JP3453577B2 - Flow velocity distribution measuring device under microgravity - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the velocity distribution inside a liquid column under microgravity.

[0002]

2. Description of the Related Art As the development of space equipment such as a space station progresses, fluid physical properties under microgravity are becoming more important. As such a fluid property measuring device, for example, a device as shown in FIG. 4 has already been developed in order to form a liquid column under microgravity and measure the behavior of the liquid column and the flow velocity distribution inside. This device supplies the liquid in the reservoir 4 between the two disks 2 and 3, and forms a liquid column 1 between the disks 2 and 3 by surface tension. Aluminum powder is mixed in the liquid, and the liquid column 1 is moved by the CCD cameras 5 and 6.
Is observed and the flow velocity distribution in the liquid column 1 is measured from the behavior of the aluminum powder by image processing. Incidentally, 7 is an observation window provided on the disk 2, and 8 is a mirror.

[0003]

It has been found that under microgravity, the surface tension of a liquid has a great influence on convection in the liquid. Therefore, it has been desired to heat one of the disks 2 and 3 and cool the other to generate convection in the liquid column 1 and measure the flow velocity distribution near the surface thereof. However, the above-described conventional measuring device has a problem that the observation window 7 provided in the disk 2 is small and the vicinity of the surface of the liquid column, which is easily affected by the surface tension, cannot be observed through the disk 2.
Further, if the observation window 7 is enlarged so that the vicinity of the surface of the liquid column can be observed through the disk 2, there is a problem that the disk 2 cannot be heated / cooled and sufficient convection cannot occur in the liquid column 1.

Further, in the observation from the side surface of the liquid column 1 (by the CCD camera 6), an error is likely to occur in the position measurement of the tracer particles (aluminum powder) inside due to the deformation of the liquid column.
There were problems such as a decrease in measurement accuracy due to blind spots, and a difficulty in calibrating the CCD camera on the spot due to mechanical problems.

The present invention was devised to solve such problems. That is, the first object of the present invention is to form a liquid column between two discs, heat or cool the discs to cause convection in the liquid column, and observe the flow velocity distribution inside the liquid column through the discs. An object of the present invention is to provide a flow velocity distribution measuring device capable of performing microgravity. Furthermore, another object of the present invention is to perform accurate position measurement without observing from the side surface, and the decrease in measurement accuracy due to blind spot is small,
And it is easy to calibrate the CCD camera under microgravity. 3
It is to provide a three-dimensional flow velocity distribution measuring device.

[0006]

According to the present invention, the axis A
A transparent first disc rotatably provided around
A temperature-adjustable second disk provided so as to face the first disk so as to be rotatable about its axis and movably along the axis; and the first disk and the second disk A liquid supply device that supplies a liquid between them to form a liquid column therebetween, a plurality of cameras that capture an image from the end surface of the liquid column through the first disk, and an inside of the liquid column by processing the images of the cameras. And a plurality of cameras are arranged at different angles with respect to the axis A, respectively, and a three-dimensional flow velocity distribution measuring apparatus under microgravity. Will be provided.

According to a preferred embodiment of the present invention, the plurality of cameras is three. Further, the liquid supply device,
A hollow cylindrical cylinder concentrically connected to the second disk, a piston slidably provided inside the cylinder, and a piston rod having one end connected to the piston and the other end fixed. The second disk has a through hole that connects the inside of the cylinder and the first disk. Furthermore, the first disk is made of glass that absorbs infrared rays, and further includes an infrared laser device that irradiates the first disk with infrared rays. Also, the first
The disk comprises a transparent hollow container, and further comprises a heat medium line for circulating a transparent heat medium in the hollow container, and a temperature adjusting device connected to the heat medium line for adjusting the temperature of the heat medium, It is preferable.

[0008]

According to the structure of the present invention described above, since the first disk is transparent, the inside of the liquid column can be observed through the entire transparent first disk. Further, since the temperature of the second disk can be adjusted, appropriate convection can be generated in the liquid column by heating or cooling the second disk.

Further, since a plurality of cameras for taking images from the end surface of the liquid column through the first disk are arranged at different angles with respect to the axis A, the respective observed images are processed by the image processing device. Then, the three-dimensional position of the tracer particles can be reconstructed, and the three-dimensional flow velocity distribution in the liquid column can be accurately measured.

Further, the liquid supply device includes a hollow cylindrical cylinder concentrically connected to the second disk, a piston slidably provided inside the cylinder, and one end connected to the piston and the other end. Is fixed to the piston rod, and the second disc is inside the cylinder and the first disc.
Since it has a through hole that communicates with the disk, by moving the cylinder, the liquid sealed in the cylinder is supplied between the first disk and the second disk through the through hole, and the liquid is supplied to the first disk under microgravity. A liquid column can be easily formed between the first disc and the second disc.

