JP6638777B2 - Method for generating wet snow and apparatus for generating wet snow - Google Patents

Description

  The present invention relates to a method for generating wet snow and an apparatus for generating wet snow, and more particularly, when transporting dry snow in an airflow using a flow path, the dry snow adheres to the inner surface of the flow path. The present invention relates to a method for generating wet snow and an apparatus for generating wet snow, which can efficiently flow out of a flow path as wet snow having a desired moisture content without causing the wet snow to flow.

2. Description of the Related Art Conventionally, an environmental test room has been used for placing a completed model vehicle in a room, setting various natural environment and weather conditions, and collecting and analyzing a load on the vehicle as data.
As an example, simulate snowstorm with artificial snow in the environmental test room, blow out the snowstorm toward the vehicle, and address the problem of inconvenience caused by snow entering the engine room and the problem of icing such as freezing of underbody parts. That is being done.

For this reason, the environmental test room has a wind tunnel in which a vehicle is arranged and has a sufficient space for blowing snowstorm toward the vehicle, and a snowstorm generator.
The snowstorm generator is simulated by an ice maker that produces flake-shaped ice pieces, an ice crusher that crushes the produced flake-shaped ice pieces into ice particles of a predetermined particle size, and an ice crusher that crushes the ice particles of a predetermined particle size. It has a pipe for conveying the artificial snow into the wind tunnel, and a blowing nozzle installed at the tip of the pipe and blowing 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 snowstorm toward a vehicle in a wind tunnel using a snowstorm generator.

At this time, it is necessary to simulate snowstorm in a natural state in order to perform a proper and effective environmental test. In particular, from the viewpoint of reproducing the adhesion of the snowstorm to the vehicle, the temperature and particle size of the snow constituting the snowstorm It is important to generate the desired wet snow by adjusting the water content as the snow quality while ensuring the amount of snow necessary for the test.
On the other hand, in the wind tunnel where the vehicle is arranged, there is a restriction that the distance between the vehicle and the airflow outlet is short (about 1 to 2 meters). Need to spray on the vehicle.

In this regard, as disclosed in Patent Literature 1, the conventional snow blowing apparatus generates dry snow from the viewpoint of preventing artificial snow from adhering to the inside of the apparatus before blowing the snow toward the vehicle. Blown out, and the snow was wet outside the device before reaching the vehicle.
More specifically, as shown in FIG. 8, a water injection nozzle 124 that injects water is provided between an air outlet 122 installed in front of an air outlet 120 in a wind tunnel and a vehicle. Then, water was sprayed from a water spray nozzle 124 to the dry snowstorm 123 simulated by the low-temperature airflow 121 from the blower port 120, and the snow was wet.

However, such a wet snow technology has the following technical problems.
First, even if the moisture content of the entire blizzard is equivalent to that of wet snow in the natural state, some of the dry snow that composes the blizzard is too wet or insufficiently wet, The dry snow itself is not wet.
Second, the dry snow that composes a snowstorm only wets its surface with the sprayed water, and has different properties from wet snow in a natural state.
From the above, conventional wet snow technology cannot simulate natural wet snow, so it is difficult to perform an appropriate and accurate environmental test when evaluating the adhesion of wet snow-like snowstorms to vehicles. is there.

In this regard, Patent Document 2 discloses, as a wet snow technology, a step of transporting dry snow toward an outflow opening by carrying the air in a flow path at a predetermined speed or more in a flow path, and forming a flow path upstream of the outflow opening. Supplying hot air of a predetermined temperature or higher into the flow path from around the outer peripheral surface, and uniformly mixing the carrier airflow and dry snow with the hot air in the flow path, thereby forming dry snow in the flow path. Disclosed is a step of forming an atmosphere having a uniform temperature sufficient for melting, and thereby, while transporting each piece of dry snow on a carrier airflow, melting and wet snow, and blowing wet snow from an outflow opening. .

