JPH0755632A - Wind tunnel test equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To achieve low, transonic, and supersonic gas velocities in one wind tunnel test facility without having to replace the blower. [Structure] A low pressure blade 18 having a rotation diameter substantially the same as that of the air passage 5 is sucked into a required position inside a wind tunnel main body 3 which is annularly configured to circulate and circulate the gas 4 through a measurement portion. Is provided with a blower 20 each having a high-pressure blade 19 having a rotation diameter smaller than that of the low-pressure blade 18 on the discharge side, and a gas flow 4a flowing outside the air passage 5 around the high-pressure blade 19. And a cylindrical body 23 for partitioning the gas flow 4b flowing inside the air passage 5
The flow passage 5a formed on the outer side of the tubular body 23 is switched by the flow passage switching device 24 between the inside of the wind tunnel body 3 and the outside of the wind tunnel body 3 so that they communicate with each other. Can be changed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a wind tunnel test facility.

[0002]

2. Description of the Related Art In the aerospace industry, a wind tunnel test is indispensable for confirming the performance of an aircraft, especially transonic velocity (Mach 0.8
~ 1.4) and supersonic wind speed (Mach 1.5 or higher) wind tunnel test equipment is increasing in demand.

FIG. 5 shows an example of the wind tunnel test facility. In the figure, 1 is a plenum chamber surrounding a measuring section 2, and 3 is a plenum chamber.
Indicates a wind tunnel main body connected to the plenum chamber 1 so as to circulate and circulate the gas 4 through the internal air passage 5 with respect to the measurement unit 2, and the wind tunnel main body 3 includes a first diffusion cylinder 6, a first bending cylinder 7, First parallel body 8, second bent body 9, second parallel body 1
0, third parallel body 11, second diffusion body 12, third bending body 1
3, a fourth parallel cylinder 14, and a fourth bending cylinder 15 are connected in a substantially rectangular shape, and a blower 16 for circulating the gas 4 in the second parallel cylinder 10 counterclockwise in the drawing. Is provided.

On the upstream side of the measuring section 2 in the plenum chamber 1, a contraction nozzle 2a is provided so that the gas 4 introduced from the fourth bending cylinder 15 can be contracted and guided to the measuring section 2.
Is provided on the downstream side of the measurement unit 2 in the plenum chamber 1 so that the gas 4 delivered from the measurement unit 2 can be recovered well, and the upstream end of the first diffusion cylinder 6 ( The small diameter side end) is inserted and arranged.

When performing a wind tunnel test, a test piece such as a model of an aircraft is placed in the measuring unit 2 and the blower 16 is driven to circulate and circulate the gas 4 in the air passage 5. The test piece in the measurement unit 2 is exposed to a transonic or supersonic gas flow, and various test data are obtained by sensors (not shown) arranged together with the test piece in the measurement unit 2.

[0006]

However, the blower 16 has a stable operation range corresponding to its capacity, and the air passage 5 is not changed by changing the rotation speed of the blower 16 within this stable operation range.
It is impossible to adjust the flow velocity of the gas 4 circulated in the inside to a transonic speed or a supersonic speed.

Therefore, in order to obtain the transonic and supersonic wind tunnel test data respectively, it is necessary to properly use a transonic or supersonic blower, and a wind tunnel test facility equipped with a transonic blower is required. It is conceivable to separately construct a wind tunnel test facility equipped with a blower dedicated to supersonic speed, or to replace the blower dedicated to transonic speed and the blower dedicated to supersonic speed as appropriate.

However, construction of a wind tunnel test facility requires enormous construction costs of several billion yen or more per unit, so that construction of a plurality of wind tunnel test facilities causes a drastic increase in construction cost. In addition, when replacing a fan for transonic speed and a fan for supersonic speed, since the fan is large and heavy, the replacement work requires a lot of labor and time, and moreover, the fan for the air passage is required. There was a problem that vibration was generated during operation unless the core alignment was performed accurately.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to realize low-speed, transonic, and supersonic gas flow velocities in one wind tunnel test facility without replacing the blower. .

