JP6160936B2 - How to spread snowstorm - Google Patents

Description

  The present invention relates to a method for diffusing snowstorms, and more particularly, when dry snow is diffused and squirted using a diffusing surface, by preventing adhesion and growth of snowstorm on the diffusing surface, The present invention relates to a method for diffusing snowstorms that can suppress fluctuations in diffusion characteristics over time.

2. Description of the Related Art Conventionally, an environmental test room has been used for placing a complete model vehicle indoors, setting various natural environments and weather conditions, and collecting and analyzing loads on the vehicle as data.
As an example, we simulate snowstorms with artificial snow in an environmental test room, blow off the snowstorms toward the vehicle, and deal with problems such as problems caused by snow in the engine room and icing problems such as freezing of suspension parts. Things have been done.

For this reason, an environmental test room has a wind tunnel of a space enough for a vehicle to be arranged and blowing a snowstorm toward the vehicle, and a snowstorm generating device.
The snowstorm generator is simulated by an ice making machine that produces flaky ice pieces, an ice breaker that breaks the produced flaky ice pieces into ice particles of a predetermined particle size, and ice particles of a predetermined particle size that are crushed ice A pipe that conveys the artificial snow into the wind tunnel, and a blowing nozzle that is installed at the tip of the pipe and blows out toward the front of the vehicle.
According to such an environmental test room, it is possible to perform an environmental test simulating natural environment and weather conditions by blowing a snowstorm toward a vehicle in a wind tunnel using a snowstorm generator.

At this time, in order to perform an appropriate and effective environmental test, it is necessary to simulate a snowstorm in a natural state, and in particular, from the viewpoint of reproducing the adhesion growth characteristics of a snowstorm on a vehicle, the temperature and grain of the snow constituting the snowstorm It is important to secure the diameter and the amount of snow necessary for the test.
On the other hand, in the wind tunnel where the vehicle is placed, there is a restriction that the distance between the vehicle and the air flow outlet is short (about 1 to 2 meters), and a natural snowstorm is simulated between these short distances, Need to spray on the vehicle.

In this regard, as shown in FIG. 8, it is possible to increase the spread of snow blowing, that is, the diffusibility, by providing a facing surface in front of the nozzle that blows snow, and hitting the snow to be blown against the facing surface. The snow is attached to and grows on the opposite surface regardless of whether it is dry or wet, or artificial or natural, and becomes a tapered mountain shape toward the nozzle that blows off over time, so that the spread of the snow is narrowed In any case, since the diffusion characteristics fluctuate or the snow blown out from the nozzle that blows out may be hindered, the smooth execution of the environmental test using the snowstorm is hindered.
In this case, if the air velocity for simulating a snowstorm is reduced, the degree of adhesion growth on the facing surface can be reduced to some extent, but in an environmental test using a snowstorm, While used, it is an important test parameter for simulating a traveling vehicle, and the restriction on the air velocity is not a fundamental solution.

The present inventor has proposed a member for diffusing snowstorm as disclosed in Patent Document 1 against wet snow. More specifically, it is a member for diffusing snowstorm that is simulated by snow carried in an airflow, and is located outside a blowout port that blows out snow along the airflow traveling direction and at a predetermined position in front of the airflow traveling direction. Provided with a diffusion surface facing the blowout port, and the diffusion surface has a conical shape formed in such a manner that the material with poor adhesion growth and / or the top portion approaches the blowout port so as to have a poor adhesion growth property against snow As a result, the snowstorm that is blown out from the air outlet and is generated along the airflow traveling direction on the airflow is guided along the diffusion surface and diffuses toward the four sides outward of the diffusion surface. .

  According to the blowing snow diffusing member having the above-described configuration, the snow blown out from the blowout port rides on the airflow and flows as a snowstorm along the traveling direction of the airflow. The diffusion surface is disposed at a predetermined position in front of the traveling direction so as to oppose the blowout port, and the diffusion surface has a poor adhesion growth material and / or so as to have a difficulty adhesion growth property against snow. Since the top part has a conical shape formed so as to approach the blowout port, the snowstorm is guided along the diffusion surface without adhering to the diffusion surface and diffuses outward in all directions. It is possible to suppress the fluctuation of diffusion characteristics with time due to adhesion growth on the surface.

