Snow environment test device and snow environment test method

Abstract

To reduce the time and effort for reproducing a snow environment to dump snow of desired snow quality.SOLUTION: A snow environment test device comprises: an injector 14 that is composed of a two-fluid nozzle; a temperature setting unit 30a that sets a room temperature; an air conditioner 12 that cools the inside of a test chamber; a temperature control unit 30e that controls the air conditioner 12; a water flow rate setting unit 30b that sets the flow rate of supply water to the injector 14; a water supply unit 18 that supplies water of a prescribed temperature to the injector 14; a snow quality selection unit 30d that selects snow quality; a related information storage unit 30f in which the internal temperature of the test chamber, the flow rate of supply water to the injector 14, the pressure of air supplied to the injector 14, and snow quality are stored in association; and a pressure adjustment unit 30g that adjusts the pressure of air supplied to the injector 14 to the pressure obtained using the information stored in the related information storage unit 30f.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a snow environment testing device and a snow environment testing method. [Background technology]

[0002] Conventionally, a snow environment test device that reproduces a snow environment in a test room has been known, as disclosed in the following Patent Document 1. This snow environment test device uses a two-fluid nozzle that sprays water and air, and the two-fluid nozzle is capable of spraying fine water droplets, making it possible to create powdery snow. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 56-17548 Summary of the Invention [Problem to be solved by the invention]

[0004] To recreate a snow environment, the test room must be adjusted to a temperature below 0°C, but because snow quality is affected by factors such as the temperature in the test room, to achieve the desired snow quality, it is necessary to actually let a certain amount of snow fall in the test room, check the snow quality, and then adjust the temperature in the test room. For this reason, adjusting the conditions to recreate a snow environment that will produce snow of the desired quality is time-consuming.

[0005] Therefore, the present invention has been made in consideration of the above-mentioned conventional technology, and its purpose is to reduce the effort required to recreate a snow environment that produces snow of the desired quality. [Means for solving the problem]

[0006] The snow environment testing device of the present invention is a snow environment testing device for creating a snow environment in a test chamber, and is equipped with: an injector composed of a two-fluid nozzle and configured to inject water and air; a temperature setting unit that sets the temperature inside the test chamber; an air conditioner for cooling the test chamber; a temperature control unit that controls the air conditioner so that the temperature inside the test chamber becomes the temperature set by the temperature setting unit; a water flow rate setting unit that sets the flow rate of water supplied to the injector; a water supply unit that supplies water at a flow rate set by the water flow rate setting unit; an air supply unit that supplies air at a predetermined pressure to the injector; a snow quality selection unit that selects dry snow, wet snow, or sleet as the snow quality; an associated information memory unit that stores information correlating the temperature inside the test chamber, the flow rate of water supplied to the injector, the temperature of the water supplied to the injector, and snow qualities representing dry snow, wet snow, or sleet; and a water temperature adjustment unit that adjusts the temperature of the water supplied to the injector to a temperature obtained using the information stored in the associated information memory unit so that the snow quality selected by the snow quality selection unit is achieved.

[0007] In the snow environment testing device of the present invention, the temperature control unit controls the air conditioner so that the temperature in the test chamber is maintained at a set temperature. The water temperature adjustment unit adjusts the temperature of water supplied to the injector to a water temperature obtained using the snow quality selected by the snow quality selection unit and information stored in the related information storage unit. This allows water having the adjusted temperature and at a flow rate set by the water flow rate setting unit, and air at a predetermined pressure, to be supplied to the injector. Therefore, a snow environment with the snow quality selected by the snow quality selection unit can be obtained, and a test specimen can be exposed to such a snow environment.

[0008] In other words, since snow quality (representing dry snow, wet snow, or sleet) varies depending on the temperature in the test room, the water flow rate and water temperature supplied to the injector consisting of a two-fluid nozzle, it is impossible to know whether the desired snow quality can be obtained until snow is actually made to fall. In contrast, the present invention is provided with a related information storage unit that stores information relating three conditions to snow qualities representing dry snow, wet snow, or sleet. This information is used to adjust the temperature of the water supplied to the injector under a set test room temperature, a predetermined air pressure, and a set water flow rate, thereby achieving a snow environment with the desired snow quality. This reduces the effort required to obtain the desired snow quality. The information stored in the related information storage unit can be obtained through a preliminary test in which snow is made to fall after adjusting these three conditions and the snow quality is confirmed.

[0009] The snow environment testing apparatus may include a blower that generates an airflow in the testing chamber, and an airflow control unit that controls the blower.

[0010] In this case, the speed of the airflow generated in the test chamber can be changed, which allows the time it takes for the water droplets sprayed from the sprayer to reach the test piece to be changed. This means that the quality of the snow that reaches the test piece can also be adjusted by the air flow speed. This means that the amount of snow that accumulates on the test piece and the quality of the snow that adheres to it can be changed.

