-shaped hollow shape along the air blowing direction A, has a fine particle discharge port 7 for discharging fine particles formed at a trailing edge 9a on the downstream side of the air blowing direction A, and is arranged so as to cover the duct 8.
It is comprised including. In addition, the air intake unit 6 is not limited to the structure in which the air is introduced in the air blowing direction A, but may be a structure in which the air is forcibly blown by a fan or the like.

The duct 8 is formed, for example, in a substantially rectangular tube shape, and the air intake portion 6 provided at the one end portion 8a in the longitudinal direction is expanded toward the upstream side of the air blowing direction A and connected to the duct 8. Therefore, the air blown in the wind tunnel can be effectively guided into the duct 8. Opening part 4 of this embodiment
Has a plurality of through holes 11 formed in one line on the rear wall surface 10 along the longitudinal direction of the duct 8. The diameter of this through hole 11 is selected to be, for example, 1 cm, and the distance L1 between each through hole 11 is selected to be, for example, 2 cm.

The fine particles supplied from the fine particle supply device 5 into the duct 8 are evenly filled in the duct 8 by the air flowing in from the air intake section 6. Further, the air intake part 6 and / or the fine particle supply device 5 may be provided outside the wind tunnel. Since the fine particle supply device 5 supplies the fine particles into the duct 8 through the run-up tube 12 having an appropriate length, the fine particles are constantly supplied. Further, the fine particle supply device 5 may be one, or may be provided in plural.

A mixing section 13 is provided between the through hole 11 closest to the one end 8a and the mounting position 5a of the particulate supply device 5 by a predetermined distance L2. Therefore, the fine particles supplied from the fine particle supply device 5 and the air introduced from the air intake section 6 are effectively mixed in the mixing section 13. By providing the mixing section 13 in this way, it is possible to prevent the concentration of the fine particles discharged from each of the through holes 11 from becoming substantially constant, and to prevent the thickness of the sheet-like fine particles to be formed from becoming uneven. Note that the distance L2
Is selected to be, for example, about 50 cm.

The streamlined member 9 is disposed immediately after the particulate supply device 5 and covers the duct 8 over the other end 8b of the duct 8. The particulate discharge port 7 formed at the trailing edge 9a of the streamlined member 9 is formed to have a constant width over the entire width of the streamlined member 9 in the longitudinal direction. By covering the duct 8 with the streamlined member 9 in this manner, it is possible to almost prevent the main flow in the wind tunnel from being disturbed.

Fine particles that are mixed with air and are forcibly discharged from each through hole 11 at a constant concentration by the air flowing in from the air intake section 6 are discharged to the outside from the fine particle discharge port 7 at a constant concentration. . The particles discharged from the particle discharge port 7 are discharged in the form of a sheet by the airflow flowing along the streamlined member 9. Thus, the sheet-shaped fine particle generator 1
As a result, the fine particles are discharged in the form of a sheet having a constant and constant concentration and a thin thickness.

The length L3 in the longitudinal direction of the streamlined member 9
Is, for example, about 2 m, and the chord length L of the streamlined member 9 is
4 is selected to be about 40 cm, for example.

FIG. 3 is a plan view schematically showing a sheet-shaped fine particle generator 15 according to the second embodiment of the present invention.
The sheet-shaped fine particle generator 1 shown in FIGS.
The same reference numerals are given to the same configurations as.

The sheet-shaped fine particle generator 15 is similar to the sheet-shaped fine particle generator 1, and it should be noted that the streamlined member 9 is used.
The back pressure reducing member 16 for reducing the air pressure outside the particle discharge port is provided near the particle discharge port 7. The back pressure reducing members 16 are formed of a pair of rectangular strips, face each other with the particulate discharge port 7 of the streamlined member 9 in between, and are provided along the particulate discharge port 7 over the entire width of the streamlined member 9 in the longitudinal direction. . The width L5 of the back pressure reducing member 16 is selected to be about 40 mm, for example. One end 16a of the back pressure reducing member 16 has a streamlined member 9 on which the particulate discharge port 7 is formed.
The other ends 16b are respectively connected to the trailing edges 9a, and are provided so as to incline in a direction in which they are separated from each other as they go from the particulate discharge port 7 toward the downstream side in the air blowing direction A.

By providing the back pressure reducing member 16 with the other end 16a opened in this way, when the fine particles are discharged from the streamlined member 9 to the outside, the pressure of the fine particle discharge port 7 and immediately after the fine particle discharge port 7 are discharged. With the above pressure, the pressure immediately after is reduced by the back pressure reducing member 16, and the fine particles in the streamlined member 9 can be effectively discharged to the outside. According to an experiment conducted by the present inventor, when the other end 16b of the back pressure reducing member 16 is opened by about 5 mm, there is almost no difference from the state of the fine particles discharged from the sheet-like fine particle generating device 1 shown in FIGS. Although it does not occur, it has been confirmed that the fine particles are effectively discharged from the fine particle discharge port 7 at a uniform concentration when the other end 16b is expanded to 20 mm or more. By adjusting the opening degree of the other end 16b in this way, the discharge amount of the fine particles can be easily adjusted.