According to such a wet snow technology, since the snow itself is melted in the flow path, the first and second problems can be solved to some extent as compared with Patent Document 1.
However, after the carrier airflow and dry snow and the hot air are uniformly mixed, heat is exchanged between the carrier airflow and dry snow and the hot air before the hot air is blown out of the outflow opening, thereby converting the dry snow into wet snow. There is no heat exchange area or heat exchange time until the aging area (aging space) for heat exchange.
When the transport speed of the transport airflow is high, dry snow is less likely to adhere to the inner surface of the flow path, but it is difficult to secure a heat exchange time and the wetness of the dry snow becomes insufficient. When the transfer speed is low, it is possible to secure the wet snow of the dry snow by securing sufficient heat exchange time, but on the other hand, the dry snow tends to adhere to the inner surface of the flow path, and in some cases, the flow path The blockage makes it difficult to transport the snow itself.
As described above, it is an important issue to prevent the wet snow from adhering to the inner surface of the pipeline while ensuring sufficient dry snow.
JP-A-2000-65690 JP-A-63-217172

  In view of the above technical problems, an object of the present invention is to efficiently transport dry snow without transporting the dry snow to the inner surface of the flow path when the dry snow is carried in an airflow using the flow path. Provided are a method for generating wet snow and a device for generating wet snow, which can be made to flow out of a flow path as wet snow having a desired moisture content.

In order to achieve the above object, a method for producing wet snow of the present invention comprises:
Transporting the dry snow toward the outflow opening by carrying the transport airflow at a predetermined speed or higher in the flow channel, and intersecting the flow direction of the transport airflow from around the outer peripheral surface of the flow channel on the upstream side of the outflow opening. Dissolving dry snow in the flow path by supplying hot air having a predetermined temperature and a predetermined humidity into the flow path in the direction, and uniformly mixing the carrier airflow and dry snow with the hot air in the flow path. Forming an atmosphere having a uniform temperature sufficient in the flow path, by providing an aging space of a predetermined length in the transport direction between the hot air supply section and the outflow opening in the flow path, Exchanging heat between the conveying airflow and dry snow and the hot air up to the outlet opening, whereby the dry snow is conveyed on the conveying airflow while being melted and wet. It snows and spills wet snow The method further includes a step of performing a test using snow blowing on the specimen by blowing wet snow from the mouth and supplying wet snow blown from the outflow opening toward the specimen installed in the blowing direction downstream from the outflow opening. In the heat transfer step, it is possible to secure a sufficient heat exchange time for converting the dry snow into wet snow while preventing the dry or wet snow from adhering to the inner surface of the flow path in the transporting step. In addition, the speed of the transport airflow is selected.

In order to achieve the above object, a method for producing wet snow of the present invention comprises:
Transporting the dry snow toward the outflow opening by carrying the transport airflow at a predetermined speed or higher in the flow channel, and intersecting the flow direction of the transport airflow from around the outer peripheral surface of the flow channel on the upstream side of the outflow opening. Dissolving dry snow in the flow path by supplying hot air having a predetermined temperature and a predetermined humidity into the flow path in the direction, and uniformly mixing the carrier airflow and dry snow with the hot air in the flow path. Forming an atmosphere having a uniform temperature sufficient in the flow path, by providing an aging space of a predetermined length in the transport direction between the hot air supply section and the outflow opening in the flow path, Exchanging heat between the conveying airflow and dry snow and the hot air up to the outlet opening, whereby the dry snow is conveyed on the conveying airflow while being melted and wet. It snows and spills wet snow The method further includes a step of performing a test using snow blowing on the specimen by blowing wet snow from the mouth and supplying wet snow blown from the outflow opening toward the specimen installed in the blowing direction downstream from the outflow opening. In the heat transfer step, it is possible to secure a sufficient heat exchange time for converting the dry snow into wet snow while preventing the dry or wet snow from adhering to the inner surface of the flow path in the transporting step. In addition, the length of the flow path from the mixed region of the conveying airflow and the dry snow and the hot air to the outflow opening is selected.

In order to achieve the above object, an apparatus for generating wet snow of the present invention comprises:
It has a snow pipe that conveys dry snow by a carrier airflow and blows out snow from an outflow opening, and a hot air supply pipe that communicates with the snow pipe at an upstream side of the outflow opening. The downstream end has a hot air inflow portion that forms an annular space that covers the entire outer peripheral surface of the snow pipe over a predetermined length in the direction in which the snow pipe extends, and is covered by the annular space. A plurality of hot air inflow openings are provided evenly on the outer peripheral surface of the snow pipe, so that a sufficient amount of heat exchange time can be secured to make dry snow wet and snowy. The length of the conduit from the mixing area of the snow and the hot air flowing in the direction intersecting with the flow direction of the carrier airflow to the outflow opening is selected, and a portion of the snow pipe where the hot air inflow portion is provided Downstream of the snow pipe An aging space of a predetermined length is formed in the transport direction, and the wet snow blown out from the outflow opening is supplied from the outflow opening toward the test piece installed downstream in the blowing direction, so that the snow blowing on the test piece is used. The test is conducted.

