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辻井 剛
2003 年 23 巻 Supplement1 号 p.
1
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
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滝川 雅之, 秋元 肇, 須藤 健悟, 高橋 正明
2003 年 23 巻 Supplement1 号 p.
5-6
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
A quasi-realtime calculation system for the global distribution of O
3, NO
x, HO
x, and NMHCs by using a chemical AGCM for study of atmospheric environment and radiative forcing (CHASER) has been developed. The model is based on the version 5.4g of the Center for Climate System Research/National Institute for Environmental Studies (CCSR/NIES) AGCM. A7 days'forecast is executed once a day by using the NCEP reanalysed and forecasted dynamical field, and the model result is available on the WWW.
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加藤 貞二
2003 年 23 巻 Supplement1 号 p.
7-10
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
In-situ visualization of structures of monolayers (Gibbs monolayers and Langmuir monolayers) at the water surface by the phase contrast microscope, the fluorescent microscope, Brewster angle microscope and second harmonic generation microscope is summarized. Ex-situ visualization of the monolayer structures using the friction force microscope is also explained.
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山口 玲央
2003 年 23 巻 Supplement1 号 p.
11-12
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Web3D is the general term for techniques of three dimensional computer graphics on Internet(Web). The idea of VRML of which mechanism was formed at the beginning of 90's, was completely hanged. It is characteristic that the shift to the offer of rich media contents with pursued realistic image by utilizing the broad-band network. This Web3D techniques was developed mainly aiming at the electronic commerce etc. It is further used as a visualization tool for the simulation system solved on a large-scale computer. An example of the Optimum Towing Support System using Web3D is referred.
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近江 和生
2003 年 23 巻 Supplement1 号 p.
13-16
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The genetic algorithm (GA) had been already effectively applied by the present authors to the temporal particle pairing problem of the two-dimensional PTV (Particle Tracking Velocimetry) system software. The algorithm has been further refined and is now applied to the spatial particle pairing problem of the stereoscopic three-dimensional PTV system software. Every individual particle in the left-camera image should be correctly paired with the most probable partner in the right-camera image. The basic methodology of this spatial particle pairing is a classical epipolar line analysis and the object (fitness) function of the present genetic algorithm also uses the concept of this type of analysis. As a result of the performance check using synthetic PIV images, the new algorithm is capable of increasing the number of correct particle paring by a factor of 8 to 22% with respect to the classical epipolar line analysis method.
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西尾 茂, 岡本 孝司
2003 年 23 巻 Supplement1 号 p.
17-20
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Present study considers the mathematical basis of PIV analysis for multiple-time-step image, which enables to obtain the acceleration and spatial derivatives of velocity field directly from the image information. The advantage of present approach is the possibility to get the spatial derivatives at the same time of velocity and acceleration. The algorithm keeps consistency of measurement principles whole through the procedure. Total consideration of mathematical background for higher-order terms enables to derive appropriate approaches for the modification of PIV algorithms and it will contribute to achieve higher performances.
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山本 恭史, 赤松 祐也, 米原 紀吉, 植村 知正
2003 年 23 巻 Supplement1 号 p.
21-24
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Some calculation schemes of spatial gradient for spatio-temporal derivative method, which was used for sub pixel displacement detection, were evaluated. It was found that the second-order accurate central finite difference scheme tends to underestimate the gradient of tracer-particle's intensity, so that it leads to overestimation of sub-pixel displacements. In this study, upstream and downstream finite difference scheme was proposed and evaluated. It was shown that the proposed scheme has high accuracy and is robust to noise.
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藤田 一郎
2003 年 23 巻 Supplement1 号 p.
25-28
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
It can be expected from the recent developments of high-speed video camera that novel image analysis methods would be devised by utilizing its advantages over conventional video cameras. The most advantageous feature of a high-speed video camera is of course its improved time resolution. In this paper, a new PIV method that uses more than two consecutive images is proposed in order to improve the measurement accuracy under uniform and shearing flow conditions. The use of a few consecutive images with a small time separation is possible only when a high-speed camera is available. The accuracy of the proposed method based on the optical flow technique was evaluated by means of a synthetic particle image simulation.