FIG. 4 is a horizontal sectional view schematically showing a sheet-shaped fine particle generator 18 according to a third embodiment of the present invention. The sheet-shaped particle generator 18 is similar to the sheet-shaped particle generator 1, and it should be noted that the back pressure reducing member 19 is provided on the side surface of the streamlined member 9.

The back pressure reducing member 19 projects substantially vertically from the side surface 9a of the streamline member 9 in the vicinity of the particle discharge port 7 of the streamline member 9 and is parallel to the particle discharge port 7 over the entire width of the streamline member 9 in the longitudinal direction. It is provided in. By providing such a back pressure reducing member 19, the pressure on the downstream side in the air blowing direction A from the back pressure reducing member 19 is set to be smaller than the pressure of the fine particle discharge port 7 as in the sheet-shaped fine particle generating device 15 shown in FIG. Can also be lowered. Therefore, the particulate discharge port 7
Therefore, the fine particles can be effectively discharged to the outside.

The back pressure reducing member 19 may be mounted not only vertically to the side surface of the streamlined member 9 but also at an angle of about 20 ° to 160 ° with respect to the side surface. Further, the back pressure reducing member 19 is not limited to one side surface, but may be provided on both side surfaces of the streamlined member 9.

FIG. 5 is a horizontal sectional view schematically showing a sheet-shaped fine particle generator 21 according to a fourth embodiment of the present invention. The sheet-shaped particle generator 21 is similar to the sheet-shaped particle generator 1 shown in FIGS. 1 and 2, and it should be noted that the streamlined member 9 that covers the duct 8 is not provided.
Even with such a configuration, the fine particles can be constantly discharged in a thin sheet form from the opening 4 at a uniform concentration.

FIG. 6 is a horizontal sectional view schematically showing a sheet-shaped fine particle generator 23 according to a fifth embodiment of the present invention. The sheet-shaped particle generator 23 is similar to the sheet-shaped particle generator 1 shown in FIGS. 1 and 2, and it should be noted that the streamlined member 24 forms a part of the airfoil hollow shape along the air blowing direction A. However, it is arranged close to one of the side wall surfaces of the duct 8. The streamlined member 24 has one of the shapes obtained by dividing the streamlined member 9 of the sheet-shaped fine particle generator 1 shown in FIG. 2 into two along the air blowing direction A at the center of the blade thickness direction, The duct 8 is arranged close to one side surface 25 along the air blowing direction A. Also in the sheet-shaped particle generator 23 having such a configuration, the opening 4 of the duct 8 is formed.
Particles discharged from the streamlined member 24 are guided to the downstream side in the air blowing direction A along the inner surface of the streamlined member 24, and discharged from the trailing edge 24a of the streamlined member 24 in the form of a thin sheet having a constant and constant concentration. It

FIG. 7 is a rear view schematically showing a duct 28 which is another form of the duct 8 shown in FIGS. 1 to 6, and FIG. 8 is a duct 29 which is a further form of the duct 8.
FIG. The same components as those of the duct 8 shown in FIG. 1 are designated by the same reference numerals.

The opening 4 formed on the rear wall surface 10 of the duct 28 has a plurality of through holes 26 on the entire surface of the rear wall surface 10 and is made of a perforated plate. Further, in the opening 4 of the duct 29, the slit 27 is formed on the rear wall surface 10 over the entire width in the longitudinal direction. Even with such a porous plate or slit 27, the fine particles can be uniformly discharged from the opening 4, and the fine particles can be discharged in the form of a sheet having a constant and constant concentration.

FIG. 9 is a perspective view showing a sheet-shaped fine particle generator 30 according to a sixth embodiment of the present invention, and FIG. 10 is a horizontal sectional view schematically showing the sheet-shaped fine particle generator 30. The same components as those in the sheet-shaped particle generation device 1 shown in FIGS. 1 and 2 are designated by the same reference numerals.

The sheet-shaped particle generating device 30 is similar to the sheet-shaped particle generating device 1, and it should be noted that the opening 4 of the duct 8 is substantially parallel to the air blowing direction A and the side wall surface 3 of the duct 8.
1, instead of the particulate discharge port 7 formed at the trailing edge of the streamlined member 9, the side surface particulate discharge formed near the maximum blade thickness of the streamlined member 9 and connected to the opening 4 of the duct. The outlet 32 is formed.

Since the streamlined member 9 has an airfoil shape along the air blowing direction A, the pressure of the air flowing along the streamlined member 9 becomes the lowest near the maximum blade thickness. Therefore,
Duct 8 with high pressure due to the inflow of air from air intake unit 6
The fine particles having a uniform concentration inside are effectively discharged to the outside from the side surface fine particle discharge port 32 formed near the maximum blade thickness where the pressure is lowest, and the discharged fine particles are blown along the streamlined member 9. The sheet is guided to the downstream side in the air blowing direction A, has a constant and constant concentration from the trailing edge 9a of the streamlined member 9, and is discharged into the main stream in the form of a thin sheet.