[0011] In addition, the snow environment testing method of the present invention is a snow environment testing method that creates a snow environment in a test chamber, setting the temperature in the test chamber, selecting dry snow, wet snow, or sleet as the snow quality using a snow quality selection unit, setting the flow rate of water supplied to an injector consisting of a two-fluid nozzle using a water flow rate setting unit, controlling an air conditioner so that the temperature in the test chamber becomes the set temperature, using information stored in a related information memory unit that correlates the temperature in the test chamber, the flow rate of water supplied to the injector, the temperature of the water supplied to the injector, and snow qualities representing dry snow, wet snow, or sleet, to derive the temperature of water to be supplied to the injector that will result in the selected snow quality, supplying water having the derived temperature and at the flow rate set by the water flow rate setting unit to the injector, and supplying air having a predetermined pressure to the injector, and spraying the water and air from the injector.

[0012] In the snow environment testing method of the present invention, the snow quality is selected by the snow quality selection unit, the flow rate of water supplied to the injector is set, and the air conditioner is controlled so that the temperature in the test chamber becomes the set temperature. Then, water having a temperature obtained using information stored in the related information storage unit and at a flow rate set by the water flow rate setting unit is supplied to the injector, and air having a predetermined pressure is supplied to the injector. Therefore, a snow environment with the snow quality selected by the snow quality selection unit can be obtained, and a test specimen can be exposed to such a snow environment. [Effects of the Invention]

[0013] As described above, according to the present invention, it is possible to reduce the effort required to recreate a snowy environment that produces snow of a desired quality. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram schematically illustrating a snow environment testing device according to a first embodiment. [Figure 2] FIG. 2 is a diagram for explaining the function of a controller. [Figure 3] FIG. 2 is a diagram for explaining information stored in a related information storage unit. [Figure 4] FIG. 2 is a diagram for explaining a snow environment testing method according to the first embodiment. [Figure 5] FIG. 2 is a diagram for explaining an example of a snow environment testing method according to the first embodiment. [Figure 6] FIG. 10 is a diagram for explaining the function of a controller in the snow environment testing device according to the second embodiment. [Figure 7] FIG. 2 is a diagram for explaining information stored in a related information storage unit. [Figure 8] FIG. 10 is a diagram for explaining water temperature adjustment in the snow environment testing method according to the second embodiment. [Figure 9] FIG. 10 is a diagram for explaining the function of a controller in the snow environment testing device according to the third embodiment. [Figure 10] FIG. 10 is a diagram for explaining adjustment of air pressure and water temperature in a snow environment testing method according to a third embodiment. [Figure 11] FIG. 10 is a diagram for explaining the function of a controller in the snow environment testing device according to the fourth embodiment. [Figure 12] FIG. 2 is a diagram for explaining information stored in a related information storage unit. [Figure 13] FIG. 10 is a diagram for explaining water temperature adjustment in a snow environment testing method according to a fourth embodiment. [Figure 14] FIG. 10 is a diagram schematically illustrating a snow environment testing device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0016] (First embodiment) As shown in FIG. 1 , the snow environment test apparatus 10 according to the first embodiment is an apparatus for creating a snow environment of a desired snow quality in a test chamber 1 and conducting a test by exposing a test specimen placed in the test chamber 1 to the snow environment. Here, "snow quality" refers to the properties of snow, such as dry snow, wet snow, or sleet. Since the snow environment test apparatus 10 of this embodiment is capable of creating a rainy environment in addition to a snow environment of a desired snow quality, the snow quality referred to here also includes rain. Snow quality may also include properties of snow, such as moisture content. The snow environment test apparatus 10 of this embodiment can create not only a snow environment that produces snow, but also a snow environment that produces sleet, a mixture of snow and rain. Furthermore, the snow environment test apparatus 10 of this embodiment is configured to create not only these snow environments but also a rainy environment.

[0017] The snow environment testing device 10 includes an air conditioner 12 configured to cool the inside of the test chamber 1, an injector 14 configured to inject air and water into the test chamber 1, an air supply unit 16 that supplies air to the injector 14, and a water supply unit 18 that supplies water to the injector 14.

[0018] The air conditioner 12 is configured to generate low-temperature air so as to cool the air in the test chamber 1, and by controlling the air conditioner 12, the inside of the test chamber 1 can be adjusted to a predetermined temperature at least below 0°C. In other words, the air conditioner 12 adjusts the temperature of the air in the test chamber 1 so that the temperature is at a temperature at which the fine water droplets sprayed from the sprayer 14 freeze. The air conditioner 12 can adjust the temperature in the test chamber 1 to a range of, for example, 0°C to -30°C. When creating a rainy environment, the air conditioner 12 may adjust the temperature to a temperature above 0°C, for example, 0 to 20°C.

[0019] The temperature inside the test chamber 1 is detected by a room temperature sensor 20 .

[0020] The injector 14 is configured as a two-fluid nozzle and is configured to be able to inject a fluid in a state in which fine water droplets and air are mixed together. That is, the two-fluid nozzle injects water supplied from the water supply unit 18 and air supplied from the air supply unit 16 together. At this time, the injected water is pulverized by the injected air, so that fine water droplets and air are ejected from the two-fluid nozzle.