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堀 俊夫, 榊原 潤
2003 年 23 巻 Supplement1 号 p.
29-32
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Measurement error of particle image velocimetry (PIV) associated with calibration functions based on polynomial camera model and pinhole camera model was evaluated numerically. The fitting error of each calibration function was evaluated using a virtual calibration grid generated by ray-tracing method. Pinhole camera model gave smaller calibration error than polynomial model. Error including grid-detecting procedure was also evaluated by the simulated calibration grid image. The error was larger than the fitting error only, and has no obvious dependency on the camera model. Stereo-PIV measurement was performed using the simulated particle image of the uniform flow field with the above calibration functions. Both camera models gave approximately the same magnitude of errors, but strongly sensitive to the angle between camera axis.
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明渡 佳憲, 大島 まり, 佐賀 徹雄, 小林 敏雄
2003 年 23 巻 Supplement1 号 p.
33-36
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
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, the flow structure is in the three-dimensions. The Stereo PIV is a suitable method for measurement of complicated flow phenomena. The Stereo PIV uses a plate in a measurement domain for calibration. However, if the domain is complicated, it is difficult to place such an object. In this research, we have presented a noninvasive calibration method using a calibration point created by laser beams.
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植村 知正, 山本 恭史, 米原 紀吉, 赤松 祐也
2003 年 23 巻 Supplement1 号 p.
37-38
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The spatio-temporal differential method(gradient method) can be one of the high precision algorithms for PIV analysis. But, when the method is applied to actual PIV pictures, measurement precision cannot be so good as is expected. It is found that inadequate numerical differentiations and peak-locking phenomenon degrade its intrinsic characteristics. The first issue is discussed in a separate paper. In this paper, the peak-locking phenomena for PTV with various picture conditions and influences of interpolation methods on the phenomenon are examined and discussed. Some methods to reduce the peak-locking error are recommended, and the precision of less than 0.05 pixel ambiguity could be realized.
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西尾 茂, 村田 滋
2003 年 23 巻 Supplement1 号 p.
39-42
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
An error-evaluation method in PIV image analysis was considered, and error indexes for the evaluation were proposed. The error sources in PIV image analysis was categorized into two groups, i.e., (1) pair matching error (PME), (2) peak identification error (PIE). The evaluation method based on the analysis of correlation map, and statistical error indexes were proposed. The indexes aim to show the error appearance possibility of each error source. The errorevaluation method was examined by means of numerical simulations.
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新美 智秀, 森 英男, 岡部 和毅, 政井 佑介, 谷口 真潮, 西平 竜太郎
2003 年 23 巻 Supplement1 号 p.
43-46
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Aerospike nozzles have been expected as a candidate for an engine of reusable space shuttles to respond to growing demand for rocket-launching and its cost reduction. In this study, the flow field structure in any cross sections around the linear-type aerospike nozzle are visualized and analyzed, using laser induced fluorescence (LIF) of NO seeded in the carrier gas N
2 Since the flow field structure is affected mainly by the pressure ratio (P
s/P
a), the linear-type aerospike nozzle is set inside the vacuum chamber to carry out the experiments in the wide range of pressure ratios from 75 to 250. Flow fields are visualized in several cross-sections, demonstrating the complicated three-dimensional flow field structures. Pressure sensitive paint (PSP) of PtTFPP bound by poly(TMSP) is also applied successfully to measurement of the complicated pressure distribution on the spike surface.
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濱田 隆弘, 野崎 勉, 福原 稔, 向井 佑樹
2003 年 23 巻 Supplement1 号 p.
47-48
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
A doublet flow, which consists of a coaxial annular suction flow and a free jet was proposed by the authors and is useful for the devices, for examples, the collectors and the suction units. In order to investigate the aspects of the interaction between the free jet and the annular section flow, flow visualization was carried out using the closed flow region. As a result, there exists the very stable flow in the case of small closed flow region, but it becomes unstable flow as the closed flow region is larger.
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河原 伸幸, 冨田 栄二, 中山 崇
2003 年 23 巻 Supplement1 号 p.