[0010]

SUMMARY OF THE INVENTION According to the present invention, a low pressure having a rotation diameter substantially the same as that of the air passage is provided at a required position of a wind tunnel main body which is configured in an annular shape so as to circulate and circulate gas through a wind passage to a measuring section. A blower provided with a blade on the suction side and a high-pressure blade having a rotation diameter smaller than the low-pressure blade on the discharge side is disposed, and around the high-pressure blade of the blower, a gas flow flowing outside in the air passage. And a tubular body for partitioning the gas flow flowing inside the air duct are provided, and the flow path formed on the outside of the tubular body is switched between the blower downstream side inside the wind tunnel main body and the outside of the wind tunnel main body for communication. The present invention relates to a wind tunnel test facility including a flow path switching device.

[0011]

According to the present invention, therefore, when performing a supersonic wind tunnel test, the blower is rotationally driven while the flow passage formed by the flow passage switching device communicates with the outside of the wind tunnel main body. , A gas flow with a large flow rate and a small pressure ratio is formed by the low pressure blade in the flow path outside the tubular body, and a gas flow with a small flow rate and a high pressure ratio is formed by the high pressure blade in the flow path inside the tubular body. However, since the gas flow having a large flow rate and a small pressure ratio formed on the outside of the tubular body is discharged to the outside of the wind tunnel main body from the opening on the wind tunnel main body side, in the downstream air passage of the blower,
Only a gas flow having a small flow rate and a large pressure ratio formed inside the tubular body is allowed to flow, and a supersonic gas flow can be easily realized by operating the blower in a high-speed rotation range. Can be sent to.

When conducting a transonic wind tunnel test,
When the blower is driven to rotate while the flow passage formed by the flow passage switching device is connected to the downstream side inside the wind tunnel main body, a gas with a large flow rate and a small pressure ratio is formed outside the cylindrical body. Since the flow is made to flow to the downstream side inside the main body of the wind tunnel, the gas flow on the outer side and the gas flow on the inner side in the air duct are mixed as it goes to the downstream side, the flow velocity distribution is averaged to a relatively low flow velocity, and It is possible to easily realize a transonic gas flow without lowering the rotational speed to a rotational speed that deviates from the stable operating range and to supply the gas to the measurement unit.

Further, when performing a low-speed wind tunnel test, as in the case of performing the transonic wind tunnel test described above, the flow passage formed on the outer side of the tubular body by the flow passage switching device is set at the inside of the wind tunnel main body. When the blower is driven with the rotation speed lowered while communicating with the side, the flow rate of the gas flow with a small pressure ratio on the outside in the air passage is larger than the gas flow inside, so that the gas flow on the outside toward the downstream side The flow velocity of the final gas flow formed by mixing with the inner gas flow can be effectively reduced by a relatively small decrease in the rotation speed of the blower, and the rotation speed of the blower can be stably operated. It is possible to easily realize a low-speed gas flow without lowering the rotation speed so as to deviate from the range, and to feed the gas flow to the measurement unit.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show an embodiment of the present invention, in which parts designated by the same reference numerals as those in FIG. 5 represent the same parts.

In the figure, reference numeral 17 denotes a wind tunnel test facility which is constructed in substantially the same manner as the wind tunnel test facility of FIG. 5 described above. In the wind tunnel test facility 17, the air duct 5 is provided in the second parallel body 10 of the wind tunnel body 3. A blower 20 having a low-pressure blade 18 having a rotation diameter of substantially the same diameter on the suction side and a high-pressure blade 19 having a rotation diameter smaller than the low-pressure blade 18 on the discharge side is provided. It is connected via a drive shaft 22 to an electric motor 21 arranged outside the wind tunnel body 3.

In the drawing, the low-pressure blade 18 of the blower 20 has one stage and the high-pressure blade 19 has two stages.
Actually, one or two stages of the low pressure blade 18 and the high pressure blade 1
Set 9 to 7 steps.

Further, the high-pressure blade 19 of the blower 20
A gas flow 4a flowing outside in the air passage 5 and a gas flow 4b flowing inside in the air passage 5 are provided around the
Cylindrical body 23 that is partitioned to have a flow rate ratio of approximately 6: 1
Is provided, and on the downstream side of the tubular body 23, the flow path 5a formed outside the tubular body 23 is switched between the downstream side of the blower 20 inside the wind tunnel body 3 and the outside of the wind tunnel body 3 for communication. A flow path switching device 24 is configured.