[0021] The air supply unit 16 includes an air pipe 16a connected to the injector 14 and a compressor 16b for supplying air through the air pipe 16a toward the injector 14. The air pipe 16a is provided with a pressure sensor 16c for detecting the pressure of the air flowing through the air pipe 16a and a pressure regulation valve 16d for adjusting the pressure of the air flowing through the air pipe 16a. The pressure of the air flowing through the air pipe 16a is adjusted by the pressure regulation valve 16d, thereby adjusting the pressure of the air introduced into the injector 14. The air pipe 16a is also provided with a heater / cooler 16e for heating or cooling the air flowing through the air pipe 16a. The heater / cooler 16e may be driven to maintain a constant temperature of the air supplied to the injector 14, in which case the quality of snow can be consistent depending on the air supplied to the injector 14. The heater / cooler 16e may be omitted.

[0022] The water supply unit 18 includes a water pipe 18a connected to the injector 14 and a pump 18b for causing water to flow through the water pipe 18a toward the injector 14. A heater / cooler 18c is provided in the water pipe 18a, and water heated or cooled by the heater / cooler 18c (water temperature regulator) to a predetermined temperature is introduced into the injector 14. The water pipe 18a is also provided with a flow meter 18d for detecting the flow rate of water flowing through the water pipe 18a and a flow rate adjustment valve 18e that can adjust the flow rate of water flowing through the water pipe 18a. The flow rate of water flowing through the water pipe 18a is adjusted by the flow rate adjustment valve 18e, thereby adjusting the flow rate of water introduced into the injector 14. The heater / cooler 18c may or may not be connected to a controller 30, which will be described later. The heater / cooler 18c is provided to maintain the temperature of the water supplied to the injector 14 at a predetermined temperature, but if the temperature of the water discharged from the pump 18b is stable, the heater / cooler 18c can be omitted.

[0023] The room temperature sensor 20, pressure sensor 16c, pressure adjustment valve 16d, heater / cooler 18c, flow meter 18d, and flow adjustment valve 18e are connected to a controller 30 so as to be able to exchange signals. The controller 30 is a computer for controlling the various operations of the snow environment test apparatus 10, and is composed of a microcomputer equipped with a central processing unit (CPU) for executing arithmetic processing, a ROM for storing processing programs and data, and a RAM for temporarily storing data, and is connected to an input device 31. By executing the processing programs stored in the controller 30, as shown in FIG. 2, the controller 30 can function as a temperature setting unit 30a, a water flow rate setting unit 30b, a test time setting unit 30c, a snow quality selection unit 30d, a temperature control unit 30e, a related information storage unit 30f, and a pressure control unit 30g.

[0024] The temperature setting unit 30a is a functional unit for setting the temperature in the test chamber 1, and stores information indicating the temperature input by the tester through the input device 31, for example.

[0025] The temperature control unit 30e is configured to control the air conditioner 12 so that the temperature detected by the room temperature sensor 20 becomes the temperature set by the temperature setting unit 30a.

[0026] The water flow rate setting section 30b is a functional section for setting the flow rate of water supplied to the injector 14, and stores information indicating the water flow rate input by the tester through the input device 31, for example.

[0027] The test time setting unit 30c is a functional unit for setting a test time for which the created snow environment will continue, and stores information indicating the test time input by the tester through the input device 31, for example.

[0028] The snow quality selection unit 30d is a functional unit for selecting the snow quality and is configured to be able to select any one of dry snow, wet snow, sleet, and rain. The snow quality selection unit 30d may also be configured to be able to select or set the degree of sleet and moisture content. Dry snow, wet snow, sleet, and rain are selected via the input device 31. For example, if dry snow is selected via the input device 31, information indicating that dry snow has been selected is stored in the snow quality selection unit 30d. Furthermore, although the snow quality selection unit 30d may be configured to be able to select only one of dry snow, wet snow, sleet, and rain, in this embodiment, it is configured to be able to select multiple of them. In other words, if multiple of dry snow, wet snow, sleet, and rain are selected, a test can be performed in which one of the selected snow environments (or rain environments) is created and then changed to another selected snow environment (or rain environment). For example, dry snow can be selected as a first test and wet snow can be selected as a second test. In this case, the snow environment test device 10 first lets dry snow fall for a predetermined period of time, and then lets wet snow fall for a predetermined period of time.

[0029] It should be noted that the snow types available as options are not limited to dry snow, wet snow, sleet, and rain; for example, snow and sleet may be available as options while rain is excluded, or only dry, wet, and wet snow may be available as options.

[0030] The related information storage unit 30f is a functional unit that stores information correlating the temperature in the test chamber 1, the flow rate of water supplied to the injector 14, the pressure of the air supplied to the injector 14, and snow quality. As shown in FIG. 3, the related information storage unit 30f may include, for example, a first map 32a correlating the water flow rate, air pressure, and snow quality at a first test temperature (e.g., −5°C), a second map 32b correlating the water flow rate, air pressure, and snow quality at a second test temperature (e.g., −10°C), and a third map 32c correlating the water flow rate, air pressure, and snow quality at a third test temperature (e.g., −15°C). In other words, by using the stored information, it is possible to derive which snow quality will be obtained at each test temperature for a certain air pressure and a certain water flow rate. Furthermore, it is possible to derive what MPa the air pressure should be set to at a certain water flow rate to obtain a certain snow quality at each test temperature. The information stored in the first to third maps 32a to 32c can be obtained by a preliminary test in which the temperature, water flow rate, and air pressure in the test room are adjusted, snow is allowed to fall, and the snow quality is confirmed.