49-52
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Experimental investigations of primary spray structure very close to nozzle of practical high-pressure swirl injector, which is used in gasoline direct injection (GDI) engine, were carried out. Visualizations of primary spray structure were demonstrated using a high-speed video camera with a long-distance microscope. Evaluation of system performance was investigated. Three kinds of light source, such as metal-halido lump, laser beam and laser sheet of Ar-ion laser were applied. Strong intensity of the light source is needed to obtain the image with very high camera speed. Moreover, initial state and development of the spray of the swirl injector were discussed. It has been shown that the liquid fuel column without swirl motion was injected as a compact jet at the beginning of the injection. During the injection period, the spray indicates the quasi-steady state mode. Liquid sheet from the nozzle exit has a ligament structure. Using Ar-ion laser sheet and high-speed camera, length and thickness of the liquid sheet can be measured.
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劉 渝, 児島 忠倫, 藤田 泰志
2003 年 23 巻 Supplement1 号 p.
53-56
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
In this study, the supersonic jet from a nozzle with different outlet divergent angles was visualized, and unsteady pressure and noise were conducted. The temporal averages and instantaneous flow visualization were taken by shadowgraph method. In addition, the pressure fluctuation and also occurrence of noise were examined by the change of the nozzle exit divergent angle and difference of the pressure ratio. As a result, the jet structure and also the relevancy between the self-excited vibration and jet noise were clarified.
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上埜 安隆, 村井 祐一, 山本 富士夫
2003 年 23 巻 Supplement1 号 p.
57-58
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Drops and particles will accumulate inside in a tornado even if their relative density to fluid is large enough. Our study aims to analyze the particle behavior in an artificial tornado. The visualization experiment revealed that there was an equilibrium radius where particles have a peak concentration. Numerical simulation using Rankine vortex showed that the high inertia particles are easily captured inside the vortex.
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PIV計測の精度向上
宮田 寛之, 金澤 純太郎, 高間 信行, 吉識 晴夫, 加藤 千幸
2003 年 23 巻 Supplement1 号 p.
59-60
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The purpose of this investigation is to visualize the unsteady flow induced by variable inlet guide vane (VIGV) of a small turbine for automobiles. Instantaneous flow fields of the VIGV are visualized with PIV and phase averaging method. Experimental conditions of the flow around the VIGV depend on the existence of air bubbles. In order to remove these air bubbles, stabilizing core is installed at the center of the VIGV. Rotating cells of high velocity are moving from the pressure side to the suction side, which is synchronized with pressure fluctuation. A region with strong vorticity is also moving. When the leading and trailing vorticity is increasing, throat velocity of VIGV is increasing.
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Iliana MARINOVA
2003 年 23 巻 Supplement1 号 p.
61-64
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The image processing technique based on the field theory is applied for visualization of electromagnetic fields. The inverse color problem is formulated over the image. The color source densities have been evaluated from the color distributions of the field data set. The Generalized Vector Sampled Pattern Matching method is applied to solve an ill-posed linear system of equations. The new color distributions are generated using the obtained color source densities. With the proposed approach the quality of the images can be essentially improved. Different field characteristics are obtained during image processing of the field distribution. The current distributions are determined from the locally measured magnetic field.
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新井 康平, 瀬戸 要
2003 年 23 巻 Supplement1 号 p.
65-68
発行日: 2003/07/01
公開日: 2009/12/08
ジャーナル
フリー
A compression method for earth observation data according to a chaotic behavior based on Wavelet MRA (Multi-Resolution Analysis) is proposed. The proposed method is examined by using the observed time series data of SST (Sea Surface Temperature) and the SOI (Southern Oscillation Index) data. It is found that the RMS (Root Mean Square) error of the proposed method depends on the support length of the mother wavelet.
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松山 佐和
2003 年 23 巻 Supplement1 号 p.
69-72
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
A number of data for a discrete wavelets transform is required to be a power of 2, and therefore, part of the data obtained by field observations or laboratory experiments are not frequently applied for the analyses. We propose that Fourier transform is useful to interpolate and extrapolate the data for increasing or decreasing the number of data for the discrete wavelets analysis. The raw data is firstly transformed to the Fourier coefficients by Fourier transform. Then the inverse Fourier transform makes it possible to the number of data comprising a power of 2.
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内田 朝天, 土井 達也, 増田 則夫
2003 年 23 巻 Supplement1 号 p.
