JP2023067346A - Snowstorm density adjustment-purpose snow jetting nozzle, snowstorm density adjustment device, snowstorm density adjustment method and environment testing system - Google Patents

Abstract

To provide a snowstorm density adjustment-purpose snow jetting nozzle, snowstorm density adjustment device, snowstorm density adjustment method and environment testing system that can adjust density of snowstorm desirably when simulatedly blowing the snowstorm to an object of an environment test.SOLUTION: A snowstorm density adjustment-purpose snow jetting nozzle is a snow jetting nozzle 36 that conveys snow inside, and is rotatably insertable to an out-flow exit of a hose 204 flowing out the snow from the out-flow exit 202, and the snowstorm density adjustment-purpose snow jetting nozzle has: a first straight pipe part 206 that is arranged inside an air duct 16 blowing simulated snow from an exit opening, and each has an in-flow entrance insertable to the out-flow exit; a second straight pipe part 212 that has the out-flow exit; and a curved pipe part 218 that connects to the first straight pipe part and second straight pipe part. The out-flow exit of the second straight pipe part is provided with a plurality of snow jetting nozzles 36 constituting an exhaust nozzle, and the plurality of snow jetting nozzles is different from each other in a length of the curved pipe part, and different from each other in an intersection angle α between the first straight pipe part and second straight pipe part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a snow blowing nozzle for adjusting snowstorm concentration, a snowstorm concentration adjustment apparatus, a snowstorm concentration adjustment method, and an environmental test system. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow blowing nozzle for adjusting the concentration of snow blowing that can be adjusted as desired, a snow blowing concentration adjusting device, a snow blowing concentration adjusting method, and an environmental test system.

Conventionally, an environmental test room has been used in which a complete model vehicle is placed indoors, various natural environments and weather conditions are set, and the load on the vehicle is collected as data and analyzed.
As an example, artificial snow is used to simulate a snowstorm in an environmental test room, and the snowstorm is blown toward the vehicle to deal with problems caused by snow entering the engine room and icing problems such as freezing of suspension parts. is being done.

To this end, the environmental test chamber has a wind tunnel in which the vehicle is located and of sufficient space to blow a snowstorm toward the vehicle, and a snowstorm generator.
The blizzard generating device is simulated by an ice maker that produces flaky ice pieces, an ice crusher that crushes the produced flaky ice pieces into ice particles of a predetermined particle size, and crushed ice particles of a predetermined particle size. It has a pipe for conveying the artificial snow into the wind tunnel, and a blowout nozzle installed at the tip of the pipe and blowing out toward the front of the vehicle.
According to such an environmental test chamber, it is possible to conduct an environmental test simulating the natural environment and weather conditions by blowing a snowstorm toward the vehicle in the wind tunnel using the snowstorm generator.

At this time, in order to conduct an appropriate and effective environmental test, it is necessary to simulate a snowstorm in a natural state. Furthermore, it is important to secure the amount of snow necessary for the test.
On the other hand, in the wind tunnel where the vehicle is placed, there is a constraint that the distance between the vehicle and the airflow outlet is short (about 1 to 2 meters). You have to spray the vehicle.

Conventionally, as a principle for generating a snowstorm, there has been a water spray method in which water is sprayed into a low-temperature air current, frozen by the ambient temperature, and a snowstorm is generated in the space just before it is sprayed onto the vehicle.
With this principle, it is difficult to secure the amount of snow necessary for the test, and it is difficult to simulate the adhesion of a snowstorm, making it difficult to conduct an appropriate and effective environmental test.

On the other hand, for example, Patent Document 1 discloses a deflector system. According to this system, an opening and closing deflector is arranged in a tapered blowout nozzle that generates an air flow, and the opening and closing deflector causes the flow area to increase toward the downstream side. By using the snow from the snow removal shooter provided on the ceiling of the tapered nozzle, the snow swirls and floats due to the spiral turbulent state generated in the tapered nozzle. It is possible to make the density distribution uniform in the vertical direction.
However, according to this principle, the following technical problems exist.

First, it is difficult to adjust the spread of the snowstorm as desired under the constraint that the distance between the vehicle and the airflow outlet is short.
More specifically, in the case of the deflector method, the spread of the snowstorm is limited by the opening area of the outlet of the tapered nozzle. , in this case it is difficult to regulate the spread of the snowstorm.

Second, snow accumulates in the converging nozzle, making continuous testing difficult.
More specifically, the snow from the snow removal shooter is deflected by the opening and closing deflector, but a part of the snow falls to the bottom of the nozzle without flowing out from the tapered blowout nozzle as a snowstorm, and accumulates over time. It becomes necessary to remove the mountain of snow that has accumulated once, making it difficult to continue the test.

In order to solve the first and second technical problems, the applicant of the present application has proposed a member for diffusing a snowstorm in Patent Document 2.
This blizzard diffusing member is for diffusing a blizzard simulated by snow carried on an airflow, and is located outside the blowout port for blowing snow along the direction of travel of the airflow and in front of the direction of travel of the airflow. A diffusing surface facing the air outlet is provided at a position, and the diffusing surface is made of a material that does not easily adhere to snow and/or has a conical shape with the top facing the air outlet. and the distance between the outlet and the diffusion surface is variable, so that the snowstorm that is blown out from the outlet and is carried by the airflow along the direction of travel of the airflow is guided along the diffusion surface, It is a configuration that achieves desired diffusion characteristics while diffusing outward in all four directions of the diffusing surface.
According to the blizzard diffusing member having the above configuration, the snow blown out from the blowout port rides on the airflow and flows as a blizzard along the traveling direction of the airflow. When it hits the diffusion surface arranged to face the blowout port at a predetermined position in the forward direction of the movement, the diffusion surface is made of a material that is difficult to adhere to snow and / or the top is made of a material that is difficult to adhere to snow. Due to the conical shape that is formed in a direction that approaches the air outlet, the snowstorm is guided along the diffusion surface without adhering to the diffusion surface, spreads outward in all directions, and adheres to the diffusion surface. It is possible to suppress temporal fluctuations in the diffusion characteristics associated with

However, the snowstorm diffusion member has the following technical problems.
That is, although the diffusion range of the snowstorm can be adjusted by the snowstorm diffusion member, it is difficult to adjust the density distribution of the snowstorm itself.
More specifically, a plurality of snow blowing nozzles, each having an outlet for blowing out snow along the traveling direction of the airflow, are distributed substantially uniformly as a whole in a cross section perpendicular to the flow of the airflow in the wind tunnel. The snow blown out from the nozzle hits the diffusion surface and spreads in all directions, and is blown out as a snowstorm from the outlet of the wind tunnel as a whole. The density distribution of snowstorms tends to increase toward the bottom.
Also, depending on the test conditions, the concentration distribution of the snowstorm may not be uniform, and the distribution may be intentionally shifted in the height direction and/or the lateral direction depending on the position.
In this case, if the snow transport flow rate is constant, if the diffusion range is expanded by the snowstorm diffusion member, the concentration of the snowstorm will decrease accordingly. , the density of the blizzard will be high, and it is particularly difficult to adjust both the diffusion range and the blizzard density as desired.

