JP4274680B2 - Impact wind tunnel device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an impact-type wind tunnel device used for wind tunnel experiments, for example, various fluid machines or various flying objects such as airplanes and space rockets as an object to be measured.
[0002]
[Prior art]
In a wind tunnel device used for a wind tunnel experiment, for example, an upstream side passage through which a gas flowing into a measurement chamber in which an object to be measured is arranged passes and a downstream side passage through which a gas flowing out of the measurement chamber passes are annular. There is what is called a so-called continuous wind tunnel device connected so as to form a passage. In this continuous wind tunnel device, a large blower is installed at a predetermined position in the annular passage. By continuously operating the large blower so that the gas in the annular passage flows into the measurement chamber from a predetermined direction, the gas in the annular passage continuously circulates in a certain direction in the annular passage. it can. The speed at which the gas circulates and circulates in the annular passage can be set to a predetermined size by changing the blowing force of the large blower. Further, the flow velocity of the gas blown to the object to be measured can be set to a predetermined size by changing the size of the diameter of the throttle portion (throat portion) of the nozzle installed on the upstream side of the measurement chamber. .
[0003]
In addition, as a wind tunnel device having a configuration different from the continuous type described above, for example, the gas stored on the upstream side of the measurement chamber is installed on the downstream side of the measurement chamber and is evacuated in advance. There is what is called a so-called impact wind tunnel device that uses a vacuum chamber to suck abruptly in an extremely short time. In this impact type wind tunnel device, the object to be measured is arranged in the measurement chamber from the upstream side of the measurement chamber as the high pressure side to the downstream side of the measurement chamber as the low pressure side, that is, toward the vacuum chamber side. The same effect can be obtained as when a high-speed air stream is sprayed on the surface. The flow rate of the gas blown to the object to be measured includes the pressure of the gas stored upstream of the measurement chamber, the size of the diameter of the throttle portion of the nozzle installed upstream of the object to be measured, and the vacuum chamber The internal pressure (degree of vacuum) and the like can be set to a predetermined magnitude by changing them independently of each other. The duration of the airflow that can be used in the measurement experiment generated by the impact type wind tunnel device is generally about 1 second.
[0004]
[Problems to be solved by the invention]
In the continuous wind tunnel device described above, the gas once passed through the measurement chamber can be repeatedly used, but in order to continuously circulate the gas, it is necessary to continuously operate the large blower described above, Running cost is high. In addition, a large blower used for a wind tunnel device that can reproduce a high-speed gas flow including a speed close to the speed of sound to a speed that greatly exceeds the speed of sound is expensive. At the same time, a wind tunnel device equipped with such a large blower may have a huge construction cost or a maintenance cost for repair or maintenance. Furthermore, it is difficult to secure a space for installing a large blower.
[0005]
Further, in this continuous wind tunnel device, the flow velocity of the gas flowing into the measurement chamber is set in a so-called transonic region where the Mach number (flow velocity / sonic velocity) is about 0.85 to 1.20, for example. In this case, when the air flow accelerated to such a flow velocity collides with the object to be measured in the measurement chamber, a shock wave that repeatedly reflects between the object to be measured and the wall portion of the measurement chamber is generated. This shock wave may give a measurement error that cannot be ignored in the measurement result of the physical quantity in the wind tunnel experiment. Further, in the measurement chamber, for example, when the inclination in the longitudinal direction of the measured object with respect to the direction of the air flow in which the flow velocity is set in the transonic region increases, the projected area on the plane orthogonal to the direction of the air flow increases. Then, the flow path area of the gas flowing around the object to be measured is smaller than the cross-sectional area of the internal passage in the throttle portion of the nozzle that is the minimum flow area of the air flow in the continuous wind tunnel device. That is, the flow of gas flowing out of the measurement chamber from the measurement chamber is hindered. As a result, in order to obtain a measurement result that satisfies the accuracy desired by the experimenter, the gas flow velocity around the object to be measured that requires the highest accuracy speed setting may not reach the predetermined transonic speed set in advance. There is.
[0006]
In order to remove such shock waves that may interfere with the measurement result, or to allow gas to flow smoothly around the object to be measured, for example, so-called plenum suction is performed. The method is used. In order to perform this plenum suction, the wall portion of the measurement chamber is formed of a highly breathable porous material. An empty chamber called a plenum chamber is provided so as to cover the measurement chamber from the outside with the porous wall portion therebetween. An exhaust pipe communicating with the plenum chamber is attached to the outer wall of the plenum chamber. In such a configuration, the gas flowing from the measurement chamber into the plenum chamber through the porous wall is sucked and exhausted outside the plenum chamber through the exhaust pipe. Predetermined exhaust means is provided on the ventilation path of the exhaust pipe, and by operating the exhaust means, so-called plenum suction is performed in which the gas in the plenum chamber is sucked and exhausted to the outside of the plenum chamber. By performing this plenum suction, shock waves, turbulent flow, and the like generated in the measurement chamber are sucked into the plenum chamber through the porous wall portion together with the gas as the medium. Further, the gas in the plenum chamber is exhausted to the outside of the plenum chamber through an exhaust pipe. Accordingly, it is possible to easily escape the gas from the measurement chamber to the plenum chamber and easily flow the airflow in the measurement chamber. In particular, the airflow state desired by the experimenter can be substantially accurately reproduced around the object to be measured, and a highly accurate wind tunnel experiment can be performed. That is, the experimenter of this continuous wind tunnel device can obtain a highly accurate measurement result.
[0007]
However, in this continuous wind tunnel device, in addition to the large blower, in addition to the large blower, in addition to the large blower, a dedicated plenum suction dedicated is used in order to perform the plenum suction without reducing the generation and sustainability of the circulating airflow by the large blower. It is common to install an auxiliary blower. In order to keep the transonic airflow flowing smoothly in the measurement chamber, it is necessary to use the auxiliary blower having power performance (air blowing capacity) according to the large fan. For this reason, while the running cost of a continuous wind tunnel apparatus becomes still higher, the installation cost accompanying the installation of an auxiliary air blower, its maintenance cost, etc. rise. Moreover, since an installation space for attaching an auxiliary blower is further required for this continuous wind tunnel device, it is more difficult to secure the installation space.