73-76
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
This paper describes FDTD simulations of three-dimensional electromagnetic fields for high frequency current measurement in a micro-strip line. First, three dimensional FDTD method is applied to a micro-strip line model. Second, high frequency current distribution model is applied to identifying current distribution in a micro-strip line.
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Hui LI, Masahiro TAKEI, Yoshifuru SAITO, Kiyoshi HORII
2003 年 23 巻 Supplement1 号 p.
77-78
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
In this study, the wavelets-based PIV technique is developed for improving spatial resolution and reducing physical storage. For evaluating the effect of image parameters, this technique is applied to standard experimental PIV images. It is found that the higher accuracy of PIV measurement can be achieved by using wavelet multi-resolution technique without losing information of flow structure.
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中島 正弘, 田畑 隆英, 李 輝, 野崎 勉
2003 年 23 巻 Supplement1 号 p.
79-80
発行日: 2003/07/01
公開日: 2009/12/08
ジャーナル
フリー
By using the method of the flow visualization and the wavelet multi-resolution method, the water jet flow issuing from the rotating circular pipe with the inclined section has been studied. The bird-eye views of large-scale structure in the jet cross-section were constructed by applying a volume rendering method to the images of the large scale structure of the jet (the sum of wavelet levels 1 and 2) in layers in the wavelet multi-resolution analysis. In order to clarify the change with the time of the jet diffusion, the large-scale structure of the jet has been investigated in the cases of various rotating speeds of the pipe and inclined angles of the section. As a result, it has been found that the jet diffusion is affected by the inclined angle and the rotating speed of the pipe.
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山崎 照佳, 武居 昌宏, 越智 光昭, 李 輝, 斎藤 兆古, 堀井 清之
2003 年 23 巻 Supplement1 号 p.
81-82
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
This study evaluates particle density distribution images in a pipe cross-section by means of 3D-wavelet transform that is a parameter to indicate the dominant transition among CT time-space frames. It is clarified a time level 5 and space level 3 is the most particle density transition. The density distributions of solid-air two-phase flow with a time-space transition are measured by a capacitance CT.
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小島 和朗, 脇 祥之, 田代 伸一
2003 年 23 巻 Supplement1 号 p.
83-86
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
This paper describes the velocity fluctuation of flow around a rectangular cylinder, when the free stream velocity changes in time. This change is made by a flow control device placed at the exit of the wind tunnel. In this report we focused on the case where the free stream was decelerated, in Re number, from 4000 to 0 and then was accelerated up to 4000 again. Experimental results obtained by means of a hot-wire anemometer were processed by through wavelet transform in order to examine the relation between the free stream velocity and the fluctuation frequency spectrum which indicates the scale of vortices shed from the cylinder. Flow visualization was also carried out by the smoke wire method. Results show dearly the developing and collapsing process of vortices in the wake according with the velocity change. Especially, with respect to the vortex developing with the free stream acceleration, noteworthy differences were observed in beginning of vortex shedding according to whether the acceleration was following to the deceleration or not.
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山岸 真幸, 門叶 智子, 田代 伸一
2003 年 23 巻 Supplement1 号 p.
87-90
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The vortex structures in a separated flow region are generated by the motion of the separated shear layer caused by the introduction of periodic fluctuation. The main cause of the motion of the separated shear layer is the external fluctuation with the characteristic frequency. In order to investigate the principle motion of the velocity field, 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 averaged velocity could be found and discussed. The profiles vary dynamically at each phase angle and show the periodic motion of the shear layer. The separated shear layer flutters with the external fluctuation in the mean flow. If the suitable frequency is selected in the external fluctuation, the separated flow region disappears in almost all phase angles owing to the depression of the shear layer near the wall.
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新井 康平
2003 年 23 巻 Supplement1 号 p.
91-94
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
A method for discrimination between raindrops and cloud particles with TRMM/PR(Tropical Rainfall Measuring Mission satellite/Precipitation Radar) data based on Wavelet analysis is proposed together with methods for data. compression and feature extraction.
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丸山 和夫, 早野 誠治, 齋藤 兆古, 堀井 清之
2003 年 23 巻 Supplement1 号 p.