Furthermore, by providing an opposing surface in front of the snow blowing nozzle and blowing snow against the opposing surface, it is possible to increase the spread of the snowstorm, that is, to increase the diffusivity. Regardless of whether it is artificial snow or natural snow, it adheres to the opposing surface and forms a tapered mountain shape toward the nozzle that blows out over time, and the diffusion characteristics change so that the spread of the snowstorm narrows. In any case, it impedes the smooth execution of the environmental test using the blowing snow because the blowing of the snow from the blowing nozzle is hindered.
In this case, it is possible to reduce the degree of adhesion to the facing surface to some extent by slowing down the air velocity to simulate a snowstorm. However, it is an important test parameter for simulating a running vehicle, and restrictions on the airflow velocity are not a fundamental solution.

Patent No. 2739716 JP 2017-21037

SUMMARY OF THE INVENTION In view of the above technical problems, an object of the present invention is to provide a snow blowing nozzle for adjusting the concentration of snow blowing, and a snow blowing concentration adjusting device, which can adjust the concentration of snow blowing to a desired object when simulating a snow blowing. and to provide a snowstorm concentration adjustment method and an environmental test system.

In order to solve the above problems, the snow blowing nozzle for adjusting the concentration of blowing snow according to the present invention includes:
A snow blowing nozzle rotatably insertable into an outlet of a hose for conveying snow inside and discharging snow from the outlet,
Placed inside a wind tunnel that blows simulated snowstorms from the exit opening,
A first straight pipe portion having an inlet that can be inserted into the outlet, a second straight pipe portion having an outlet, and a curved pipe portion connecting the first straight pipe portion and the second straight pipe portion, respectively. a plurality of snow blowing nozzles having an outflow port of the second straight pipe portion forming a jet port,
The plurality of snow blowing nozzles have different lengths of the curved pipe portions and different crossing angles between the first straight pipe portion and the second straight pipe portion.

In order to solve the above problems, the snowstorm concentration adjusting device of the present invention
a hose for conveying snow inside and for outflowing the snow from the outlet;
a snow blowing nozzle rotatably insertable into the outflow port of the hose;
a wind tunnel in which the hose and the snow blowing nozzle are arranged inside, and a simulated snow blowing is blown out from the outlet opening by riding the blowing snow on an air current directed from the back toward the outlet opening,
A first straight pipe portion having an inlet that can be inserted into the outlet, a second straight pipe portion having an outlet, and a curved pipe portion connecting the first straight pipe portion and the second straight pipe portion, respectively. a plurality of snow blowing nozzles having an outflow port of the second straight pipe portion forming a jet port,
The plurality of snow blowing nozzles have different lengths of the curved pipe portions and different crossing angles between the first straight pipe portion and the second straight pipe portion.

According to the snowstorm concentration adjustment device having the above configuration, in the wind tunnel, the snow is transported inside, and the snow is blown from the hose that discharges the snow from the outflow port to the blowout port of the snow blowing nozzle that is inserted into the outflow port of the hose. A plurality of such snow blowing nozzles are provided, and it is possible to carry the blowing snow on the airflow directed from behind to the outlet opening and blow out the simulated snow blowing from the outlet opening of the wind tunnel.
At that time, in each of the plurality of snow blowing nozzles, a first straight pipe portion having an inlet that can be inserted into the outlet, a second straight pipe portion having an outlet, and the first straight pipe portion and the second straight pipe The outlet of the second straight pipe constitutes a jet outlet, and the plurality of snow blowing nozzles have curved pipe portions with different lengths, and the first straight pipe Since the intersection angle between the part and the second straight pipe part is different, the vertical direction of the snow blowing nozzle can be adjusted by selecting the snow blowing nozzle, and the rotation of the snow blowing nozzle with respect to the corresponding hose can be adjusted. By adjusting the angle, the snow blowing horizontal direction can be adjusted. By adjusting the snow blowing vertical direction and the snow blowing horizontal direction for each snow blowing nozzle, a plurality of snow blowing nozzles as a whole can be configured. The density of the snowstorm can be adjusted as desired.

Further, the curved pipe portions of the plurality of snow blowing nozzles preferably have the same radius of curvature and different center angles from the center of curvature.
Furthermore, the horizontally arranged hose and the snow blowing nozzle are preferably arranged in the vicinity of the outlet opening in the wind tunnel.
Additionally, the hose may be adjustable in height within the wind tunnel.
In addition, the plurality of snow blowing nozzles are divided into a plurality of sets having different levels in the wind tunnel, and each of the plurality of sets includes the snow blowing nozzles arranged at intervals in the lateral direction, and the snow blowing nozzles are arranged within the entire cross section of the wind tunnel. should be uniformly distributed with
Furthermore, it is preferable that a flow contraction channel is provided on the most downstream side of the wind tunnel, and a plurality of snow blowing nozzles are arranged on the upstream side of the flow contraction channel.
In addition, the intersection angle between the first straight pipe portion and the second straight pipe portion is preferably 10° or more and 45° or less.
Furthermore, it further has a diffusion member for diffusing the blown snow from the snow blowing nozzle, the diffusion member
A diffusion surface facing the snow blowing hole is provided at a predetermined position outside the snow blowing hole and in front of the snow blowing direction,
The diffusion surface is made of a material that is difficult to adhere to snow and/or has a conical shape with a top portion that is formed in a direction approaching the snow nozzle,
Thereby, it is preferable that the blowing snow blown out from the snow blowing port is guided along the diffusion surface and diffused outward in all directions of the diffusion surface.
Furthermore, the distance between the snow vent and the diffusion surface may be variable depending on the desired diffusion characteristics of the snowstorm.
Additionally, the air velocity may be fine-tuned depending on the distance between the snow vent and the diffusion surface and/or the divergence angle.

