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Masaaki Kawaashi
2004 Volume 24 Issue Supplement1 Pages
1
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Computer Aided Surgery in the 21st century
Takeyoshi DOHI
2004 Volume 24 Issue Supplement1 Pages
5-8
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Realization of new surgical treatment in the 21st century, it is necessary to use various advanced technologies; surgical robots, three-dimensional (3-D) medical images, computer graphics, computer simulation technology and others. Three-dimensional medical image for surgical operation provides surgeons with advanced vision. A surgical robot provides surgeons with advanced hand, but it is not a machine to do the same action of a surgeon using scissors or scalpels. Recently, as an advanced vision. "Integral Videography (IV)" which can project full color 3-D video image in real 3-D space is developed in Japan. The advanced vision and hands available to surgeons are creating new surgical fields, which are minimally invasive surgery, non-invasive surgery, virtual reality microsurgery, telesurgery, fetus surgery. neuro-informatics surgery and others in the 21st century.
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Michitaka Hirose
2004 Volume 24 Issue Supplement1 Pages
9-12
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Since the word "Virtual Reality" was invented in 1989, quality of the technology has been improved more and more. Especially, development of IPT (Immersive Projection Technology) largely contributed to generate highly defined virtual world, and to give VR technology lots of 'serious applications'. Doubtlessly, visualization is one of the most promising applications. In this paper, several recent topics of VR technology such as virtual archeology and multi-sensory info-communication technology are introduced in terms of visualization technology.
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Tokuji MIYASHITA, Masaya MITSUISHI
2004 Volume 24 Issue Supplement1 Pages
13-16
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Recently, bottom-up nanotechnology for constructing soft-nanodevices with nano-structured materials such as supramolecules, organic thin films, nano-particles, and nanotubes have been of interest. Precise control of their surfaces and interfaces becomes gradually key technique. We have developed a new type of polymer nano-sheets with Langmuir-Blodgett technique for the surface coating and interface control in fabrication of nano-devices.. It is found that N-alkylacrylamide polymers form a two-dimensional net-work on the water surface with most condensed molecular packing. The condensed polymer monolayers (polymer nano-sheet) can be transferred onto solid substrates to build up various functional molecular devices. In this presentation, the surface modification with fluorinated polymer nano-sheet and visualization of nano-confined area with emissive ruthenium complex and rare earth metal complex nano-sheets are described.
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"Macro, Mezzo to Micro/Nano"
Koichi Hishida, Yohei Sato
2004 Volume 24 Issue Supplement1 Pages
17-20
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Adding particles or bubbles to a flow dramatically complicates characterization of the flow and quantitative measurement techniques are expected to elucidate the mechanisms of two-phase flow, especially multi-scale dependency on its structure. The authors have developed visualization techniques such as particle image velocimetry and particle tracking velocimetry, which are applicable to fluid flows with the range from macro, mezzo to micro/nanoscale. From a viewpoint of macroscale, the energy transfer from large to small eddies in a turbulent two-phase flow has been quantitatively investigated by a high-speed CCD camera and a laser. While the effect of electric field on a microchannel flow has been analyzed by an optical measurement system with a spatial resolution of a few μm. Quantitative visualization will advance our understanding of the interactions between two phases, which are not yet fully understood.
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Tsutomu TAJIKAWA, Kenkichi OHBA, Katsuhiro HIGUHCI
2004 Volume 24 Issue Supplement1 Pages
21-24
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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It is the first step to proper appreciation of human cardiovascular system to clarify the microcirculatory blood flow. Especially, because of red blood cell (RBC) play an indispensable role in mass and gas transfer in capillary vessel, it is important to make clear the behavior of RBC in capillary. And it is well know that RBC passes through capillary whose diameter is smaller than that of RBC with small pressure gradients. In this study, new micro-channel array devices which are able to adapt to evaluating both the throughput of whole blood and the deformability of RBC are developed. As a result of observing RBC in micro channel, deformation of RBC can observed clearly. And 3 kinds of typical deformation were observed. In the case of bullet-shaped deformation, the RBC was not deformed as the well known parachute-shape in narrowest capillary vessel whose diameter was smaller than RBC diameter.