On the other hand, the present inventor has proposed a snowstorm generating device for dry snow. More specifically, it is a snowstorm generator that simulates a snowstorm by placing snow on the airflow, and is provided with a blowout port that blows snow along the traveling direction of the airflow. A facing surface facing the air outlet is arranged at a predetermined position in the forward direction of the traveling direction, so that the snowstorm blown out from the air outlet and generated along the air flow traveling direction is deflected by hitting the opposing surface. The structure is such that it diffuses outward in the four directions of the opposing surface.

  According to the snowstorm generator having the above-described configuration, the snow blown out from the air outlet rides on the airflow and flows as a snowstorm along the direction of the airflow, and the snowstorm is outside the air outlet, It hits the opposite surface arranged to face the air outlet at a predetermined position in the front of the traveling direction, and as in the conventional case, snow accumulates until it reaches the air outlet, and it is not difficult to continuously generate snowstorm. Diffuses outward in all directions along the opposing surface, and the diffused snowstorm flows further along the airflow, and the snowstorm also circulates in the area behind the opposing surface, adjusting the speed of the airflow By doing so, it becomes possible to broaden the spatial distribution through which the snowstorm flows as desired.

However, even if the present inventor is dry snow, if the range of the particle size distribution is on the small side as a whole, in a certain case, snow will grow on the surface of the diffusing member, and the outlet will be blocked. I found a problem.
In particular, the degree of adhesion growth on the surface of the diffusing member according to the mass ratio of the dry snow in the small area when the particle size distribution is divided into two for a given particle size to the total mass of dry snow over the entire particle size distribution Found different.
In recent years, in environmental tests using snowstorms for automobiles, there has been a high demand for tests using fine snowstorms, but the evaluation of tests has also become strict.
In this sense, it is difficult to perform an effective environmental test if a change in diffusion characteristics over time occurs as the adhesion grows on the diffusion member.
JP 2014-094835 A

  In view of the above technical problems, the object of the present invention is to prevent the growth of snow blown to the diffusion surface when the dry snow is diffused by using the diffusion surface. Another object of the present invention is to provide a method for diffusing snowstorms that can suppress fluctuations in diffusion characteristics over time.

In order to achieve the above object, a method for diffusing a snowstorm according to the present invention includes:
A method of diffusing snowstorms simulated by dry snow in an air current,
It is a diffusion surface facing the air outlet at a predetermined position in front of the air flow direction outside the air outlet that blows dry snow along the air flow direction, and has a low adhesion growth property against the dry snow. In addition, a step of forming a diffusion surface that is formed in a direction in which the top portion approaches the outlet and that is a curved surface shape that spreads from the top portion in the airflow direction;
In the particle size distribution of the dry snow blown out, according to the mass ratio of the dry snow in the region on the smaller side when the particle size distribution is divided into two at a predetermined particle size to the total mass of the dry snow over the entire particle size distribution, Selecting a curved surface shape of the diffusing surface,
Thereby, the blowing snow blown out from the outlet and generated along the airflow traveling direction on the airflow is guided along the diffusion surface and diffused toward the outer side of the diffusion surface. .

According to the method for diffusing a snowstorm having the above configuration, the snow blown out from the air outlet rides on the airflow and flows as a snowstorm along the traveling direction of the airflow, and the snowstorm is outside the air outlet, The snowstorm is guided along the diffusion surface and diffuses outward in all directions, without adhering to the diffusion surface, when it hits the diffusion surface arranged to face the air outlet at a predetermined position in the forward direction. At the same time, it is possible to suppress the fluctuation of the diffusion characteristics over time associated with the adhesion growth on the diffusion surface.
More specifically, in the curved shape of the end spread from the top of the diffusion surface, the larger the end spread (180 degrees in the case of a flat plate diffusion plate), the greater the diffusion range, but the diffusion over time On the other hand, the adhesion growth of dry snow on the surface becomes stronger, while the smaller the spread, the smaller the diffusion range tends to be, but the dry snow tends to peel off from the diffusion surface, and the adhesion growth on the diffusion surface is weak. Therefore, in the particle size distribution of the dry snow that is blown out, the mass ratio of the dry snow in the region on the smaller side when the particle size distribution is divided into two at a predetermined particle size, to the mass ratio to the total mass of dry snow over the entire particle size distribution Accordingly, by selecting a curved surface shape of the diffusion surface, for example, a curved surface shape that spreads from the top of the diffusion surface, fluctuations in diffusion characteristics over time due to adhesion growth on the diffusion surface are suppressed. Possible it is.
Here, “snow” has a broad meaning that includes both snowflakes in which snowflakes overlap like natural snow and snow particles like artificial snow made of ice particles. "Has a broad meaning which means not only a snowstorm state due to snowfall but also a situation in which such snowflakes or snow particles move due to wind or passing of a car.