[0008]
In the above-described impact wind tunnel device, the running cost of the wind tunnel device can be suppressed as compared with the continuous wind tunnel device, and it can be constructed in a space-saving manner. However, the velocity of the airflow that can be used for a measurement experiment that can be generated by this impact type wind tunnel device is a supersonic region having a Mach number of 4 or more, or a supersonic velocity having a Mach number of less than 1.4 to 4. It is an area. There is no impact wind tunnel device that can generate an airflow that can be used for a measurement experiment in which the Mach number is set to a flow velocity in the transonic region. Also, in contrast to a continuous wind tunnel device in which the airflow duration is theoretically unlimited, the impact type wind tunnel device is configured such that the flow rate of the gas flowing in the measurement chamber is the amount of gas stored upstream of the measurement chamber, and the vacuum Since it depends on the internal volume of the tank, the air flow duration is also limited to an extremely short time.
[0009]
Therefore, the first problem to be solved by the present invention is to obtain a low-cost and compact impact type wind tunnel device that can set the flow velocity in an arbitrary velocity region.
[0010]
The second problem to be solved by the present invention is to obtain an impact wind tunnel device capable of adjusting the airflow duration.
[0011]
[Means for Solving the Problems]
In order to solve the first problem, an impact wind tunnel device according to the present invention includes a measurement chamber in which an object to be measured is disposed, a plenum chamber provided outside the measurement chamber and in communication with the measurement chamber. A fluid accelerating means for accelerating the velocity of the gas and flowing to the measurement chamber; and a plenum suction means for sucking the gas flowing into the plenum chamber to the outside of the plenum chamber. The plenum suction means is a vacuum tank, and the fluid accelerating means and the plenum suction means are communicated with each other, and these two means are both evacuated by a single vacuum pump. It is characterized by that.
[0014]
In carrying out the present invention, in order to solve the second problem, a traverse chamber is provided on the downstream side of the plenum chamber so as to communicate with the plenum chamber, and the traverse chamber and the plenum chamber are provided between them. The damper may be provided to adjust the flow rate of the gas flowing from the plenum chamber to the traverse chamber.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an impact type wind tunnel device 1 according to a first embodiment of the present invention will be described with reference to FIGS.
[0018]
The impact type wind tunnel device 1 of the present embodiment includes a measurement chamber 3 in which an object to be measured 2 is disposed, a plenum chamber 4 provided in communication with the outside of the measurement chamber 3, and a measurement by accelerating the gas velocity. A fluid accelerating means 5 for flowing into the chamber 3 and a plenum suction means 6 for sucking the gas flowing into the plenum chamber 4 to the outside of the plenum chamber 4 are provided.
[0019]
In the impact type wind tunnel device 1, as shown in FIG. 1, dry air as a gas used in a wind tunnel experiment is stored from the upstream side toward the downstream side along the flow of gas flowing through the inside. A dry air chamber 7 is installed in communication with the downstream side of the dry air chamber 7 and passes through the rubber nozzle 8 for adjusting the flow rate of the dry air flowing from the dry air chamber 7 into the measurement chamber 3. The measurement chamber 3 to which the air flow of the dry air set at a predetermined speed is blown, the position of the flying object model 2 as the object to be measured arranged in the measurement chamber 3, and the arrangement state such as the posture thereof. Rapidly opening and closing the diaphragm that connects or shuts off the traverse chamber 9 to be adjusted, the chambers upstream from the traverse chamber 9 and the fluid acceleration means 5 for sucking the air stored in the chamber. 10. A second measuring chamber 11 which is provided in communication with the downstream side of the rapid diaphragm opening / closing valve 10 and is formed in a spherical shape, and a suction which communicates the second measuring chamber 11 with the fluid acceleration means 5. The cylinder 12 and the accelerating vacuum tank 5 as fluid accelerating means are installed in this order. The acceleration vacuum tank 5 is evacuated by a single vacuum pump 13 together with the plenum suction means 6 described later.
[0020]
As shown in FIG. 1, the dry air chamber 7 communicates with the traverse chamber 9 via a gas drying device 14. The gas drying device 14 is installed in the traverse chamber 9 on the first exhaust pipe 15 provided in communication with the interior of the traverse chamber 9 and the air passage of the first exhaust pipe 15, and the air flowing into the traverse chamber 9 is removed. A blower 16 that circulates and circulates toward the dry air chamber 7, a second exhaust pipe 18 that guides the air circulated and circulated by the blower 16 to the dehumidifying device 17, and the second exhaust pipe 18 that is sent from the traverse chamber 9. A dehumidifying device 17 that dries the air, a dry air supply pipe 19 that guides the dry air dried by the dehumidifying device 17 into the dry air chamber 7, and the like.
[0021]
According to the gas drying device 14 having such a configuration, for example, by operating the blower 16 and the dehumidifying device 17 before performing a wind tunnel experiment described later, the air used for the wind tunnel experiment is measured. Can be dried to such an extent that no significant error occurs. Specifically, the air accelerated at a high speed rapidly flows from the inside of the dry air chamber 7 into the wide measurement chamber 3 through the narrow rubber nozzle 8. Then, the air that has flowed into the measurement chamber 3 vigorously undergoes adiabatic expansion, and moisture contained in the air is condensed. This condensed moisture generates a shock wave (relatively weak), which may affect the air flow field in the measurement chamber 3. Alternatively, the dew condensation generated in the measurement chamber 3 may interfere with normal operation of various sensors (not shown) attached in the measurement chamber 3. The air that has passed through the gas drying device 14 is dried to such an extent that it does not cause the fear described above. The blower 16 used in the gas drying device 14 does not need to accelerate the air at high speed for wind tunnel experiments, so a small one with a low output is sufficient. Therefore, by attaching the blower 16 to the impact type wind tunnel device 1, there is almost no fear that the running cost and the construction cost will increase or it will be difficult to secure the installation space.
[0022]
The dry air stored in the dry air chamber 7 passes through the rubber nozzle 8 and flows into the measurement chamber 3. The rubber nozzle 8 is a dryer that flows into the measurement chamber 3 from the dry air chamber 7 by changing the diameter of the throttle portion (throat portion) 8b provided in the central portion in the axial direction of the internal passage 8a. It can be set by adjusting the air flow rate to a predetermined speed.