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Norichika KOJIMA, Toru MIYOSHI, Fumihiko MIKAMI, Nobuhide NISHIKAWA
2004 Volume 24 Issue Supplement1 Pages
25-28
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Hele-Shaw flows around micro obstacles are visualized by using micro streaklines generated by two-beam interference technique of UV laser, in combination with the photochromic method. This type of flow is a model of blood flow in the lung. Two types of flow channels are used: (1) the Hele-Shaw cell on the slide glass containing irregular shaped obstacles of about 300μm in size, (2) the microfluidic PDMS chip containing 200μm diameter cylinders. The flow in the both cells are visualized by streaklines with their interval in the order from 80μm to 90μm. It was found that the visualized image agrees with the potential streaklines calculated by a panel method.
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Kensuke KANDA, Hisamasa TAUCHI, Ming YANG
2004 Volume 24 Issue Supplement1 Pages
29-30
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This study aims at visualization of the flow near the wall surface in microchannelusing evanescent wave on a near-field optical microscope. A system was developed for the visualization, which consists of total reflection fluorescent microscopy, Intensified CCD camera, PIV image processing system, microchannel, syringe pump. Including Brownian motion of particle with diameter of 100nm or less was evaluated. Flowanalysis near the surface of a wall was performed. The influential factors onvisualization of micro-flow were evaluated quantitatively. The flow rate near the surfacein a microchannel is measured. The validity of developed experimental system wasshown. On the other hand, using 60nm diameter fluorescent particles, flow analysis was performed. The technique is applicable for analyzing bio-fluid with bio-molecules tracer.
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Satoshi SOMEYA, Shin NAKANE, Yasuhiko SUGII, Koji OKAMOTO, Haruki MADA ...
2004 Volume 24 Issue Supplement1 Pages
31-32
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Ethanol-Water parallel flow in a micro-channel is numerically studied. A non-linear share stress near the interface is rudimentary represented using Kortweg-stress-model, which depends on a concentration gradient. The Korteweg-stress-model works well and the calculated share stress corresponds with the measured one, though there are many assumptions in our simulation.
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Yasuhiko Sugii, Remi Okuda, Koji Okamoto
2004 Volume 24 Issue Supplement1 Pages
33-36
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper describes a new high-speed micro PIV technique for measuring both of red blood cells velocity and plasma velocity to investigate rheology of blood flow in a microcirculation. The measurement system consisted of epi-fluorescent microscope equipped with high-speed camera with image intensifier and two sets of color filters. The technique was applied to in vitro blood flow through micro round tube of 100μm diameter. Velocity distributions of fluorescent dyed RBC and plasma seeded with fluorescent particle were obtained separately. The obtained velocity distribution achieved high spatial resolution with 9.0μm×2.2μm and high temporal resolution at 6000Hz. The technique is useful for investigation of blood rheology in a microcirculation.
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Noriyoshi YONEHARA, Yasufumi YAMAMOTO, Tomomasa UEMURA
2004 Volume 24 Issue Supplement1 Pages
37-38
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Velocities in a micro-channel, 100μm in width and 30μm in depth, are measured by using a newly developed micro-PTV system. The experimental channel is straight and its upper and lower sidewalls are partly replaced by air-water interfaces. Stereo pictures are taken by high resolution video cameras. Diameter of tracer particles was 2μm. This system enables to measure 3D velocity components in a micro-scale space. By utilizing a pair of telecentric lenses, deeper depth of fields and parallel projection pictures can be realized. The depth of fields covers up to 100μm, and parallel projection pictures make calculations of 3D recovery far simpler than that using perspective pictures.
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Kyosuke SHINOHARA, Yasuhiko SUGII, Arata AOTA, Akihide HIBARA, Takehik ...
2004 Volume 24 Issue Supplement1 Pages
39-42
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper reports a new technique of micro-resolution Particle Image Velocimetry (PIV). To investigate transient phenomena in a microfluidic device, a high-speed micro-PIV technique was developed by combining a high-speed camera and a continuous wave (CW) laser. The technique was applied to a micro-counter-current flow, consisting of water and butyl acetate. The velocity fields of water in the micro counter-current flow were visualized for a time resolution of 500μs and a spatial resolution of 2.2 x 2.2 μm. Using the micro-PIV technique, the vortex-like motions of fluorescent particles around the water-butyl acetate interface were captured clearly.
