JP2008180630A - Fluid measuring system, fluid measuring method and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring technique capable of carrying out a noncontact measurement of fluid around a vehicle by using a PIV system without approaching the object to be measured, and measuring an actual traveling state of the vehicle as it is. <P>SOLUTION: A system is equipped with: a photographing means (40) for photographing a subject including the fluid to be measured surrounding the vehicle (10) at a minute time interval; an image processing means for measuring a movement direction and a movement amount of a prescribed picture dot in a photographed subject by comparing acquired brightness pattern distributions at a plurality of clock times; an airborne particle generating device (20) for making a particle airborne around the subject, which is used as the picture dot; an irradiating means (30) for irradiating the subject in a space where the particle exists; and an eddy flow structure extracting means for extracting an eddy flow structure of the fluid to be measured from a particle image acquired by the photographing means (40). The image processing means analyzes a flow field of the fluid to be measured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique capable of performing measurement of a fluid around a moving body in a non-contact manner without approaching a measurement target.

  Wind tunnel experiments are generally performed as a technique for measuring the aerodynamic performance of a moving object, for example, an automobile. As a technique related to a wind tunnel experiment, for example, Patent Document 1 discloses a wind tunnel experiment apparatus for the purpose of measuring an amount of vertical displacement close to an actual traveling state.

JP-A-6-341920

  Moreover, the technique disclosed by patent document 2 and patent document 3 is known as a system which observes smoke (for example, smoke discharged | emitted from chimneys, such as a power generation facility) from a distant place. These use a plurality of ITV cameras and color cameras, and detect the presence or absence of smoke discharged from the chimney using the parallax and color difference between the cameras.

JP-A-63-88428 Japanese Patent Laid-Open No. 10-232198

  On the other hand, in recent years, a particle image velocimeter (hereinafter referred to as “PIV system”) that measures the flow in a complicated flow field with high accuracy and precision has been known. Briefly, laser light is injected into the flow field of the fluid to be measured in the form of a sheet to form a laser sheet, and particle images at two times on the laser sheet are continuously captured, and the luminance pattern distribution is determined. This is a technique for measuring the flow velocity and direction of fluid in comparison.

  Now, as shown in FIG. 7, the automobile wind tunnel test apparatus runs the automobile on the moving belt, and reproduces the simulated running state by moving the air around the stationary automobile. Yes, not on the actual road surface. However, it is originally desirable that the actual running state can be measured as it is, and this is not done because the measurement technique has not been established.

  Moreover, even if the technique disclosed in Patent Documents 2 and 3 and the PIV system described above are simply combined, the fluid around the moving body cannot be measured. In other words, no technique is provided for calculating the aerodynamic performance by directly measuring the actual driving state of the automobile.

The present invention has been made in view of the above, and by using the PIV system to measure the fluid around the moving body in a non-contact manner without approaching the measurement target, the actual traveling state of the moving body is obtained. It is an object to provide a measurement technique that can be measured as it is.
An object of the invention according to claims 1 to 6 of the present invention is to provide a fluid measurement system capable of measuring an actual running state of a moving body as it is.
Another object of the present invention is to provide a fluid measuring method capable of measuring an actual traveling state of a moving body as it is.
In addition, an object of the invention described in claims 10 to 12 is to provide a fluid measurement program that can measure the actual running state of the moving body as it is.

(Claim 1)
According to the first aspect of the present invention, there is provided an imaging unit (40) for imaging a subject including a fluid to be measured surrounding the moving body (10) at a minute time interval, and a plurality of time-lapse luminance patterns acquired by the imaging unit (40). The present invention relates to a fluid measurement system including an image processing unit that measures a moving direction and a moving amount of a predetermined image point in a subject by comparing distributions.
There are floating particle generators (20) for floating particles for the image point in the imaging means (40) around the subject, and particles generated by the floating particle generators (20). Irradiating means (30) for irradiating the subject in the space.
The imaging means (40) includes a long focal point optical system, so that it is possible to image a subject that is separated by a long distance, and from the particle image obtained by the imaging means (40), a turbulent flow structure of the fluid to be measured Turbulent flow structure extracting means for extracting. The image processing means measures the moving direction and the moving amount of the turbulent flow structure extracted by the turbulent flow structure extracting means, and analyzes the flow field of the fluid to be measured.