[0023]
In the measurement chamber 3, as shown in FIGS. 1 and 2, the flying object model 2 supported by a traverse device 20 installed in a traverse chamber 9 described later is disposed. The wall 3a of the measurement chamber 3 is made of a material that easily absorbs air waves. At the same time, the wall 3a of the measurement chamber 3 is provided with a large number of vent holes 21 that are formed in such a size that air can easily pass from the inside of the measurement chamber 3 to the outside through the wall 3a. It is made of a porous material. Thereby, for example, a shock wave generated when a flow of dry air whose flow velocity is set to a predetermined speed in the transonic region collides with the flying object model 2 in the measurement chamber 3 is generated for each dry air that is the medium. It is possible to escape from the measurement chamber 3 to the plenum chamber 4 described later. Further, the air flowing into the plenum chamber 4 can be exhausted from the inside of the impact wind tunnel device 1 to the outside by performing plenum suction described later.
[0024]
Further, by operating the traverse device 20, the flow area of the dry air flowing around the flying object model 2 in the measurement chamber 3 is, for example, relative to the cross-sectional area of the internal passage 8 a in the throttle portion 8 b of the rubber nozzle 8. If the attitude of the flying object model 2 is set so as to have the same size, the airflow flowing from the measurement chamber 3 into the traverse room 9 is blocked in the vicinity of the flying object model 2. However, since the wall portion 3 a of the measurement chamber 3 is provided with a large number of the above-described vent holes 21, air that stagnates in the vicinity of the flying object model 2 passes through the vent holes 21 in the measurement chamber 3. Can escape into the plenum room 4. The air flowing into the plenum chamber 3 can be exhausted from the inside of the impact wind tunnel device 1 to the outside by performing plenum suction. Thereby, in order to obtain a measurement result that satisfies the accuracy desired by the experimenter, the flow velocity of the air around the flying object model 2 for which the most accurate speed setting is required is set, for example, in a predetermined transonic region. The speed can be maintained almost reliably.
[0025]
In the measurement chamber 3, there are a plurality of sensors for measuring various physical quantities around the flying object model 2 during the wind tunnel experiment, or a plurality of measurement chamber monitoring monitors for monitoring the internal state of the measurement chamber 3. It is attached.
[0026]
A traverse device 20 is installed in the traverse chamber 9. The flying object model 2 is attached to the tip of the traverse device 9. The positioning of the flying object model 2 in the measurement chamber 3 or the posture maintenance thereof can be set substantially accurately in the arrangement state desired by the experimenter by operating the traverse device 20. Further, the traverse chamber 9 is formed in such a size that the diameter of the communicating portion with the measurement chamber 3 and the internal volume thereof can accommodate the airflow flowing in from the measurement chamber 3 with almost no resistance. At the same time, the internal volume of the traverse chamber 9 is formed in such a size that the above-described operation of mounting the flying object model 2 can be easily performed manually inside the traverse chamber 9. As shown in FIG. 3, a traverse door 38 that allows the inside and outside of the traverse chamber 9 to communicate with each other or can be shut off while maintaining airtightness is attached to the lower portion of the traverse chamber 9 so as to be freely opened and closed. For the installation work of the flying object model 2 to the traverse device 20 and the like, while the operation of the impact type wind tunnel device 1 is stopped, the traverse room 9 is opened from the outside of the traverse chamber 9 to the inside thereof. It can be done by inserting it. After the installation work of the flying object model 2 and the like is completed, the traverse door 38 is closed, whereby the airtightness in the traverse chamber 9 and thus the inside of the impact wind tunnel device 1 can be maintained, and the preparation for the wind tunnel experiment is completed.
[0027]
As shown in FIG. 4, the non-diaphragm rapid opening / closing valve 10 passes through an opening / closing valve case 22 connected to the traverse chamber 9 while maintaining airtightness, and a downstream end portion of the opening / closing valve case 22. And the valve opening / closing body 23 attached so as to be positioned on the same axis as the suction hole 9a provided at the downstream end of the traverse chamber 9, and at the upstream end of the valve opening / closing body 23, From the valve body 24 slidably attached along the axial direction and the sub-piston 25 attached slidably along the axial direction inside the downstream end of the valve opening / closing body 23. It is configured. The diaphragm rapid opening / closing valve 10 communicates with a valve opening / closing compressor 26 for supplying compressed air to the diaphragm rapid opening / closing valve 10 in order to close the diaphragm rapid opening / closing valve 10 via an air supply valve 27 provided outside the diaphragm. Has been. At the same time, the rapid diaphragm opening / closing valve 10 is communicated with the outside of the impact wind tunnel device 1 through an air discharge valve 28 provided outside the diaphragm.
[0028]
Inside the valve opening / closing body 23, as shown in FIG. 4, there is a valve opening / closing air passage 29 through which compressed air supplied from the valve opening / closing compressor 26 is passed from the axial intermediate portion to the upstream end portion. Is provided. At the same time, in the valve opening / closing body 23, an air vent hole 30 for extracting the compressed air supplied into the valve opening / closing air passage 29 to the outside of the valve opening / closing body 23 is provided in the middle portion in the axial direction. It is provided in communication with the air passage 29 for use. A sub-piston cylinder 31 in which a sub-piston 25 is slidably housed along the axial direction of the valve opening / closing body 23 is provided at the downstream end of the valve opening / closing body 23.
[0029]
As shown in FIG. 4, the valve body 24 attached to the valve opening / closing body 23 is integrated with a valve body lid portion 24a for sealing the suction hole 9a of the traverse chamber 9, and on the downstream side of the valve body lid portion 24a. It is comprised from the provided valve body engaging part 24b. The valve body cover part 24a is formed in the flat plate shape of the magnitude | size which can seal the suction hole 9a. The valve body engaging portion 24b can be slidably engaged with the outer periphery of the valve opening / closing body 23 along the axial direction of the valve opening / closing body 23, and the outer periphery of the valve body engaging portion 24b and the valve opening / closing body 23. It is formed in the substantially cylindrical shape of the magnitude | size which can maintain airtightness between. The valve body engaging portion 24 b forms a main cylinder 32 together with the valve opening / closing body 23.