Furthermore, when the predetermined particle diameter is 0.2 mm to 0.4 mm, a diffusion surface that is a conical shape or a part of a spherical surface is preferably used if the mass ratio is 50% or more.
Furthermore, a coating layer made of a fluororesin or silicon is preferably provided on the diffusion surface.
In addition, the snowstorm diffusion member may be a fluororesin material or a silicon material.

The distance between the blowout port and the diffusion surface may be variable according to the desired diffusion characteristics of the snowstorm.
Furthermore, it is preferable that the conical axis is disposed along the direction of air flow and the apex of the conical axis overlaps the center of the outlet.
Furthermore, the spread angle around the apex of the conical shape may be determined according to the desired diffusion characteristics of the snowstorm.
In addition, the moisture content of dry snow should be 0% and the most frequent particle size should be 0.2 to 0.5 mm.
Further, it is preferable that the diffusion surface has a curved shape that is diverging from the center toward the downstream side in the ejection direction, and the step of selecting the curved shape of the diffusing surface preferably selects the degree of diverging.
In addition, the predetermined particle size may be the peak of the mountain shape of the particle size distribution.

The snowdrift diffusing member of the present invention will be described in detail below by taking as an example a case where a snowstorm is simulated by the snowdrift diffusion method of the present invention and used for 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 composed of ice particles and simulates a snowstorm by placing the artificial snow on an airflow from behind. Thus, it is configured to spray toward the vehicle V, which is a test specimen, and for that purpose, it has a snowstorm supply system 12 and an airflow supply system 14.
In particular, when the required amount of dry snow blizzard with a predetermined snow quality, where the particle size of ice particles is the main influencing factor, is sprayed continuously toward the vehicle V, it diffuses throughout the height of the vehicle V. However, in some cases, in order to achieve a desired snowstorm concentration distribution in the height direction of the vehicle V, an ice particle group used as artificial snow is manufactured immediately before the test under a predetermined temperature and humidity control. And prompt supply is required.

More specifically, the snow environment test system 10 includes a wind tunnel 16 in which the vehicle V to be tested is disposed, a low temperature chamber 18 disposed above the wind tunnel 16, and an ice making chamber disposed above the low temperature chamber 18. 20, an ice making machine 22 is arranged in the ice making chamber 20, and an ice temperature stabilizing conveyor 24, an ice breaker 26, a blower 28, a cooler 30, and artificial snow distribution are arranged in the low temperature chamber 18. A device 34 is arranged, and an artificial snow blowing nozzle 36 and a snow collecting device 38 are arranged in the wind tunnel 16. In general, ice pieces made in the ice making chamber 20 are crushed in the low temperature chamber 18. Then, artificial snow is produced by icing, and the artificial snow is pumped toward the wind tunnel 16, and the dry snow artificial snow is distributed in the wind tunnel 16 to be blown into a low temperature air current, It is configured to spray toward the vehicle V.

The wind tunnel 16 is an open type circulation type, and a measurement chamber 300 in which a vehicle to be measured is installed (open type), and first to fourth bent cylinders 302, 304, 306, 308 (bent portions). Are formed in a substantially rectangular shape in plan view. The airflow generated by the blower 25 passes through the second diffusion cylinder 310, the third bending cylinder 306, the fourth bending cylinder 308, the rectifying cylinder 312, and the contraction cylinder 314, and then from the outlet 316 that opens to the measurement chamber 300 to the measurement chamber 300. The first bending cylinder 302 and the second bending cylinder 304 flow in this order.
The airflow blown by the blower 25 is measured by once reducing the wind speed (dynamic pressure) of the entire airflow and increasing the pressure (static pressure) in the intermediate body portion, and then passing through the contracted flow drum 314. Therefore, an air flow having a necessary and sufficient air volume (wind speed) can be blown out from the blow-out port 316 to the measurement chamber 300.

As a result, as will be described later, the ice particles that are conveyed by air through the ice making process, the ice breaking process, the separation process, and the wet snow process are blown into the measurement chamber 300 by riding on the airflow from the back toward the vehicle. By adjusting the wind speed of the airflow with the blower 25, the traveling vehicle can be simulated while being a stationary vehicle.
Further, in the case of the circulating wind tunnel 16 for a snowstorm test, a snow repair device 38 is separately provided downstream of the vehicle V in order to separate and collect the snow after the test. In order to separate snow by the inertia effect, an area where the airflow is not rectified is provided downstream of the vehicle V.