In order to solve the above problems, the snowstorm concentration adjustment method of the present invention includes:
In the wind tunnel, when the blowing snow is put on the air current from the back toward the exit opening, simulating a snowstorm from the exit opening and blowing out toward the test object,
measuring a snowstorm concentration distribution at an exit opening of the wind tunnel without the snowblower nozzle of claim 1;
Depending on the measured snowstorm density distribution, the rotation angle of each of the snow blowing nozzles is adjusted with respect to the corresponding hose, thereby adjusting the left and right diffusion range and adjusting the height of the corresponding hose. It is configured to adjust the vertical diffusion range of snowfall.

In addition, when the plurality of snow blowing nozzles are divided into a plurality of sets having different levels in the wind tunnel, and the snow blowing nozzles are arranged in each of the plurality of sets at intervals in the horizontal direction,
The higher the level of the set of snow blowing nozzles, the longer the length of the corresponding curved pipe portion.

In order to solve the above problems, the environmental test system of the present invention includes:
In an environmental test system in a wind tunnel, blowing snow is placed on the air current from behind toward the exit opening, simulating a snowstorm from the exit opening, and blown out toward the test object.
The snow blowing nozzle according to claim 1 is provided in the wind tunnel.

According to the blizzard diffusing member having the above configuration, the snow blown out from the blowout port rides on the airflow and flows as a blizzard along the traveling direction of the airflow. When it hits the diffusion surface arranged to face the blowout port at a predetermined position in the forward direction of the movement, the diffusion surface is made of a material that is difficult to adhere to snow and / or the top is made of a material that is difficult to adhere to snow. Due to the conical shape that is formed in a direction that approaches the air outlet, the snowstorm is guided along the diffusion surface without adhering to the diffusion surface, spreads outward in all directions, and adheres to the diffusion surface. It is possible to suppress temporal fluctuations in the diffusion characteristics associated with
The term “snow” here has a broad meaning including both snowflakes in which snow crystals overlap like natural snow, and snow particles such as artificial snow made of ice grains. has a broader meaning, meaning not only snowstorm conditions due to snowfall, but also situations in which such snowflakes or snow particles are moved by wind, passing vehicles, or the like.

The snowstorm concentration adjusting apparatus of the present invention will be described in detail below, taking as an example a case where the snowstorm diffusion member of the present invention simulates a snowstorm and is used in a snow environment test.
First, the snow environment test system will be described. As shown in FIG. 1, the snow environment test system 10 uses artificial snow made of ice particles and puts the artificial snow on an air current from behind to simulate a snowstorm. , and is configured to blow toward a vehicle V, which is a test specimen, and has a blizzard supply system 12 and an airflow supply system 14 for that purpose.
In particular, when using a required amount of snowstorm with a predetermined snow quality in which ice grain size and moisture content are the main influencing factors, and blowing continuously toward the vehicle V, the entire height of the vehicle V Immediately before the test, a group of ice grains to be used as artificial snow is manufactured under prescribed temperature and humidity control in order to diffuse and possibly achieve the desired snowstorm concentration distribution in the height direction of the vehicle V. It is required to supply it promptly.

More specifically, the snow environment test system 10 includes a wind tunnel 16 in which a vehicle V to be tested is placed, a cold room 18 placed above the wind tunnel 16, and an ice making room placed above the cold room 18. 20, in which an ice maker 22 is located, and in the cold room 18, an ice temperature stabilization conveyor 24, an ice crusher 26, a blower 28, a cooler 30, and a distribution of artificial snow. A device 34 is arranged, and in the wind tunnel 16, a wet snow device 32, a snow blowing nozzle 36 for artificial snow, and a snowstorm collecting device 38 are arranged. Artificial snow is produced by crushing ice in a low-temperature room 18 and turning it into ice particles, and the artificial snow is pumped toward a wind tunnel 16, and the wet snow artificial snow is distributed in the wind tunnel 16 to create a low-temperature air current. It is configured to be placed on the vehicle V to turn it into a snowstorm and blow it toward the vehicle V.

The wind tunnel 16 is an open-type circulation type, and includes an (open-type) measurement chamber 300 in which a vehicle to be measured is installed, and four first to fourth bending tunnels 302, 304, 306, and 308 (bending portions). and is formed in a substantially rectangular shape in plan view. The airflow generated by the blower 25 passes through the second diffusion drum 310, the third curved cavity 306, the fourth curved cavity 308, the rectifying cavity 312, and the contraction cavity 314, and then flows into the measurement chamber 300 from the air outlet 316 opening into the measurement chamber 300. , and flows through the first sinus 302 and the second sinus 304 in that order.
The airflow blown by the blower 25 is measured by temporarily decreasing the wind speed (dynamic pressure) of the entire airflow and increasing the pressure (static pressure) in the intermediate body, and then passing through the contraction cavity 314. The necessary and sufficient amount (air velocity) of airflow can be blown out from the outlet 316 to the measurement chamber 300 for the measurement.

As a result, as will be described later, the ice particles that have been air-conveyed through the ice-making process, ice-breaking process, separation process, and wet-snow process are carried in the measurement chamber 300 by air currents from behind them, and are blown toward the vehicle. By adjusting the wind speed of the airflow with the blower 25, the stationary vehicle can simulate a moving vehicle.
In the case of the circulating wind tunnel 16 for the snowstorm test, a separate snow repair device 38 is provided downstream of the vehicle V in order to separate and collect the snow after the test. In order to separate the snow by the inertia effect, an area is provided downstream of the vehicle V where the airflow is not rectified.

The snow blowing supply system 12 has three systems, each of which includes a snow supply pipe 40 connecting the ice crusher 26 and the snow blowing nozzle 36, and an air duct connecting the suction port 42 in the wind tunnel 16 and the ice crusher 26. 44 is provided, and in the snow supply pipe 40, the artificial snow distribution device 34 and the snow wetting device 32 are connected in this order between the ice crusher 26 and the snow blowing nozzle 36, while in the air duct 44, the wind tunnel A blower 28 and a cooler 30 are connected between the suction port 42 in 16 and the ice crusher 26 .
The reason why the artificial snow distribution device 34 is installed on the upstream side of the wet snow device 32 is that if the artificial snow distribution device 34 is installed on the downstream side, the wet snow is sent to the distribution device 34 and the inside of the distribution device 34 to prevent clogging.