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Won-je Lee, Masaaki Kawahashi, Hiroyuki Hirahara
2004 Volume 24 Issue Supplement1 Pages
43-46
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Pulsatory or oseillatory gas flows in micro-channel are obsorved in some engineering devices and biological cases. One of the typicral cases is the oscillatory air flow in bronchiole of human lung. The mechanism of gas transfer and diffusion in it has nut been clarified in detail. As the first approach of the subject. oscillatory flows in straight and T-shalred micro-channels have been measured by PIV at different phase of the oscillation in order to eslablish the fundamental technique of PIV measurements on oscillatory air flow in a micro-channel and the techniques of tracer particle suspension. illumination. image capturing and so on have been investigated in this report
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3rd Report: Finite Difference Analysis of Two-Dimensional Steady-State Heat Conduction Problem by Icon Cell
Toshio TOMIMURA, Shigeki HIRASAWA, Mitsuaki HANEDA
2004 Volume 24 Issue Supplement1 Pages
47-50
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A new visual-oriented numerical method which applies the spreadsheet of Excel has been proposed. In the present study, a programming process on two-dimensional steady-state heat conduction problem in the rectangular coordinate system is explained by way of a specific example, where a volumetrically heat generating rectangular region with a concave is heated uniformly at one wall and other walls are kept at some temperatures. The present steady-state numerical calculation has been realized by introducing icon cells in which difference equations concerning the inner, boundary and singular points etc. are embedded. Through the programming process using this specific model, the proposed method is shown one of the useful numerical methods.
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Susumu SHIRAYAMA, Yuichiro UENO
2004 Volume 24 Issue Supplement1 Pages
51-52
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In this paper, we propose a new displaying system of the visualized results. The concept of tangible user interface (TUI) that can operate digital information physically and intuitively is introduced into wall visualization (WV) that has achieved various effects such as the collaborations among researchers, a presence and a full-scale, and provided an immersive virtual environment by displaying information to a large screen. And then, key techniques for constructing a system are examined, and the part of the system is implemented.
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an attempt of interactive visual data mining
Machiko Nakagawa, Chiemi WATANABE, Sachiko HAYASHIDA, Kazuki JO
2004 Volume 24 Issue Supplement1 Pages
53-54
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In recent years visualization technologies are used not only for presentation but also for visual data mining which are techniques for mining new knowledge by visualizing and analyzing the data from multiple view point. In this paper, we considered about visual data mining for atmospheric data, and actually implemented the interactive visualization system which lends to visual data mining using the polar stratospheric data.
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Akiyoshi IIDA, Akisato MIZUNO
2004 Volume 24 Issue Supplement1 Pages
55-58
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Vorticity structures and flow field around a rotating circular cylinder at Reynolds numbers between 102 and 104 was numerically visualized. Velocity ratio of the uniform velocity and the rotational velocity of the cylinder was changed from 0 to 3. At low velocity ratio, the wake has anti-symmetric vorticity structure and lift-drag ratio is rapidly increasing. However, when the velocity ratio exceeds about 2, an absolute value of lift-drag ratio becomes small and alternative vorticity structure disappears. As a result, fluctuation of the aerodynamic forces turn weakness and the resulting aerodynamic sound becomes small. Source term of aerodynamic sound was also visualized by using results of CFD analysis. Sound source term generated large scale eddies disappeared at high velocity ratio. It reveals that rotating cylinders are effective for reduction of aerodynamic sound.
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Shu TAKAGI, Gota KIKUGAWA, Yoichiro MATSUMOTO
2004 Volume 24 Issue Supplement1 Pages
59-62
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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We present a novel definition of the local and instantaneous interface of the liquid-vapor equilibrium system from the microscopic point of view. In this definition, the density distribution, which is given by the position of discrete particles from molecular dynamics (MD) simulation, is described as the field quantity. In other words, we make the density distribution, which is inherently described by the summation of the delta functions, smoothed by distributing the smoothed delta function on the position of each molecule. The surface position is defined as the position on which the field has the certain density value, and the distance function from the surface can be evaluated by the reinitialization procedure of the level set method. In order to investigate the physical meaning of our proposed definition of the instantaneous interface, we calculated the averaged position of the instantaneous interface, and found that it shows a good agreement with the position of the equimolar surface which is defined thermodynamically in the Gibbs's manner.
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Motohiko ARAI, Tsuneaki ISHIMA, Tomio OBOKATA
2004 Volume 24 Issue Supplement1 Pages
63-66
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A water storage tank is proposed to be used at the heavy damage of water supply lines in a city. Though the tank is a part of water pipeline in usual case, it works as the storage tank for drinking water at the emergency case like as an earthquake. As water is used for drinking, it is not expecting to have spoiled water in the stagnation zones. In this study several inlet nozzles were tested in the CFD, flow visualization and concentration measurement in a one fifth scale transparent model of the storage tank. It is shown from the results that the axial angle of water injection from the center line of the cylinder is important parameter to control the flow in the tank. Difference of flow rate brings various flow patterns at the beginning and show almost same patterns finally. The exchange rates of water are independent from the flow rate.