(Glossary)
The “moving body” is an automobile, a ship, or the like that wants to obtain aerodynamic characteristics by fluid analysis, and is located far from the “imaging means”.
As the “imaging means”, a camera (CCD camera) provided with a CCD imaging device is used, but instead, a camera provided with a CMOS imaging device can be used.
The “floating particle generator” is, for example, a carbon dioxide generator using dry ice or a smoke generator for spraying fine particles.
The term “long distance” in the “long focus optical system” means that the distance is longer than the laboratory level.

(Function)
The suspended particle generator floats the suspended body around the subject including the fluid to be measured surrounding the moving body. When the moving body enters the space where the floating body floats, the irradiation means irradiates the subject. Then, the imaging means images the irradiated subject at a minute time interval. Since the imaging means includes a long focal point optical system, it is possible to image a subject that is separated by a long distance, and it is possible to take a picture from a location slightly away from the subject.
From the particle image obtained by the imaging means, the turbulent flow structure extracting means extracts the turbulent flow structure of the fluid to be measured. Then, the moving direction and moving amount of the turbulent flow structure are measured to analyze the flow field of the fluid to be measured.
Here, analysis of the flow field around the moving body, which has been simulated in wind tunnel experiments, can be performed in a state very close to the actual running state.

(Claim 2)
The invention according to claim 2 limits the fluid measurement system according to claim 1.
That is, the irradiating means forms a plurality of irradiation surfaces on the subject.
Here, the “plurality” for the irradiated surface is two or more. There are a case where two or more irradiation surfaces are formed simultaneously and a case where two or more irradiation surfaces are formed continuously.
When two or more irradiation surfaces are formed at the same time, the images of the irradiation surfaces can be separated by irradiating lasers having different wavelengths. In addition, by using a long-focus optical system for the imaging system, the in-focus range is widened, and it is possible to obtain an in-focus image on a plurality of irradiation surfaces.
By forming a plurality of laser light sheets, multifaceted measurement is possible. In addition, by complementing a plurality of two-dimensional measurements, three-dimensional measurement and reproduction are possible.

(Claim 3)
The invention according to claim 3 limits the vibration measurement system according to claim 1 or claim 2.
That is, the irradiation unit includes a laser light sheet forming apparatus that irradiates a sheet-like laser beam and a laser sheet control apparatus that controls the laser light sheet forming apparatus. The laser sheet control apparatus is characterized in that the laser light sheet forming apparatus irradiates a laser light sheet that is partially blocked by a moving body in the subject at the moment of photographing the subject.

(Claim 4)
The invention according to claim 4 limits the fluid measurement system according to claim 3.
That is, when the moving operator is on the moving body (10), the laser light sheet forming device is configured to irradiate the laser light sheet from outside the field of view of the moving operator. Features.

(Function)
When the moving body (10) is operated not by automatic steering but by a moving operator, the laser light sheet is not useful for the moving operator. That is, there is no risk of damage to vision. Therefore, the laser light sheet is devised so that it is difficult to enter the field of view of the moving operator.

(Claim 5)
The invention according to claim 5 limits the fluid measurement system according to claim 3.
That is, when the moving operator is on the moving body (10) that moves, the laser light sheet forming device relates to a fluid measurement system that irradiates the laser light sheet with an eye-safe laser.

  “Eye-safe laser” refers to near-infrared laser light having a wavelength of 1.4 μm to 2.6 μm. It does not reach the retina and is difficult to damage the eyes. For this reason, unlike claim 4, there is no restriction that the laser light sheet has to be irradiated from outside the visual field of the moving operator. Examples of eye-safe lasers include InGaAsP semiconductor lasers, Er: glass lasers, Er-doped fiber lasers, and KTP optical parametric oscillators.

(Claim 6)
The invention according to claim 6 limits the fluid measurement system according to any one of claims 1 to 4.
That is, the irradiation surface formed by the irradiation means (30) is vertical, and the imaging means (40) is capable of photographing the irradiation surface at a right angle.

  Determining the right angle and the parallelism with reference to any part of the moving body (10) varies depending on the road surface condition on which the moving body (10) moves, and thus is difficult to use as a reference. Therefore, the irradiation surface formed by the irradiation means (30) is made vertical so as to reduce the labor of setting the equipment, and if necessary, correction or multiplication is performed based on data on the road surface.