The ice-making machine 22 is a so-called reamer-type ice-making machine 22 that produces flake-shaped ice pieces, and a plurality of ice-making machines 22 that produce crack-shaped ice pieces according to the total required amount of artificial snow used in the snow environment test. An arbitrary number of machines are selected from among them, and ice is made by the selected ice making machine 22 according to changes in the required amount of artificial snow to be used in the environmental test. In each of the selected ice making machines 22, the evaporation temperature and/or the water temperature and/or the rotation speed of the reamer are adjusted according to the difference between the required amount of artificial snow and the coarsely adjusted ice-making amount. and a control device (not shown) that finely adjusts the amount of ice to be made.

The ice crusher 26 mainly consists of a rotary feeder (not shown) located at the top and a pair of crushing drums (not shown) located at the bottom, fed by the ice temperature stabilization conveyor 24. Ice pieces are quantified by a rotary feeder, supplied to a pair of crushing drums, crushed by the pair of crushing drums, and supplied to a snow supply pipe 40 as ice particles of a predetermined grain size.

The snowmaking distribution device 34 is used to distribute the snowmaking carried by the snow supply pipe 40 to a plurality of branch pipes (not shown), more specifically, the snow blowing nozzles 36 at the same level. The snow supply pipe 40 in each system is branched into a plurality of branch pipes in the width direction of the vehicle V so that a plurality of branches are provided in the width direction of the vehicle V, and a wet snow device 32 is provided for each branch pipe. A snow blowing nozzle 36 is provided at the tip of the pipe.

The artificial snow distribution device 34 includes a rotating body (not shown) having an upstream end face and a downstream end face parallel to the downstream end face of the snow supply pipe 40 and the upstream end faces of the plurality of branch pipes, respectively; It has a rotation drive section (not shown) that rotates the rotating body at a predetermined rotational speed about its axial direction. ), and the pumping channel has an intake (not shown) disposed in a non-contact manner at its upstream end face and in close opposition to an outflow opening (not shown) provided at the downstream end face of the snow supply pipe 40 . and a discharge port (not shown) arranged in a non-contact manner so as to closely face an inflow opening (not shown) provided on the upstream end face of each of the plurality of branch pipes. The discharge port is provided such that the inflow opening of each of the plurality of branch pipes is positioned on the passage path of the discharge port caused by the rotation of the rotating body.

The wet snow device 32 has a hot air supply pipe (not shown) communicating with the snow supply pipe 40, and the hot air supply pipe extends at its downstream end over a predetermined length in the direction in which the snow supply pipe 40 extends. A hot air inlet (not shown) forms an annular space covering the entire outer peripheral surface of the snow supply pipe 40. The outer peripheral surface of the snow supply pipe 40 covered by the annular space has a hot air inlet opening (not shown). ) are provided evenly, thereby forming an aging space (heat exchange ripening area) in the snow supply pipe 40 downstream of the portion of the snow supply pipe 40 to which the hot air inlet is attached. It is made to be wet snow.

Regarding the airflow supply system 14, the wind tunnel 16 is formed in a part of the circulation space, and is configured to blow a snowstorm over the height of the vehicle V in one direction from the front to the rear of the vehicle V. Specifically, the blower 25 installed in the circulation space generates an airflow with a predetermined wind speed in one direction from the front to the rear of the vehicle V. After passing through the vehicle V, the airflow is cooled to a predetermined temperature by the cooler 27. After being cooled, it is returned to the blower 25 to generate an air flow again, and this is repeated.

Regarding the snow blowing nozzles 36 of the snow blowing density adjusting device, three blowing snow nozzles 36 are arranged at a predetermined distance in front of the vehicle V, with predetermined intervals in the height direction over the vehicle height of the vehicle V. , and the density of the supplied snowstorm can be adjusted for each snow blowing nozzle 36 . A snow collecting device 38 is arranged at a predetermined distance behind the vehicle V, and the blowing snow that has passed through the snow collecting device 38 passes through a suction port 42 in the wind tunnel 16 to a blower arranged in the low-temperature chamber 18 . 28, cooled by the cooler 30, returned to the ice crusher 26, made by the ice machine 22, fed to the ice crusher 26 by the ice temperature stabilization conveyor 24, mixed with ice grains to be crushed, and supplied again with snow. It is adapted to be used to blow a snowstorm from the snow blowing nozzle 36 through the pipe 40. - 特許庁The snow blowing nozzles 36 are arranged along the traveling direction of the airflow, and the blowout port 102 is installed within the band of the airflow blown out from the blower 25 .
In this regard, the blowing snow blows off from each snow blowing nozzle 36 by the air blown by the blower 28, and is blown toward the vehicle V by the air current blown from the blower 25. As long as the supply pipe 40 is not clogged with snow, the speed is preferably as low as possible.
More specifically, when the snowstorm is spread by the diffusion plate 74 (described later) and blown toward the vehicle V, if the pumping speed of the pumping air is high, the speed of the snowstorm only at the snow blowing nozzle 36 is high. While deviating from a natural snowstorm, by changing the speed of the airflow blown out from the blower 25, it is possible to uniformly vary the speed of the entire spread snowstorm. When simulating a vehicle, it is advantageous to vary the speed of the airflow blown from the blower 25 .

Specifically, as shown in FIG. 1, each of the snow blowing nozzles 36 is provided on the upstream side of the boundary between the rectifying cavity 312 and the contraction cavity 314 in the flow direction of the airflow.
It is preferable that the plurality of snow blowing nozzles 36 are evenly distributed in the cross section of the wind tunnel 16 in the height direction and the lateral direction. By adjusting the vertical direction and horizontal direction of each snow blowing nozzle 36, the concentration of snow blowing out from the outlet of the wind tunnel 16 can be made uniform in the vertical direction and horizontal direction, or a desired concentration distribution can be obtained. Is possible.
More specifically, the plurality of snow blowing nozzles 36 are divided into a plurality of sets at different levels in the wind tunnel 16, and the snow blowing nozzles 36 are arranged in each of the plurality of sets at intervals in the lateral direction. , are uniformly distributed within the entire cross-section of the wind tunnel 16 .
As shown in FIG. 2, each snow blowing nozzle 36 is rotatably insertable into an outlet 202 of a hose 204 for conveying snow therein and for discharging snow, and an inlet 208 insertable into the outlet 202 . , a second straight pipe portion 212 having an outflow port 216, and a curved pipe portion 218 connecting the first straight pipe portion 206 and the second straight pipe portion 212; The outflow port 216 of the two straight pipe portions 212 constitutes a jet port.
The material of the plurality of snow blowing nozzles 36 is arbitrary as long as the snow grains are conveyed by the conveying air inside, and may be made of resin or metal (for example, copper). It should be coated to prevent snow particles from sticking to it.
The first straight pipe portion 206, the second straight pipe portion 212, and the curved pipe portion 218 may be, for example, integrally molded from resin, or may be separate elements and fixed by adhesion or welding.

