scholarly journals Characteristics of Coherent Structure in Compound Open Channel Flow

2008 ◽  
Vol 28-1 (1) ◽  
pp. 121-121
Author(s):  
Katsutoshi WATANABE
Keyword(s):  
Channel Flow ◽  
Coherent Structure ◽  
Open Channel ◽  
Open Channel Flow

scholarly journals Visualization of Large-scale Coherent Structure in an Turbulent Open Channel Flow

1991 ◽  
Vol 11 (Supplement2) ◽  
pp. 209-212
Author(s):  
Takanori SAGA ◽  
Hirofumi OHNARI ◽  
Katsutoshi WATANABE ◽  
Takashi SAITOU
Keyword(s):  
Channel Flow ◽  
Coherent Structure ◽  
Large Scale ◽  
Open Channel ◽  
Open Channel Flow

The visualization of turbulent coherent structure in open channel flow

2019 ◽  
Vol 31 (2) ◽  
pp. 266-273 ◽  
Author(s):  
Xiao-dong Bai ◽  
Wei Zhang ◽  
Qing-he Fang ◽  
Yong Wang ◽  
Jin-hai Zheng ◽  
...  
Keyword(s):  
Channel Flow ◽  
Coherent Structure ◽  
Open Channel ◽  
Open Channel Flow ◽  
Turbulent Coherent Structure

scholarly journals Coherent structure in turbulent open channel flow in corners.

1992 ◽  
pp. 55-63 ◽  
Author(s):  
Takanori SAGA ◽  
Hirofumi OHNARI ◽  
Takashi SAITOU
Keyword(s):  
Channel Flow ◽  
Coherent Structure ◽  
Open Channel ◽  
Open Channel Flow

Experimental study on the coherent structure of turbulent open-channel flow using visualization and picture processing

1987 ◽  
Vol 174 ◽  
pp. 399-440 ◽  
Author(s):  
Tadashi Utami ◽  
Tetsuo Ueno
Keyword(s):  
Flow Visualization ◽  
Channel Flow ◽  
Coherent Structure ◽  
Open Channel ◽  
Open Channel Flow ◽  
Wall Region ◽  
Turbulence Structure ◽  
Two Dimensional ◽  
Picture Processing ◽  
Three Components

Coherent structures of turbulent open-channel flow in the wall region of a channel bed were examined quantitatively using experimental data obtained by flow visualization. Successive pictures of flow patterns in two horizontal cross-sections at different levels near the channel bed were taken, and then were digitized and analysed by a computer.This method of flow visualization and picture processing enabled us to calculate the distributions of the three components of the velocity vectors. The distributions of velocities, streamlines, two-dimensional divergence and three components of vorticity could be calculated and are displayed as graphical output. In our numerical analyses, the idea of a two-dimensional correlation coefficient is introduced, through which the degree of similarity of turbulence structures can be better estimated than with the usual one-dimensional coefficient. Use of the data was based on the premise that the essential element in a turbulence structure is vortex motion.We propose a conceptual model of turbulence structure in which the elementary unit of coherent structure in the buffer layer is presumed to be a horseshoe vortex and in which the characteristics of the multiple structure of turbulence are shown with respect to the scale, arrangement and generating process of horseshoe vortices and longitudinal vortices. Our model clearly explains the generating mechanism and mutual relations of low-speed regions, high-speed regions, ejections, sweeps and localized free-shear layers.

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