Further, the first disk is made of glass which absorbs infrared rays, and the infrared laser device for irradiating the glass with infrared rays is provided, so that the first disk can be heated without impairing the transparency of the first disk. Therefore, desired convection can be generated in the liquid column. Further, if the first disk is composed of a transparent hollow container and the transparent heat medium heated or cooled by the temperature control device is passed through the heat medium line into the hollow container, the transparency of the first disk is impaired. The first disk can be freely heated or cooled without the need for convection in the liquid column to be measured with higher precision.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the drawings, common parts are designated by the same reference numerals and used. FIG. 1 is an overall configuration diagram of a flow velocity distribution measuring apparatus under microgravity according to the present invention. In this figure, a flow velocity distribution measuring device according to the present invention shows a transparent first disk 10 rotatably provided around an axis A, and an axis A facing the first disk 10.
A second disc 12 which is rotatably provided around the first disc 10 and is movable along an axis A;
A liquid supply device 14 for supplying the liquid L between the second disk 12 and the second disk 12 to form the liquid column 1 therebetween, and the first disk 10
A plurality of cameras 16 that capture images from the end surface of the liquid column 1 through the image processing apparatus 20 and an image processing device 20 that measures the flow velocity distribution in the liquid column 1 from the images of the cameras 16 are provided. In FIG. 1, the plurality of cameras is three.

The first disk 10 is made of transparent glass, plastic or the like, and can be rotated about its axis by an appropriate rotation driving means, for example, an ultrasonic motor 11. The second disk 12 incorporates, for example, a heating / cooling device (not shown) and other heating / cooling device (not shown) utilizing the Peltier effect, and the temperature can be adjusted to a desired temperature, for example, 0 to 100 ° C. You can do it. The shape of the first disk 10 and the second disk 12 is preferably a combination of a cylinder and a truncated cone, as shown in the figure.
In particular, the surface that contacts the cylinder 1 is substantially flat, and the edge of the frusto-conical portion that contacts the cylinder 1 preferably has an acute angle. As a result, the cylinder 1 can be formed by surface tension under microgravity and can be stably held.

Further, the three cameras 16 are arranged at different angles with respect to the axis A, whereby
By observing the movement of the tracer particles in the liquid column 1 from three directions, it is possible to reconstruct the three-dimensional position of each tracer particle by performing image processing on each observation image. The camera 16 is a CCD camera for capturing an image, and can capture the movement of a tracer such as aluminum powder mixed in the liquid L as an image. The image processing device 20 is, for example, a three-dimensional image processing device, and is capable of processing the images of the three cameras 16 to measure the flow velocity distribution in the liquid column 1 three-dimensionally.

With the above-mentioned configuration, the disks 10 and 12
The liquid L is supplied between the disc 10 and the surface tension of the disc 10,
The liquid column 1 is formed between the two columns 12, the liquid column 1 is observed by the CCD camera 16, and the flow velocity distribution in the liquid column 1 is 3 by the image processing.
It can be measured dimensionally. Also, the first disc 1
Since 0 is transparent, the first disk 1 that is transparent inside the liquid column
It can be observed through 0. Further, since the temperature of the second disk 12 can be adjusted, the second disk 1
Appropriate convection can be generated in the liquid column 1 by heating or cooling 2.

Further, since the three cameras for taking images from the end face of the liquid column through the first disk are arranged at different angles with respect to the axis A, each observation image is imaged by the image processing device. By processing the tracer particles to reconstruct the three-dimensional position, the three-dimensional flow velocity distribution in the liquid column can be accurately measured.

Further, in FIG. 1, the liquid supply device 14 is
A hollow cylindrical cylinder 21 concentrically connected to the second disk 12, a piston 22 slidably provided inside the cylinder 21, one end connected to the piston 22 and the other end fixed to the main body 15. It consists of a piston rod 23. The second disk 12 is located inside the cylinder 21 and the first disk.
It has a through hole 12a communicating with the disk 10 side. The cylinder 21 is rotatably supported by a bearing 24,
Further, the two friction rollers 25 and 26 that are in contact with the outer surface of the roller can rotate about the axis and move along the axis. With this configuration, the second disc 1
The 2 can be rotated about its axis and moved along the axis. Further, the liquid L sealed in the cylinder by the movement of the cylinder 21 is supplied between the first disk 10 and the second disk 12 through the through hole 12a, so that the liquid L is separated between the first disk 10 and the second disk 12 under microgravity. The liquid column can be easily formed in the liquid column.

FIG. 2 shows another embodiment of the first disk 10. In this figure, the first disk 10 is made of glass that absorbs infrared rays. An infrared laser device 30 for irradiating the first disk 10 with infrared rays is also provided. It is preferable that a plurality of infrared laser devices 30 are provided in the circumferential direction so that the first disk 10 can be irradiated with uniform infrared rays. With this configuration, the first disc 10 can be heated without impairing the transparency of the first disc 10,
A desired convection can be generated in the liquid column 1.