First, the snow environment test system will be described. As shown in FIG. 1, the snow environment test system 10 simulates a snowstorm by using artificial snow made of ice particles and placing the artificial snow in an airflow from behind. It is configured to blow toward the vehicle V, which is a test specimen, and has a snowstorm supply system 12 and an airflow supply system 14 for that purpose.

In particular, when continuously blowing toward the vehicle V using a required amount of snowstorm having a predetermined snow quality, in which the particle size of the ice particles and the water content are the main influencing factors, the entire height of the vehicle V is increased. In order to diffuse and possibly achieve the desired snow concentration distribution in the height direction of the vehicle V, a group of ice particles to be used as artificial snow is manufactured immediately before the test under a predetermined temperature and humidity control. And prompt supply.

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. An ice making machine 22 is disposed in the ice making room 20, and an ice temperature stabilizing conveyor 24, an ice crusher 26, a blower 28, a cooler 30, and an artificial snow distribution are provided in the low temperature room 18. A device 34 is disposed, and a wet snow device 32, an artificial snow blowing nozzle 36, and a snow blowing device 38 are disposed in the wind tunnel 16. Artificial snow is produced by crushing ice in the chamber 18 and forming ice, and the artificial snow is pumped toward the wind tunnel 16, and in the wind tunnel 16, the artificial snow that has become wet and snow is distributed to generate a low-temperature airflow. It is configured to put it on the snow and blow it toward the vehicle V To have.

The wind tunnel 16 is an open type circulating type, and has a measurement chamber 300 (open type) in which a vehicle to be measured is installed (open type), and first to fourth four bending cylinders 302, 304, 306, 308 (bending portions). And 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 (see FIG. 2), and the contraction cylinder 314 (see FIG. 2). The air flows into the measurement chamber 300 from an air outlet 316 (see FIG. 2) that opens to the first bending cylinder 302 and the second bending cylinder 304 in this order.

The airflow blown by the blower 25 is measured by lowering the wind speed (dynamic pressure) of the airflow as a whole, increasing the pressure (static pressure) in the intermediate body, and then passing the airflow through the contraction drum 314. An airflow having an air volume (wind speed) necessary and sufficient can be blown out from the outlet 316 to the measurement chamber 300.

Accordingly, as described later, ice particles conveyed by air through the ice making step, the ice breaking step, the separation step, and the wet snow step cause the snow to flow toward the vehicle in the measurement chamber 300 by riding the airflow from behind. By adjusting the wind speed of the airflow by the blower 25, it is possible to simulate a traveling vehicle while being a stationary vehicle.

  Further, 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 intentionally rectified.

The snowstorm supply system 12 is provided in three systems, and in each system, a snow supply pipe 40 connecting the icebreaker 26 and the blowing nozzle 36 and an air duct 44 connecting the suction port 42 in the wind tunnel 16 and the icebreaker 26 are provided. In the snow supply pipe 40, an artificial snow distribution device 34 and a wet snow device 32 are connected in this order between the ice breaker 26 and the blowing nozzle 36, while the air duct 44 is provided in the wind tunnel 16. The blower 28 and the cooler 30 are connected between the suction port 42 and the ice crusher 26.

The reason why the artificial snow distributing device 34 is installed on the upstream side of the wet snow device 32 is that when the artificial snow distributing device 34 is installed on the downstream side, the wet snow is sent to the distributing device 34 and To prevent clogging.

The ice maker 22 is a so-called reamer type ice maker 22 for producing flake-shaped ice chips, and a plurality of ice maker 22 for producing cracked ice chips according to the total amount of artificial snow used for a snow environment test. An arbitrary number is selected from among them, and ice is made by the selected ice maker 22 in accordance with a change in the required amount of artificial snow used for the environmental test. In accordance with the difference between the required amount of artificial snow and the roughly adjusted amount of ice for the change in the required amount of ice, in each of the selected ice maker 22, the evaporation temperature and / or the water temperature and / or the rotation speed of the reamer are changed. A control device (not shown) for finely adjusting the amount of ice making by making adjustments.

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 and 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 size.

The artificial snow distribution device 34 is used for distributing the artificial snow conveyed by the snow supply pipe 40 to a plurality of branch pipes (not shown). 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 the vehicle V, and a wet snow device 32 is provided for each branch pipe. A blowing nozzle 36 is provided at the end of the nozzle.