95-98
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Most of the conventional image cognition methodologies are based on the geometrically singular points extraction such as eyes in human face. When applying these conventional image cognition methods to the geometrically deformed targets, it is difficult to cognize them exactly. In order to overcome this difficulty, we have previously proposed a new image cognition methodology based on the color information extracting strategy. In the present paper, we apply this new color information approach to the dynamic image cognition. To improve the cognition reliability of the color information based method, we propose the multi CCDs(Charge Coupled Device) method. As a result, we have succeeded in working out a new dynamic image cognition method having decision capability of correct or incorrect cognized result.
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長屋 嘉明, 遠藤 久, 高木 敏行, 内一 哲哉, 黄 皓宇
2003 年 23 巻 Supplement1 号 p.
99-102
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
This paper proposes a novel method for visualizing the multiple cracks from ECT image. Assumed two-dimensional scanned ECT signals to be a picture image, then a template matching method predicts crack shapes. Moreover, comparing ECT image of the unknown multiple cracks and that of the known crack separates into each of the cracks. Genetic algorithm performs faster search algorithm in our template matching. Shape reconstructions are achieved in the multiple cracks at intervals of 2 mm with a satisfactory degree of accuracy.
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音川 英一, 早野 誠治, 齋藤 兆古, 堀井 清之
2003 年 23 巻 Supplement1 号 p.
103-106
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
With the developments of modern high-speed digital computer, X-ray as well as MRI (Magnetic Resonance Imaging) tomography is widely used as one of the most effective instruments for medical diagnosis. On the other side, EIT (Electrical Impedance Tomography) is developing only for the industrial use. This is because EIT is one of the functional types of tomography, which require a solution of ill posed system of equations while the X-ray and MRI need not solve such an ill posed system of equations.
In order to overcome such difficulty in EIT, this paper proposes a new deterministic method, which consists of a new solving strategy, i.e. GVSPM (Generalized Sampled Pattern Matching) for the ill posed linear system of equations and image processing tool, i.e., convolution strategy to extract the common parts in the images. As a result, it is revealed that our method promises the highly reliable tomography.
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相原 昭洋, 阿部 至雄, 及川 智宏
2003 年 23 巻 Supplement1 号 p.
107-110
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
This paper reports the application of a PTV-technique to the measurement of flow velocity in the open-channel with vegetation. The features on the local hydraulic characteristics of flows around the vegetative groins are discussed through the hydraulic experiments. It is shown that the vegetative groin work, which was made of vegetation as a part of river training works, has the basic function as groin work on reducing the velocity inside the groin region and on splashing water toward the main flow. The effects on splashing water and reducing the velocity depend on vegetative compactness. Consequently, the present vegetative groin work seems to function well as habitats for the aquatic life, because the areas of low flow velocity are formed inside the groin region, which shifts locally with change of the vegetative compactness of groin and its angle.
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流速と乱れの計測
南條 雅志, 道奥 康治, 竹原 幸生, 江藤 剛治, 花谷 清明
2003 年 23 巻 Supplement1 号 p.
111-114
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Recently, permeable river structures such as a rubble mound weir attract attention from an environmental point of view. A permeable structure minimizes negative impact on natural environment compared to conventional solid structures made of concrete and steel. This type of weir purifies water through aeration as well as provides passage of aquatic lives in the longitudinal direction. In order to evaluate these environmental functions, it is necessary to analyze internal flow in the structure.
In this study, flow fields in a rubble-mound weir were visualized by adjusting refractive index between solid-fluid phases. The flow velocity and turbulence are measured from image analysis, and the flow properties inside rubble-mound was analyzed. The present research will be useful in making hydraulic design of a permeable rubble mound.
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菅 貞博, 桂樹 哲雄, 馬場 信弘
2003 年 23 巻 Supplement1 号 p.
115-118
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
In this study, we visualize the transition of state and the sand distribution of the transported sediment in an oscillatory flow. The visualized images of sediment transport in an oscillatory flow in a small tank are taken with a digital video camera. The variation of brightness from the initial image is measured by the personal computer on every pixel in the flame. It is transformed to the concentration of sand by using the calibration relationship between the brightness and the distribution of sand. The result shows that distribution of transported sand is dependent on the velocity or flow like eddy of external fluid.