The details of the flow path switching device 24 are as shown in FIGS. 2 and 3, and a taper is formed between the rear end of the cylindrical body 23 and the wind tunnel main body 3 around the blower 20 so as to widen toward the downstream side. A skirt portion 25 having a shape is provided, and openings 26 and 27 are provided at a plurality of circumferential positions in the wind tunnel main body 3 around the skirt portion 25 and the skirt portion 25, and hinge connection is made to upstream end portions of the openings 26 and 27. The opening / closing doors 28 and 29 can open and close the openings 26 and 27.

The opening / closing doors 28 for opening / closing the respective openings 26 of the skirt portion 25 can be simultaneously opened / closed via a link mechanism 31 by an opening / closing servomotor 30 arranged on the outer peripheral surface of the tubular body 23. Further, the opening / closing door 29 for opening / closing each opening 27 of the wind tunnel main body 3 is
An opening / closing servomotor 32 arranged on the outer peripheral surface is simultaneously operated to open / close via a link mechanism 33.

Further, the outer periphery of the opening / closing door 29 on the side of the wind tunnel main body 3 is surrounded by a manifold 34, and the discharge port 35 of the manifold 34 is connected via a communication pipe 36.
Is connected to the air passage 5 on the upstream side of the blower 20.

Reference numeral 37 in the figure denotes a current transformer arranged so that the flow of the gas 4 smoothly bends 90 ° at the bending angle of the wind tunnel body 3.

When conducting a supersonic wind tunnel test, the link mechanisms 31 and 33 are retracted by the opening and closing servomotors 30 and 32 to open and close the skirt portion 25 side and the wind tunnel body 3 side open and close doors 28 and 28, respectively. 29 is tilted outward in the radial direction of the air passage 5, all the opening portions 26 of the skirt portion 25 are closed by opening / closing doors 28, and all the opening portions 27 of the wind tunnel main body 3 are opened to be formed outside the tubular body 23. When the blower 20 is rotationally driven by the electric motor 21 in a state (see FIG. 1) in which the flow passage 5a to be communicated is connected to the manifold 34 outside the wind tunnel body 3, the flow passage 5a outside the cylindrical body 23 has a large flow rate and a small pressure ratio. Of the gas flow 4a of the low pressure blade 18 and
A gas flow 4b with a small flow rate and a large pressure ratio is formed by the high-pressure blade 19 in the flow path 5b inside the tubular body 23, but a gas flow with a large flow rate and a small pressure ratio is formed outside the tubular body 23. Four
a is from the opening 27 on the wind tunnel body 3 side to the manifold 34.
Is discharged to the air passage 5 upstream of the blower 20 of the wind tunnel main body 3 through the communication pipe 36, and thus is formed inside the tubular body 23 in the downstream air passage 5 of the blower 20. Only the gas flow 4a having a small flow rate and a large pressure ratio is allowed to flow, and by operating the blower 20 in a high-speed rotation range, a supersonic gas flow can be easily realized, and the measurement unit 2 (see FIG. 5) can be obtained. It will be possible to send.

When conducting a transonic wind tunnel test,
The link mechanism 3 is formed by the opening / closing servomotors 30 and 32.
1, 33 are pushed out to the skirt portion 25 side and the wind tunnel body 3
The opening / closing doors 28, 29 on the side are tilted so as to be parallel to the axis of the blower 20, and all the opening portions 26 of the skirt portion 25 are
Is opened by the opening / closing door 28 and all the openings 27 of the wind tunnel body 3 are closed, and the flow path 5a formed outside the tubular body 23 is communicated with the downstream side inside the wind tunnel body 3 (see FIG. 4). When the blower 20 is rotationally driven by the electric motor 21, the gas flow 4a having a large flow rate and a small pressure ratio formed on the outside of the tubular body 23 flows from the opening 26 on the skirt portion 25 side to the downstream side inside the wind tunnel body 3. Therefore, the flow velocity distribution immediately after the blower 20 has a low flow velocity outside the air passage 5 and a high flow velocity inside the air passage 5 as shown by A in FIG. Inside gas flow 4
Since it is about 6 times larger than b, the gas flow 4a on the outer side and the gas flow 4b on the inner side are mixed together toward the downstream side, and the flow velocity distribution is averaged to a relatively low flow velocity as shown by B in FIG.

