JP3865472B2 - Vertical wind tunnel for free descent training - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a saddle-type wind tunnel for free descent training in which a trainee floats in the air at a wind speed simulating a descent speed for training of a parachute descent.
[0002]
[Prior art]
In the case of descent with a parachute, the umbrella string may be pulled down from the beginning, but as in skydiving, first the descent position is controlled in a free descent state to reach the vicinity of the descent target point, and then the umbrella is opened. Then descend and land. In order to train such a free descent state, a vertical wind tunnel for free descent training is used.
[0003]
FIG. 5 shows an example of a blowing type free descent simulated vertical wind tunnel used conventionally. In the figure, the wind tunnel includes a circular or polygonal outer cylinder 21 and an inner cylinder 22. The outer cylinder 21 is covered with a bottom 23 and a top plate 24, and a space between the outer cylinder 21 and the inner cylinder 22 forms an air supply passage 25. The air supply passage 25 is horizontal at the bottom 23 and is connected to a blower passage 26 provided on the central axis of the outer cylinder 21 and the inner cylinder 22. A floating chamber 27 that realizes a free fall simulation state is provided in the upper portion of the air passage 26, and an exhaust air passage 28 is connected to the upper portion of the floating chamber 27.
[0004]
An air supply port 29 is provided in the upper part of the air supply passage 25, sucks air, passes through the silencer 30, and flows into the air supply passage 26. An axial flow fan 31 is provided in the air passage 26 to accelerate the sucked air to a speed necessary for floating a floating person in the floating chamber 27. A rectifying honeycomb 32 is provided on the outlet side of the axial flow fan 31, and a fall prevention net 33 is doubled at the outlet of the air passage 26. A suction prevention net 34 is provided at the top of the floating chamber 27 to protect the floating person. In the exhaust passage 28, one vertical passage exiting from the floating chamber 27 is divided into a plurality of, for example, 6 to 8 at the top, the total cross-sectional area is 6 to 8 times that of the vertical passage, and the flow rate is 1/6 to 1 / 8 so that the silencer 30 provided at the outlet works effectively.
[0005]
FIG. 6 is a diagram showing an example of a recirculating free descent simulated vertical type wind tunnel, which is described in “Hydraulic pressure and air pressure” Vol. 22, No. 4, July 1991. This wind tunnel is provided with a blower directly connected to an electric motor at the lower part of the air passage, and circulates air by the rotation to generate a high-speed air flow. The swimming room is located near the middle part of the vertical airway. Since the air passage is crowed, it is difficult for noise to leak outside, so no silencer is provided.
[0006]
[Problems to be solved by the invention]
In the case of the blow-out type wind tunnel shown in FIG. 5, the air supply passage 25 has a double structure surrounding the blower passage 26 and the exhaust passage 28, and there are many bends in the passage, resulting in a large pressure loss and a complicated passage structure. It has become. Moreover, since the position where the silencer 30 is placed is limited, the silencing efficiency is poor. Further, the floating chamber 27 was directly exposed to the noise of the blower 31. In the case of the circulating wind tunnel shown in FIG. 6, the silencer is not provided because there is little noise to the outside. The swimming room is directly exposed to blower noise. In addition, since air is circulated, the temperature becomes high, so a cooling device is required.
[0007]
The present invention has been made in view of such problems of conventional wind tunnel equipment, and (1) simplifies the arrangement of the air passage to reduce loss and reduce manufacturing costs, and (2) to improve the efficiency of the silencer. An object of the present invention is to provide a device that increases the noise reduction efficiency by placing it at a position, and (3) reduces noise in the training room.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a horizontal blower provided with a silencer on the suction side and the discharge side, and an elbow that is provided on the outlet side of the discharge side silencer and guides the airflow to be discharged vertically. A reducer section that squeezes the air flow from the elbow section to a uniform flow, a training room that is provided above the reducer section and floats the trainer by an upward air flow, and an upper section of the training room. And an exhaust unit that discharges exhaust from the training room to the atmosphere.
[0009]
The ventilation path is L-shaped, and since it is simple, there is little pressure loss and it is easy to manufacture, so the manufacturing cost is low. Moreover, since the silencer is provided on the suction side and the discharge side of the blower that is a noise source, it can be effectively silenced. The training room is supplied with the air flow silenced by the silencer on the discharge side, so there is little noise.