The snow blowing supply system 12 is provided in three systems. In each system, a snow supply pipe 40 that connects the ice breaker 26 and the blowing nozzle 36 and an air duct 44 that connects the suction port 42 in the wind tunnel 16 and the ice breaker 26 are provided. In the snow supply pipe 40, an artificial snow distribution device 34 is connected between the ice breaker 26 and the blowing nozzle 36, while in the air duct 44, the suction port 42 in the wind tunnel 16 and the ice breaker are connected. 26, a blower 28 and a cooler 30 are connected.

The ice making machine 22 is a so-called reamer type ice making machine 22 that produces flaky ice pieces, and a plurality of ice making machines 22 that produce cracked ice pieces according to the total required amount of artificial snow used in the snow environment test. By selecting an arbitrary number from the above and making ice with the selected ice making machine 22 according to the change in the required amount of artificial snow used for the environmental test, the ice making amount is roughly adjusted and the artificial snow used for the environmental test In accordance with the difference between the required amount of artificial snow and the roughly adjusted ice making amount, the evaporating temperature and / or the water temperature and / or the reamer rotation speed are selected in each selected ice making machine 22 in accordance with the change in the required amount of It has a control device (not shown) that finely adjusts the amount of ice making by adjusting.

The ice crusher 26 mainly includes a rotary feeder (not shown) arranged at the upper part and a pair of crushing drums (not shown) arranged at the lower part, and is supplied by the ice temperature stabilizing conveyor 24. Ice pieces are quantified by a rotary feeder, supplied to a pair of crushing drums, crushed by a pair of crushing drums, and supplied to the snow supply pipe 40 as ice particles having a predetermined particle diameter.

As shown in FIG. 10, the ice crusher 26 mainly includes a rotary feeder 46 disposed in the upper part and a pair of crushing drums 106 </ b> A and B disposed in the lower part, and is supplied by the ice temperature stabilizing conveyor 24. The ice pieces are quantified by the rotary feeder 46, supplied to the pair of crushing drums 106A, B, crushed by the pair of crushing drums 106A, B, and supplied to the snow supply pipe 40 as ice particles of a predetermined particle size. ing.
The ice piece crushing device 26 includes a casing 104 having an opening 102 for introducing ice pieces therein, and a pair of crushing drums 106 </ b> A and 106 </ b> B disposed in the casing 104.

The rotary feeder 46 is a conventionally known type, and detailed description thereof is omitted. However, a rotary shaft (not shown) is disposed horizontally, and the material to be granulated, which is input from above, is quantified and rotated. It is configured to supply downward.
More specifically, the rotary feeder 46 includes a blade between adjacent blades that fall from a hopper or the like when a rotor in which a plurality of rotating blades (not shown) are radially arranged rotates in the casing 104. It rotates so that it drops from the lower outlet. More specifically, in the rotor, a plurality of rotating blades are arranged radially around a rotary shaft supported via the casing 104, and a rotor for filling granular material between adjacent rotating blades. A pocket is formed, and for example, the rotary shaft is driven by a drive motor (not shown).

As shown in FIGS. 11 and 12, the pair of crushing drums 106 </ b> A and 106 </ b> B are arranged in the casing 104 at a predetermined interval with the outer peripheral surfaces 108 facing each other in parallel with each other. It is supported in a non-contact manner with respect to the inner surface 116 of the casing 104 so as to be rotatable in the direction of heading.
The pair of crushing drums 106A and 106B are arranged so as to be able to receive the ice pieces to be charged in the space above the narrowest portion 110 between the pair of crushing drums 106A and 106B. The interval between the narrowest portions 110 is determined by how much particle size is required to break the ice pieces into ice particles.

The pair of crushing drums 106 includes a high-speed crushing drum 111 and a low-speed crushing drum 112. The ice breaker is a conventionally known type, and detailed explanation thereof is omitted. However, the ice pieces are crashed by both drums to form artificial snow, and a pair of drums provided in the casing 104 of the ice breaker is used. On the outer periphery of each drum, a plurality of rows of protruding teeth are formed in the circumferential direction of the drum in which triangular pyramid-shaped protruding teeth are formed in the circumferential direction. Each drum is rotated in the opposite direction by a drive motor (not shown), for example, and ice pieces dropped between the drums are crushed at the narrowest portion 110 to form artificial snow.
The projecting teeth are formed on the outer peripheral surface of the drum such that the bottom surface of the triangular pyramid forms an isosceles triangle, the isosceles side of the long side is in the drum circumferential direction, and the short side is perpendicular to the circumferential direction of the drum. ing. In particular, the triangular cutting surface formed by the short side and the apex of the triangular pyramid is preferably formed on the outer peripheral surface of the drum by retreating, for example, about 6 ° with respect to the rotation direction.