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Shinji NAKAGAWA, Kazuyuki NAKAYAMA, Masaru ISHIZUKA
2004 Volume 24 Issue Supplement1 Pages
67-68
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Cooling air flow in a thin electronics casing was measured using PIV. Temperature rise in the casing was also measured. The effect of the arrangement of the inlet opening on cooling performance was examined. Measured vector maps shows that the change of flow direction is relatively small. As a result, cooling performance is maximized when the distance between the opening and the heat source is small.
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Yoji KITAMUA, Masaru ISHIZUKA, Shinji NAKAGAWA, Yasushi NISHINO
2004 Volume 24 Issue Supplement1 Pages
69-72
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper presents the results of experimental and numerical studies on the effect of casing inclination on the temperature rise across the casing. The numerical simulation was carried out to find the thermal behavior inside a thin electronic casing. The simulation results are in good agreement with the experimental data. From the results, it was found that the natural air cooling capacity was improved by increasing the inclination angle of the casing. In addition, comparison between the visualization results of PIV and a numerical simulation results was carried out.
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Ken ISHIHARA, Naofumi SAEKI, Haruo OHNO, Nao NINOMIYA, Hitoshi SUGIYAM ...
2004 Volume 24 Issue Supplement1 Pages
73-76
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In order to minimize the wind noise generated by a Sirocco fan, it is most important to understand the details of the flow field about a Sirocco fan. As the shape of a Sirocco fan is very complicated, it has not been very easy to capture the flow patterns. Presently, the authors have utilized the spark tracing method to visualize the flow field around a Sirocco fan and have observed the flow patterns between the blades with and without the intake load. It has been proved that the intake load causes the drastic changes on the inflow pattern and thus the changes of the flow pattern, which might be the major cause of noise, in the scroll chamber. In order to visualize the flow pattern between the blades of a rotating fan, presently the visualized images have been rotated digitally, instead of using complex image rotator such as Pecham prism.
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Teruyoshi YAMAZAKI, Masahiro TAKEI, Yoshifuru SAITO, Kiyoshi HORII
2004 Volume 24 Issue Supplement1 Pages
77-78
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This study proposes a novel image processing for PIV images which is called a modal wavelet transform. In this study, green function type of modal wavelet transform has the analysis as well as Dirichlet type and Neumann type. Green function type of modal wavelet transform has high performance in the same way as Neumann type of modal wavelet transform for image correlation of a PIV image.
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Masaki YAMAGISHI
2004 Volume 24 Issue Supplement1 Pages
79-82
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The vortex structures in a wake of Savonius rotor are different from those of circular cylinder. The structures are generated in synchronization with rotation of rotor. In order to investigate the velocity field and its principle motion, phase averaging was conducted to the velocity signals obtained by single hot-wire measurement. In phase averaging, wavelet transformation was applied to obtained the dominant frequency and the characteristic phase angle in the fluctuation. The profiles of the phase-averaged velocity could be found and discussed. The accelerated velocity region behind the advancing bucket shed to downstream in a half cycle of rotation. In a cycle of rotation, two accelerated regions merge into one structure. On the other hand, behind the reversing bucket one accelerated region shed in a cycle.
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A. RINOSHIKA, Y. ZHOU, T.M. ZHOU, M. NAKANO
2004 Volume 24 Issue Supplement1 Pages
83-86
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper presents an investigation of the Reynolds number effect on vorticity in the turbulent intermediate wake of a circular cylinder. All three components of the vorticity vector were simultaneously measured using a multi-X-wire probe. The measured data were analyzed by a wavelet multi-resolution technique that decomposed each vorticity component into a number of wavelet components based on different characteristic frequencies. It is observed that the measured rms values of all the vorticity components increase as Reynolds number increases. However, the spanwise worticity variance of large and intermediate-scale structures are quite evenly contribution at Re=5000 and 2500, respectively.
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Masami NAKANO, Daiki TSUCHIDOI, Koji KOHIYAMA, Akira RINOSHIKA, Keiich ...