(Claim 7)
According to a seventh aspect of the present invention, there is provided an imaging unit that images a subject including a fluid to be measured surrounding a moving body at a minute time interval, and a luminance pattern distribution at a plurality of times acquired by the imaging unit, thereby comparing the luminance pattern distributions within the subject. The present invention relates to a fluid measurement method for realizing a fluid measurement method including an image processing means for measuring the movement direction and the movement amount of a predetermined image point.
In order to irradiate a subject in a space in which particles generated in the imaging means are suspended around the subject, and in a space where particles generated in the suspended particle generation procedure exist Irradiating procedure, an imaging procedure for imaging an object separated by a long distance by the imaging means, and a turbulent flow structure of the fluid to be measured from the particle image obtained by the imaging procedure An image for analyzing the flow field of the fluid to be measured by the image processing means by measuring the moving direction and the moving amount of the turbulent flow structure extracted by the turbulent flow structure extracting procedure And a processing procedure.

(Claim 8)
The invention according to claim 8 limits the fluid measuring method according to claim 7.
That is, the irradiation procedure forms a plurality of irradiation surfaces simultaneously on the subject, and the imaging procedure images a plurality of irradiation surfaces formed in the irradiation procedure simultaneously.

(Claim 9)
The invention according to claim 9 limits the fluid measuring method according to claim 7.
In the irradiation procedure, a plurality of irradiation surfaces are continuously formed on the subject, and in the imaging procedure, the plurality of irradiation surfaces formed in the irradiation procedure are imaged in the order of formation. To do.

(Claim 10)
According to a tenth aspect of the present invention, there is provided an imaging unit that images a subject including a fluid to be measured surrounding a moving body at a minute time interval, and particles that serve as image points in the imaging unit are suspended around the subject. A plurality of time-dependent luminance pattern distributions acquired by the imaging unit, and an irradiation unit for irradiating the subject in a space where particles generated by the suspended particle generation unit exist Thus, the present invention relates to a computer program for realizing a fluid measuring method including an image processing means for measuring the moving direction and moving amount of a predetermined image point in a subject.
That is, an irradiation procedure for controlling the irradiation unit, an imaging procedure for imaging a subject separated by a long distance by providing a long focal point optical system in the imaging unit, and a particle image obtained by the imaging procedure A turbulent flow structure extracting procedure for extracting a turbulent flow structure of the fluid, a moving direction and a moving amount of the turbulent flow structure extracted by the turbulent flow structure extracting procedure, And a computer program for causing a computer to execute an image processing procedure to be analyzed in (1).

(Claim 11)
The invention according to claim 11 limits the computer program according to claim 10.
That is, the irradiation procedure relates to a computer program in which a plurality of irradiation surfaces are simultaneously formed on the subject, and the imaging procedure is to simultaneously image a plurality of irradiation surfaces formed in the irradiation procedure.

(Claim 12)
The invention according to claim 12 also limits the computer program according to claim 10.
That is, in the irradiation procedure, a plurality of irradiation surfaces are continuously formed on the subject,
The imaging procedure relates to a computer program that images a plurality of irradiation surfaces formed by the irradiation procedure in the order of formation.

  The computer program according to any one of claims 10 to 12 can be stored in a recording medium (for example, CD-R, DVD-R, etc.) and distributed, or transmitted to another recording medium through a communication line. It is also possible.

According to the first to sixth aspects of the present invention, it is possible to provide a fluid measurement system that can measure the actual traveling state of the moving body as it is.

Moreover, according to the invention of Claim 7 to Claim 9, the fluid measuring method which can measure the actual driving | running | working state of a moving body as it was was able to be provided.
Further, according to the invention described in claims 10 to 12, it is possible to provide a fluid measurement program that can measure the actual traveling state of the moving body as it is.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 conceptually illustrates a fluid measurement system according to an embodiment of the present invention, and FIGS. 2 to 5 are conceptual diagrams illustrating variations regarding the relationship between an irradiation apparatus and an imaging apparatus. .

(Figure 1)
Here, it is assumed that the aerodynamic characteristics of the moving body 10 having a newly designed appearance are to be examined.
When the moving body 10 passes at a predetermined speed through a point with conditions such as road surface and inclination suitable for examining the aerodynamic characteristics, the entire point is set as a subject. The suspended particle generator 20 for generating the smoke 19 and the suspended particle generator 20 so that the subject can be photographed in a state where the moving body 10 is included. , An irradiation unit 30 for forming a laser light sheet, and an imaging device 40 for imaging a subject illuminated by the laser light sheet formed by the irradiation unit 30 are prepared.