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ランダム図形を用いた場合
中面 祐樹, 鈴木 敏夫
2003 年 23 巻 Supplement1 号 p.
119-122
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The ocean wave information is indispensable to study the ocean environment and also important for safety and economical ship navigation. Remote sensing technology using a satellite image is the useful way to measure it. This technology isn't accurate to know the more detailed information around a small area, for example, fishing port, etc. It is suitable for getting the average information of the large area.
The projected light distribution method was kept proceeding to measure the detailed wave height distribution of the limited part. But, it's very difficult to exceed a laboratory scale.
This paper presents the way to measure the unsteady wave height distributions using the wave surface inclination distributions. The wave surface inclination distributions are analyzed the movement of images random pattern. (e.g. cloud images) An unsteady wave height distribution is measured by this method and compared with the results measured by super-sonic wave height meters. The results show good agreement between them.
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真田 有吾, 鈴木 敏夫, 戸田 保幸
2003 年 23 巻 Supplement1 号 p.
123-126
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Gravity currents are very important phenomenan for the marine environment.
In this paper, a new and original technique for simultaneous measurement of density field and velocity field is proposed.
If a density distribution changes in a certain area, the refractive index distribution in that area will change. So, the volume areas with a density distribution are inserted between a CCD camera and a picture, the picture moves small displacement corresponding to the density gradient. Integrate the displacement, density distribution is reproduced numerically.
Combining PIV method with the above procedure, it enable to measure both density and velocity simultaneously.Steady and unsteady flow fields are measured and compared with the data which measured by conductive salinity probes. The results show good agreement between them.
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檀 和秀, 山本 佳代, 中嶋 綾
2003 年 23 巻 Supplement1 号 p.
127-130
発行日: 2003/07/01
公開日: 2009/07/31
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フリー
When the natural light waves travel into the interface between water and air a part of the light waves refracts and diffracts at the interface. When these waves travel to the horizontal observation plane located at the bottom of the water these waves make the light intensity profile in this observation plane. It is possible to calculate the wave profile by applying Suzuki-Sumino's method to the light intensity profile observed at the bottom in the shallow water. When it becomes deeper the wave profile can be estimated using the relation between the gradient of the water surface and the intensity gradient of light observed at the bottom.
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石原 健, 佐伯 尚文, 大野 陽男, 二宮 尚, 杉山 均
2003 年 23 巻 Supplement1 号 p.
131-134
発行日: 2003/07/01
公開日: 2009/07/31
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フリー
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, the flow patterns about a Sirocco has not been examined in detail. Recently, the authors of this study have succeeded in reducing the wind noise of a Sirocco fan more than 1dB by placing a blocking plate at 90 degree from the tongue of the scroll. Despite of the reduction of the wind noise, its mechanism has not been made clear and thus the further reduction may not be expected without the understandings of the changes in the flow field with the presence of a blocking plate. Presently, the flow field of a Sirocco fan with a blocking plate at various locations have been examined in detail by the spark tracing method.
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須藤 路久, 二宮 尚, 寺島 祥夫
2003 年 23 巻 Supplement1 号 p.
135-138
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Trajectories of the billiard balls have long been assumed to behave as the collision of mass points. As a matter of fact, the beginners can enjoy the games with this simple approximation. On the contrary, the professional players know the differences from the theory by their plentiful experiences and adjust them by intuitions. For example, the target ball does not go in the direction which is perpendicular to the surface of contact. This difference from the theory is well known as "throw". In order to investigate the mechanisms of the differences from the theory and to quantify them under various conditions, the authors of this study have visualized the motions of the balls by the high-speed camera and have investigated the trajectories of the balls quantitatively by using the digital image processing techniques. As a result, the maximum "throw" is found to occur at the contact angle of 30 degree.
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初木 勇哉, 江藤 剛治, 竹原 幸生, 森 理至
2003 年 23 巻 Supplement1 号 p.