[0031] Although dry snow, wet snow, sleet, and rain are stored as snow qualities, the degree of sleet or moisture content may be stored instead of or in addition to these. The information stored in the related information storage unit 30f may be information expressed as a relational expression, information in a list format, or the like. The number of test temperatures provided is not limited to three, and information for one, two, or even more test temperatures may be provided. When information for multiple test temperatures is stored, a new map of test temperatures corresponding to the temperature of the test chamber 1 set in the temperature setting unit 30a can be obtained by interpolation, such as linear interpolation.

[0032] The pressure control unit 30g derives the pressure of the air to be supplied to the injector 14 using the temperature of the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and information stored in the related information storage unit 30f. For example, if the related information storage unit 30f stores the information shown in FIG. 3, the pressure control unit 30g references a map of test temperatures that match or are similar to the temperature of the test chamber 1 set in the temperature setting unit 30a. The pressure control unit 30g then derives, from the referenced map, an air pressure that corresponds to the water flow rate set in the water flow rate setting unit 30b and the snow quality set in the snow quality selection unit 30d. The pressure control unit 30g is configured to control the pressure adjustment valve 16d so that the pressure of the air supplied to the injector 14 becomes the pressure derived using the temperature of the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and the information stored in the related information storage unit 30f. That is, the pressure control unit 30g and the pressure regulating valve 16d function as a pressure regulating unit that regulates the pressure of the air supplied to the injector 14 to a pressure obtained using the information stored in the related information storage unit 30f.

[0033] Here, a method for conducting a snow environment test using the snow environment test device 10 will be described with reference to Fig. 4. As an example of the test method, an example will be described in which tests are conducted in the order of rainfall (first test), sleet (second test), and wet snow (third test), as shown in Fig. 5. Because the injector 14 is configured as a two-fluid nozzle, when a rainfall test is conducted, the water droplets become drizzle-like with relatively small size.

[0034] In the snow environment testing method, first, a test specimen is placed in the test chamber 1, and then the test temperature and test time are input through the input device 31. At this time, the test temperature and test time are input for each of the first test, second test, and third test. As a result, the test temperature is set in the temperature setting unit 30a, and the test time is set in the test time setting unit 30c (steps ST11 and ST12).

[0035] The water flow rate to be sprayed from the injector 14 is input through the input device 31. At this time, for example, the same water flow rate is input for the first to third tests. This sets the water flow rate in the water flow rate setting unit 30b (step ST13). Also, the snow type is selected through the input device 31. At this time, for example, rain is selected for the first test, sleet for the second test, and wet snow for the third test. This causes the snow type to be selected in the snow type selection unit 30d (step ST14). The water flow rate may be constant for the first to third tests, or the water flow rate for the second and third tests may be smaller or larger than that for the first test. The test temperature may be gradually lowered in the second test, or may be maintained at a constant temperature in the second test as well.

[0036] Next, the air conditioner 12 is operated, and the temperature control unit 30e controls the air conditioner 12 so that the temperature in the test chamber 1 detected by the room temperature sensor 20 becomes the temperature set in the temperature setting unit 30a (step ST15). Then, when the temperature in the test chamber 1 reaches the set temperature, the test starts (step ST16). At this time, since the first test is started first, the air conditioner 12 is controlled so that the temperature in the test chamber 1 becomes the temperature set as the temperature for this first test. Also, the air supply unit 16 supplies air to the injector 14 through the air pipe 16a, and the water supply unit 18 supplies water to the injector 14 through the water pipe 18a. As a result, a fluid in a state where fine water droplets and air are mixed is sprayed from the injector 14.

[0037] During the test, the pressure control unit 30g derives the pressure of the air to be supplied to the injector 14 using the temperature in the test chamber 1 set by the temperature setting unit 30a, the water flow rate set by the water flow rate setting unit 30b, the snow quality set by the snow quality selection unit 30d, and the information stored in the related information storage unit 30f (step ST17), and controls the pressure adjustment valve 16d according to this derived pressure. As a result, during the test, the pressure of the air supplied to the injector 14 is adjusted to the derived pressure (step ST18). Meanwhile, the temperature of the water supplied to the injector 14 is adjusted to a predetermined temperature by the heater / cooler 18c, and the flow rate is adjusted by controlling the flow rate adjustment valve 18e so that the flow rate measured by the flow meter 18d is the water flow rate set by the water flow rate setting unit 30b. The rainfall test continues under this condition.

[0038] In this state, when the set test time has elapsed, the process moves to the second test (step ST19). In the second test, the air conditioner 12 is controlled to achieve the test chamber temperature set for the second test, and water cooled by the heater-cooler 18c at the set water flow rate is supplied to the injector 14. Also in the second test, the pressure of the air to be supplied to the injector 14 is derived using the set temperature in the test chamber 1, the set water flow rate, the set snow quality, and the information stored in the related information storage unit 30f (step ST20), and the pressure adjustment valve 16d is controlled according to this derived pressure (step ST21). In this way, the sleet test continues.