These triangular pyramid-shaped projecting teeth are continuously arranged on the outer peripheral surface of the drum to form a projecting tooth row. In one crushing drum 106A, the projecting tooth rows are spaced apart from each other by several millimeters in the rotation axis direction of the drum. A pair of feed drums 106B that are formed in a plurality of rows and have the same structure are paired, and the flake ice pieces are crushed by rotating synchronously in opposite directions to generate artificial snow.

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

The artificial snow distribution device 34 includes a rotating body (not shown) in which an upstream end face and a downstream end face are respectively arranged in parallel with a downstream end face of the snow supply pipe 40 and an upstream end face of each of the plurality of branch pipes; A rotation drive unit (not shown) that rotates the rotating body at a predetermined rotation speed about its axial direction, and the rotating body has a pressure feed passage (not shown) penetrating the rotating body in the axial direction inside thereof. ), And the pressure-feed passage is disposed on the upstream end face in a non-contact manner in close proximity to an outflow opening (not shown) provided on the downstream end face of the snow supply pipe 40 (not shown). And a discharge port (not shown) arranged in a non-contact manner in close proximity to an inflow opening (not shown) provided on the upstream end surface of each of the plurality of branch pipes. Equipped with a plurality of branch pipes on the passage trajectory of the discharge port by rotation of the rotating body Inlet openings respectively are provided so as to be located.

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

As shown in FIG. 1, three blowing nozzles 36 for blowing snow are arranged at a predetermined distance in front of the vehicle V at a predetermined distance in the height direction over the vehicle height of the vehicle V. Thus, the concentration of the snowstorm to be supplied can be adjusted for each blowing nozzle 36. A snow collecting device 38 is arranged at a predetermined distance behind the vehicle V, and the snowstorm that has passed through the snow collecting device 38 is blower arranged in the low temperature chamber 18 through the suction port 42 in the wind tunnel 16. 28, cooled by the cooler 30, returned to the ice breaker 26, iced by the ice making machine 22, supplied to the ice breaker 26 by the ice temperature stabilizing conveyor 24, mixed with the ice particles to be crushed, and supplied again with snow. It is used for blowing snow from the blowing nozzle 36 through the tube 40. The blowout nozzle 36 is arranged along the direction of airflow, and the blowout port 102 is installed in the zone of the airflow blown from the blower 25.
In this regard, snow blowing is performed when the snow blown out from each blowing nozzle 36 by the air blown by the blower 28 is blown toward the vehicle V on the air flow blown out from the blower 25. As long as snow clogging in the tube 40 does not occur, the speed is preferably as low as possible, and the speed of snow blowing is preferably simulated by the airflow blown from the blower 25.
More specifically, when the blizzard is diffused by the diffusion plate 74 (described later) and blown toward the vehicle V, if the pumping speed of the pumped air is high, the speed of the blizzard increases only in the blizzard of the blowing nozzle 36 portion. In addition, while deviating from the natural snowstorm, it is possible to change the speed of the entire diffused snowstorm uniformly by changing the speed of the airflow blown from the blower 25. When simulating the above, it is advantageous to vary the speed of the airflow blown from the blower 25.

As shown in FIG. 2, a diffusion plate 74 is provided in front of each blowing nozzle 36, and the snowstorm blown out from the blowing nozzle 36 on the low temperature airflow from the blower toward the vehicle V is shown in FIG. 6. In this way, it hits the diffusion plate 74 and diffuses outward in all directions, and the three blowing snow blowout nozzles 36 cooperate with each other, so that the snowstorm occurs in the front part of the vehicle V over the height direction of the vehicle V. 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 blowing nozzle 36 and the front portion of the vehicle V is about 1 to 3 meters. The snowstorm blown out from the blowout nozzle 36 over a short distance is diffused over the entire height at the front portion of the vehicle V.
A plurality of air outlets 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 air outlet 102 can be adjusted independently of each other. According to the height of the vehicle V, the concentration distribution of the snowstorm can be adjusted.

