Three-dimensional Particle Image Velocimetry (PIV) requires that the three-dimensional positiosn of particle tracers in a flow field be found. In this study, a simple and easy calibration technique is proposed, which uses a cross-correlation technique between camera images. The function between image distortion and the Z coordinate (perpendicular to the image) is obtained using a cross-correlation between camera images. The function includes the error of the camera setup and refraction at the test section tank wall. Then the 3D positions can be easily calculated with high accuracy using the calculated function. The technique is applied to the natural convective field, showing the high effectiveness.

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An image measurement technique for time-mean velocity through the possibility of particle passing has been developed by the authors. Present paper describes the error correction for the effect of particle concentration and the uncertainty analysis of the measured data. The measurement of a rotating speed of a particle image patterned disk and the wake of circular cylinder was carried out to examine the correction method and the uncertainty band.

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This paper reports on the visualization of the flow generated by flapping of the dragonfly, Sympetrum frequens, fixed in a uniform flow velocity 0.6 m/s with smoke wire method. Two types of flapping, smaller and larger rotational angular oscillations withh mean angle 3-5 degree and about 80 degree, respectively, were observed. For smaller flapping, regular and irregular types of a sheet of shed vortices were observed. One in the regular type showed the locking phenomenon, in which the flapping frequency agreed with that of vortices as observed in Karman vortex. For larger flapping, it was clearly observed that the uniform flow was induced toward the dragonfly and the wake led into largely disturbed region. Also, it was identified that the wake velocity was faster than that of uniform flow, and then the flow exerted forward force on the dragonfly.

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The in-line laser-holography method has been used to measure the location and diameter of small particles. This, however, takes only one hologram to analyze particles so that it is not possible to measure particles with large spatial and diametric dispersion. To overcome this difficulty, the present study develops the multiple-stage holography method that takes two or more holograms at one time. This method is tested for the breakup process of a water droplet by a supersonic freejet and is proved to give an accurate means of the particle sizing.

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A detailed experimental investigation of shock wavelturbulent boundary layer interaction in a supersonic nozzle was carried out using a schlieren visualization and multiple pressure transducers. The chosen Mach numbers at just upstream of shock are 1.37 and 1.60 which show a bifurcated normal shock and a multiple shocks, respectively. The visualization results show nominal variation of shock patterns from a simple normal shock to a pseudo-shock system as increasing flow Mach number. The measurements of wall pressure using multiple transducers and simultaneous sampling method show the propagation of pressure waves caused by shock and boundary layer interaction. In particular, it becomes clear that the upstream moving pressure waves from reattachment point of boundary layer exist in the case of multiple shock case. However, more detailed investigation is required in the case of a single bifurcated shock system.

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A free piston shock tunnel (FPST) is one of the most useful test facilities for generating high enthalpy flow. Therefore, the FPST has been intensively used in conjunction with the development of re-entry vehicles and SCRAM jet engine. In this study, piston motion in a compression tube of a free piston compression tube was measured continuously in order to obtain the quantitative piston speed of a FPST by means of a high resolution interferometer and results were compared the computation based on concept of " Tuned Operation Condition"which uses a quasi-1D ENO scheme with 4th order accuracyGood agreement was obtained between measured numerical results and predictions. A double exposure holographic interferometric visualization of a shock wave released from the compression tube was carried out.

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Fine particles often flood uncontrollably from bins, hoppers and processing vessels, which is sometimes called flushing. A particle flow pattern in a vessel is visualized by tracer method when the flushing occurs. Experimental apparatus consists of a rectangular vessel having a narrow slit at the bottom and a piston that compresses the powder bed. It is found that the particles in the vessel uniformly move toward the slit.

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Metal flow representing continuous plastic deformation in a metal forming process is visualized by mathematical tequnique such as FEM analysis or by experimental tequnique such as Visioplasticity method. The authors developed the physical simulation system by which a metal flow characteristics and strain conditions in the workpiece can be visualized quantitatively in the realistic deformation conditions. The flow field can be observed from the distortion of grid pattern which has been placed by print or by machining on the observation plane in the physical simulation.
Model material, Plasticine in the present workpiece, or actual material, was deformed by in-cremental steps, and the metal flow and strain condition in a workpiece in non-steady state deformation condition could be observed and determined by numerical analyses. The above procedure was applied to optimal process design of bolt head forging process, heading.