139-140
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
An ultra high-speed video camera whose frame rate is 1 million frames/second was developed by a cooperative R and D project of Kinki University and Shimadzu Corporation in September, 2001. In this ultra high-speed video camera, the continuous overwriting system is used. Number of recorded frame is 103. In case of high-speed image capturing, a method of sending a trigger signal for stopping continuous overwriting becomes important. Currently available trigger systems are mainly a trigger by sound and a trigger by laser. In the case of image capturing of a bursting balloon, we can use the sound and/or laser trigger. However, it is difficult to capture images at an ultra-high frame rate under a microscope. A video trigger system, which can be applied to microscopic ultra high-speed image capturing, is under development. In this paper, an algorithm for detection of a sudden change of brightness in an image is presented.
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梅田 眞三郎, 長谷川 盛三, 谷口 輝, Wen-Jei YANG
2003 年 23 巻 Supplement1 号 p.
141-144
発行日: 2003/07/01
公開日: 2009/07/31
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フリー
The authors explained the mechanisms that caused the reciprocating bubble migration with flip-flop phenomenon in a diamond-shaped cylinder bundle. However, it lacks sufficient, quantitative explanation due to complexity in these flows. An experimental study is performed to determine flow instability in the diverging-flow region with flip-flop phenomenon inside diamond-shaped cylinder bundles. The velocity variations in their flow fields were measured using two-dimensional laser Doppler velocimetry(LDV). The study leads to the following disclosures in the diverging region with flip-flop phenomenon: (i) Power spectrum distribution with identical dominant frequency prevails in every row, indicating flow oscillations propagate over the entire passage. (ii) At the third row, the magnitude of power spectra reaches maximum near the "energy supply point", but subsequently diminishes to the minimum value at the apex of the succeeding cylinder. (iii) The flow exhibits the characteristics of a edge tone.
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宇宙研大型風洞における試み
大内 弘文, 藤松 信義, 中井 祐輔, 藤井 孝藏, 林 光一
2003 年 23 巻 Supplement1 号 p.
145-148
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Experiments of transonic fields over a delta wing are carried out in the ISAS large-scaled wind tunnel and the flow fields are investigated using both PSP and TSP measurements. Blue LED is used for a light source, and Ruthenium(II) complex is used for dye as the multipurpose PSP measuring method. Ruthenium(II) complex considered to be uncongenial to the binder of a polymer base, provides sufficient luminescence intensity when the combination ratio of dye and a binder is properly arranged. The Cp distributions on the delta wing measured by the PSP agree well with the pressure tap data at Mach number of 0.9 and angle of attack of 20 deg.
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江上 泰広, 飯島 由美, 浅井 圭介
2003 年 23 巻 Supplement1 号 p.
149-152
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
We have applied PSP to low-speed wind tunnel tests of an automobile model. PSP measurements at low speeds are difficult because of small changes of pressure on a model. To evaluate the accuracy of current PSP system, we made low-speed PSP experiments using an automobile model in the range of 10-50m/s (36-180 km/h). Effects of averaging, image registration, flat-field correction and calibration were investigated. It was found that, using an in situ calibration, quantitative pressure distributions of the automobile model could be obtained down to 25m/s. A comparison of the PSP data with conventional pressure tap measurements revealed that the largest source of an error was derived from the temperature dependence of PSP.
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森 英男, 新美 智秀, 近藤 誠, 大島 佑介, 平光 円
2003 年 23 巻 Supplement1 号 p.
153-156
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Recently many results related to PSP have been reported, but the PSP technique has been considered inadequate to be applied to low pressure range. In this study, to inspect the feasibility of PSP for measurement of pressure on a solid surface in the low density gas flows, fundamental properties of two types of PSP [PtTFPP/poly(TMSP) and PdOEP/poly(TMSP)] are examined especially in the range of pressure below 133.3 Pa (1 Torr). As an application of PSP to low density gas flows, we measure the pressure distribution on a spike surface of the Aerospike nozzle, using PtTFPP/poly(TMSP) with high pressure sensitivity over a wide range of pressure. The pressure sensitivities against nitrogen oxide are also examined for the above PSPs, to develop a technique for the simultaneous measurement of the flow field structure and the surface pressure, using NO-LIF and PSP, respectively.
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松本 尚之, 板倉 正幸, 福里 克彦, 坂村 芳孝, 鈴木 立之
2003 年 23 巻 Supplement1 号 p.