As shown in FIG. 9, in the artificial snow distributing device 34, the upstream end face 105 and the downstream end face 107 are respectively parallel to the downstream end face 106 of the snow supply pipe 40 and the upstream end face 104 of each of the plurality of branch pipes 58. The rotating body 110 includes a rotating body 110 disposed therein, and a rotation driving unit (not shown) for rotating the rotating body 110 at a predetermined rotation speed about the axial direction thereof. And a pressure-feeding channel 114 that penetrates the snow supply pipe 40 in a non-contact manner at the upstream end face in close proximity to an outflow opening 116 provided in the downstream-side end face 106 of the snow supply pipe 40. An inlet 118 is provided, and a downstream end face is provided with a non-contact type discharge port 122 which is disposed close to and opposed to an inflow opening 120 provided at the upstream end face of each of the plurality of branch pipes 58. , A plurality of branch pipes 58 each of the inlet openings 120 on the passing track of the discharge port 122 by the rotation of the rotary body 110 is provided so as to be located.
As described above, the snow pumped in the snow supply pipe 40 is distributed to the plurality of branch pipes 58 via the rotating body 110 of the artificial snow distribution device 34.

The wet snow apparatus 32 has a hot air supply pipe 50 communicating with the branch pipe 58, and the hot air supply pipe 50 is provided at a downstream end thereof over a predetermined length in the extending direction of the branch pipe 58. It has a hot air inflow portion 54 that forms an annular space that covers the entire outer peripheral surface, and a plurality of hot air inflow openings 56 are uniformly provided on the outer peripheral surface of the branch pipe 58 that is covered by the annular space. An aging space 116 (heat exchange aging region) is formed in the branch pipe 58 downstream of the portion where the hot air inflow portion 54 is provided, so that wet snow is formed there.

For the airflow supply system 14, the wind tunnel 16 is formed in a part of the circulation space, and is configured to blow snow in one direction from the front to the rear of the vehicle V over the height of the vehicle V. Specifically, an airflow 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 airflow passing through the vehicle V is cooled to a predetermined temperature by the cooler 30. After being cooled, it is returned to the blower 25 to generate an air flow again, and this is repeated.

Regarding the snow blowing device, three blowing nozzles 36 for blowing snow are arranged at a predetermined distance in front of the vehicle V at predetermined intervals in the height direction over the height of the vehicle V. The density of the supplied snowstorm can be adjusted for each blowout nozzle 36. A snow collecting device 38 is arranged at a position at a predetermined distance behind the vehicle V, and the snowstorm that has passed through the snow collecting device 38 is blown into the low-temperature chamber 18 through a suction port 42 in the wind tunnel 16. 28, cooled by the cooler 30, returned to the ice crusher 26, made ice by the ice maker 22, supplied to the ice crusher 26 by the ice temperature stabilizing conveyor 24, mixed with the ice particles to be crushed, and then branched again. The blowout nozzle 36 is used to blow out snow through the blowout nozzle 58. The blowout nozzle 36 is arranged along the direction of travel of the airflow, and the blowout port 102 is provided in a zone of the airflow blown out from the blower 25.

In this regard, the snow blowing is such that the snow blown from each blowing nozzle 36 by the air blown by the blower 28 is blown toward the vehicle V on the airflow blown from the blower 25. The speed is preferably as low as possible unless snow clogging occurs in the pipe 40 and the branch pipe 58. The speed of the snowstorm is preferably simulated by the airflow blown out from the blower 25.
More specifically, when the snowstorm is diffused by the diffusion plate 74 (described later) and blown toward the vehicle V, if the speed of the compressed air is high, only the speed of the snowstorm at the blowing nozzle 36 increases. By changing the speed of the airflow blown from the blower 25 while deviating from the natural snowstorm, it is possible to uniformly vary the speed of the entire snowstorm to be diffused. Is simulated, it is advantageous to change the speed of the airflow blown from the blower 25.

A diffusion plate 74 is provided in front of each blowing nozzle 36, and the snow blown from the blowing nozzle 36 toward the vehicle V on the low-temperature airflow from the blower is, as shown in FIG. In this case, the snow blows out in four directions, and the three blowing nozzles 36 of the snowstorm cooperate with each other so that the snowstorm is distributed at the front of the vehicle V along the height direction of the vehicle V.
In this regard, 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 of the vehicle V is about 1 to 3 meters. During a short distance, the snow blowing from the blowing nozzle 36 diffuses over the entire height at the front of the vehicle V.