[0039] In this state, when the set test time has elapsed, the system proceeds to the third test (step ST22). In the third test, the air conditioner 12 is controlled to achieve the test chamber temperature set for the third test, and water cooled by the heater-cooler 18c at the set water flow rate is supplied to the injector 14. Similarly, in the third test, the pressure of the air supplied to the injector 14 is derived using the set temperature in the test chamber 1, the set water flow rate, the set snow quality, and the information stored in the related information storage unit 30f (step ST23), and the pressure adjustment valve 16d is controlled according to this derived pressure (step ST24). Specifically, the pressure of the air supplied to the injector 14 is adjusted to increase so that the snow changes from sleet in the second test to wet snow in the third test. In this way, the wet snow test continues. Then, when the set time has elapsed, the third test is terminated.

[0040] As described above, in this embodiment, the temperature control unit 30e controls the air conditioner 12 so that the temperature in the test chamber 1 is maintained at a set temperature. The pressure adjustment valve 16d adjusts the pressure of the air supplied to the injector 14 to a pressure determined using the snow quality selected by the snow quality selection unit 30d and the information stored in the related information storage unit 30f. This allows air with the adjusted pressure to be supplied to the injector 14, and water at a predetermined temperature and at a flow rate set by the water flow rate setting unit 30b to be supplied to the injector 14. This allows a snow environment with the snow quality selected by the snow quality selection unit 30d to be obtained, and the test specimen can be exposed to such a snow environment. Moreover, since the snow quality can be changed by adjusting the pressure of the air supplied to the injector 14, the snow quality can be changed quickly. For example, when transitioning from the second test, in which sleet is used, to the third test, in which wet snow is used, a smooth transition from sleet to wet snow can be achieved.

[0041] In addition, an associated information storage unit 30f is provided that stores information relating three conditions (temperature in the test chamber 1, water flow rate supplied to the injector 14, and air pressure supplied to the injector 14) to snow quality. This information is used to adjust the pressure of the air supplied to the injector 14 at a predetermined test chamber temperature and a predetermined water flow rate at a predetermined temperature, thereby obtaining a snow environment with the desired snow quality. This reduces the effort required to obtain the desired snow quality. The information stored in the associated information storage unit 30f can be obtained by a preliminary test in which snow is allowed to fall after adjusting these three conditions and the snow quality is confirmed.

[0042] (Second embodiment) 6, in the second embodiment, the controller 30 also functions as a water temperature control unit 30h to adjust the temperature of the water supplied to the injector 14 using information stored in a related information storage unit 30f. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0043] In the second embodiment, unlike the first embodiment, the pressure control unit 30g is omitted. Therefore, although a pressure adjustment valve 16d is provided in the air pipe 16a, this pressure adjustment valve 16d does not have to be connected to the controller 30. The pressure adjustment valve 16d is provided to maintain the pressure of the air supplied to the injector 14 at a predetermined pressure, but if the pressure of the air discharged from the compressor 16b is stable, the pressure adjustment valve 16d can be omitted.

[0044] The related information storage unit 30f is a functional unit that stores information correlating the temperature in the test chamber 1, the flow rate of water supplied to the injector 14, the temperature of the water supplied to the injector 14, and snow quality. As shown in FIG. 7, the related information storage unit 30f may include, for example, a first map 34a correlating the water flow rate, water temperature, and snow quality at a first test temperature (e.g., −5°C), a second map 34b correlating the water flow rate, water temperature, and snow quality at a second test temperature (e.g., −10°C), and a third map 34c correlating the water flow rate, water temperature, and snow quality at a third test temperature (e.g., −15°C). In other words, by using the stored information, it is possible to derive which snow quality will be obtained at each test temperature for a certain water temperature and a certain water flow rate. It is also possible to derive what temperature the water temperature should be set to at a certain water flow rate to obtain a certain snow quality at each test temperature. Although dry snow, wet snow, sleet, and rain are stored as snow types, the degree of sleet or moisture content may be stored instead of or in addition to these. The information stored in the related information storage unit 30f may be information expressed as a relational expression, information in a list format, or the like. The number of test temperatures provided is not limited to three, and information for one, two, or more test temperatures may be provided.

[0045] The water temperature control unit 30h derives the temperature of the water to be supplied to the injector 14 using the temperature in the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and the information stored in the related information storage unit 30f. For example, if the related information storage unit 30f stores the information shown in FIG. 7, the water temperature control unit 30h references a map of test temperatures that match or are similar to the temperature in the test chamber 1 set in the temperature setting unit 30a. Then, from the referenced map, the water temperature corresponding to the water flow rate set in the water flow rate setting unit 30b and the snow quality set in the snow quality selection unit 30d is derived. The water temperature control unit 30h is configured to control the heater / cooler 18c so that the temperature of the water supplied to the injector 14 becomes a temperature derived using the temperature in the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and the information stored in the related information storage unit 30f. In other words, the water temperature control unit 30h and the heater / cooler 18c function as a water temperature adjustment unit that adjusts the temperature of the water supplied to the injector 14 to a temperature obtained using the information stored in the related information storage unit 30f.