FIG. 3 shows still another embodiment of the first disk 10. In this figure, the first disk 10 comprises a transparent hollow container 32. Further, a heat medium line 34 for circulating the transparent heat medium M in the hollow container 32, a temperature adjusting device 36 connected to the heat medium line 34 for adjusting the temperature of the heat medium M, and a circulation pump (not shown). It has and. The heat medium M is preferably a transparent liquid having a high specific heat, such as silicone oil, a transparent organic liquid, or water. The temperature adjusting device 36 is a normal heating device that heats or cools the heat medium M in the range of 0 to 100 ° C., for example. Further, the ultrasonic motor 11 preferably has a partial through hole so as to guide the heat medium M into the hollow container 32 via the main body 15.
Further, a normal bearing may be provided at the position of the ultrasonic motor 11 so that the ultrasonic motor 11 can be rotated by another rotation driving device. With this configuration, the first disk 10 can be freely heated or cooled without impairing the transparency of the first disk 10, and the convection in the liquid column to be measured can be controlled more precisely.

[0020]

As described above, according to the flow velocity distribution measuring apparatus under microgravity of the present invention, the first disk which is transparent near the surface of the liquid column, which is difficult to observe due to the lens effect of the liquid column when observed from the side. It can be observed throughout.
Further, since the temperature of the second disk can be adjusted, appropriate convection can be generated in the liquid column by heating or cooling the second disk. Furthermore, the first disk can be heated or cooled without impairing the transparency of the first disk,
It is possible to generate a desired convection in the liquid column and three-dimensionally measure the flow velocity distribution in the liquid column.

Further, since the liquid column is observed only from the end face, not from the side face, it is not affected by the deformation of the liquid column, an error does not easily occur in the position measurement of the tracer particles inside, and the observation is made by the lens effect of the liquid column. Since the blind spot does not occur, the measurement accuracy is less likely to decrease, the CCD camera is mechanically easy to calibrate, and so-called “in-situ calibration” is possible.

Therefore, the flow velocity distribution measuring apparatus under microgravity of the present invention forms a liquid column between two disks,
The disk is heated or cooled to cause convection in the liquid column, and the flow velocity distribution near the surface of the liquid column can be observed through the disk. Furthermore, the position can be accurately measured without observing from the side, and the measurement is performed by the blind spot. Less deterioration of accuracy and CC
It has excellent effects such as easy calibration of the D camera.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a flow velocity distribution measuring device under microgravity according to the present invention.

2 is another embodiment of the first disc in FIG. 1. FIG.

FIG. 3 is still another embodiment of the first disc in FIG.

FIG. 4 is an overall configuration diagram of a conventional flow velocity distribution measuring device under microgravity.

[Explanation of symbols]

1 liquid column A few discs 4 reservoir 5, 6 CCD camera 7 Observation window 8 mirror 10 First disc 11 Ultrasonic motor 12 Second disc 12a through hole 14 Liquid supply device 15 body 16 cameras 20 Image processing device 21 cylinders 22 pistons 23 Piston rod 24 bearing 25, 26 Friction roller 30 infrared laser device 32 hollow container 34 Heat medium line 36 Temperature control device L liquid M heat medium

Claims (5)

(57) [Claims] 1. A transparent first disk rotatably provided about an axis A, and a rotatably provided centering on the axis of the transparent first disk facing the first disk. A movably provided second disk, a liquid supply device for supplying a liquid between the first disk and the second disk to form a liquid column therebetween, and the liquid through the first disk It is composed of a plurality of cameras that capture images from the end faces of the columns, and an image processing device that processes the images of the cameras to measure the flow velocity distribution in the liquid column. A flow velocity distribution measuring device under microgravity, characterized in that they are arranged at different angles. 2. The flow velocity distribution measuring apparatus under microgravity according to claim 1, wherein the plurality of cameras is three. 3. The liquid supply device includes a hollow cylindrical cylinder concentrically connected to the second disk, a piston slidably provided inside the cylinder, and one end thereof connected to the piston. 3. A piston rod, the other end of which is fixed, and the second disk has a through hole that communicates between the inside of the cylinder and the first disk. Flow velocity distribution measurement device under microgravity. 4. The microgravity according to claim 1, wherein the first disk is made of glass that absorbs infrared rays, and further comprises an infrared laser device that irradiates the first disk with infrared rays. Flow velocity distribution measuring device below. 5. The first disk comprises a transparent hollow container, and a heat medium line for circulating a transparent heat medium in the hollow container; and a temperature of the heat medium connected to the heat medium line to control the temperature of the heat medium. A temperature control device for controlling the flow velocity distribution measuring device under microgravity according to claim 1 or 2.