  In this embodiment, a smoke generator is employed as the suspended particle generator 20. More specifically, there is a smoke generator MODEL8304 manufactured by Nippon Kanomax Co., Ltd., and ALPHA 900v2 manufactured by Nippon Koban Co., Ltd. The smoke generated by these smoke generators is very fine and can be pumped at room temperature. For this reason, if a smoke hose is used, it can guide to arbitrary places. In addition, if a water-soluble smoke generating agent is used, the smoke evaporates and vaporizes in a few minutes, so that subsequent processing is unnecessary.

The imaging device 40 often uses a CCD camera. The CCD camera is equipped with a long focus optical system. As the long focus optical system, it is preferable to use a single focus lens (hereinafter referred to as “single lens”). In this case, it is more preferable to provide a turret so that a plurality of types of single lenses can be selected. By using the turret, a single lens can be automatically selected. When the Cassegrain optical system is employed, an optical system having a long focal length can be made compact. It is preferable to use Maxstow Cassegrain or Schmidt Cassegrain, which adds one lens to the entire surface, because it can improve aberrations. In the case of a lens having a zoom function, there is generally a drawback in that the curvature of field is large, but any lens can be used as long as a stable image can be obtained with glass having a high refractive index.
In this embodiment, a camera (CCD camera) provided with a CCD image pickup device is used as the image pickup means, but a camera provided with a CMOS image pickup device may be used instead.

(Figure 2)
In FIG. 2, there are two irradiation means 31 and 32, each of which irradiates the laser light sheet vertically. Both laser light sheets are parallel to the traveling direction of the moving body 10, and one is irradiated so that one is located in the center in the left-right direction of the moving body 10 and the other is located in the vicinity of 1/4 of the left-right direction in the moving body 10 To do.
The irradiation means 31 and 32 both irradiate in the traveling direction. This is to prevent the laser light sheet from entering the field of view of the driver of the moving body 10.
A halogen light source can also be used as the irradiation means.

In this case, for example, the irradiation means 31 irradiates a red laser having a wavelength of 660 nm and the irradiation means 32 irradiates a green laser having a wavelength of 532 nm. If an imaging device capable of color photography is used as the imaging device 40 due to the difference in wavelength between the two, it is possible to determine from which image data the laser sheet data from which irradiation means is taken.

Although not shown, the imaging device 40 is controlled by a computer that controls the timing of the imaging, and the timing of the imaging is controlled to be synchronized with the timing of irradiation of the irradiation units 31 and 32. Further, the control means includes a focal length adjustment means for calculating an appropriate focal length f of the CCD camera 2 and the like.
The image signal photographed by the CCD camera is provided with image capturing means and image processing means for receiving the image signal and executing predetermined processing.

The image capturing means includes a frame grabber board for digitizing an analog image signal from the CCD camera. The image processing means analyzes the image frame, which is a digital image signal output from the frame grabber board, by the PIV method. Note that a circuit for correcting image distortion aberration or the like may be provided in front of the image processing means.
In the case where the focal distance adjusting means is provided, an operation for obtaining an appropriate focal distance f is performed so that the moving distance of the particle group in the particle images at two times obtained by the image processing means is within the above range. Do.

  In the image processing means, the particle images at two times captured by the CCD camera at a minute time interval are regarded as luminance pattern distributions, and the movement amount of the particle group is estimated by comparing and analyzing the two particle images. That is, the value of one point in the particle image is set as a luminance value, and the luminance value is distributed in a predetermined region in the particle image as a luminance pattern, and the luminance pattern is obtained by the cross-correlation method or the luminance difference accumulation method. The amount of movement and the direction of movement of the particle group on the pixel between the two images are obtained. Then, the actual flow velocity and flow direction of the fluid to be measured are obtained by the movement amount / movement direction of the particle group on the pixel and the minute time interval Δt, and the flow field is analyzed.

  When calculating the amount of movement of the particle group by analysis processing by the image processing means, if the particle group constituting the predetermined luminance pattern in the particle image at two times is too far away, the correlation between both can be known. Have difficulty. Accordingly, the moving distance of the particle group is about 0.5 to 10% with respect to the total number of vertical or horizontal pixels (for example, 5 to 100 pixels in the case where the total number of vertical (or horizontal) pixels is 1000 pixels). It is preferable to be within the range.