2004 Volume 24 Issue Supplement1 Pages
87-90
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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An active control strategy is applied to a circular air jet impinging on a plate with a hole of a jet axis, in order to suppress the self-sustained oscillation of the jet (Hole-tone phenomenon) and the associated noise. The jet shear layer is acoustically excited at the jet exit using six loud speakers installed in an excitation chamber, in a manner of sinusoidal mode. The jet responses have been investigated by the spectrum and wavelet analyses. It was found that the response characteristics were varied variously with the excitation frequency fe and amplitude, and were clearly classified into fe lock-in, fe/2 lock-in, and non folock-in regimes. The excitation condition for each regime was clarified. The periodic phenomenon with periodic vortex rings of uniform scale and the non-periodic phenomenon with the vortex rings of many different scales were visualized by the smoke-wire visualization technique of the jet and the wavelet analysis.
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Hitoshi MIYAMOTO, Daisuke YAMANAKA
2004 Volume 24 Issue Supplement1 Pages
91-94
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Organized motions and mean flow structures in an open-channel cavity flow are examined by using wavelet transforms. Experimental data of velocity vectors are obtained by the particle image velocimetry (PIV). The multiresolution approximation (MRA) is used to extract velocity components of the organized turbulence and the mean flow structures from the PIV data. Distributions of an instantaneous Reynolds stress of the organized turbulence are analyzed by using the two-dimensional continuous wavelet transform (2D-CWT) to detect spatial scales and locations of the organized motions. Characteristics of the organized motions and their dependence on the hydraulic parameters, such as Reynolds number and Froude number, are discussed in detail.
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Wavelet multi-resolution Analysis
Takahide TABATA, Masahiro NAKASHIMA, Hui LI, Tsutomu NOZAKI
2004 Volume 24 Issue Supplement1 Pages
95-96
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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By using the methods of the flow visualization and the PIV, the diffusion of water jet flow issuing from the circular pipe with the fluttering fin has been described in this paper. Moreover, the large and middle scale structures of the jet have been investigated by applying the wavelet multi-resolution analysis to the image information obtained from the LIF method. As a result, it has been found that the jet diffusion is largely affected by the fluttering fin and the difference of the structure is recognized between the water jet with the fluttering fin and that without one.
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Nobuatsu TANAKA, Takaya TAGUCHI
2004 Volume 24 Issue Supplement1 Pages
97-98
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Direct numerical simulation of two-dimensional incompressible flow is performed using 4
th order spline wavelet. The Poisson. equation between stream-function and vorticity can be efficiently solved by diagonal preconditioning following discrete wavelet transform. The transform coefficients of vorticity or stream-function make clearly understandable of the multiscale structure of solution.
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Takuya Tsuji, Takehiko Yokomine, Akihiko Shimizu
2004 Volume 24 Issue Supplement1 Pages
99-100
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Extraction of coherent structure of turbulence by the wavelet thresholding method is demonstrated. The method is not only a basis of dynamically adaptive algorithm but a powerful tool to improve our understanding of physics of turbulence. The method is applied to steady isotropic homogeneous turbulence filed. It is shown that the wavelet can extract the energetic components with lower degree of freedom while the multi-scale nature of turbulence is not destroyed.
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Tomomasa Uemura, Yasufumi Yamamoto, Noriyoshi Yonehara, Manabu Iguchi
2004 Volume 24 Issue Supplement1 Pages
101-104
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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When bubbles rise through a liquid-liquid (water-oil) interface, the lower liquid is entrained into the upper liquid. Many water droplets are generated in oil layer, and they influence the phenomena of heat and mass transfer between the liquids.
In the experiments, silicone oil of 1 cSt is poured on water with 100mm depth. By utilizing a high-speed and hi-resolution video camera, it is found that there are three different processes in generating droplets. The largest class of droplets originated from entrained water columns, while the second class ones were born when penetrating water jets break. The jet appears when water film, which wraps up a bubble, is broken and slips down to a bottom of the bubble. The smallest droplets appear in the vicinity of bubbles when entrained water leaves bubbles.
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Fumio TAKEMURA
2004 Volume 24 Issue Supplement1 Pages
105-106
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Migration velocities of spherical, solid particles suspended in silicon oil near a vertical wall were measured at finite Reynolds number. The sedimentation velocity and the distance between the particle and the wall were measured as a function of time and the lateral migration velocity calculated. The migration velocity was also estimated by assuming that for the flow disturbance produced by the particle, the wall lies in either the Stokes or Oseen regions. The measured and calculated velocities were compared. The results indicate that as the particle migrates away from the wall, that the velocity components parallel to and normal to the wall transits from the Stokes to the Oseen regions. The results also show that the deviation of the calculated values from the measured values increases as Re increases. Empirical equations are proposed to estimate the velocities parallel to and normal to the wall for Re<5, including the transition regions.