As shown in FIG. 2, the diffusion plate 74 has a diffusion surface 104 that faces the blowing nozzle 36 at a predetermined position in front of the airflow direction. The diffusion plate 74 is attached to the snow supply pipe 40 around the blowing nozzle 36 via the L-shaped member 120 for the 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 blowing nozzle 36, and the other portion 120B of the L-shaped member 120 extends downward. The diffusion plate 74 is attached to the tip of the other portion 120B of the L-shaped member 120 so as to face the blowing nozzle 36. As will be described later, the distance d between the blowing nozzle 36 and the diffusion plate 74 affects the diffusion range of the blowing snow when the blowing snow blown from the blowing nozzle 36 strikes the diffusion plate 74 and diffuses. More specifically, the larger the d, the narrower the blizzard diffusion range, and the smaller d, the wider the blizzard diffusion range. In this regard, when the snowstorm diffused by the diffusion plate 74 reaches the vehicle V as 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 blowing nozzle 36. When the air flow velocity is varied to simulate the traveling vehicle, one of the L-shaped members 120 is made variable so that the distance d can be varied in order to realize a desired diffusion range using the same diffusion plate 74 accordingly. It is preferable to make the portion 120A extendable.

The diffusion surface 104 has a conical shape formed such that the material having a poor adhesion growth property and the top portion approach the blowout port 102 so that the diffusion surface 104 has a low adhesion growth property against snow. The snowstorm that occurs along the airflow traveling direction along the airflow is guided along the diffusing surface 104 and diffuses outward in the four directions of the diffusing surface 104.

More specifically, the diffusion surface 104 may be provided with a coating layer made of fluororesin or silicon, or the blowing snow diffusion member 100 may be made of a fluororesin material or a silicon material.
As shown in FIG. 2 and FIG. 3, with respect to the shape of the diffusing surface 104, the conical axis is arranged along the traveling direction of the air flow, and its apex is arranged so as to overlap the center P of the outlet 102. The blowing nozzle 36 extends substantially horizontally, and the flow of the air flow blown from the blowing port 102 becomes a substantially parallel flow. Therefore, the outer diameter D of the bottom surface of the diffusion surface 104 is slightly larger than the diameter of the blowing port 102. Preferably, the snowstorm blown out from the outlet 102 can hit the diffusion surface 104.
The spread angle α around the apex of the conical shape is determined according to the desired diffusion characteristics of the snowstorm. The air velocity is finely adjusted according to the distance d and / or the spread angle α between the air outlet 102 and the diffusion surface 104.

Alternatively, as shown in FIG. 4, the conical outer surface 106 forms a curved surface that curves inwardly or outwardly. FIG. 4A shows a case in which the snow is curved inward. As compared with FIG. 3, the snowstorm tends to be diffused in a wider range by the diffusion surface 104, and FIG. 4B is curved outward. Compared to FIG. 3, the snowstorm tends to be diffused to a narrower range by the diffusion surface 104.
As a further modification, as shown in FIG. 5, a conical surface and a bottom surface of the diffusing surface 104 are provided with a notch 122 in a direction perpendicular to the blowing direction of the snow blown from the blowing port 102, or the blowing port 124. In some cases, a slit 124 is provided in a direction perpendicular to the blowing direction of the snowstorm blown out. Thereby, it is possible to adjust the diffusion characteristic when the snowstorm hits the diffusion surface 104.

The effect | action of the spreading | diffusion method of the snowstorm which has the above structure including the method of an environmental test method is demonstrated below.
First, in each system, ice pieces made by the ice making machine 22 are crushed by the ice breaker 26 and pass between the rotating drums 106A and B, thereby forming ice particles having a given particle size distribution. It is pumped by an air stream through the snow supply pipe 40 and is branched into a plurality of branch pipes by the distribution device 34, and reaches the blowing nozzle 36 as dry snow in each branch pipe.
In this case, the blowing nozzles 36 are arranged at intervals in the vehicle height direction for each system, and the plurality of blowing nozzles 36 of the same system are arranged at intervals in the width direction of the vehicle V.