The plural snow blowing nozzles 36 have different lengths of curved pipe portions 218 and different intersection angles α between the first straight pipe portion 206 and the second straight pipe portion 212 .
The curved pipe portions 218 of the plurality of snow blowing nozzles 36 may have the same radius of curvature R and different center angles β from the center of curvature, so that the crossing angles α may be different.
Specifically, in FIG. 2, in FIGS. 2A to 2C, the length l1 of the first straight pipe portion 206 and the length l2 of the second straight pipe portion 212 are common. The central angle β of the portion 218 is 20° (FIG. 2(A)), 30° (FIG. 2(B)), and 40° (FIG. 2(C)), so that the intersection angle α is 2(A) is the minimum, and FIG. 2(C) is the maximum.
The crossing angle α may be appropriately determined according to the conditions required by the environmental test and the distribution state of the plurality of snow blowing nozzles 36 in the cross section of the wind tunnel 16 in the height direction and the lateral direction, but is 0° or more and less than 90°. and preferably 10° or more and 45° or less.
The material of the hose 204 is preferably hard resin so that the snow blowing nozzle 36 can be inserted into the outflow port 202 and, for example, it can be suspended in the wind tunnel 16 to maintain its shape retention. A material that can ensure durability against temperatures below freezing is preferable. The hose 204 is preferably height adjustable within the wind tunnel 16 .

The diameter of the hose 204 may be appropriately set according to the flow rate of the snowstorm used in the environmental test, and is, for example, several tens of millimeters. Even if the hose 204 is made of a soft material, the snow blowing nozzle 36 may be fitted into the outflow port, and the outer peripheral surface of the hose 204 around the outflow port 202 may be tightened in a ring shape. In any case, a plurality of types of snow blowing nozzles 36 are prepared, and a suitable one is selected from the plurality of types of snow blowing nozzles 36 according to the conditions of the environmental test and the position. It is preferable that the hose 204 can be detachably inserted so that it can be inserted.
In each of the plurality of snow blowing nozzles 36 , the axial direction of the first straight pipe portion 206 is preferably arranged in the horizontal direction, that is, parallel to the longitudinal direction of the wind tunnel 16 . The larger the center angle β from the center of curvature, the larger the intersection angle α between the first straight pipe portion 206 and the second straight pipe portion 212, and the corresponding upward angle of the second straight pipe portion 212. It is better to
According to the snowstorm concentration adjusting device having the above configuration, the snow blowing nozzle 36 is inserted into the outflow port 202 of the hose 204 from the hose 204 that conveys the snow inside the wind tunnel 16 and outflows the snow from the outflow port 202 . A plurality of such snow blowing nozzles 36 are provided, and the simulated snow blowing can be blown out from the outlet opening of the wind tunnel 16 by putting the blowing snow on the airflow heading for the outlet opening from behind.
At that time, in each of the plurality of snow blowing nozzles 36, a first straight pipe portion 206 having an inlet that can be inserted into the outlet 202, a second straight pipe portion 212 having an outlet 218, and a first straight pipe portion 206 and a second straight pipe portion 212, and the outlet 216 of the second straight pipe portion 212 constitutes an ejection port. Since the length of the portion 218 is different and the crossing angle α between the first straight pipe portion 206 and the second straight pipe portion 212 is different, depending on the selection of the snow blowing nozzle 36, the snow blowing from the snow blowing nozzle 36 can be adjusted vertically. By adjusting the direction and the rotation angle of the snow blowing nozzle 36 with respect to the corresponding hose 204, the snow blowing horizontal direction can be adjusted. and the snow blowing horizontal direction, the snow blowing density formed by the plurality of snow blowing nozzles 36 as a whole can be adjusted as desired.

As shown in FIG. 3, a diffusion plate 74 is provided in front of each snow blowing nozzle 36, and the snow blowing off from the snow blowing nozzles 36 toward the vehicle V on the low-temperature airflow from the blower spreads as shown in FIG. As shown in , the snow hits the diffusion plate 74 and spreads outward in all directions, and the three snow blowing nozzles 36 cooperate with each other to cover the height direction of the vehicle V at the front of the vehicle V. , the blizzard is to be distributed.
In this respect, since the wind tunnel 16 is not a so-called aerodynamic wind tunnel 16 but a simple wind tunnel 16, the distance between the snow nozzle 36 and the front of the vehicle V is about 1 to 3 meters, The snow blowing from the snow blowing nozzle 36 spreads over the entire height in front of the vehicle V during this short distance.

A plurality of blowout ports 102 are provided at intervals in the height direction so as to cover the entire height of the vehicle V, and the amount of snow blown out from each blowout port 102 can be adjusted independently of each other. , the density distribution of the snowstorm can be adjusted according to the height of the vehicle V.

As shown in FIG. 3, the diffusion plate 74 has a diffusion surface 104 facing the snow blowing nozzle 36 at a predetermined position forward in the direction of travel of the airflow. The diffuser plate 74 is attached to the snow supply pipe 40 around the snow blowing nozzle 36 via an L-shaped member 120 for convenience of attachment. More specifically, one portion 120A of the L-shaped member 120 extends forward from the side peripheral surface of the vertical portion of the snow supply pipe 40 around the snow blowing nozzle 36, and the other portion 120B of the L-shaped member 120 extends downward. A diffusion plate 74 is attached to the tip of the other portion 120</b>B of the L-shaped member 120 so as to face the snow blowing nozzle 36 .