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Syuuzou YAMADA, Satoru USHIJIMA
2004 Volume 24 Issue Supplement1 Pages
107-110
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The incipient motion of a solid particle in water flows is experimentally and numerically investigated. The critical flow rate, in which an acrylic cylinder starts to move, was evaluated in a duct flow. Then, the flow field in the critical flow rate was measured by PTV and it was shown that the wake region is turbulent and that the intermittent vortex shedding occurs. The incipient motion of a particle was numerically predicted with MICS, which allows us to predict incompressible flows including multiple moving bodies and particles. As a result of computations, it was shown that the flow field and the initial movement of a particle are satisfactorily predicted.
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Hiroshi FUKUDA, Yoshihiko OISHI, Yuichi MURAI, Fujio YAMAMOTO
2004 Volume 24 Issue Supplement1 Pages
111-112
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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As a basic study of skin friction reduction using bubbles, the relationship between the skin friction and the bulk void fraction in a horizontal rectangular channel is investigated experimentally for Re=9700. The skin friction is reduced for the void fraction larger than 17% in our test facility, in which the bubble size ranges from 2 to 30mm. The negative correlation between the local skin friction and the local void fraction is confirmed by a time-resolved synchronized measurement, and we also found that the local skin friction decreased in the rear region of large bubbles.
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Kazuma YASUDA, Nao NINOMIYA, Hitoshi SUGIYAMA, Daisuke HITOMI
2004 Volume 24 Issue Supplement1 Pages
113-114
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Although the phenomena related to the multiphase flow can be found in many kinds of industrial and engineering applications, the physical mechanism of the multiphase flow has not been investigated in detail. The major reason for the lack of data in the multiphase flow lies in the difficulties in measuring the flow quantities of the multiple phases simultaneously. Presently, the simultaneous visualization and the velocity measurement have been carried out about the both phases of the liquid-liquid two-phase flow. The difference in the reflective indices makes the visualization in the vicinity of the boundary of the multiple phases almost impossible. In this study, the reflective index of the aqueous phase has been equalized to that of the oil phase by adjusting the concentration of aqueous solution. The results show the flow structure both inside and outside of a falling water droplet in the stationary oil simultaneously.
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Shigeo HOSOKAWA, Kenjiro IMAI, Akio TOMIYAMA
2004 Volume 24 Issue Supplement1 Pages
115-116
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Three-dimensional PIV, which can measure the three-dimensional distribution of three components of fluid velocity, was developed in this study. This method utilizes the fact that the intensity of scattered light from a particle is proportional to the intensity of laser beam at the particle position. Making the intensity ratio of two laser beams as a function of position realizes the determination of particle position from the intensity ratio of scattering of the two beams. The velocity vectors can be measured by using the cross-correlation of thus measured particle distributions. The developed method was applied to flow around drops and its feasibility was confirmed through the measured results.
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Naohisa TAMURA, Norihiro FUKAMACHI, Tatsuya HAZUKU, Tomoji TAKAMASA, T ...
2004 Volume 24 Issue Supplement1 Pages
117-120
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In view of the great importance of two geometrical parameters such as void fraction and interfacial area concentration to the accurate two-phase flow analysis at microgravity conditions, axial developments of flow parameters such as void fraction, interfacial area concentration, bubble Sauter mean diameter, and bubble number density were measured by image-processing in bubbly flow at microgravity and low liquid Reynolds number conditions where the gravity effect on the flow parameters were pronounced. Negligible bubble breakup was observed because of weak turbulence under tested flow conditions. The velocity profile entrainment effect under microgravity was likely to be comparable to the wake entrainment effect under normal gravity in the tested flow conditions.
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Akiko FUJIWARA, Kazuhiro WATANABWE, Shu TAKAGI, Yoichiro MATSUMOTO
2004 Volume 24 Issue Supplement1 Pages
121-122
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In the present study one of the effective techniques for micro-bubble generation by using converging-diverging nozzle (venturi tube) is introduced. Rapid pressure recovery in the diverging area induces bubble fission. The purpose of the present study is to clarify the mechanism of the bubble breakup. The results suggest that micro-bubbles are generated by the bubble fission in the case of the cavitation number of less than 1.0. By using a high-speed camera, several kinds of bubble breakup phenomena were observed in detail.