As shown in FIG. 2, in each system, the wet snow apparatus 32 is provided in each branch pipe 58 on the downstream side of the distribution apparatus 34, but since each wet snow apparatus 32 has the same structure, One will be described.
The wet snow apparatus 32 is provided with a hot air inflow section 54 around a branch pipe 58, and the branch pipe 58 extends to the blowout nozzle 36 downstream of the hot air inflow section 54, and is made wet and wet in the hot air inflow section 54. The ice particles P are pressure-fed by the airflow in the branch pipe 58 and are blown out from the blowing nozzle 36.
More specifically, as shown in FIG. 3, the wet snow apparatus 32 has a hot air supply pipe 50 communicating with a branch pipe 58 on the downstream side of the distribution apparatus 34, and the hot air supply pipe 50 has a downstream end. The portion has a hot air inflow portion 54 that forms an annular space 52 that covers the entire outer peripheral surface of the branch pipe 58 over a predetermined length in the direction in which the branch pipe 58 extends.

The hot air supply pipe 50 may convey hot air heated to a predetermined temperature by a known heating means (not shown) toward the hot air inflow section 54 by a blower, for example. The hot air may be supplied to the hot air inflow section 54 by utilizing the natural suction by the air flow.
The hot air inflow portion 54 has a cylindrical shape concentric with the branch pipe 58, and a hot air supply pipe 50 is connected to an outer peripheral surface 53 of the hot air inflow section 54. Hot air flowing from the hot air supply pipe 50 into the hot air inflow section 54 is formed into an annular space 52. Through the inside of the branch pipe 58 uniformly over the outer peripheral surface of the branch pipe 58.

In the branch pipe 58, the downstream position of the distribution device 34 forming the hot air inflow section 54 may be determined as appropriate. The predetermined length L of the annular space 52 in the direction in which the branch pipe 58 extends is determined by the temperature and flow rate of the hot air flowing through the hot air supply pipe 50 and the temperature and flow rate of the air flow in the branch pipe 58. The temperature may be determined appropriately so that an atmosphere having a uniform temperature sufficient for melting is formed in the branch pipe 58.
By adjusting the humidity, temperature and / or flow rate of the hot air, and the temperature and / or flow rate of the carrier airflow, the moisture content of the wet snow is adjusted through adjustment of the ambient temperature in the branch pipe 58. The moisture content of wet snow is, for example, 1% to 30% in a snow environment test using a vehicle as a specimen.

In this case, while the ice particles P moistened and snowed in the branch pipe 58 are pumped by the airflow, they adhere to the inner surface 55 of the branch pipe 58 and cause a temporal variation in the flow rate of the ice particles P being pumped. In order to reliably prevent the ice particles P from being unable to be pumped due to, or in some cases, blockage of the branch pipe 58, the predetermined speed of the carrier airflow is preferably 15 meters per second or more. More preferably, it is at least 20 meters per second. The higher the moisture content of the wet snow, the higher the tendency to adhere to the inner surface 55 of the branch pipe 58. Therefore, it is necessary to increase the speed of the transport airflow accordingly.
The temperature of the hot air is preferably 0 ° C. to 50 ° C. If the temperature is 0 ° C. or lower, the ice particles P cannot be melted. On the other hand, if the temperature exceeds 50 ° C., the ice particles P can be melted. However, air has a low heat transfer coefficient, and even if the temperature of the hot air is high, heat exchange between the ice particles P and the air stream for pumping is not immediately promoted correspondingly, but on the other hand, some Since the melting may proceed rapidly only by the ice particles P, it is set in such a range.

A plurality of hot air inflow openings 56 are uniformly provided on the outer peripheral surface 53 of the branch pipe 58 covered by the annular space 52, so that the branch pipe 58 has a branch at the downstream side of the portion where the hot air inflow portion 54 is attached. An aging space 116 is formed in the tube 58. Here, the aging space 116 is used to mean an aging region in which the ice particles P pumped in the branch pipe 58 are gradually and uniformly melted in a uniform temperature atmosphere.
The inflow opening 56 may be provided, for example, as a through hole of a cylindrical punched metal material, and the number of the inflow openings 56 and the opening area thereof are uniform over the outer peripheral surface 53 of the branch pipe 58 in the hot air inflow section 54. This may be determined appropriately as long as an atmosphere having a uniform temperature can be formed in the branch pipe 58 by providing the branch pipe 58.
The portion of the supply pipe 40 covered by the annular space 52 is preferably formed of a snow-resistant fluororesin.