[0030]
As shown in FIG. 4, the sub-piston 25 is slidably attached along the axial direction of the valve opening / closing body 23 in a sub-piston cylinder 31 provided in the downstream end of the valve opening / closing body 23. Yes. The sub-piston cylinder 31 is supplied with compressed air from the valve opening / closing compressor 26 through a sub-piston cylinder opening 31a provided at the downstream end thereof. The sub-piston cylinder 31 communicates with the outside of the impact wind tunnel device 1 via an air discharge valve 28 for discharging compressed air from the inside.
[0031]
By operating the diaphragm rapid opening / closing valve 10 having the above-described configuration to open / close the suction hole 9a of the traverse chamber 9, the downstream side of the diaphragm rapid opening / closing valve 10 is evacuated or the dry air chamber is opened. The dry air can be accelerated and flowed vigorously from 7 to the accelerating vacuum tank 5.
[0032]
First, the case of evacuating the downstream side from the rapid diaphragm opening / closing valve 10 will be described in detail. While the air supply valve 27 is opened and the air discharge valve 28 is closed, the valve opening / closing compressor 26 is operated. Compressed air generated by the valve opening / closing compressor 26 is supplied into the valve opening / closing air passage 29 through a compressed air inflow opening 29a provided on the side of the valve opening / closing body 23 in the axially intermediate portion. . The compressed air supplied into the valve opening / closing vent passage 29 is filled into the main cylinder 32 through the compressed air outflow opening 29 b provided at the upstream end of the valve opening / closing body 23. Thereby, the valve body 24 is biased toward the traverse chamber 9 side. At this time, the compressed air generated by the valve opening / closing compressor 26 is also filled into the sub piston cylinder 31 through the sub piston cylinder opening 31a. As shown by the solid line in FIG. 4, the sub-piston 25 is urged toward the upstream side by the compressed air so as to block the air vent hole 30 provided in the intermediate portion in the axial direction of the valve opening / closing body 23. Next, the sub piston cylinder 31 is moved. As a result, the compressed air filled in the valve opening / closing vent passage 29 and the main cylinder 32 has no outlet to the outside thereof, and the valve body 24 is pressed toward the traverse chamber 9 by the internal pressure. . The valve body 24 can seal and close the suction hole 9a by the valve body lid portion 24a that the valve body 24 has so as to maintain airtightness in the traverse chamber 9. As a result, the downstream side from the rapid diaphragm opening / closing valve 10 can be evacuated until a substantially complete vacuum is achieved.
[0033]
The pressure of the compressed air supplied from the valve opening / closing compressor 26 into the valve opening / closing air passage 29, the main cylinder 32, and the sub-piston cylinder 31 is almost completely evacuated downstream from the diaphragm rapid opening / closing valve 10. Even in this state, the valve body lid portion 24a is set to a height at which the suction hole 9a can be sealed and closed. At the same time, the internal volume of each of the valve opening / closing passage 29, the main cylinder 32, and the sub-piston cylinder 31, the internal shape, and the like are substantially completely evacuated downstream from the diaphragm rapid opening / closing valve 10. Even in the state, the size and shape of the compressed air supplied to them from the valve opening / closing compressor 26 can be maintained at such a height that the valve body cover 24a can seal and close the suction hole 9a. Is formed. Thereby, even in a state where the downstream side from the diaphragm rapid opening / closing valve 10 is almost completely evacuated, the pressure difference between the upstream side from the traverse chamber 9 and the downstream side from the diaphragm rapid opening / closing valve 10 causes a valve There is almost no possibility of air leakage due to the body lid portion 24a being separated from the suction hole 9a. Further, when performing the evacuation described above, the valve opening / closing compressor 26 is continuously operated, and the compressed air set to the above-described pressure is always directed toward the inside of the diaphragm rapid opening / closing valve 10. It is set to be supplied. As a result, it is possible to prevent a situation in which the valve body 24 suddenly leaves the suction hole 9a in the on-off valve case 22 that is almost completely evacuated.
[0034]
Next, a detailed description will be given of the case where the dry air is accelerated and flows from the dry air chamber 7 toward the accelerating vacuum tank 5. In the state where the downstream side is substantially completely evacuated from the diaphragm rapid opening / closing valve 10 by the above-described operation, the operation of the valve opening / closing compressor 26 is stopped and the air discharge valve 28 is opened. As a result, the compressed air is exhausted from the inside of the sub-piston cylinder 31 to the outside, and the sub-piston 25 is released from the pressure that urges it to the upstream side. At the same time, the sub-piston 25 is disposed downstream of the diaphragm rapid opening / closing valve 10 in a substantially complete vacuum state, and inside each of the valve opening / closing vent passage 29 and the main cylinder 32 filled with compressed air. The pressure difference is biased toward the downstream side. As a result, the sub-piston 25 moves in the sub-piston cylinder 31 toward the downstream side, as indicated by the phantom line in FIG. Then, the air vent hole 30 sealed by the sub-piston 25 is opened, and the inside and outside of the valve opening / closing vent passage 29 and the main cylinder 32 are communicated with each other. Is exhausted to the outside of the valve opening / closing body 23 through the air vent hole 30. As a result, the valve body 24 is released from the pressure that urges the valve body lid portion 24a so as to seal and close the suction hole 9a. Due to the pressure difference between the upstream side from the traverse chamber 9 and the downstream side from the non-diaphragm rapid opening / closing valve 10 that is in a substantially complete vacuum state, the valve body cover 24a is rapidly removed from the suction hole 9a. Pulling back toward the downstream side in a very short time so as to leave, the suction hole 9a is opened.
[0035]
As a result, the dry air upstream from the traverse chamber 9 passes through the suction hole 9a and the opening / closing valve vent hole (not shown) provided in the non-diaphragm rapid opening / closing valve 10 at a high speed to enter the acceleration vacuum tank 5. Inhaled. Thereby, the dry air can be accelerated and flowed vigorously from the dry air chamber 7 toward the accelerating vacuum tank 5. That is, in the impact type wind tunnel device 1, an air flow of dry air flowing at high speed is generated from the dry air chamber 7 installed on the most upstream side toward the vacuum tank 5 for acceleration installed on the most downstream side. Can be made.