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Masaaki ISHIKAWA, Koji OKAMOTO, Haruki MADARAME
2004 Volume 24 Issue Supplement1 Pages
123-124
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Bubbly flow is a complicated flow because a bubble is deformable and the bubble-bubble and interactions work in local area including a lot of bubbles. Such flow occurring turbulence in liquid phase by each bubble is called "pseudo turbulence". A PIV is most effective to measure bubbly flow because of multidimensional measurement. Recently Dynamic PIV system consisted of high-speed camera and high-repetition laser is developed, it is possible to capture images with high resolution and time series. In this study simultaneous measurement of bubble and liquid phase is carried out using Dynamic PIV system with a high-speed camera and a double-pulse laser and an infrared laser.
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Yoshihiko OISHI, Yuichi MURAI, Fujio YAMAMOTO
2004 Volume 24 Issue Supplement1 Pages
125-126
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Particle tracking velocimetry is applied to a bubbly two-phase flow in a horizontal channel to investigate the mechanism of turbulent shear stress reduction using bubbles. We derived three componential stresses to express the phenomenon hidden in the turbulent shear layer and measured them with the PTV data at Re=4×104. It is newly found that the role of a vertically correlated shear stress is important to reduce the total stress effectively.
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Makoto YAMAUCHI, Akihiro SHIMOTANI, Yasumasa YOSHITANI, Tomomasa UEMUR ...
2004 Volume 24 Issue Supplement1 Pages
127-128
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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It is an important problem to understand the amount of heat and mass transfer phenomenon between two kinds of fluids in multi-phase flows. The inner flow of the bubble is driven by the outer flow trough the interface, when a bubble rises in a continuous phase such as water. The interfacial property shows the solid wall by the influence of a strong contamination. However, there is no experimental data such as the quantitative relation between the interface flow and contaminated interface of the bubble. This study aims to measure the velocity of interface flow by using image measurement technique. In this paper, the interface velocity could be estimated. As a result, interface flow of a spherical bubble corresponded to the theoretical solution by Hadamard. Therefore, inner flow of a bubble must be the theoretical flow pattern.
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Kazuya HASHIMOTO, Hiroki TANNO, Satoshi KOIKE, Tetsuo Izumi, Eiji EJIR ...
2004 Volume 24 Issue Supplement1 Pages
129-132
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Water management is one of the most important factors in efficient operation of a polymer electrolyte fuel cell, which is now actively under development aiming at practical application to home cogeneration systems, automobiles and mobile machines. This paper describes the influence of cell posture, humidity and utilization factor of supplied gases, and duration time of operation on the fuel cell performance of power generation in terms of water management. A test single cell with open channel separators and transparent endplates was specially manufactured to visualize moisture generation and two-phase flow in the anode and cathode channels of the cell. The results show that the amount of condensed water in the channels greatly varies with operating conditions and directly links to the cell performance of power generation.
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Kenji KIKUCHI, Osamu MOCHIZUKI
2004 Volume 24 Issue Supplement1 Pages
133-134
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The purpose of our study is to apply Mosquito's sucking blood mechanism to a pump of μ-TAS for checking blood. We want to know how high the power of Mosquitos pump is have. This paper presents a structure of Mosquitos bio-pump, and its characteristics as mechanical pump. We made the mosquito feed blood of an arm. Pictures are taken by SEM, and many slices of a mosquito with 2μm thickness after fixed by wax were made. We anatomized the mosquito's head and picked up the bio-pump under the microscope. The mosquitos bio-pump is found to be enough power to apply a pump of μ-TAS.
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Arao KAMOI, Yoshizo OKAMOTO
2004 Volume 24 Issue Supplement1 Pages
135-136
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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It is said that an eye reflects the condition of heart in the facial expression. This paper describes the experimental results on behaviors of eyes of a youth and an old age before and after physical exercise or spiritual mind's change. They were evaluated by the power spectral density of temporal radiation temperature distributions of an eye which were appeared in the dynamic thermograms of face by using infrared thermography. In this experiment the authors clarify that dynamic behavior of an eye does not follow the 1/f theory which is adopted in the natural phenomena such as twinkling of stars, murmuring of a stream, and so on.
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In the case of existence of airway mucus
Ryosuke KOMIYA, Masataka Iwasaki, Atsushi SAKURAI, Tsutomu TAJIKAWA, K ...