The aging space 116 of the branch pipe 58 has a double-pipe configuration with an outer pipe (not shown), and an airflow that flows a temperature-controlled airflow into an annular space (not shown) between the inside of the branch pipe 58 and the outer pipe. Supply means (not shown) is provided. Thereby, it is possible to maintain the ice temperature of the ice particles P in the aging space 116 by flowing cool air into the annular space, and to melt the clogging in the aging space 116 by flowing warm air into the annular space. It is possible.
When the hot air is high temperature and the flow rate is large and the transport airflow speed is slow, the required heat exchange time is short, and the length of the aging space can be shortened accordingly, and when the hot air is low temperature and the flow rate is small and the transport airflow speed is fast Therefore, the required heat exchange time is long, and the length of the aging space is correspondingly long.

At this point, in order to prevent a dry or wet snow from adhering to the inner surface of the branch pipe 58, it is possible to secure a sufficient heat exchange time to make the dry snow wet in the heat exchange stage. The speed of the conveying airflow and / or the length of the aging space from the mixing area of the conveying airflow and dry snow and hot air to the outlet opening may be selected. For example, the length of the aging space is 3 meters or more.

The operation of the wet snow apparatus 32 having the above configuration will be described below while describing the environmental test method.
First, in each system, ice pieces made by the ice making machine 22 are crushed into ice particles P having a predetermined particle size by the ice crusher 26, and the ice particles P are put on a carrier airflow at a predetermined speed or higher by the branch pipe 58. The pressure is sent to the blowing nozzle 36.
Next, the ice particles P are distributed from the snow supply pipe 40 to the corresponding branch pipe 58 by the distribution device 34, and around the outer peripheral surface 53 at the hot air inflow portion 54 of the branch pipe branch pipe 58 upstream of the outflow opening 102. Then, hot air of a predetermined temperature and a predetermined humidity is supplied into the branch pipe 58 through the inflow opening 56. In this case, the humidity, the temperature and / or the flow rate of the hot air, and the temperature and / or the flow rate of the carrier airflow are adjusted based on the desired moisture content set for the ice particles P.

More specifically, the hot air is provided at the hot air inflow portion 54 through a plurality of inflow openings uniformly provided over the outer peripheral surface 53 of the hot air inflow portion 54 of the branch pipe 58 via the annular space 52 around the branch pipe 58. It flows into the branch pipe 58 through 56.
Next, in the branch pipe 58 of the hot air inflow section 54, the carrier airflow and the ice particles P are uniformly mixed with the hot air, so that an atmosphere having a uniform temperature sufficient to melt the ice particles P is formed in the branch pipe 58. As a result, each of the ice particles P is melted and made wet snow while being carried on the carrying airflow, and the wet snow is blown out from the outflow opening 102.

At this point, as shown in FIG. 4 and FIG. 5, the air temperature of the compressed air flow gradually increases from a minus range of 0 ° C. or less to 0 ° C.
More specifically, in the aging space 116 of the branch pipe 58 downstream of the hot air inflow section 54, heat exchange is gradually performed between the carrier airflow and the ice particles P and the hot air in an atmosphere having a uniform temperature. As a result, the temperature of the carrier airflow increases, and each of the ice particles P starts to melt from the outer surface in contact with the hot air, turns into wet snow, and forms artificial snow which is the ice particle P having a desired moisture content.

In this case, utilizing the property of air having a low heat transfer coefficient, each of the ice particles P to be pumped in the aging space 116 in the uniform temperature atmosphere in the branch pipe 58 as a whole gradually It is possible to melt by heating, for example, so that only a part of the ice particles P does not melt or only a part of the ice particles P does not melt rapidly.
Next, the temperature of the inner surface 55 of the branch pipe 58 is maintained at zero temperature on the downstream side of the branch pipe 58 where the snow and snow is formed, and each of the ice particles P is melted before being blown out from the blow-out nozzle 36. So that the water content does not increase.

Next, in each system, the wet snow distributed from the blowing nozzle 36 at the tip of each branch pipe 58 is blown out, and is blown toward the vehicle by blowing air from behind the blowing nozzle 36.
In this case, by simulating wet snow in a natural state, when evaluating the adhesion of a wet snow-like snowstorm to a vehicle or the like, the wet snow does not adhere to the inner surface 55 of the branch pipe 58, Appropriate and accurate environmental tests can be performed.
If the ice temperature of the ice particles P in the aging space rises with the progress of the test, or if the ice particles P freeze up to cause clogging in the aging space 116, the inside and outside of the branch pipe 58 may be removed. The ice temperature of the ice particles P in the aging space is maintained by flowing cold air in the annular space between the pipes, and the clogging in the aging space 116 is thawed by flowing hot air in the annular space. Is also good.

