Field temperature measurement technique using the flow visualization with the thermochronic liquid crystal has been investigated and is applied to the three-dimensional temperature measurement by scanning the thermometry. The color to temperature calibration of the liquid crystal is carried out by the neural network, where the effect of view angle relative to the light sheet is considered by distributing multi networks with an optimum smoothing technique over the image plane. The calibration error of temperature due to the view angle is much reduced by the present technique. And this technique is proved to be very useful by application to the temperature measurement of thermal convection over a heated surface. The three-dimensional temperature distribution of thermal convention is reconstructed from the measured temperature field and the structure of thermal plumes is examined.

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A new fast algorithm to extract circular pattern is developed. The method utilizes geometrical relationships between points on a circular boundary and a center point The procedure extracts first points on circles along horizontal lines, then each point is grouped according to a circle it belongs to.
Performance of the algorithm is examined by analyzing two kinds of pictures of circular patterns, a concentric circle and scattered circles. Comparing to pattern matching methods, the new method can detect circular patterns in a far shorter time.

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Infrared thermography is one of most attractive techniques for diagnosing various invisible defects included in objects or bodies, because two-dimensional field of testing targets can be evaluated nondestructively and instantaneously. In this paper, three-dimensional numerical simulation of thermal conduction is performed for nondestructive diagnosis using infrared rays to confirm the applicability and to establish the diagnostic standard. They are evaluated by changing size of defects and thermophysical properties of testing targets. It is revealed from a series of numerical simulation and image processing that the infrared thermography is useful in diagnosing invisible defects.

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Self-Compensation Doppler Global Velocimetry is applied to visualize a under-expansion supersonic free jet. A detail flow structure is visualized and its velocity is measured in high accuracy using a high resolution and high sensitivity CCD camera.

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Pressure-sensitive paint (PSP) is a measurement technique based on the quenching phenomena of luminescent molecules. Using PSP, pressure field on model surfaces can be evaluated from luminescence intensity of the paint emission. In order to use PSP in production wind tunnel testing, the measurement system called Pressure-Field Imaging Camera System (PICS) has been developed. The hardware of PICS is consists of an excitation light, light delivery system, a filter wheel, a high-resolution CCD camera, computer system, a sample calibration chamber, etc. The whole processes, including data acquisition, image processing, and paint calibration are handled by a set of dedicated software. Simple image processing is made on site in an interactive manner and data is stored for more sophisticated post processing. In this paper, the specification and construction of PICS are described in detail and applications of PICS to transonic wind tunnel testing is presented.

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The three-dimensional density distribution could be measured using the computer tomography technique with interferogram image. The photoconductor-plastic hologram (PPH) is a new hologram device which can easily make the hologram for the real-time interferometer. Since the image contains 2D information, lots of images taken from different angles should be needed to reconstruct the 3D information. However, the optics configuration will be too complex to obtain the multi-directional image sirmaltaneously, even in the PPH system. Using the diffusion plate, the laser light could be diffused to multi-direction. When the hologram is recorded with the diffused laser, the multi-directional image can be obtained using only one hologram plate. In the computer tomography technique, only the holizontal direction is effective, while the diffused laser contains the whole direction, causing the noise on the hologram. In this study, the lenticular lens is used as the diffusion plate. The lenticular lens reflects the laser only in horizontal direction without the vertical (non-horizontal) direction. Therfore the multi-directional fringe images could be clearly obtained. In the experiment the helium jet was measured to demonstrate the effectiveness of the proposed system.

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Field measurement and CFD(Computational Fluid Dynamics) have been used widely to understand flow field. But, field measurement usually has experimental errors. Meanwhile, CFD result also contains numerical errors. Therefore, we have proposed a new technique to predict whole field flow by combining PIV and CFD. In this work, we use the cost function which represents the sum of the adjusted amount of observed data and the residual of fundamental equations, and obtain whole- field flow by minimizing it. To examine this technique, we confirm the performance of our three-dimensional velocity measurement method at first, and apply the technique to a case of three-dimensional non-isothermal flow fields.

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An intelligent jet nozzle equipped with an array of magnetic flap actuators on its circular nozzle lip was developed. The actuators were driven by the electromagnetic force between copper coils formed on the flaps and embedded permanent magnets. The spatial evolution of the submerged jet issued at a Reynolds number of 3600 was studied with flow visualization and laser Doppler anemometry. Azimuthal disturbance generated by the flaps and coupled axial forcing can modify the jet structure significantly; when the frequency of the axial forcing is twice or three times that of the azimuthal disturbance, the jet exhibits distinct splitting into two or three branches, respectively.

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In this paper, the structure and behavior of the supersonic jets issuing from asymmetric single nozzle which had oblique outlet and two parallel asymmetric nozzles were studied mainly by the flow visualization. The flow visualization of mean and instantaneous flows with time were conducted by the schieren and shadowgraph methods, moreover mean total pressure distributions were measured. It was clarified that effect of oblique nozzle outlet on structure of pseudo-shock wave, and relation between distance of two parallel asymmetric nozzles and interference characteristics of two oblique jets.

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Local heat transfer characteristics of high temperature impinging two-dimensional air jets were investigated by using a novel multi-pulsed laser holographic interferometry. Thermal flow fields at nozzle-to-plate space were visualized real-time for various jet velocities and nozzle-to-plate distances, which were recorded by using a high-speed streak camera(5000fps). Instantaneous development and growth of streamwise vortices were clearly visualized by this novel method. The results indicate that the local heat transfer coefficients are greatly affected by the large-scale vortices which appear in the wall jet region. Furthermore, it could be demonstrated that this multi-pulsed laser holographic technique is effectively applicable to the high-speed observation of the impinging jets.

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This study deals with the mechanism of a local wind called "Hijikawa Arashi" which is a down slope wind observed along the Hijikawa river near Nagahama in Ehime Prefecture. This river is connected to an inland basin (Ohsu basin) where a cold air mass is accu nulated during nighttime by radiation cooling and overflows to the sea (Iyo-nada of Seto Inland Sea) through a valley along the Hijikawa river. Hijikawa Arashi gives a considerable influence to daily life of the people in the area, because the wind speed sometimes exceeds 10m/s and fog associated with the wind reduces the visibility significantly. The mechanism of the strong wind is not known yet, and remains as an interesting problem to meteorologists.
In this study, Hijikawa Arashi is studied by means of a shallow water theory, laboratory experiment and field observation. It is shown that the strong wind is caused by a hydraulic jump of the down slope wind which is produced by the effect of topography of the valley. The theory and the laboratory experiments predict that a steady hydraulic jump is produced in the downstream side of the narrowest portion of the valley. The result was confirmed by a videotape record of the fog which visualized the hydraulic jump of the Hijikawa Arashi.

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