2004 Volume 24 Issue Supplement1 Pages
137-138
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Bronchial asthma is a kind of chronic bronchitis. It causes the airway narrowing happen and so makes breathing difficult. Generally, airway has many folds into the airway lumen on buckling, but thickening airway wall in asthmatic airway decreases folds. Besides, discharged airway mucus in asthmatic airway is much and thick, so it is caused to airway obstruction by retention of mucus. In this study, to clarify the mechanism for re-opening on occluded airway, we tried to visualize tube cross-section and a re-opening process using a collapsible tube applied silicone oil as a model of an airway with an airway mucus. The tube was applied a rapid transmural pressure change. As a result, a model with oil took longer time until re-opening than that without oil and re-opening time became shorter with increasing in buckling mode number.
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Shinnichi IIDA, Kenkichi OHBA, Tsutomu TAJIKAWA, Masataka YOSHIDA, Fuy ...
2004 Volume 24 Issue Supplement1 Pages
139-140
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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One of the known cure for ascending aortic aneurysm is vascular grafting surgery using composite graft. But almost conservative grafts don't have Valsalva sinus, and the influence of existence of Valsalva sinus isn't clarified. In order to understand effect of Valsalva sinuses, some realistic models of aortic valve were manufactured. In this study, we have produced modeled aortic valves with three-dimensional modeling machine, and have investigated the effect of the Valsalva sinus and leading angle of coronary artery on blood flow and the flow field in the Valsalva sinus. As the result, displacement of the valve leaflet of which the model has Valsalva sinus is smaller than that of model without Valsalva sinus.
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Takahiro CHIDA, Masahiro NISHIDA, Katsunobu NONAKA, Takashi YAMANE, Ka ...
2004 Volume 24 Issue Supplement1 Pages
141-142
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A circulatory assist pump, which can be used for around two weeks after an operation, is under development by AIST. The centrifugal impeller is supported with a magnetic suspension and a monopivot. The effect of the expansion of the back gap of the impeller was investigated with flow visualization in the present study. Since a sufficient wash by a secondary flow was found around the pivot, no thrombus will be expected and a longer durability of the pivot can also be expected for a monopivot pump. Regarding the outlet and the tongue, it was found that a model with a round tongue and a smoothly expanding outlet is more suitable to the blood pump.
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Masahiro NISHIDA, Daisuke SUGIYAMA, Hanako JOHO
2004 Volume 24 Issue Supplement1 Pages
143-144
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Quantitative flow visualizations using Particle Tracking Velocimetry (PTV) and Particle Image Velocimetry (PIV) were performed to remove the origin of hemolysis to obtain the suitable design criteria. Particular attention was paid to the relationship between the high shear area and hemolysis. As a result, the shear velocities in the high hemolysis pump were higher than those in the low hemolysis pump near the casing wall by the results of both PTV and PIV. However, the shear velocities by PIV were half times as large as those by PTV in a current comparison.
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Yoshinori AKEDO, Marie OSHIMA, Tetsuo SAGA
2004 Volume 24 Issue Supplement1 Pages
145-148
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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It is assumed that cerebral homodynamics is an important factor for the cerebrovascular disorders such as subarachnoid hemorrhage. Since a blood vessel has bend and bifurcation with pulsatile blood flow, the flow structure becomes complex and in the three-dimensions. In order to obtain the information on velocity components at an orbital location and time, the stereo PIV technique is applied to measure and visualize flow in the realistic cerebral aneurysm model, which is based on the medical image data. Because it is difficult to place the calibration plate, the paper presents the calibration method such that laser beams create calibration points. As a result, the flow structure along the aneurysm is observed successfully.
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Koichi NISHINO, Daisuke KAWAGUCHI, Hidetaka SATO, Haruo ISODA, Takashi ...
2004 Volume 24 Issue Supplement1 Pages
149-152
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper presents PIV results and CFD results obtained for in vitro flow behaviors in a cerebral aneurysm. Non-pulsating flow, Re=700, is investigated as a first step. The MRI data acquired from an actual patient are reconstructed into a digital three-dimensional model, from which a transparent silicone rubber model suitable for flow visualization is fabricated by using a rapid-prototyping technique. A commercial CFD code based on the finite volume method is utilized. The PIV measurement, realized by the index matching technique, has revealed that the flow velocity in the aneurysm is low, that there is a recirculation zone in the center of the aneurysms and that the flow in the bleb is stagnant. These features are in agreement with the CFD result, which shows in addition that the wall shear stress is high at the entrance and the exit of the aneurysm but low on its internal wall.
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