The present embodiment aims to analyze the aerodynamic characteristics of the moving body 10 by analyzing the flow field of a fluid to be measured at a long distance away from the CCD camera, which is an imaging means, and the CCD camera has a long focal point. Although the optical system is mounted, whether or not the amount of movement of the particle group is within the above-mentioned region depends on the focal length f of the long focal length optical system, the imaging time interval Δt at two times, and the fluid to be measured It depends on the distance.
For example, when the distance to the laser light sheet is short, the relationship between the image size per pixel and the focal length f is non-linear. In this case, a non-linear table indicating the correlation between the two is set. You can deal with it.

For example, 1027 time images are taken every 1/100 s, and 1026 velocity vectors are obtained. From this velocity vector, 1024 acceleration vectors are calculated from the center difference of secondary accuracy, and low-pass filter processing is performed. Once done, a power spectrum can be obtained using FFT (Fast Fourier Transform).
The low-pass filter process is a means for converting an image into a spatial frequency component of luminance, and a filtering process that leaves a predetermined frequency component or less from the converted frequency component. After the filtering process, a means for converting the frequency component into an image is also necessary.

(Figure 3)
FIG. 3 differs from FIG. 2 in that only one irradiation unit 31 is used, and the two laser light sheets irradiated by the two irradiation units 31 and 32 in FIG. Irradiation is continuous. While there is a merit in control by using one irradiation means, there is a demerit such that it is difficult to make the two laser light sheets accurately parallel.

(Fig. 4)
In FIG. 4, unlike the case of FIG. 3, the single irradiation means 31 irradiates continuously in a very short time, but the subjects by the respective laser light sheets are photographed by the separate imaging means 41 and. is there.
Since the imaging means 41 and 42 are located on the left and right of the subject, a captured image can be obtained for each laser light sheet.

(Fig. 5)
In FIG. 5, unlike the case of FIG. 4, a plurality of irradiation means 31, 32 form a laser light sheet, and a subject by each laser light sheet is photographed by separate imaging means 41, 42.
While there is a demerit that it takes time to set the irradiation means 31, 32 and the imaging means 41, 42, a parallel laser light sheet can be formed, and a captured image can be obtained for each laser light sheet.

(Fig. 6)
FIG. 6 differs from FIGS. 2 to 5 in that the irradiation means 31 forms a laser light sheet perpendicular to the moving direction of the moving body 10 and photographs the subject by the laser light sheet with separate imaging means 40. It is.
When analyzing the aerodynamic characteristics with respect to the moving body 10, when a three-dimensional analysis is required, a necessary captured image can be obtained.

  In addition, although illustration is abbreviate | omitted, it is also possible to install the irradiation means 30 in the road surface side of the mobile body 10, and to obtain the image for analyzing the aerodynamic characteristic in the lower part.

  The present invention can be used in the industry of automobile manufacturers, the inspection industry that undertakes aerodynamic performance tests for automobiles, the wind tunnel manufacturer, and the industry that undertakes performance tests for various moving objects using wind tunnels.

1 is a conceptual diagram of a fluid measurement system according to an embodiment of the present invention. It is a conceptual diagram which shows 1st embodiment about the relationship between an irradiation apparatus and an imaging device. It is a conceptual diagram which shows 2nd embodiment about the relationship between an irradiation apparatus and an imaging device. It is a conceptual diagram which shows 3rd embodiment about the relationship between an irradiation apparatus and an imaging device. It is a conceptual diagram which shows 4th embodiment about the relationship between an irradiation apparatus and an imaging device. It is a conceptual diagram which shows 4th embodiment about the relationship between an irradiation apparatus and an imaging device. It is a figure which shows an example of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Mobile body 19 Smoke 20 Generator 30, 31, 32 Irradiation device 40, 41, 42 Imaging device

Claims (12)