For example, when the blower 20 is rotating at a high speed, the low pressure blade 18 is used to move the Mach 0.
A transonic gas stream 4a of 9 is formed and the high pressure blade 19
Assuming that a supersonic gas flow 4b of Mach 1.8 is formed inside the tubular body 23 by the following, the gas flow velocity mixed at a flow rate ratio of 6: 1 on the downstream side of the blower 20 is:

[Equation 1] (1 × 1.8 + 6 × 0.9) / (6 + 1) ≈1.03 gives a transonic speed of about Mach 1.03, and the rotational speed of the blower 20 deviates from the stable operating range. It is possible to easily realize a transonic gas flow without lowering it to the measuring unit 2
(See FIG. 5).

Further, in the case of performing the low speed wind tunnel test, the flow path 5a formed on the outer side of the cylindrical body 23 is provided downstream of the inside of the wind tunnel main body 3 in the same manner as in the case of performing the transonic wind tunnel test described above. The blower 20 is rotatably driven by the electric motor 21 in a connected state (see FIG. 4), and a low-speed gas flow of about Mach 0.3 to 0.7 is realized by lowering the rotation speed.

That is, when the rotational speed of the blower 20 is lowered in a state where the flow path 5a formed on the outside of the tubular body 23 is communicated with the inside of the wind tunnel main body 3, the gas flow 4a having a small outside pressure ratio is obtained.
Is about 6 times larger than the gas flow 4b having a large pressure ratio inside, the flow velocity of the final gas flow formed by the mixture of the gas flow 4a on the outer side and the gas flow 4b on the inner side toward the downstream side. Can effectively decelerate by a relatively small reduction in the rotation speed of the blower 20, and the low-speed gas flow can be achieved without reducing the rotation speed of the blower 20 to a rotation speed that deviates from the stable operation range. It can be easily realized and can be delivered to the measuring unit 2 (see FIG. 5).

Therefore, according to the above-mentioned embodiment, it is possible to realize low, transonic, and supersonic gas flow velocities without having to replace the blower 20 with one wind tunnel test facility 17.
The investment effect on the wind tunnel test facility 17 and the facility operating rate can be significantly improved as compared with the conventional one.

The wind tunnel test equipment of the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0030]

According to the above-described wind tunnel test equipment of the present invention, low-speed, transonic, and supersonic gas flow velocities can be realized in one wind tunnel test equipment without performing replacement work of the blower. It is possible to achieve an excellent effect that the investment effect on the test facility and the facility operation rate can be significantly improved as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a schematic diagram when a supersonic wind tunnel test is performed in an embodiment of the present invention.

FIG. 2 is a perspective view of an opening of the skirt portion and an opening / closing door of FIG.

FIG. 3 is a perspective view of an opening and an opening / closing door of the wind tunnel main body of FIG.

FIG. 4 is a schematic diagram when performing a transonic or low-speed wind tunnel test in one embodiment of the present invention.

FIG. 5 is a plan view showing an example of a conventional wind tunnel test facility.

[Explanation of symbols]

 2 Measurement part 3 Wind tunnel main body 4 Gas 4a Gas flow 4b Gas flow 5 Air passage 5a Flow path 17 Wind tunnel test equipment 18 Low pressure blade 19 High pressure blade 20 Blower 23 Cylindrical body 24 Flow path switching device

Claims (1)

[Claims] 1. A low-pressure blade having a rotation diameter substantially the same as that of the air passage is provided on a suction side at a required position of a wind tunnel main body which is annularly configured to circulate and circulate gas through the air passage with respect to a measurement unit. A blower provided with a high-pressure blade having a rotation diameter smaller than that of the low-pressure blade on the discharge side is disposed, and around the high-pressure blade of the blower, a gas flow that flows outside in the air passage and an inside flow in the air passage. A tubular body for partitioning the gas flow is provided, and a passage switching device is provided for switching the passage formed on the outside of the tubular body to the downstream side of the blower inside the wind tunnel body and the outside of the wind tunnel body for communication. Wind tunnel test facility.