As will be described later, the distance d between the snow blowing nozzle 36 and the diffusion plate 74 affects the diffusion range of the snow blowing when the snow blowing from the snow blowing nozzle 36 hits the diffusion plate 74 and spreads. More specifically, the larger d is, the narrower the diffusion range of snowstorm is, and the smaller d is, the wider the diffusion range of snowstorm is. In this regard, when the snowstorm diffused by the diffusion plate 74 reaches the vehicle V which is the test specimen, it needs to spread over the entire height direction and width direction of the vehicle V. is also affected by the air velocity from behind the snow nozzle 36 . When varying the air velocity to simulate a moving vehicle, one side of the L-shaped member 120 can be adjusted to vary the spacing d accordingly to achieve the desired diffusion range using the same diffuser plate 74. Preferably, portion 120A is telescopic.

As shown in FIG. 4, the diffusing surface 104 is made of a material that is difficult to adhere to snow and has a conical shape with a top portion that is formed in a direction approaching the outlet 102, thereby Blowing snow blowing off from the blowing port 102 and riding on the air current and generated along the direction of air flow is guided along the diffusion surface 104 and diffused outward in all directions of the diffusion surface 104.例文帳に追加

More specifically, the diffusion surface 104 may be provided with a coating layer of fluororesin or silicon, or the snowstorm diffusion member 100 may be made of a fluororesin material or a silicon material.
As shown in FIG. 3 , regarding the shape of the diffusion surface 104 , the cone-shaped axis is arranged along the traveling direction of the airflow, and the apex thereof is arranged so as to overlap the center P of the outlet 102 . The snow blowing nozzle 36 extends substantially horizontally, and the air flow blown out from the blowing port 102 is substantially parallel, so the outer diameter D of the bottom surface of the diffusion surface 104 is slightly larger than the diameter of the blowing port 102. is preferred, so that a snowstorm blown from the outlet 102 can strike the diffuser surface 104 .
The divergence angle α around the apex of the cone is determined according to the desired diffusion properties of the snowstorm. The airflow velocity is fine-tuned according to the distance and/or spread angle α between the outlet 102 and the diffuser surface 104 .

The operation of the snowstorm diffusion member 100 having the above configuration will be described below.
First, in the wind tunnel 16, when blowing snow is put on the airflow heading from behind to the exit opening, simulating a snowstorm from the exit opening, and blowing out toward the test object, the flow of the wind tunnel 16 required by the environmental test Determine the blizzard concentration distribution and diffusion range at the outlet. For example, as shown in FIG. 7, assume that the snowstorm is concentrated in the upper left part Z of the outlet of the wind tunnel 16 .
Next, in accordance with the determined snowstorm concentration distribution and diffusion range, the rotation angle of each of the plurality of snow blowing nozzles 36 with respect to the corresponding hose 204 is adjusted to adjust the left and right diffusion ranges, and the corresponding hose 204 By adjusting the height, the vertical spread range of the snowfall is adjusted. For example, as indicated by arrow A in FIG. 7, the direction of each snow blowing nozzle 36 is different.

The snow blowing nozzles 36 are spaced apart in the height direction of the vehicle for each system, and the plurality of snow blowing nozzles 36 of the same system are spaced apart in the width direction of the vehicle V. of snow blowing nozzles 36 are divided into a plurality of sets of different levels in the wind tunnel 16, and each of the plurality of sets is laterally spaced apart from each other, and when the snow blowing nozzles 36 are arranged, the level is high It is preferable that the length of the curved tube portion 218 corresponding to the set of snow blowing nozzles 36 is longer.
For example, as shown in FIG. 7, when the required distribution of the snowstorm concentration at the outlet of the wind tunnel 16 is concentrated in the upper left of the wind tunnel 16 according to the conditions of the environmental test, each snow blowing nozzle 36 is indicated by an arrow A. It is better to adjust the direction of the nozzle as follows.
As described above, snow blowing from the snow blowing nozzle 36 falls under the influence of gravity, and the lower the level, the higher the concentration of snow blowing is suppressed, and the uniformity of snow blowing concentration in the height direction is achieved. Alternatively, as shown in FIG. 7, it is possible to flexibly respond to the diffusion range and snowstorm density by increasing the snowstorm density in a predetermined range or decreasing the snowstorm density in a predetermined range.

Next, in each system, the ice pieces made by the ice making machine 22 are crushed by the ice crusher 26 to become ice particles of a predetermined particle size, which are then pressure-fed by the snow supply pipe 40 by the air current, and distributed to the plurality of branch pipes by the distribution device 34. At each branch pipe, wet snow having a predetermined moisture content is made into wet snow by the wet snow device 32 and reaches the snow blowing nozzle 36 .
The snow blown out from the blowout port 102 rides on the airflow and flows as snowstorm along the traveling direction of the airflow. The diffusing surface 104 is made of a material that does not easily adhere to snow and has a conical shape whose top is directed toward the outlet 102 so as to have resistance to adhering to snow. Due to the shape, the snowstorm is guided along the diffusion surface 104 without adhering to the diffusion surface 104 and diffuses outward in all directions. fluctuation can be suppressed.
In this case, it may be prepared in advance by the method of forming the diffusion surface 104 described above.
This allows environmental testing using snowstorms, especially when wet snow is used, without changing the diffusion characteristics so as to narrow the spread of the snowstorm or interfering with the blowing of snow from the blowing nozzles. can be carried out smoothly.

According to the snowstorm concentration adjusting device having the above configuration, the snow blowing nozzle 36 is inserted into the outflow port 202 of the hose 204 from the hose 204 that conveys the snow inside the wind tunnel 16 and outflows the snow from the outflow port 202 . A plurality of such snow blowing nozzles 36 are provided, and the simulated snow blowing can be blown out from the outlet opening of the wind tunnel 16 by putting the blowing snow on the airflow heading for the outlet opening from behind.
At that time, in each of the plurality of snow blowing nozzles 36, a first straight pipe portion 206 having an inflow port that can be inserted into the outflow port 202, a second straight pipe portion 212 having the outflow port 202, and a first straight pipe portion 206 and a curved pipe portion 218 connecting the second straight pipe portion 212, the outflow port 202 of the second straight pipe portion 212 constitutes an ejection port, and the plurality of snow blowing nozzles 36 are connected to each other by the curved pipe portion. Since the length of the portion 218 is different and the crossing angle α between the first straight pipe portion 206 and the second straight pipe portion 212 is different, depending on the selection of the snow blowing nozzle 36, the snow blowing from the snow blowing nozzle 36 can be adjusted vertically. By adjusting the direction and the rotation angle of the snow blowing nozzle 36 with respect to the corresponding hose 204, the snow blowing horizontal direction can be adjusted. and the snow blowing horizontal direction, the snow blowing density formed by the plurality of snow blowing nozzles 36 as a whole can be adjusted as desired.