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Flow Visualization studies in intersecting ducts have been conducted to disclose the mechanics of the flow phenomena in the intersecting zone. In this study, experiments in two intersecting ducts with the circular perforated zone are performed to investigate the secondary flow in the perforated zone by changing the conditions of the upper water levels. The flow characteristics are clarified in the intersecting ducts using the circular perforated zone. The flow pattern is visualized by the particle tracing method using ion exchange resin.

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In this study, experiments in two intersecting ducts with the circular perforated zone inclusive of a splitter are performed to investigate the secondary flow in the perforated zone and the flow separated to the left and right downstream ducts by the splitter. The flow characteristics are clarified in the intersecting ducts with the circular perforated zone inclusive of the splitter. The flow pattern is visualized by the particle tracing method using ion exchange resin.

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Visualization and velocity measurement of flow through impeller of a multi blade fan have been carried out with PIV technique. Tracer particle image was taken by a still camera. Test section was illuminated by dual laser beam sweep method. The obtained double exposured photograph was low density particle image. It was analyzed by auto-correlation method with personal computer. Reconstructed vector diagram shows a good agreement with that obtained by a particle tracking method.

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The Savonius rotor with two semicylindrical blades is known as a dragtype wind turbine of vertical axis operation. The visualization of the flow fields around the Savonius rotor blades were observed by the tracer method using aluminum powder suspended in the water stream. The flow visualization was carried out for the absolute and relative flows with rigid and rotation camera devices.
In the case of stationary rotor, the effect of flow through the overlapping section decreases of a minus torque acting on the returning blade. The torque and power performances of rotating rotor were considerably improved by Coanda-like flow on the convex side of the advancing blade.

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In order to evaluate the comfort of the office worker, the numerical simulations of the temperature and the velocity distributions of a model room where a fan-coil unit type cooling system sets up were carried out for several different kinds of furnitures set up in the room. The value of NTDA(Number of Temperature Distribution Area) is introduced to evaluate the comfort. As a result, the value of NTDA does not show clearly the effects of each furniture itself and its configuration. Then, by using the value of local NTDA, the effects of each furniture on the comfort can be well described.

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It is difficult to remove the dust burried among the grass or a long pile of the carpet by using a conventional electric vacuum cleaner. Moreover, since the exhaust air from the cleaner contains a lot of small dust particles, this sometimes comes into question from the environmental viewpoint. For these reasons the sweeper with the "twin-swirl tube" has been newly developed by the authors. The air flow from this type of sweeper is introduced into the dust removal part and is used to fluidize and transport the dust. Therefore, it is easy to remove the dust, by using this method. Furthermore, the circulation of the flow in the sweeper has no influence on the environment. In this paper, the flow in this sweeper has been investigated by the flow visualization technique.

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Diesel fuel spray injected into air flow having a uniform velocity was visualized by shadow-graph method and its image taken by CCD camera. Spray development was considerably influenced by environmental air movement. High concentration of fuel was observed at the upstream side of spray developed along an impingement wall, and at the downstream side, fuel particles were strongly dispersed.

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The present algorithm aims to make use of wide register-width of recent microprocessois, for digital image processing. It offers simultaneous processing method of multiple pixel data which are packed in a long register.
In this paper, a simultaneous subtraction algorithm is explained first, then some examples are shown to prove. the effectiveness of the method. As applications of the algorithm, a new binarization method and simultaneous calculation of four absolutes differences. are proposed. For the four-pixel simultaneous binarization, the computation time becomes half comparing to that of an ordinary method. For the latter .calculation, it is shorten only 10% in the worst case, and 40% in the best condition. The performances are varies depending on an operating system and CPUs.

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The vortex wake generated behind two circular cylinders in staggered arrangement is investigated by discrete vortex calculation and flow visualization experiment. The discrete vortex model is based on the inviscid flow theory (Reynolds number at infinity), while the visualization experiment is carried out at Reynolds numbers from 80 to 300. The cylinder spacing parameters L/d and T/d are varied in both approaches, the former between 0.5 and 8.0 and the latter between 0.5 and 4.0. The main interest of the study consists in interaction of the wakes generated from the two cylinders, as well as phase and frequency of vortex shedding between them.

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