157-158
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Pressure sensitive paint (PSP) is a novel measurement system developed to obtain surface pressure distribution on wind-tunnel testing models. The objective of the present work is to examine the feasibility of this novel surface pressure mapping technique for truly unsteady supersonic flow testing. Using a fast-responding porous PSP and a fast-framing complementary metal oxide semiconductor (CMOS) camera, we have measured unsteady flows induced in a two-dimensional Laval nozzle of a blow-down supersonic wind tunnel. The PSP used in this study was composed of a dye (bathophenanthroline ruthenium(II) complex, Ru(Ph
2-phen) and a silica-gel thin layer chromatography (TLC) plate, on which the dyes were absorbed. The PSP was illuminated by light-emitting-diode (LED) lamps. The results obtained by the present measurement system shows the starting process of supersonic wind tunnel at 5kHz frame rate.
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田部井 孝聡, 満尾 和徳, 浅井 圭介, 亀田 正治
2003 年 23 巻 Supplement1 号 p.
159-162
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The dual luminophore pressure/temperature sensitive paint (DPTSP) has been developed to correct the temperature dependence of pressure-sensitive paint (PSP). The DPTSP is composed of two luminophores, whose emissions are available for pressure and temperature measurements. In order to correct temperature dependence of the PSP, both emissions are measured simultaneously by using two CCD cameras with different filter wavelengths. The DPTSP developed in this study was composed of PtTFPP and Coumarin307. The emission wavelengths of PtTFPP and Coumarin307 were so separated that the interference of emissions could be neglected. In addition the present DPTSP could be applied to a wide temperature range. This paint was resolved in thinner so that it could be coated on the model surface smoothly. To validate the performance of DPTSP for temperature correction, the pressure and temperature fields induced by sonic-jet impingement were measured by the present DPTSP system. The temperature-corrected PSP data agreed well with the pressure tap data.
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藤松 信義, 田村 善昭, 藤井 孝藏
2003 年 23 巻 Supplement1 号 p.
163-166
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Image processing procedure to automatically carry out the image registration in the PSP experiments is investigated. A few algorithms to detect the marker location are proposed and tested. The marker location can be successfully captured using these algorithms. Two types of algorithms based on the algebraic and optimization method are proposed for the decision of the pair of markers for the image registration. These methods can correctly find a pair of the markers. The results indicate that the image registration can be automated using the method developed in this paper.
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武居 昌宏, 斎藤 兆古, 堀井 清之
2003 年 23 巻 Supplement1 号 p.
167-168
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
A new reconstruction method, which is called Generalized Vector Sampled Pattern Matching (GVSPM) method, has been applied to an ill-posed inverse problem of a capacitance-computed tomography for solid air two-phase flow. The time-mean correlation between the experimental capacitance and the capacitances from the reconstruction method is calculated. As a result, GVSPM method improves the correlation by 23.6% as compared with LW method. The accurate reconstruction of GVSPM results from an inner product calculation between the experimental capacitance and the capacitance from the reconstructed images as an objective function.
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川口 達也, 菱田 公一, 前田 昌信
2003 年 23 巻 Supplement1 号 p.
169-170
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
The paper describes the quantitative visualization technique for the entire structure of CO
2 gas dissolution processes into liquid by means of three-dimensional Computed Tomography technique. Concentration distribution was obtained by the laser absorption technque by noting the pH dependency on the absorption spectrum of pH indicator. The measurement method enables to investigate the mass transport phenomena and the dynamic interaction among them in conjunction with other measurement technique.
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町田 雅志
2003 年 23 巻 Supplement1 号 p.
171-172
発行日: 2003/07/01
公開日: 2009/07/31
ジャーナル
フリー
Sensor is a very important part of process tomography system. Tribo-electric tomography system, it is also called electrodynamic tomography system, bases on sensing of electrostatic charges carried by particles. This sensor is passive and number of measurements is quite small comparing to other tomography system with same number of sensors. This restriction brings poor and coarse image by least square image reconstruction method for its large division of sensing zone with small number. Although back projection method is highly underdetermined, it gives better results than least square method. Other method. like iterative method or the combination of the above two, must be developed in future.
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