[0036]
The sub-piston 25 is regulated so as not to fall out of the sub-piston cylinder 31 by an unillustrated stopper.
[0037]
As shown in FIG. 1, the second measurement is performed separately from the measurement chamber 3 and performs predetermined measurement on the downstream side of the rapid diaphragm opening / closing valve 10 in order from the upstream side to the downstream side. A chamber 11 and a suction cylinder 12 for connecting the second measurement chamber 11 and the accelerating vacuum tank 5 installed on the most downstream side in communication are provided. The dry air upstream from the traverse chamber 9 is sucked into the accelerating vacuum tank 5 through the inside of the second measurement chamber 11 and the suction cylinder 12 by opening the diaphragm rapid opening / closing valve 10.
[0038]
The accelerating vacuum tank 5 is connected to a vacuum pump 13 that can evacuate the interior to a substantially complete vacuum state. The accelerating vacuum tank 5 is a wind tunnel that uses the shock wind tunnel device 1 to generate an air flow generated by accelerating the internal volume so as to have a predetermined flow velocity set in the shock wind tunnel device 1 in advance. It is preferable to have a size that can last for a time that can sufficiently obtain an effective measurement result of an experiment. Specifically, the internal volume of the accelerating vacuum tank 5 is within the range from the velocity region close to the sonic velocity to the hypersonic velocity (Mach number 4 or more) region in the impact type wind tunnel device 1, for example, transition. It is preferable that the airflow generated by being accelerated so as to have a predetermined speed in the sound velocity region has a size capable of sustaining for 1 second or longer.
[0039]
The vacuum pump 13 also has a power performance capable of evacuating the accelerating vacuum tank 5 and the plenum suction means 6 formed in such a size to a substantially complete vacuum state in a short time. Is preferred.
[0040]
As shown in FIGS. 1 to 3, the impact wind tunnel device 1 of the present embodiment is provided with a plenum chamber 4 on the outside of the measurement chamber 3 in communication with the air, and air that has flowed into the plenum chamber 4. Is provided with a plenum suction means 6 for sucking the air to the outside of the plenum chamber 4.
[0041]
The plenum chamber 4 is provided across a measurement chamber wall 3a provided with a large number of vent holes 21 so as to cover the measurement chamber 3 from the outside. The air in the measurement chamber 3 can flow into the plenum chamber 4 through the large number of air holes 21. The plenum chamber 4 is sized so that the internal volume of the plenum chamber 4 can be set almost accurately so that the state of the airflow in the measurement chamber 3 becomes a predetermined state desired by the experimenter by performing plenum suction described later. It is preferable to be formed.
[0042]
The plenum chamber wall 4a of the plenum chamber 4 has a pair of first plenum exhaust pipe 33a and second plenum exhaust pipe 33b for exhausting the air flowing into the plenum chamber 4 to the outside of the plenum chamber 4. It is attached in communication with the inside of the plenum chamber 4. These two first plenum exhaust pipes 33a and second plenum exhaust pipes 33b are combined as one ventilation path by a plenum collecting pipe 34.
[0043]
The plenum collecting pipe 34 includes a plenum diaphragm rapid opening / closing valve 35 that communicates or blocks the ventilation portion from the plenum chamber 4 to the plenum collecting pipe 34 and the plenum suction means 6, and the plenum diaphragm. It communicates with the plenum suction means 6 through a third plenum exhaust pipe 33c attached to the downstream side of the quick opening / closing valve 35.
[0044]
In the present embodiment, the plenum diaphragm rapid opening / closing valve 35 may have the same configuration as that of the diaphragm rapid switching valve 10 described above. By configuring the plenum non-diaphragm rapid opening / closing valve 35 as described above, the same effect as the non-diaphragm rapid opening / closing valve 10 can be obtained. In addition, since the valve opening / closing compressor 26 connected to the rapid diaphragm opening / closing valve 10 can be shared, the running cost or the maintenance cost for operating the plenum diaphragm rapid opening / closing valve 35 increases. Can be suppressed. At the same time, the impact wind tunnel device 1 can be made compact and installed in a space-saving manner.
[0045]
In this embodiment, a vacuum tank is used for the plenum suction means 6 connected to the plenum non-diaphragm rapid opening / closing valve 35 through the third plenum exhaust pipe 33c. The plenum vacuum tank 6 serving as the plenum suction means is connected to the acceleration vacuum tank 5 and connected to the acceleration vacuum tank 5 described above. In addition, it is assumed that a vacuum is drawn until a substantially complete vacuum state is obtained. Thereby, it is possible to suppress an increase in running costs for performing plenum suction, or costs such as maintenance costs. At the same time, the impact wind tunnel device 1 can be made compact and installed in a space-saving manner.
[0046]
The plenum vacuum tank 6 continuously performs so-called plenum suction, in which air is sucked out from the plenum chamber 4 while the internal volume of the plenum vacuum tank 5 is sustained by generating an air flow. It is preferable that it is formed in such a size that can be formed. Thereby, for example, when conducting a wind tunnel experiment of an object flying at a transonic speed using the impact wind tunnel device 1, the flow velocity of the airflow around the flying object model 2 is set to a predetermined predetermined value in the transonic region. It is possible to maintain the speed almost reliably. Specifically, the pressure in the plenum chamber 4 can be set lower than the pressure in the measurement chamber 3 by sucking the air in the plenum chamber 4 into the plenum. Thereby, for example, since the airflow that stays in the measurement chamber 3 or becomes turbulent can be actively sucked into the plenum chamber 4, the pressure in the measurement chamber 3 can be lowered. Therefore, it is possible to obtain the same effect as removing the factor that obstructs the flow of the dry air flowing into the measurement chamber 3 from the dry air chamber 7, and the air flow set to the transonic region flow velocity in the measurement chamber 3. Can be actively maintained. Therefore, the flow velocity of the airflow around the flying object model 2 in the measurement chamber 3 can be substantially reliably maintained at a predetermined speed set in the transonic region. Thereby, in the wind tunnel experiment using this impact type wind tunnel device 1, it is possible to obtain a measurement result that substantially satisfies the accuracy desired by the experimenter.