[0046] Here, as in the first embodiment, an example of conducting the test shown in FIG. 5 will be described. In the second embodiment, as shown in FIG. 8, in each of the first to third tests, the water temperature control unit 30h derives the temperature of the water to be supplied to the injector 14 using the temperature in the test chamber 1 set by the temperature setting unit 30a, the water flow rate set by the water flow rate setting unit 30b, the snow quality set by the snow quality selection unit 30d, and information stored in the related information storage unit 30f (step ST31), and controls the heater-cooler 18c according to the derived temperature. As a result, during the test, the temperature of the water supplied to the injector 14 is adjusted to the derived temperature (step ST32). Specifically, the temperature of the water supplied to the injector 14 is adjusted to be lower so that the snow condition changes from sleet in the second test to wet snow in the third test. At this time, the water flow rate is adjusted to the water flow rate set by the water flow rate setting unit 30b. Meanwhile, the pressure of the air supplied to the injector 14 is adjusted to a predetermined pressure by the pressure regulating valve 16d. In other words, unlike the first embodiment, the second embodiment does not include steps of deriving air pressure using information stored in the related information storage unit 30f (steps ST17, ST20, ST23) and steps of adjusting air pressure using information stored in the related information storage unit 30f (ST18, ST21, ST24).

[0047] Therefore, in this embodiment, the temperature control unit 30e controls the air conditioner 12 so that the temperature in the test chamber 1 is maintained at the set temperature. The heater / cooler 18c adjusts the temperature of the water supplied to the injector 14 to a water temperature determined using the snow quality selected by the snow quality selection unit 30d and the information stored in the related information storage unit 30f. This allows water with the adjusted temperature and a flow rate set by the water flow rate setting unit 30b, along with air at a predetermined pressure, to be supplied to the injector 14. This allows a snow environment with the snow quality selected by the snow quality selection unit 30d to be obtained, and the test specimen can be exposed to such a snow environment. Furthermore, the second embodiment, in which the water temperature is adjusted using the information stored in the related information storage unit 30f, allows for a wider range of snow quality adjustment compared to the first embodiment, in which the air pressure is adjusted.

[0048] Although the description of other configurations, actions, and effects will be omitted, the description of the first embodiment can be applied to the second embodiment.

[0049] (Third embodiment) 9, in the third embodiment, the controller 30 also functions as a pressure control unit 30g and a water temperature control unit 30h to adjust the pressure of air and the temperature of water supplied to the injector 14 using information stored in a related information storage unit 30f. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0050] In the third embodiment, the controller 30 also functions as a pressure control unit 30g, as in the first embodiment, and also functions as a water temperature control unit 30h, as in the second embodiment.

[0051] The pressure control unit 30g is configured to control the pressure adjustment valve 16d so that the pressure of the air supplied to the injector 14 becomes a pressure derived using the temperature in the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and the information stored in the related information storage unit 30f. In other words, the pressure control unit 30g and the pressure adjustment valve 16d function as a pressure adjustment unit that adjusts the pressure of the air supplied to the injector 14 to a pressure obtained using the information stored in the related information storage unit 30f.

[0052] The water temperature control unit 30h is configured to control the heater / cooler 18c so that the temperature of the water supplied to the injector 14 becomes the temperature in the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and a temperature derived using the information stored in the related information storage unit 30f. In other words, the water temperature control unit 30h and the heater / cooler 18c function as a water temperature adjustment unit that adjusts the temperature of the water supplied to the injector 14 to a temperature obtained using the information stored in the related information storage unit 30f.

[0053] The related information storage unit 30f is a functional unit that stores information correlating the temperature in the test chamber 1, the flow rate of water supplied to the injector 14, the temperature of the water supplied to the injector 14, the pressure of the air supplied to the injector 14, and snow quality. The related information storage unit 30f may include, for example, a first map correlating the water flow rate, water temperature, air pressure, and snow quality at a first test temperature (e.g., −5°C), a second map correlating the water flow rate, water temperature, air pressure, and snow quality at a second test temperature (e.g., −10°C), and a third map correlating the water flow rate, water temperature, air pressure, and snow quality at a third test temperature (e.g., −15°C). In other words, by using the stored information, it is possible to derive which snow quality will be obtained at each test temperature for a certain water temperature, a certain water flow rate, and a certain air pressure. Furthermore, when a certain snow quality is desired at each test temperature, it is possible to derive what temperature the water temperature should be set to and what MPa the air pressure should be at a certain water flow rate. While dry snow, wet snow, sleet, and rain are stored as snow qualities, the degree of sleet or moisture content may be stored instead of or in addition to these. The information stored in the related information storage unit 30f may also be information expressed as a relational expression, information in a list format, or the like. Furthermore, the number of test temperatures provided is not limited to three, and information for one, two, or even more test temperatures may be provided.

[0054] Here, as in the first embodiment, an example of conducting the test shown in FIG. 5 will be described. In the third embodiment, as shown in FIG. 10, in each of the first to third tests, the pressure control unit 30g and the water temperature control unit 30h derive the pressure of the air to be supplied to the injector 14 and the temperature of the water to be supplied to the injector 14 using the temperature in the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and the information stored in the related information storage unit 30f (step ST41). Then, the pressure adjustment valve 16d is controlled according to the derived pressure, and the heater / cooler 18c is controlled according to the derived temperature. As a result, during the test, the pressure of the air to be supplied to the injector 14 is adjusted to the derived pressure, and the temperature of the water to be supplied to the injector 14 is adjusted to the derived temperature (step ST42). At this time, the water flow rate is adjusted to the water flow rate set by the water flow rate setting unit 30b.