Although the embodiments of the present invention have been described in detail above, those skilled in the art can make various modifications and changes without departing from the scope of the present invention.
For example, in the present embodiment, the first straight pipe portion 206 and the second straight pipe portion 212 of the plurality of snow blowing nozzles 36 are commonly bent to connect the first straight pipe portion 206 and the second straight pipe portion 212 . Although the pipe portion 218 has been described as having the same radius of curvature and different center angles (the length of the bent pipe portion 218 is different), it is not limited thereto, and the desired snowstorm concentration is achieved by For the first straight pipe portion 206 and the curved pipe portion 218, for the second straight pipe portion 212, for example, bellows-shaped or a plurality of straight pipe elements that can be fitted to each other are prepared, and some of them are used for the second straight pipe portion. When the straight pipe portion 212 is configured, the pipe length may be adjustable according to the vehicle wind speed depending on how many straight pipe elements are used. It may be movable in the vertical direction and fixed in that position once the desired snowstorm density is achieved.
For example, in the present embodiment, the first straight pipe portion 206 and the second straight pipe portion 212 of the plurality of snow blowing nozzles 36 are commonly bent to connect the first straight pipe portion 206 and the second straight pipe portion 212 . Although the tubular portion 218 has been described as having the same radius of curvature and different central angles (the length of the curved tubular portion 218 is different), the curved tubular portion 218 is not limited to this, and to achieve the desired snowstorm density, The pipe portion 218 may be common, and the first straight pipe portion 206 and the second straight pipe portion 212 may have different pipe lengths. may be different from each other.
For example, in the present embodiment, each of the plurality of snow blowing nozzles 36 sprays snow from the outlet opening of the wind tunnel 16 so that the concentration of snow blowing from the outlet opening of the wind tunnel 16 is uniform over the cross-sectional area of the outlet opening. Although described as adjusting the snow vertical direction and snow blow horizontal direction, without being limited thereto, it is necessary to locally adjust the cross-sectional area of the exit opening to achieve the desired snow blow density required by the environmental test. The concentration may be high or locally low.

For example, in the present embodiment, a diffusion plate is provided for each of the plurality of snow blowing nozzles 36, and the blowing snow from the snow blowing nozzles 36 is diffused through the diffusion plate. Instead, diffusers may be provided only on specific snow blowing nozzles 36 to achieve the desired snow blowing density required by environmental testing.
For example, in the present embodiment, the snow blowing vertical direction and the snow blowing horizontal direction are adjusted for each of the plurality of snow blowing nozzles 36 according to the snow blowing density required in the environmental test. Instead, the snowfall vertical direction and the snowfall horizontal direction may be readjusted each time the snowstorm density required in the environmental test is changed.
For example, in the present embodiment, the new environmental test system is described as adjusting the snow blowing vertical direction and the snow blowing horizontal direction for each of the plurality of snow blowing nozzles 36. However, the present invention is not limited to this. An existing environmental test system may be modified so that the snow blowing vertical direction and the snow blowing horizontal direction can be adjusted for each of the plurality of snow blowing nozzles 36 .

For example, in the present embodiment, in each of the plurality of snow blowing nozzles 36, the first straight pipe portion 206 and the second straight pipe portion 212, and the curved pipe connecting the first straight pipe portion 206 and the second straight pipe portion 212 Although each of the portions 218 has been described as having a constant diameter in the pipe length direction, the pipe length The diameter may vary in the direction, for example, the diameter may decrease in the pipe length direction.
For example, in the present embodiment, the snow blowing vertical direction and snow blowing horizontal direction are adjusted for each of the plurality of snow blowing nozzles 36 in order to achieve the desired snow blowing density required in the environmental test. However, without being limited thereto, depending on the back air velocity in the wind tunnel 16, the conveying air velocity at the snow blowing nozzle 36, the snow flow rate at the snow blowing nozzle 36, the distance from the outlet opening of the wind tunnel 16 to the test specimen, When any of the snow blowing nozzles 36 are changed, the snow blowing vertical direction and the snow blowing horizontal direction may be readjusted for each of the plurality of snow blowing nozzles 36 .

For example, in the present embodiment, the snow is artificial snow that is made by crushing ice pieces that have been made into ice to form ice particles. It may be artificial crystal snow generated using cold air, or natural snow. Effective in preventing adhesion to snow.

For example, in the present embodiment, the snow is artificial snow that is made by crushing ice pieces that have been made into ice to form ice particles. It may be artificial crystal snow generated using cold air, or natural snow. Effective in preventing adhesion to snow.

Further, in the present embodiment, the diffusion surface of the diffusion member is made of a material that is difficult to adhere to snow and has a conical shape with a top portion that is formed in a direction approaching the outlet. Although it has been described, it is not limited to it, and depending on the adhesion characteristics of snow, for example, if the snow is dry snow with a moisture content of 1% or less, the adhesion is lower than that of wet snow. Either the material or the shape of the diffusing surface may be used.
Furthermore, in the present embodiment, the cone-shaped axis of the diffuser plate is arranged along the direction of air flow, and the apex is arranged so as to overlap the center of the blowout nozzle. Instead, the apex of the cone may be offset from the center of the blow nozzle if the spread needs to be biased, for example depending on the installation level of the blow nozzle.
Furthermore, in the present embodiment, the member for diffusing snowstorm is described as a plate-like diffusion plate, but the present invention is not limited to this, as long as it has a diffusion surface facing the blow nozzle, it may be not plate-like. good.

1 is an overall schematic diagram of an environmental test system in which a snowstorm concentration adjusting device according to an embodiment of the present invention is installed; FIG. It is a figure which shows the structure and kind of the snow blowing nozzle which concerns on embodiment of this invention. FIG. 3 is a partial side view showing the surroundings of the blowout portion of the snowstorm concentration adjusting device according to the embodiment of the present invention; It is a figure which shows the diffusion surface of the snowstorm concentration adjustment apparatus which concerns on embodiment of this invention. It is a figure which shows the spreading|diffusion state by the snowstorm density|concentration adjustment apparatus which concerns on embodiment of this invention. It is a figure which shows the distribution of the snow density in the snowstorm in the natural world. FIG. 4 is a diagram showing the required snowstorm concentration distribution at the outlet of the wind tunnel 16 of the environmental test system in which the snowstorm generator according to the embodiment of the present invention is installed.