[0047]
As shown in FIGS. 1 to 3, the plenum chamber 4 and the traverse chamber 9 described above communicate with each other via a pair of first flow rate adjustment openings 37 a and second flow rate adjustment openings 37 b. A pair of first flow velocity as a damper for adjusting the flow velocity of the airflow flowing from the plenum chamber 4 toward the traverse chamber 9 is provided in the two first flow velocity adjustment openings 37a and the second flow velocity adjustment openings 37b. An adjustment damper 36a and a second flow velocity adjustment damper 36b are attached to be freely opened and closed. The two first flow rate adjusting dampers 36a and the second flow rate adjusting dampers 36b are respectively connected to a first motor 39a and a second motor 39b for driving them independently of each other. . The first flow rate adjusting damper 36a and the first motor 39a, and the second flow rate adjusting damper 36b and the second motor 39b are connected via a first gear device 40a and a second gear device 40b, respectively.
[0048]
These two first gear devices 40a and second gear devices 40b are attached in the vicinity of the traverse door 38 inside the traverse chamber 9, as shown in FIG. At the same time, the two first motors 39a and the second motor 39b are arranged outside the traverse chamber 9, as shown in FIG. According to such a configuration, there is no possibility that the first motor 39a and the second motor 39b, and the first gear device 40a and the second gear device 40b prevent the traverse door 38 from being opened and closed. That is, the first flow rate adjusting damper 36a and the second flow rate adjusting damper 36b have the first flow rate adjusting opening 37a and the second flow rate adjusting opening 37b set to a predetermined size regardless of the open / closed state of the traverse door 38. The first motor 39a and the second motor 39b are driven to open and close independently of each other via the first gear device 40a and the second gear device 40b so that they can be opened and closed.
[0049]
As shown in FIG. 3, the first motor 39 a and the second motor 39 b are connected to a control device 41 that can control their drive states independently of each other outside the traverse chamber 9. The control device 41 further determines the degree of opening of the first flow rate adjusting opening 37a and the second flow rate adjusting opening 37b by the first flow rate adjusting damper 36a and the second flow rate adjusting damper 36b from the outside of the traverse chamber 9. It is connected to a monitor 42 for monitoring. According to such a configuration, the experimenter operates the operation unit (not shown) while monitoring the state in the traverse chamber 9 from the outside of the traverse chamber 9 using the monitor 42 for monitoring, and thereby via the control device 41. The degree of opening of the first flow rate adjusting opening 37a and the second flow rate adjusting opening 37b by the first flow rate adjusting damper 36a and the second flow rate adjusting damper 36b is remotely controlled independently of each other to a predetermined size. Can be set. Thereby, the flow rate of the air flowing into the traverse chamber 9 from the plenum chamber 4 is adjusted to an arbitrary size at any time, and the flow velocity (Mach number) of the air in the measurement chamber 3 is always within a predetermined range. Can be set to any size. Therefore, the state of the airflow inside the measurement chamber 3 can be set to an ideal state desired by the experimenter.
[0050]
For example, in the measurement chamber 3, the flow angle of the flying object model 2 with respect to the flow direction of the airflow flowing at the flow velocity in the transonic region is deviated in a direction that obstructs the flow of the airflow. In this case, in order to compensate for the decrease in the flow area of the airflow around the flying object model 2 due to the deflection angle, the degree of opening of the first flow velocity adjustment opening 37a and the second flow velocity adjustment opening 37b is increased. Then, the first flow rate adjusting damper 36a and the second flow rate adjusting damper 36b are operated. Thereby, the air in the plenum chamber 4 can be flowed into the traverse chamber 9 by utilizing the pressure difference between the internal pressure of the plenum chamber 4 and the internal pressure of the traverse chamber 9. As a result, since the air in the measurement chamber 3 can be actively sucked into the plenum chamber 4, the pressure in the measurement chamber 3 can be lowered. As a result, air easily flows into the measurement chamber 3 and air easily flows out of the measurement chamber 3. Therefore, it is possible to obtain the same effect as that in which the flow area of the air flow around the flying object model 2 inside the measurement chamber 3 is sufficiently larger than the flow area of the air flow in the throttle portion 8b of the rubber nozzle 8. Can do. Therefore, even when a wind tunnel experiment is performed using dry air accelerated to a flow velocity in the transonic region, a decrease in the flow velocity (Mach number) around the flying object model 2 inside the measurement chamber 3 can be suppressed, and Can be adjusted and set with high accuracy.
[0051]
Further, by operating the operation unit, the first flow rate adjusting opening 37a and the second flow rate adjusting opening 37b are opened by the first flow rate adjusting damper 36a and the second flow rate adjusting damper 36b via the control device 41. Can be set to different sizes. In this case, the state of the airflow inside the measurement chamber 3 is asymmetric with respect to the axial method of the measurement chamber 3. As a result, a complicated flow of airflow can be generated inside the measurement chamber 3, particularly around the flying object model 2, so that a flight simulation of an airplane or the like when flying in a complex atmosphere in the natural environment can be performed. Can be done with higher accuracy.
[0052]
According to the impact wind tunnel device 1 of the present embodiment having the above-described configuration, a transonic region is provided by providing the plenum chamber 4 that is not provided in the conventional impact wind tunnel device in communication with the measurement chamber 3. Even when an air flow accelerated to a certain speed is used, a highly accurate wind tunnel experiment can be performed. Further, the plenum vacuum tank 6 as the plenum suction means is communicated with the accelerating vacuum tank 5 as the fluid accelerating means, and both the vacuum tanks 5 and 6 are evacuated by using one vacuum pump 13. I was able to do it. Thus, the equipment cost and running cost of the impact type wind tunnel device 1 can be suppressed and installed at low cost, and the impact type wind tunnel device 1 can be made compact, so that it can be installed in a small space.