According to the method for generating wet snow having the above-described configuration, when the dry snow is transported toward the outflow opening 102 by being placed on the transport airflow at a predetermined speed or more in the flow path, the flow path is located upstream of the outflow opening 102. Hot air of a predetermined temperature and a predetermined humidity is supplied into the flow channel from around the outer peripheral surface 110 of the carrier, and the carrier airflow and dry snow and the hot air are uniformly mixed in the flow channel, and the dry snow flows in the flow channel. An atmosphere having a uniform temperature sufficient to melt the airflow and dry air is carried out in the formed atmosphere by exchanging heat between the carrier airflow and dry snow and the hot air until the outlet opening. As a result, heat is exchanged between the hot air and the hot air.As a result, an atmosphere with a uniform temperature sufficient to melt the dry snow is formed in the flow path, and each of the dry snow melts and becomes wet and snowy. Efficiently without snow adhering to the inner surface of the channel It can be blown from the exit aperture 102.

As a modification, as shown in FIG. 6, the portion of the branch pipe 58 where the aging space 116 is formed may be formed of a flexible pipe so that, for example, the inner surface of the branch pipe 58 If the falling snow is easily peeled off from the inner surface by the minute vibration of the branch pipe 58 due to the transport of dry snow, or by applying a deformation such as bending or twisting to the branch pipe 58, if the vinyl hose is spirally wound. An aging space of a desired distance can be provided without taking up space.
Further, as a modified example, as shown in FIG. 7, three systems of the snowstorm supply system 12 may not be provided, but a single system may be provided, and one wet snow apparatus may be provided accordingly.

Although the embodiments of the present invention have been described in detail above, 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, the description has been made on the assumption that artificial snow formed by crushing ice pieces is used as a target of wet snow making, but the present invention is not limited thereto, and cold air having a predetermined humidity and a predetermined temperature may be used. Artificial snow may be used, or natural snow having a low moisture content may be used.

Further, in the present embodiment, it has been described that the hot air is supplied to the hot air inflow portion 54 through the hot air supply pipe 50 after the ice particles P are started to be fed by the airflow by the branch pipe 58, but the present invention is not limited thereto. The hot air may be supplied before the ice particles P are pumped by the air current, as long as the ice particles P to be pumped can be melted and melted in an atmosphere at a uniform temperature. And the supply of hot air may be performed in parallel.
Furthermore, in the present embodiment, the method of adjusting the moisture content of the ice particles P has been described as adjusting the humidity, the temperature and / or the flow rate of the hot air, and the temperature and / or the flow rate of the carrier airflow, but is not limited thereto. It is also possible to adjust only the temperature and / or flow rate of the hot air, or adjust only the temperature and / or flow rate of the carrier airflow, as long as the desired moisture content of the ice particles P can be adjusted without the need.

1 is an overall schematic diagram of an environmental test system in which a wet snow apparatus according to an embodiment of the present invention is provided. It is a lineblock diagram showing the wet snow equipment concerning an embodiment of the present invention. It is a fragmentary sectional view showing the circumference of a hot air supply part of a wet snow equipment concerning an embodiment of the present invention. 5 is a graph showing a change in airflow temperature in a snow supply pipe in the wet snow apparatus according to the embodiment of the present invention. It is the schematic which shows the air flow temperature in a snow supply pipe, the hot air, and the heat exchange situation between the ice particles P in the wet snow apparatus which concerns on embodiment of this invention. FIG. 4 is a view similar to FIG. 2 of a wet snow apparatus according to another embodiment of the present invention. It is the whole schematic diagram of another environmental test system in which the wet snow equipment concerning the embodiment of the present invention is arranged. It is a figure which shows the reproduction state of wet snow in the conventional snowmaking apparatus.

V Vehicle P Ice particle D Distance between vehicle and blowing nozzle 10 Snow environment test system 12 Snow blowing supply system 14 Air flow supply system 16 Wind tunnel 18 Low temperature room 20 Ice making room 22 Ice making machine 24 Ice temperature stabilizing conveyor 26 Ice breaking machine 28 Blower 30 Cooling Device 32 wet snow device 34 distribution device 36 blowing nozzle 38 snow blowing 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 53 outer peripheral surface 54 hot air inflow part 55 inner peripheral surface 56 Inflow opening 58 Branch pipe 74 Diffusion plate 102 Outflow opening 104 Upstream end face 105 Upstream end face 106 Downstream end face 107 Downstream end face 110 Rotating body 114 Pumping flow passage 116 Outflow opening 118 Intake 116 Aging space 300 Measurement chamber 302 First Bending trunk 304 No. Bending cylinder 306 third bending cylinder 308 fourth bending cylinder 310 second dispersion drum 312 rectifying cylinder 314 Chijimiryudo 316 outlet