[0055] Therefore, in this embodiment, the temperature control unit 30e controls the air conditioner 12 so that the temperature in the test chamber 1 becomes the set temperature. The pressure regulating valve 16d adjusts the pressure of the air supplied to the injector 14 to a pressure obtained using the snow quality selected by the snow quality selection unit 30d and the information stored in the related information storage unit 30f, and the heater / cooler 18c adjusts the temperature of the water supplied to the injector 14 to a water temperature obtained using the snow quality selected by the snow quality selection unit 30d and the information stored in the related information storage unit 30f. As a result, air having the adjusted pressure is supplied to the injector 14, and water having the adjusted temperature and the flow rate set by the water flow rate setting unit 30b is supplied to the injector 14. Therefore, a snow environment with the snow quality selected by the snow quality selection unit 30d can be obtained, and the test specimen can be exposed to such a snow environment.

[0056] Although the description of other configurations, actions, and effects will be omitted, the descriptions of the first and second embodiments can be applied to the third embodiment.

[0057] (Fourth embodiment) 11, in the fourth embodiment, the controller 30 also functions as an air temperature control unit 30j to adjust the temperature of the air supplied to the injector 14 using information stored in a related information storage unit 30f. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0058] In the fourth embodiment, unlike the first embodiment, the pressure control unit 30g is omitted. Therefore, although a pressure adjustment valve 16d is provided in the air pipe 16a, this pressure adjustment valve 16d does not have to be connected to the controller 30. The pressure adjustment valve 16d is provided to maintain the pressure of the air supplied to the injector 14 at a predetermined pressure, but if the pressure of the air discharged from the compressor 16b is stable, the pressure adjustment valve 16d can be omitted.

[0059] The related information storage unit 30f is a functional unit that stores information correlating the temperature in the test chamber 1, the flow rate of water supplied to the injector 14, the temperature of air supplied to the injector 14, and snow quality. As shown in FIG. 12, the related information storage unit 30f may include, for example, a first map 36a correlating the water flow rate, air temperature, and snow quality at a first test temperature (e.g., −5°C), a second map 36b correlating the water flow rate, air temperature, and snow quality at a second test temperature (e.g., −10°C), and a third map 36c correlating the water flow rate, air temperature, and snow quality at a third test temperature (e.g., −15°C). In other words, by using the stored information, it is possible to derive which snow quality will be obtained at each test temperature for a certain air temperature and a certain water flow rate. It is also possible to derive what temperature the air temperature should be set to at a certain water flow rate to obtain a certain snow quality at each test temperature. Although dry snow, wet snow, sleet, and rain are stored as snow types, the degree of sleet or moisture content may be stored instead of or in addition to these. The information stored in the related information storage unit 30f may be information expressed as a relational expression, information in a list format, or the like. The number of test temperatures provided is not limited to three, and information for one, two, or more test temperatures may be provided.

[0060] The air temperature control unit 30j derives the temperature of the air to be supplied to the injector 14 using the temperature in the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and the information stored in the related information storage unit 30f. For example, if the information shown in FIG. 12 is stored in the related information storage unit 30f, the air temperature control unit 30j references a map of test temperatures that match or are similar to the temperature in the test chamber 1 set in the temperature setting unit 30a. Then, from the referenced map, the air temperature corresponding to the water flow rate set in the water flow rate setting unit 30b and the snow quality set in the snow quality selection unit 30d is derived. The air temperature control unit 30j is configured to control the heater / cooler 16e so that the temperature of the air supplied to the injector 14 becomes a temperature derived using the temperature in the test chamber 1 set in the temperature setting unit 30a, the water flow rate set in the water flow rate setting unit 30b, the snow quality set in the snow quality selection unit 30d, and the information stored in the related information storage unit 30f. In other words, the air temperature control unit 30j and the heater / cooler 16e function as an air temperature adjustment unit that adjusts the temperature of the air supplied to the injector 14 to a temperature obtained using the information stored in the related information storage unit 30f.

[0061] Here, as in the first embodiment, an example of conducting the test shown in FIG. 5 will be described. In the fourth embodiment, as shown in FIG. 13, in each of the first to third tests, the air temperature control unit 30j derives the temperature of the air to be supplied to the injector 14 using the temperature in the test chamber 1 set by the temperature setting unit 30a, the water flow rate set by the water flow rate setting unit 30b, the snow quality set by the snow quality selection unit 30d, and information stored in the related information storage unit 30f (step ST41), and controls the heater-cooler 16e according to the derived temperature. As a result, during the test, the temperature of the air supplied to the injector 14 is adjusted to the derived temperature (step ST42). Specifically, the temperature of the air supplied to the injector 14 is adjusted to be lower so that the condition changes from sleet in the second test to wet snow in the third test. At this time, the water flow rate is adjusted to the water flow rate set by the water flow rate setting unit 30b. Meanwhile, the pressure of the air supplied to the injector 14 is adjusted to a predetermined pressure by the pressure adjustment valve 16d. In other words, unlike the first embodiment, the fourth embodiment does not include steps of deriving air pressure using information stored in the related information storage unit 30f (steps ST17, ST20, ST23) and steps of adjusting air pressure using information stored in the related information storage unit 30f (ST18, ST21, ST24).