[0053]
Next, an outline of a wind tunnel experiment by the impact wind tunnel device 1 will be described by taking as an example a case where the velocity of the air flow is set in the transonic region. First, in a state where the operation of the impact type wind tunnel device 1 is stopped, the flying object model 2 arranged in the measurement chamber 3 from the traverse chamber 9 via the traverse device 20 is in a predetermined predetermined state. Thus, the traverse door 38 is opened and the attachment work is performed. After this mounting operation is completed, the traverse door 38 is closed to seal the inside of the traverse chamber 9 and the partitionless rapid opening / closing valve 10 is operated to seal the suction hole 9a. At the same time, the plenum-free bulk opening / closing valve 35 is also operated to shut off the air passage between the plenum chamber 4 and the plenum vacuum tank 6 while maintaining airtightness.
[0054]
In this state, the gas drying device 14 is operated, and the air existing in the dry air chamber 7, the rubber nozzle 8, the measurement chamber 3, the plenum chamber 4, the traverse chamber 9, and the like is determined in advance. Dry to the specified humidity. On the other hand, the vacuum pump 13 is operated to perform evacuation until the inside of the accelerating vacuum tank 5 and the plenum vacuum tank 6 and the like is in a substantially complete vacuum state. Further, the dry air around the flying object model 2 in the measurement chamber 3 reaches a predetermined transonic speed with a predetermined flow velocity, and a predetermined flow with a predetermined air flow state. The degree of opening of the throttle portion 8b of the rubber nozzle 8 and the first flow rate adjustment opening 37a and the second flow rate adjustment opening 37b by the first flow rate adjustment damper 36a and the second flow rate adjustment damper 36b is set as follows. , Adjust and set in advance.
[0055]
After the above preparation is completed, the partitionless rapid opening / closing valve 10 is operated to open the suction hole 9a instantaneously. Following this, the plenum is measured in consideration of the timing at which the dry air in the dry air chamber 7 calculated in advance based on the flow velocity around the flying object model 2 flows into the plenum chamber 4 through the measurement chamber 3. The partitionless rapid opening / closing valve 35 is also operated to start the plenum suction.
[0056]
As a result, the dry air in the dry air chamber 7 is accelerated to a predetermined transonic speed, becomes an air flow state desired by the experimenter, passes through the measurement chamber 3, and is sucked into the acceleration vacuum tank 5. Therefore, the experimenter can obtain the data of the wind tunnel experiment of the object flying at the transonic speed with high accuracy.
[0057]
Next, an impact type wind tunnel device 51 according to a second embodiment of the present invention will be described with reference to FIGS.
[0058]
In the impact wind tunnel device 51 of the second embodiment, the configuration in the traverse chamber 9 included in the impact wind tunnel device 51 is the same as the configuration in the traverse chamber 9 included in the impact wind tunnel device 1 in the first embodiment described above. Other configurations, functions, and effects are similar, only being different. Therefore, the different parts will be described, and the same components as those in the first embodiment described above will be denoted by the same reference numerals and the description thereof will be omitted.
[0059]
As shown in FIG. 5 and FIG. 6, the impact type wind tunnel device 51 of the present embodiment is inflated and expanded by remotely operating from the outside of the traverse chamber 9 along the inner wall side surface of the traverse chamber 9. A plurality of volume variable bodies that can be contracted, in the present embodiment, four volume variable bodies 52a, 52b, 52c, and 52d are attached. These four variable volume bodies 52a, 52b, 52c, and 52d are preferably formed of an elastic material that can expand and contract, and in this embodiment, are made of rubber. These four variable volume bodies 52a, 52b, 52c, 52d penetrate through the wall portion of the traverse chamber 9 and communicate with a volume variable device 53 (described later) provided outside thereof. One supply / exhaust pipe 54a, 54b, 54c, 54d is connected to each other via a variable volume opening / closing valve (not shown). These four variable body supply / exhaust pipes 54 a, 54 b, 54 c, 54 d are combined into one outside the traverse chamber 9, and four volume variable bodies 52 a, 52 b, 52 c are connected via the air injection valve 55. , 52d is connected to a variable volume compressor 56 for supplying compressed air. Further, the variable supply / exhaust pipes 54 a, 54 b, 54 c, 54 d combined into one branch are branched on the traverse chamber 9 side from the air injection valve 55. tube 57, the four variable volume bodies 52a, 52b, 52c, and 52d are connected to an exhaust valve 58 that exhausts compressed air from the inside to the outside.
[0060]
When preparing the experiment before conducting the wind tunnel experiment, for example, when the flying object model 2 is attached, the attachment work of the flying object model 2 is accelerated as the internal volume in the traverse chamber 9 increases. In this case, the internal volume in the traverse chamber 9 can be expanded by contracting the four variable volume bodies 52a, 52b, 52c, and 52d. That is, a wide working space can be secured. Specifically, in a state where the operation of the variable volume compressor 56 is stopped, the air injection valve 55 is closed and the exhaust valve 58 is opened. In addition, the degree of opening of the variable volume opening / closing valves provided for each of the four variable supply / exhaust pipes 54a, 54b, 54c, 54d is set to a predetermined size independently of each other. As a result, the compressed air injected into each of the variable volume bodies 52a, 52b, 52c, 52d escapes to the outside depending on the degree of opening of the open / close valves for the variable volume bodies. Each of the variable bodies 52a, 52b, 52c, and 52d contracts at a predetermined speed, and their volumes are reduced. That is, the internal volume in the traverse chamber 9 is increased, and a wide working space can be secured.
[0061]
Alternatively, during the wind tunnel experiment, the smaller the internal volume in the traverse chamber 9, the more difficult it is for the air to pass through, so the duration of the air flow becomes longer and more experimental results can be obtained. In this case, the internal volume in the traverse chamber 9 can be reduced by expanding the four volume variable bodies 52a, 52b, 52c, and 52d, respectively. That is, the air flow passage can be narrowed to increase the duration of the air flow. Specifically, the air injection valve 55 is opened and the exhaust valve 58 is closed. In addition, the degree of opening of the variable volume opening / closing valves provided for each of the four variable supply / exhaust pipes 54a, 54b, 54c, 54d is set to a predetermined size independently of each other. In this state, the variable volume compressor 56 is operated. As a result, the compressed air supplied from the variable volume compressor 56 is injected into each of the variable volume bodies 52a, 52b, 52c, 52d in accordance with the degree of opening of the open / close valves for variable volume bodies. The variable bodies 52a, 52b, 52c, and 52d each expand at a predetermined speed, and their volumes increase. That is, the internal volume in the traverse chamber 9 is reduced, and the air flow passage can be narrowed.