α Crossing angle β Central angle Θ Cone angle d Distance between outlet and diffusion surface D Outer diameter of diffusion plate Z Required distribution range of snowstorm V Vehicle 10 Snow environment test system 12 Snowstorm supply system 14 Airflow supply system 16 Wind tunnel 18 Cold room 20 Ice making chamber 22 Ice making machine 24 Ice temperature stabilization conveyor 26 Ice crusher 28 Blower 30 Cooler 32 Wet snow device 34 Distributing device 36 Blowing nozzle 38 Snowstorm collecting device 40 Snow supply pipe 42 Suction port 44 Air duct 46 Rotary feeder 48 Crushing Drum 50 Hot air supply pipe 52 Annular space 54 Hot air inlet 56 Inflow opening 58 Branch pipe 60 Rotating body 62 Rotary drive unit 64 Pressure feed channel 66 Outflow opening 68 Intake port 70 Outlet 72 Inflow opening 74 Diffusion plate 102 Blowout port 104 Diffusion surface 106 Outer surface 120 L-shaped member 122 Notch 124 Slit 202 Outlet 204 Hose 206 First straight pipe portion 208 First inlet 210 First outlet 212 Second straight pipe portion 214 Second inlet 216 Second outlet 218 Bent pipe part 220 Bent pipe inlet 222 Bent pipe outlet 300 Measurement chamber 302 First bent cave 304 Second bent cave 306 Third bent cave 308 Fourth bent cave 310 Second diffusion shell 312 Rectification cave 314 Contraction cave 316 Blowout mouth

Claims (14)

A snow blowing nozzle rotatably insertable into an outlet of a hose for conveying snow inside and discharging snow from the outlet,
Placed inside a wind tunnel that blows simulated snowstorms from the exit opening,
A first straight pipe portion having an inlet that can be inserted into the outlet, a second straight pipe portion having an outlet, and a curved pipe portion connecting the first straight pipe portion and the second straight pipe portion, respectively. a plurality of snow blowing nozzles having an outflow port of the second straight pipe portion forming a jet port,
The plurality of snow blowing nozzles have different lengths of the curved pipe portions and different intersection angles between the first straight pipe portion and the second straight pipe portion.
A snow blowing nozzle for adjusting snowstorm density, characterized by: a hose for conveying snow inside and for outflowing the snow from the outlet;
a snow blowing nozzle rotatably insertable into the outflow port of the hose;
a wind tunnel in which the hose and the snow blowing nozzle are arranged inside, and a simulated snow blowing is blown out from the outlet opening by riding the blowing snow on an air current directed from the back toward the outlet opening,
A first straight pipe portion having an inlet that can be inserted into the outlet, a second straight pipe portion having an outlet, and a curved pipe portion connecting the first straight pipe portion and the second straight pipe portion, respectively. a plurality of snow blowing nozzles having an outflow port of the second straight pipe portion forming a jet port,
The plurality of snow blowing nozzles have different lengths of the curved pipe portions and different intersection angles between the first straight pipe portion and the second straight pipe portion.
A snowstorm concentration adjustment device characterized by: 3. The snowstorm concentration adjusting device according to claim 2, wherein the curved pipe portions of the plurality of snow blowing nozzles have the same radius of curvature and different center angles from the center of curvature. 3. The snowstorm concentration adjusting device according to claim 2, wherein the horizontally arranged hose and the snow blowing nozzle are arranged in the vicinity of an outlet opening in the wind tunnel. 5. The snowstorm concentration adjusting device according to any one of claims 2 to 4, wherein the hose is adjustable in height within the wind tunnel. The plurality of snow blowing nozzles are divided into a plurality of sets with different levels in the wind tunnel, each of the plurality of sets having the snow blowing nozzles spaced apart in the lateral direction and arranged in the same direction within the entire cross section of the wind tunnel. 6. A blizzard concentration adjustment device according to claim 5, distributed evenly. 7. The snowstorm concentration adjusting device according to claim 6, wherein a contraction channel is provided on the most downstream side of the wind tunnel, and a plurality of snow blowing nozzles are arranged on the upstream side of the contraction channel. In the wind tunnel, when the blowing snow is put on the air current from the back toward the exit opening, simulating a snowstorm from the exit opening and blowing out toward the test object,
measuring a snowstorm concentration distribution at an exit opening of the wind tunnel without the snowblower nozzle of claim 1;
Depending on the measured snowstorm density distribution, the rotation angle of each of the snow blowing nozzles is adjusted with respect to the corresponding hose, thereby adjusting the left and right diffusion range and adjusting the height of the corresponding hose. A snowstorm concentration adjustment method, comprising adjusting a vertical diffusion range of snowstorm. In the case where the plurality of snow blowing nozzles are divided into a plurality of sets with different levels in the wind tunnel, and the snow blowing nozzles are arranged in each of the plurality of sets at intervals in the horizontal direction,
9. The snowstorm concentration adjustment method according to claim 8, wherein the higher the level of the set of snow blowing nozzles, the longer the length of the corresponding curved pipe portion. further comprising a diffusion member for diffusing the blown snow from the snow blowing nozzle, the diffusion member comprising:
A diffusion surface facing the snow blowing hole is provided at a predetermined position outside the snow blowing hole and in front of the snow blowing direction,
The diffusion surface is made of a material that is difficult to adhere to snow and/or has a conical shape with a top portion that is formed in a direction approaching the snow nozzle,
3. The snowstorm concentration adjusting device according to claim 2, wherein the snow blowing out from said snow blowing port is thereby guided along said diffusion surface and diffused outward on all four sides of said diffusion surface. 11. A snowstorm concentration adjustment device according to claim 10, wherein the distance between said snow blowing port and said diffusion surface is variable according to desired diffusion characteristics of the snowstorm. 11. The snowstorm concentration adjustment device according to claim 10, wherein said air velocity is finely adjusted according to the distance between said snow blowing port and said diffusion surface and/or said spread angle. In an environmental test system in a wind tunnel, blowing snow is placed on the air current from behind toward the exit opening, simulating a snowstorm from the exit opening, and blown out toward the test object.
An environmental testing system, wherein the snow blowing nozzle of claim 1 is provided in the wind tunnel. 3. The snowstorm concentration adjusting device according to claim 2, wherein an intersection angle between said first straight pipe portion and said second straight pipe portion is 10[deg.] or more and 45[deg.] or less.

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