[0062] Therefore, in this embodiment, the temperature control unit 30e controls the air conditioner 12 so that the temperature inside the test chamber 1 becomes the set temperature. The heater / cooler 16e adjusts the temperature of the air supplied to the injector 14 to a temperature obtained using the snow quality selected by the snow quality selection unit 30d and the information stored in the related information storage unit 30f. As a result, water at a predetermined temperature and at a flow rate set by the water flow rate setting unit 30b, and air at a predetermined pressure and adjusted temperature are supplied to the injector 14. Therefore, a snow environment with the snow quality selected by the snow quality selection unit 30d can be obtained, and the test specimen can be exposed to such a snow environment.

[0063] Although the description of other configurations, actions, and effects will be omitted, the descriptions of the first to third embodiments can be applied to the fourth embodiment.

[0064] (Fifth embodiment) 14 shows the fifth embodiment. Note that the same components as those in the first to third embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0065] In this fifth embodiment, a blower 41 is provided to generate an airflow in the test chamber 1, and the controller 30 also functions as an airflow control unit 30i. Note that, although Fig. 14 shows a case in which the controller 30 also functions as a pressure control unit 30g, instead of this, or in addition to this, the controller 30 may also function as a water temperature control unit 30h.

[0066] The air blowing control unit 30i is a functional unit for controlling the blower 41, and can increase or decrease the rotation speed of the blower 41 based on a signal input through the input device 31. For example, if the snow adhering to the test specimen is drier than expected, the tester operates the input device 31 to increase the rotation speed of the blower 41. This allows the fine water droplets sprayed from the sprayer 14 to reach the test specimen before they completely freeze, thereby increasing the moisture content of the snow adhering to the test specimen. Also, for example, if the amount of snow adhering to the test specimen is less than expected, the tester increases the rotation speed of the blower 41 through the input device 31. This slightly increases the moisture content of the snow that reaches the test specimen, making it easier for snow to adhere to the test specimen.

[0067] Therefore, in this embodiment, the speed of the airflow generated in the test chamber 1 can be changed, and the time it takes for the water droplets sprayed from the sprayer 14 to reach the test specimen can be changed. This makes it possible to further adjust the quality of the snow when it reaches the test specimen by changing the air flow speed. This makes it possible to change the amount of snow that accumulates on the test specimen and the quality of the snow that adheres to it.

[0068] Although the description of other configurations, actions, and effects will be omitted, the descriptions of the first to fourth embodiments can be applied to the fifth embodiment. [Explanation of symbols]

[0069] 1: Test room 10: Snow environment test equipment 12:Air conditioner 14: Injector 16: Air supply section 16d: Pressure regulating valve 16e: Heating / cooling device 18:Water supply section 18c: Heating cooler 30a: Temperature setting section 30b:Water flow rate setting part 30d:Snow quality selection department 30e: Temperature control unit 30f: Related information storage unit 30g: Pressure control section 30h: Water temperature control section 30i: Air flow control unit 30j: Air temperature control unit 41: Blower

Claims

1. A snow environment test device for creating a snow environment in a test room, an injector configured by a two-fluid nozzle and configured to inject water and air; a temperature setting unit that sets the temperature inside the test chamber; an air conditioner for cooling the inside of the test room; a temperature control unit that controls the air conditioner so that the temperature in the test room becomes the temperature set by the temperature setting unit; a water flow rate setting unit that sets the flow rate of water supplied to the injector; a water supply unit that supplies water at a flow rate set by the water flow rate setting unit; an air supply unit that supplies air at a predetermined pressure to the injector; a snow quality selection unit that selects dry snow, wet snow, or sleet as the snow quality; an associated information storage unit that stores information that associates the temperature in the test chamber, the flow rate of water supplied to the injector, the temperature of the water supplied to the injector, and snow quality indicating dry snow, wet snow, or sleet; a water temperature adjusting unit that adjusts the temperature of the water supplied to the injector to a temperature obtained using the information stored in the related information storage unit so that the snow quality selected by the snow quality selecting unit is achieved; A snow environment testing device equipped with:

2. a blower that generates an airflow in the test chamber; The snow environment testing device according to claim 1 , further comprising an air blowing control unit that controls the air blower.

3. A snow environment testing method for creating a snow environment in a test room, comprising: Setting the temperature in the test chamber; The snow quality selection department selects dry snow, wet snow, or sleet as the snow quality. a water flow rate setting unit sets a flow rate of water to be supplied to an injector configured by a two-fluid nozzle; Controlling an air conditioner so that the temperature in the test room becomes the set temperature; Using information stored in a related information storage unit that correlates the temperature in the test chamber, the flow rate of water supplied to the injector, the temperature of water supplied to the injector, and snow types representing dry snow, wet snow, or sleet, derives a temperature of water to be supplied to the injector that will result in the selected snow type; A snow environment testing method comprising: supplying water having the derived temperature and at a flow rate set by the water flow rate setting unit to the injector; supplying air having a predetermined pressure to the injector; and injecting water and air from the injector.

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