研究者詳細 - 吉田　圭介

論文 - 吉田　圭介

分割表示 158 件中 121 - 140 件目／全件表示 >>

Derivation of boundary condition for quasi-3D model of water exchange between Neijiang and Yangtze river 査読

Zhao, L., Yoshida, K., Ishikawa, T. and Futagi, K.

Proc. 16th APD-IAHR Congress 491 - 496 2008年9月

Study on turbidity increase during flood in Myoginohana area of lake Kasumigaura 査読

Yoshida, K., Ishikawa, T., Kobayashi, Y., Sasaki, F., Aoyama, S. and Ichiyama, M.

Proc. 16th APD-IAHR Congress 472 - 477 2008年9月

Depth-averaged numerical solver of meandering river flows by CIP-Soroban grids in cylindrical coordinate system 査読

Yoshida,K, Ishikawa, T

Journal of Hydroscience and Hydraulic Engineering, JSCE 26 ( 1 ) 11 - 28 2008年

鎮江市内江の流動計算のための長江水理条件の導出査読

趙聯芳, 吉田圭介, 石川忠晴, 二木敬右

水工学論文集 52 1051 - 1056 2008年

円筒座標CIP-Soroban法と境界適合座標法を組み合わせた蛇行河川の準3次元計算法査読

吉田圭介, 石川忠晴

水工学論文集 52 997 - 1002 2008年

Numerical prediction of meandering river flows by CIP-Soroban grids in cylindrical coordinate system 査読

Yoshida, K. and Ishikawa, T.

Proc. 32nd IAHR Congress 2007年7月

霞ヶ浦の妙技の鼻水域における出水時濁度上昇に関する研究査読

吉田圭介, 石川忠晴, 佐々木史, 青山貞雄, 市山誠

河川技術論文集 Vol.13 13 - 18 2007年

実体視と相関解析の併用による洪水航空写真解析の効率化査読

箕浦靖久, 石川忠晴, 吉田圭介

水工学論文集 Vol.51 1093 - 1098 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

Stereo images obtained from sequential aerial photographs of river freshets contain a lot of useful information for river hydraulics as well as river engineering works. The image correlation analysis is a standard technique for analyzing the images, but it sometimes produces anomalous results for the area where color fluctuation of the water surface is small. On the other hand, a classical manual analysis through stereo eyeglasses usually works well even in such unclear parts of the images, but the manual analysis costs much labor and time. <BR>In this study, a new technique to analyze stereo images of river flows is developed by combining the above mentioned two methods: A small amount of suggestions are made by using the results from the manual analysis for the image correlation analysis on a computer, and then the results of the second trial of the latter is much improved without any significant time consumption.

DOI： 10.2208/prohe.51.1093

CiNii Article

researchmap

円筒座標でCIP-Soroban法を拡張した蛇行河川の浅水流計算法査読

吉田圭介, 石川忠晴

水工学論文集 Vol.51 805 - 810 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

A new numerical solver is developed for a shallow-water flow model to simulate meandering river flows. This solver can investigate the flows in the curved river channel, by means of the adaptive CIP-Soroban (CIP-S) scheme in a cylindrical coordinate system. Time development of water velocity and free-surface level is computed by the orthogonal curvilinear coordinate system without any transformation of the governing equations, and the advection term is calculated by the high-accuracy CIP scheme. The numerical grid points of the waterfront line at the river bank are moved and tracked by the kinematic condition so that the grid points are always located on the line, and the rearrangement of the positions of the girds is easily conducted by the original CIP-S method. From the verification of this solver by the pure advection problem and by the numerical solution of the meandering river flows, in comparison with the CIP-S method in a Cartesian coordinate system and with the boundary fitted coordinate (BFC) method, it is shown that the proposed numerical solver reasonably predicts the main flow profile and water surface elevation and will be a promising numerical method as one of the practical solutions.

DOI： 10.2208/prohe.51.805

CiNii Article

researchmap

Fundamental investigation of depth-averaged numerical model with evolution of secondary currents in curved channels 査読

Yoshida, K. and Ishikawa, T.

Proc. 15th APD-IAHR Congress 2006年8月

2次流の時空間発展を考慮した水深積分モデルに関する基礎的検討査読

吉田圭介, 石川忠晴

水工学論文集, 第50巻 pp.781-786 781 - 786 2006年

Direct numerical simulation of two-fluid system and its application to air-water turbulent flows with deformed interfaces 査読

Yoshida, K., Ushijima, S. and Nezu, I.

Proc. 31st IAHR Congress 836 - 846 2005年9月

風シアーと底面シアーが共存する開水路混成流における組織乱流構造と気液界面気体輸送過程に関する研究査読

吉田圭介,禰津家久

土木学会論文集 803/II-73 57 - 67 2005年5月

逆流風波開水路混成場における乱れ構造と気体輸送に関する実験的研究査読

禰津家久, 福谷彰, 吉田圭介, 垂井晃一

応用力学論文集 8 911 - 918 2005年

逆流風波開水路混成場における乱流特性に関する研究査読

禰津家久, 垂井晃一, 吉田圭介

水工学論文集, 第49巻 49 505 - 510 2005年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

This study describes an experimental investigation on turbulence characteristics and the water-surface fluctuations in adverse wind-driven open-channel flows by using both a laser Doppler Anemometer (LDA) and a wave gauge simultaneously. In this study, it was shown that the velocity fluctuations of water flow near the interface in not only cocurrent flow but also adverse flow are significantly affected by the water surface in every range of frequency. However turbulence characteristics in water layer in adverse wind-driven open-channel flows are different from those in cocurrent flow, and there exists a high correlation between turbulence and the surface fluctuations in predominant frequency due to high-sheared wind flow.

DOI： 10.2208/prohe.49.505

CiNii Article

researchmap

気液2流体界面を含む混相場の直接数値計算査読

吉田圭介, 牛島省, 禰津家久

水工学論文集, 第49巻 49 709 - 714 2005年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

In this study, a direct numerical simulation for analyzing the immiscible incompressible two-fluid flows was carried out with the 3-dimensional MARS method, and the applicability of this scheme was verified in the water column collapse phenomenon, 2-dimesional channel flows between two walls and 3-dimensinal air-water co-current flows between a non-slip wall and a free-slip wall. It was shown that the present numerical simulation was in good agreement with previous experimental and numerical results, and that the volume of fluid in flows was sufficiently conserved for the long simulation time step. However, it is pointed out in the 3-D air-water co-current flows that lack of simulation grids and inadequate averaged time generates the inaccurate results in this DNS.

DOI： 10.2208/prohe.49.709

CiNii Article

researchmap

Experimental study on air-water interfacial turbulent hydrodynamics and gas transfer in wind-induced open-channel flows 査読

Yoshida, K. and Nezu, I.

Proc.4th International Symposium on Environmental Hydraulics 185 - 191 2004年12月