An imaging unit that images a subject including a fluid to be measured surrounding the moving body at a minute time interval, and a moving direction of a predetermined image point in the subject by comparing luminance pattern distributions at a plurality of times acquired by the imaging unit, and A fluid measurement system including an image processing means for measuring a movement amount,
A floating particle generator for floating particles around the subject for the image point in the imaging means;
Irradiating means for irradiating a subject in a space where particles generated by the suspended particle generator exist,
The image pickup means includes a long focal point optical system, thereby being able to image a subject separated by a long distance,
A turbulent flow structure extracting means for extracting the turbulent flow structure of the fluid to be measured from the particle image obtained by the imaging means;
The fluid measurement system characterized in that the image processing means analyzes a flow field of a fluid to be measured by measuring a moving direction and a moving amount of the turbulent flow structure extracted by the turbulent flow structure extracting means.   The fluid measurement system according to claim 1, wherein the irradiation unit forms a plurality of irradiation surfaces with respect to the subject. The irradiation means includes a laser light sheet forming apparatus that irradiates a sheet-like laser beam, and a laser sheet control apparatus that controls the laser light sheet forming apparatus,
2. The laser sheet control device according to claim 1, wherein the laser light sheet forming device irradiates a laser light sheet that is partially blocked by a moving body in the subject at the moment of photographing the subject. The fluid measurement system according to claim 2. In the case where a moving operator is on the moving body that moves,
The fluid measurement system according to claim 3, wherein the laser light sheet forming apparatus irradiates the laser light sheet from outside the visual field of the moving operator. In the case where a moving operator is on the moving body that moves,
The fluid measurement system according to claim 3, wherein the laser light sheet forming apparatus irradiates the laser light sheet with an eye-safe laser. The irradiation surface formed by the irradiation means is vertical,
The fluid measurement system according to claim 1, wherein the imaging unit is capable of photographing the irradiation surface at a right angle. An imaging unit that images a subject including a fluid to be measured surrounding the moving body at a minute time interval, and a moving direction of a predetermined image point in the subject by comparing luminance pattern distributions at a plurality of times acquired by the imaging unit, and A fluid measurement method for realizing a fluid measurement method including an image processing means for measuring a movement amount,
Suspended particle generation procedure for floating particles for the image point in the imaging means around the subject;
An irradiation procedure for irradiating a subject in a space where particles generated by the suspended particle generation procedure exist,
By providing a long focal length optical system, an imaging procedure for imaging an object separated by a long distance with the imaging means;
From the particle image obtained by the imaging procedure, a turbulent flow structure extraction procedure for extracting the turbulent flow structure of the fluid to be measured,
An image processing procedure for measuring a moving direction and a moving amount of the turbulent structure extracted by the turbulent flow structure extracting procedure, and analyzing the flow field of the fluid to be measured by the image processing means. Fluid measurement method. In the irradiation procedure, a plurality of irradiation surfaces are simultaneously formed on the subject,
The fluid measurement method according to claim 7, wherein the imaging procedure simultaneously images a plurality of irradiation surfaces formed in the irradiation procedure. In the irradiation procedure, a plurality of irradiation surfaces are continuously formed on the subject,
The fluid measurement method according to claim 7, wherein the imaging procedure images a plurality of irradiation surfaces formed in the irradiation procedure in the order of formation. An imaging means for imaging a subject including a fluid to be measured surrounding a moving body at a minute time interval, a floating particle generator for floating particles around the subject, and a floating particle generator for floating the particles around the subject A predetermined image point in the subject by comparing the luminance pattern distribution at a plurality of times acquired by the imaging unit with an irradiating unit for irradiating the subject in a space where particles generated by the particle generating unit exist A computer program for realizing a fluid measurement method comprising an image processing means for measuring the movement direction and the movement amount of
An irradiation procedure for controlling the irradiation means;
An imaging procedure for imaging a subject separated by a long distance by providing the imaging means with a long focal point optical system;
From the particle image obtained by the imaging procedure, a turbulent flow structure extraction procedure for extracting the turbulent flow structure of the fluid to be measured,
Causing the computer to execute an image processing procedure for measuring a moving direction and a moving amount of the turbulent flow structure extracted by the turbulent flow structure extracting procedure, and analyzing the flow field of the fluid to be measured by the image processing means. Computer program. In the irradiation procedure, a plurality of irradiation surfaces are simultaneously formed on the subject,
The computer program according to claim 10, wherein the imaging procedure simultaneously images a plurality of irradiation surfaces formed in the irradiation procedure. In the irradiation procedure, a plurality of irradiation surfaces are continuously formed on the subject,
The computer program according to claim 10, wherein the imaging procedure images a plurality of irradiation surfaces formed in the irradiation procedure in the order of formation.

Images