As shown in FIG. 6, the dry snow blown out from the outlet 102 rides on the airflow and flows as a snowstorm along the direction of the airflow, and the snowstorm is outside the outlet 102 and forward of the direction of the airflow. The diffusion surface 104 hits the diffusion surface 104 disposed so as to be opposed to the outlet 102 at a predetermined position of the material. Since it has a conical shape formed so as to approach the mouth 102, the snowstorm is guided along the diffusion surface 104 without diffusing and growing on the diffusion surface 104, and diffuses outward in all directions. It is possible to suppress the change in diffusion characteristics over time accompanying the adhesion growth to 104.
This makes it possible to smoothly carry out environmental tests using snowstorms without causing the diffusion characteristics to fluctuate so that the spread of the snowstorm is reduced, or without causing any trouble in the snow blowing from the nozzle that blows out. is there.
In addition, as a modification, as shown in FIG. 7, it is possible to provide only one diffusion member 100 as a single system as shown in FIG. Good.

The present inventor is conducting a test of how the degree of adhesion growth on the diffusion plate changes according to the particle size distribution of the dry snow, targeting dry snow.
(1) Test conditions (A) Dry snow Particle size range: Ice particles of 2 mm or less
Most frequent ice particles in weight ratio: 0.2 mm to 1.5 mm (B) Airflow velocity (velocity of ice particles carrying air): 15 meters to 28 meters per second (C) Type of diffusion plate: disc, Cone, hemisphere (D) Distance between diffuser plate and outlet: 10 mm to 70 mm

(2) Test results As shown in FIG. 9, when the cumulative ratio at a particle diameter of 0.3 mm in the mass-based cumulative ratio is 70% or more, dry snow adheres and grows on the diffusion surface, and the particle diameter of 0.1 mm is obtained. If the cumulative ratio at 3 mm is 50% or less, dry snow does not grow on the diffusion surface. More specifically, if it is 50% or less, even if it grows instantaneously, It was confirmed that the larger particles exfoliated together with the larger particles. It was also confirmed that this tendency did not change even when the airflow velocity was changed.
Therefore, since the degree of adhesion growth of dry snow on the diffusion surface can be adjusted by the particle size distribution, the particle size distribution and the shape of the diffusion surface are associated with each other, It is possible to select the shape and thus adjust the degree of adhesion growth of dry snow on the diffusion surface.
More specifically, the diffusing surface has a curved surface shape that spreads toward the downstream side in the ejection direction from the center, and the step of selecting the curved surface shape of the diffusing surface preferably selects the extent of the divergence.
More specifically, when the predetermined particle size is 0.5 mm or less, if the mass ratio is 50% or more, it is preferable to use a diffusion surface that is a conical shape or a part of a spherical surface. The moisture content of snow is 0%, and the most frequent particle size is 0.2 mm to 0.5 mm.
Here, the most frequent particle diameter is a particle diameter that is the most frequent in the particle size distribution, and the particle size distribution here indicates a weight ratio.

The embodiments of the present invention have been described in detail above, but various modifications or changes can be made by those skilled in the art without departing from the scope of the present invention.
For example, in the present embodiment, it has been described that snow is artificial snow that breaks ice pieces that have been made into ice particles, but the present invention is not limited thereto, and snow has a predetermined humidity and a predetermined temperature. Artificial crystal snow generated using cold air may be used, or natural snow may be used, and the snowdrift diffusion method of the present invention may be applied to any diffusion surface. It is effective in preventing growth.

Furthermore, in the present embodiment, it has been described that the conical axis of the diffusing plate is arranged along the direction of air flow, and the apex thereof is arranged so as to overlap the center of the blowing nozzle. Instead, for example, when the diffusion range needs to be biased according to the installation level of the blowing nozzle, the apex of the cone may be offset from the center of the blowing nozzle.
Furthermore, in the present embodiment, a plate-like diffusion plate has been described as a snowstorm diffusion member. However, the present invention is not limited to this, and as long as it has a diffusion surface facing the blowing nozzle, it may not be plate-shaped. Good.
Furthermore, in the present embodiment, it has been described as a member for diffusing snowstorms, but is not limited thereto, and can be used not only for snowstorms but also for snowfalls that fall naturally due to gravity. By applying, it is possible to expand the snowfall range of dry snow while preventing adhesion growth.