[0010]
According to a second aspect of the present invention, the exhaust part is a louver that covers the top and discharges exhaust from the periphery of the side surface.
[0011]
As for the exhaust part which comprises the upper part of a training room, the top part is covered and it can prevent that rain enters a training room by discharging | emitting air from a side periphery.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a vertical wind tunnel for free descent training according to the present embodiment, FIG. 2 is a view taken along the line XX in FIG. 1, and FIG. 3 is a view taken along the line YY in FIG. FIG. An intake-side silencer 2 having an air intake 1 is provided on the intake side of the blower device 3. The blower device 3 includes a horizontal type blower having a moving blade 3a directly connected to the electric motor 3c and a guide blade 3b provided on the downstream side of the moving blade 3a, a blower casing 3d for mounting the blower, and the blower casing 3d. And a soundproofing material 3e provided on the outer peripheral surface.
[0013]
A discharge side silencer 4 is provided on the discharge side of the blower device 3, and an elbow portion 5 that guides an air flow vertically by a guide vane 5 a is provided on the outlet side of the discharge side silencer 4. A reducer section 6 is connected to the outlet side of the elbow section 5 to reduce the flow and make it uniform and increase the flow velocity. For example, the reducer portion 6 has an inlet diameter of 5 mΦ and an outlet diameter of 2.5 mΦ. A cylindrical training room 7 is connected to the upper part of the reducer unit 6. As shown in FIG. 3, the reducer unit 6 and the training room 7 are connected coaxially, and the trainer swims by the air flow blown up from the reducer unit 6. The diameter of the training room 7 is, for example, 6 mΦ. The flow velocity of the air flow to be blown up is, for example, about 70 m / s. In addition, the electric motor 3c of a fan has a capacity | capacitance of 1000-1500kw.
[0014]
A discharge unit 8 is provided in the upper part of the training room 7. The discharge part 8 has a structure in which it is once squeezed into a circular shape and then expanded into an octagonal shape. An octagonal top plate 8a is provided at the top, and air is discharged by a louver 9 provided on the side surface. It is supposed to be.
[0015]
FIG. 4 shows the structure of the silencer provided before and after the blower. This silencer is a splitter-type silencer, and a splitter 12 having a thickness of 100 mm is arranged in the duct 11 at intervals of, for example, 150 mm, and the three flow paths are parallel to each other. The splitter 12 contains a sound absorbing material. By setting the duct 11 to a 7.0 × 4.5 m square and the length of the splitter 12 to around 2.2 m, it is possible to mute 27 dB.
[0016]
【The invention's effect】
As described above, according to the present invention, since the arrangement of the air passage is a simple L-shape, the pressure loss can be reduced, and the manufacturing cost can be reduced. In addition, the silencing efficiency can be improved by providing silencers before and after the noise generating fan. Further, by providing the silencer at a position where there is little interference with the others, the prediction accuracy in the design stage such as capability and function is improved, and an appropriate soundproofing device can be provided. Furthermore, since the silencer is provided between the blower and the training room, the noise in the training room can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration of a wind tunnel for free descent training according to the present invention.
FIG. 2 is a plan view taken along the line XX in FIG.
FIG. 3 represents a training room as seen in the direction of arrows YY in FIG.
FIG. 4 is a diagram illustrating an example of a configuration of a silencer.
FIG. 5 is a diagram showing the configuration of a conventional blowout freefall wind tunnel.
FIG. 6 is a diagram showing a configuration of a conventional free-flow freefall wind tunnel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air intake 2 Intake side silencer 3 Blower apparatus 3a Rotor blade 3b Guide blade 3c Electric motor 3d Blower casing 3e Soundproof material 4 Discharge side silencer 5 Elbow part 5a Guide vane 6 Reducer part 7 Training room 8 Discharge part 9 Louver 11 Duct 12 Splitter

Claims (2)

A horizontal blower with silencers on the suction side and discharge side, an elbow section on the outlet side of the discharge side silencer that guides the airflow to be discharged vertically, and narrowing the airflow from the elbow section A reducer unit that is first-class, a training room that is provided above the reducer unit and that floats the trainer by the upward air flow, and an exhaust gas that is provided above the training room and releases the exhaust from the training room into the atmosphere And a vertical wind tunnel for free descent training. The saddle-type wind tunnel for free descent training according to claim 1, wherein the exhaust part has a louver that is covered with a top part and discharges exhaust from the periphery of the side surface.

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