[0033]

As described above, according to the present invention, since the duct is provided with the air intake portion, the fine particles supplied into the duct have a constant concentration in the duct due to the air flowing in from the air intake portion. It fills up in the state, and the inside of the duct has a higher pressure than that around the particle outlet. Therefore, it is possible to discharge the fine particles having a constant concentration to the outside through the opening in the form of a sheet having a constant and thin thickness.

Further, according to the present invention, since the duct is covered by the streamlined member, the concentration of the particles can be kept constant from the particle discharge port formed at the trailing edge of the streamlined member without disturbing the air flow caused by the air flow. It can be discharged in a steady and thin sheet form.

Further, according to the present invention, since the back pressure reducing member is provided in the vicinity of the fine particle discharge port, the pressure around the fine particle discharge port is reduced, thereby effectively discharging the fine particles from the fine particle discharge port to the outside. Thus, it is possible to generate steady sheet-like fine particles having a constant thickness.

Further, according to the present invention, by arranging the streamline member forming a part of the airfoil-shaped hollow shape on the side wall surface of the duct, the sheet-like fine particles having a constant and constant concentration and a small thickness can be obtained. Can be generated.

Further, according to the present invention, since the side surface particulate discharge port is formed in the vicinity of the maximum blade thickness of the streamlined member, the particulates are effectively discharged from the inside of the duct to the outside of the trailing edge of the streamlined member. It is possible to discharge sheet-like fine particles having a constant and constant concentration and a small thickness into the main stream.

[Brief description of drawings]

FIG. 1 is a perspective view showing a sheet-shaped particle generation device 1 according to a first embodiment of the present invention.

FIG. 2 is a horizontal sectional view schematically showing the sheet-shaped particle generation device 1.

FIG. 3 is a horizontal cross-sectional view schematically showing a sheet-shaped particle generation device 15 according to a second embodiment of the present invention.

FIG. 4 is a horizontal sectional view schematically showing a sheet-shaped fine particle generator 18 according to a third embodiment of the present invention.

FIG. 5 is a horizontal cross-sectional view schematically showing a sheet-shaped particle generation device 21 according to a fourth embodiment of the present invention.

FIG. 6 is a horizontal sectional view schematically showing a sheet-shaped fine particle generator 23 which is a fifth embodiment of the present invention.

FIG. 7 is a simplified rear view of the duct 28.

FIG. 8 is a simplified rear view of the duct 29.

FIG. 9 is a perspective view showing a sheet-shaped fine particle generator 30 showing a sixth embodiment of the present invention.

FIG. 10 is a horizontal cross-sectional view schematically showing a sheet-shaped particle generation device 30.

[Explanation of symbols]

1,15,18,21,23,30 Sheet-shaped fine particle generator 2,3 End surface 4 Opening 5 Fine particle supply device 6 Air intake 7 Fine particle discharge port 8,28,29 Duct 9 Streamlined member 10 Rear wall surface 11, 26 through hole 16 back pressure reducing member 25, 31 side wall surface 27 slit 32 side wall particulate discharge port

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akihiko Dobashi 2 Kawasaki-cho, Kakamigahara-shi, Gifu Commuter Co., Ltd. Helicopter Institute for Advanced Technology (72) Inventor Osamu Kato 2 Kawasaki-cho, Kakamigahara-shi, Gifu Prefecture Commuta Co., Ltd. Helicopter Advanced Technology Laboratory (72) Inventor Hiroaki Niwa 2 Kawasaki-cho, Kakamigahara City, Gifu Prefecture Commuter Co., Ltd. Helicopter Advanced Technology Laboratory (72) Inventor Keiji Masuko 3-4-3 Uchikanda, Chiyoda-ku, Tokyo Seiki Industry Co., Ltd. (72) Inventor Kenyoshi Tokura 3-4-3 Kanda, Chiyoda-ku, Tokyo Rika Seiki Co., Ltd. (72) Inventor Kiyoshi Matsukawa 3-43 Uchikanda, Chiyoda-ku, Tokyo Rika Seiki Industry Co., Ltd.

Claims (5)

[Claims] 1. A duct which is arranged in a direction substantially perpendicular to a blowing direction and has an opening along a wall surface in a longitudinal direction,
A sheet-like particle generation device comprising: a particle supply unit for supplying particles into the duct; and an air intake section for supplying air into the duct. 2. A streamlined member having a streamlined hollow shape along the air flow direction, a fine particle discharge port for discharging fine particles is formed at a trailing edge on the downstream side in the air flow direction, and is arranged so as to cover the duct. The sheet-shaped fine particle generator according to claim 1, comprising: 3. A streamlined member near a particulate discharge port,
The sheet-shaped particle generation device according to claim 2, further comprising a back pressure reducing member that reduces the air pressure around the particle discharge port. 4. A streamlined member forming a part of a wing-shaped hollow shape along the air flow direction, the streamlined member being disposed in proximity to one of the side wall surfaces of the duct. Sheet-shaped particle generator. 5. An airfoil-shaped hollow shape along the air blowing direction,
The sheet-shaped fine particle generator according to claim 1, further comprising a streamlined member disposed so as to cover the duct and having a side surface fine particle outlet formed near a maximum blade thickness and connected to an opening of the duct. apparatus.