1 is an overall schematic diagram of an environmental test system in which a snowstorm diffusion member 100 according to an embodiment of the present invention is disposed. It is a figure which shows the arrangement | positioning state of the member 100 for a snowstorm diffusion which concerns on embodiment of this invention. It is a side view which shows the member 100 for a snowstorm diffusion which concerns on embodiment of this invention. It is a figure similar to FIG. 3 which shows another embodiment of the member 100 for a snowstorm diffusion which concerns on embodiment of this invention. It is a front view which shows another embodiment of the member 100 for a snowstorm diffusion which concerns on embodiment of this invention. It is a figure which shows the diffusion state of the snowstorm by the member 100 for snowstorm diffusion which concerns on embodiment of this invention. It is another figure of the environmental test system which arrange | positions the member 100 for diffusing the snowstorm which concerns on embodiment of this invention. It is a figure similar to FIG. 6 which shows the diffusion state of the snowstorm by the conventional member 100 for snowstorm diffusion. It is a conceptual diagram which shows the particle size distribution of an ice particle when selecting the shape of the member 100 for a snowstorm diffusion which concerns on embodiment of this invention. It is a block diagram of the ice breaker 26 of the ice piece which concerns on embodiment of this invention. It is the schematic which shows the crushing principle of the ice breaker 26 of the ice piece which concerns on embodiment of this invention. It is the bottom view which looked at the crushing part of the ice piece concerning the embodiment of the present invention from the lower part.

α Conical angle d Distance between outlet and diffusion surface D Outer diameter of diffusion plate V Vehicle 10 Snow environment test system 12 Snow blowing supply system 14 Air flow supply system 16 Wind tunnel 18 Low greenhouse 20 Ice making room 22 Ice making machine 24 Ice temperature stabilization conveyor 26 Icebreaker 28 Blower 30 Cooler 34 Distributor 36 Blowout nozzle 38 Snowstorm collector 40 Snow supply pipe 42 Suction port 44 Air duct 46 Rotary feeder 48 Crushing drum 56 Inlet opening 58 Branch pipe 60 Rotating body 62 Rotating drive part 64 Pressure feed Flow path 66 Outflow opening 68 Inlet 70 Outlet 72 Inflow opening 74 Diffusion plate 102 Outlet 104 Diffusion surface 106 Outer surface 120 L-shaped member 122 Notch 124 Slit 300 Measurement chamber 302 First bent cylinder 304 Second bent cylinder 306 First 3 bending cylinder 308 4th bending cylinder 310 2nd diffusion cylinder 31 Rectification body 314 Chijimiryudo
316 outlet

Claims (10)

A method of diffusing snowstorms simulated by dry snow in an air current,
It is a diffusion surface facing the air outlet at a predetermined position in front of the air flow direction outside the air outlet that blows dry snow along the air flow direction, and has a low adhesion growth property against the dry snow. In addition, a stage where the top is formed in a direction approaching the outlet and preparing a diffusion surface that is a curved shape spreading from the top in the airflow direction,
In the particle size distribution of the dry snow blown out, according to the mass ratio of the dry snow in the region on the smaller side when the particle size distribution is divided into two at a predetermined particle size to the total mass of the dry snow over the entire particle size distribution, Selecting a curved surface shape of the diffusing surface,
Thereby, the snowstorm blown out from the outlet and generated along the airflow traveling direction on the airflow is guided along the diffusion surface and diffused toward the outer sides of the diffusion surface. How to spread snowstorm. The method for diffusing snowstorms according to claim 1 , wherein when the predetermined particle size is 0.5 mm or less, a diffusion surface that is a conical shape or a part of a spherical surface is used if the mass ratio is 50% or more. The method for diffusing snowstorms according to claim 1, wherein a coating layer of fluororesin or silicon is provided on the diffusion surface. The method for diffusing snowstorms according to claim 3, wherein the member for diffusing snowstorms is a fluororesin material or a silicon material. The method for diffusing snowstorms according to any one of claims 1 to 4, wherein a distance between the outlet and the diffusion surface is variable according to a desired diffusion characteristic of the snowstorm. The method for diffusing snowstorms according to claim 2, wherein the conical axis is arranged along an advancing direction of the airflow, and the apex thereof is arranged so as to overlap with a center of the outlet. The spreading method of a snowstorm according to claim 6, wherein the spread angle around the apex of the conical shape is determined according to a desired diffusion characteristic of the snowstorm. The method for diffusing snowstorms according to claim 1, wherein the moisture content of the dry snow is 0%, and the most frequent particle size is 0.2 mm to 0.5 mm. 2. The snowstorm of claim 1, wherein the diffusion surface is a curved surface shape that spreads from the center toward the downstream side in the ejection direction, and the step of selecting the curved surface shape of the diffusion surface selects the extent of the edge expansion. Diffusion method. The method for diffusing snowstorms according to claim 1, wherein the predetermined particle size is a peak of a mountain shape of the particle size distribution.

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