Claims (3)

A step of simulating a snowstorm with snow diffused from the outflow opening by flowing airflow from behind the outflow opening while carrying dry snow toward the outflow opening while being carried on a conveying airflow at a predetermined speed or more in the flow path, On the upstream side of the outflow opening, supplying hot air at a predetermined temperature and a predetermined humidity into the flow path from around the outer peripheral surface of the flow path in a direction intersecting with the flow direction of the transfer airflow, Forming an atmosphere at a uniform temperature sufficient to melt the dry snow in the flow path by uniformly mixing the airflow and dry snow with the hot air; and flowing out of the hot air supply section in the flow path. By providing an aging space of a predetermined length in the transport direction between the openings, a step of performing heat exchange between the transport airflow and dry snow and the hot air in the atmosphere until the outlet opening is reached. Has Thereby, while carrying each dry snow on the carrier airflow, it melts and becomes wet snow, blows out the wet snow from the outflow opening, and installs the wet snow blown out from the outflow opening downstream from the outflow opening in the blowing direction. The method further comprises the step of performing a test using a snowstorm on the specimen by supplying the specimen toward the specimen, and in the step of flowing the airflow, the airflow is controlled so that the speed of the entire diffused snowstorm is uniform. Setting the speed, in the transporting step of transporting the dry snow toward the outflow opening by carrying the transport airflow at a predetermined speed or more in the flow path, while preventing dry snow or wet snow from adhering to the inner surface of the flow path, In the heat exchange step, a velocity of the carrier airflow is selected so as to secure a sufficient heat exchange time for converting dry snow into wet snow. A step of simulating a snowstorm with snow diffused from the outflow opening by flowing airflow from behind the outflow opening while carrying dry snow toward the outflow opening while being carried on a conveying airflow at a predetermined speed or more in the flow path, On the upstream side of the outflow opening, supplying hot air at a predetermined temperature and a predetermined humidity into the flow path from around the outer peripheral surface of the flow path in a direction intersecting with the flow direction of the transfer airflow, Forming an atmosphere at a uniform temperature sufficient to melt the dry snow in the flow path by uniformly mixing the airflow and dry snow with the hot air; and flowing out of the hot air supply section in the flow path. By providing an aging space of a predetermined length in the transport direction between the openings, a step of performing heat exchange between the transport airflow and dry snow and the hot air in the atmosphere until the outlet opening is reached. Has Thereby, while carrying each dry snow on the carrier airflow, it melts and becomes wet snow, blows out the wet snow from the outflow opening, and installs the wet snow blown out from the outflow opening downstream from the outflow opening in the blowing direction. The method further comprises the step of performing a test using a snowstorm on the specimen by supplying the specimen toward the specimen, and in the step of flowing the airflow, the airflow is controlled so that the speed of the entire diffused snowstorm is uniform. Setting the speed, in the transporting step of transporting the dry snow toward the outflow opening by carrying the transport airflow at a predetermined speed or more in the flow path, while preventing dry snow or wet snow from adhering to the inner surface of the flow path, In the heat exchange step, the length of the flow path from the transport airflow and the mixed area of the dry snow and the hot air to the outflow opening so as to ensure a sufficient heat exchange time for making the dry snow wet and snowy. Choose To, wet snow generation method, characterized in that. It has a snow pipe that conveys dry snow by a carrier airflow and blows out snow from an outflow opening, and a hot air supply pipe that communicates with the snow pipe at an upstream side of the outflow opening. The downstream end has a hot air inflow portion that forms an annular space that covers the entire outer peripheral surface of the snow pipe over a predetermined length in the direction in which the snow pipe extends, and is covered by the annular space. A plurality of hot air inflow openings are uniformly provided on the outer peripheral surface of the snow pipe, and a predetermined length in the conveying direction is provided in the snow pipe at a downstream side of a portion of the snow pipe where the hot air inflow portion is provided. Aging space is formed, the inside of the portion of the snow pipe from the aging space to the outflow opening is held at zero degree, and the blown wet snow is discharged from the outflow opening to the specimen placed downstream in the blowing direction. Offering By, then examined using a snowstorm to specimen, and wherein the generation device of wet snow.

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