[0062]
Since the impact type wind tunnel device 51 of the second embodiment is the same as the impact type wind tunnel device 1 of the first embodiment except for the points described above, the impact type wind tunnel device 1 of the second embodiment is used. As a matter of course, the problem of the present invention can be solved, but the second embodiment including the variable volume body and the variable volume device having the above-described configuration is excellent in the following points.
[0063]
In the impact type wind tunnel device 51 of the present embodiment, four volume variable bodies 52a, 52b, 52c, and 52d that can change the internal volume of the traverse chamber 9 by expanding and contracting in the traverse chamber 9. In addition, a variable volume device 53 that can expand and contract these four volume variable bodies 52a, 52b, 52c, and 52d independently of each other is provided outside the traverse chamber 9, and each of the volume variable bodies 52a, 52b, and 52c. , 52d. According to the impact type wind tunnel device 51 having such a configuration, the variable volume device 52a is operated by operating the variable volume device 53 with a predetermined setting or stopping the operation according to the working state. , 52b, 52c, 52d can be expanded or contracted to set the internal volume in the traverse chamber 9 to an arbitrary size at any time. Thereby, for example, the duration of the air stream accelerated to the speed of the transonic region flowing in the impact type wind tunnel device 51 is maintained for a long time, or the work efficiency of attaching the flying object model 2 in the traverse chamber 9 is increased. Can be increased.
[0064]
Further, if the variable volume compressor 56 included in the variable volume device 53 is configured as the valve opening / closing compressor 26 included in the above-described shock type wind tunnel device 1 according to the first embodiment, this shock type is used. The facility cost and maintenance cost of the wind tunnel device 51 can be reduced and the size can be reduced. Thereby, this impact type wind tunnel device 51 can be constructed and maintained at low cost, and can be installed in a space-saving manner.
[0065]
The impact type wind tunnel devices 1 and 51 according to the present invention are not limited to the first and second embodiments described above. For example, in the wind tunnel devices 1 and 51 described above, the air sucked by the accelerating vacuum tank 5 and the plenum vacuum tank 6 is dry air as a gas, but the natural weather conditions such as rain and snow are present in the measurement chamber 3. In order to faithfully reproduce, even if water droplets or ice is mixed in the gas, the purpose of use of the present invention is not deviated. Therefore, of course, the present invention is established even with such a configuration.
[0066]
【The invention's effect】
In the impact type wind tunnel device according to the present invention, a plenum suction means is provided outside the measurement chamber in which the object to be measured is disposed and communicates with the plenum chamber and sucks the gas flowing into the plenum chamber to the outside. Therefore, it is possible to generate an air flow having an arbitrary flow velocity including a transonic region where a shock wave is generated and perform a wind tunnel experiment using the air flow, and to reduce the cost and the size.
[0067]
Also The plenum suction means is a vacuum tank For Since there is no need to install a special drive device, the cost can be reduced and the size can be reduced.
[0068]
And The fluid accelerating means and the plenum suction means are communicated and evacuated by a single vacuum pump. For Since one vacuum pump can be shared, the cost can be further reduced and the size can be reduced.
[0069]
Further, in the impact type wind tunnel device according to the present invention, a traverse chamber is provided downstream from the plenum chamber, and a damper for adjusting the flow rate of gas flowing from the plenum chamber to the traverse chamber is provided between the two chambers. According to the configuration, the gas flowing into the plenum chamber is merged with the airflow flowing through the inside of the shock type wind tunnel device generated by the fluid acceleration means for use in the wind tunnel experiment, so that it can be easily transferred from the inside of the plenum chamber to the outside. Since the exhaust can be performed, the wind tunnel experiment can be performed by adjusting the flow velocity with higher accuracy.
[Brief description of the drawings]
FIG. 1 is a plan view showing, in partial cross section, an outline of an impact wind tunnel device according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a connecting portion of a plenum chamber and a traverse chamber provided in the impact wind tunnel device shown in FIG. 1;
FIG. 3 is a cross-sectional view showing a connecting portion of a plenum chamber and a traverse chamber provided in the impact wind tunnel device shown in FIG. 1;
4 is a cross-sectional view showing a diaphragm rapid opening / closing valve included in the impact type wind tunnel device shown in FIG. 1;
FIG. 5 shows the first of the present invention. 2 The top view which shows the outline of the impact type wind tunnel apparatus which concerns on this embodiment in a partial cross section.
6 is a plan view showing a variable volume device attached to a traverse chamber provided in the impact type wind tunnel device shown in FIG. 5;
[Explanation of symbols]
1,51 ... Shock type wind tunnel device
2 ... Flying object model (object to be measured)
3. Measurement room
4 ... Plenum room
5 ... Vacuum tank for acceleration (fluid acceleration means)
6 ... Plenum vacuum tank (plenum suction means)
9 ... Traverse room
13 ... Vacuum pump
36a ... Damper for adjusting the first flow rate
36b ... second damper for adjusting the flow rate
52a, 52b, 52c, 52d ... Volume variable body
53 ... Variable volume device

Claims (2)

A measurement chamber in which an object to be measured is disposed, a plenum chamber provided outside the measurement chamber in communication with the measurement chamber, a fluid acceleration means for accelerating the velocity of gas and flowing to the measurement chamber, and the plenum Plenum suction means for sucking the gas flowing into the chamber to the outside of the plenum chamber , the plenum suction means is a vacuum tank, and the fluid acceleration means and the plenum suction means are communicated with each other. It means impact wind tunnel device according to claim Rukoto evacuated by both single vacuum pump. A traverse chamber is provided on the downstream side of the plenum chamber in communication with the plenum chamber, and a damper is provided between the traverse chamber and the plenum chamber for adjusting the flow rate of gas flowing from the plenum chamber to the traverse chamber. The impact type wind tunnel device according to claim 1 .

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