scholarly journals 3-D Computation of Unsteady Flows in Compound Open Channels with Horizontal Vortices and Secondary Currents

1998 ◽  
Vol 42 ◽  
pp. 631-636
Author(s):  
Takashi HOSODA ◽  
Toshiyuki SAKURAI ◽  
Yoshio MURAMOTO
Keyword(s):  
Unsteady Flows ◽  
Open Channels ◽  
Secondary Currents

scholarly journals An expression for the water-sediment moving layer in unsteady flows valid for open channels and embankments

2010 ◽  
Vol 10 (5) ◽  
pp. 1051-1059 ◽  
Author(s):  
A. M. Berta ◽  
G. Bianco
Keyword(s):  
Laboratory Tests ◽  
Unsteady Flows ◽  
Friction Angle ◽  
Steep Slope ◽  
Open Channels ◽  
Sediment Layer ◽  
Equilibrium Conditions ◽  
Applied Shear Stress ◽  
Unsteady Conditions ◽  
Moving Layer

Abstract. During the floods, the effects of sediment transport in river beds are particulary significant and can be studied through the evolution of the water-sediment layer which moves in the lower part of a flow, named "moving layer". Moving layer variations along rivers lead to depositions and erosions and are typically unsteady, but are often tackled with expressions developed for steady (equilibrium) conditions. In this paper, we develop an expression for the moving layer in unsteady conditions and calibrate it with experimental data. During laboratory tests, we have in fact reproduced a rapidly changing unsteady flow by the erosion of a granular steep slope. Results have shown a clear tendency of the moving layer, for fixed discharges, toward equilibrium conditions. Knowing the equilibrium achievement has presented many difficulties, being influenced by the choice of the equilibrium expression and moreover by the estimation of the parameters involved (for example friction angle). Since we used only data relevant to hyper-concentrated mono-dimensional flows for the calibration – occurring for slope gradients in the range 0.03–0.20 – our model can be applied both on open channels and on embankments/dams, providing that the flows can be modelled as mono-dimensional, and that slopes and applied shear stress levels fall within the considered ranges.

Uniform Water Flows within Rectangular Open Channels of Composite Roughness

2012 ◽  
Vol 2 (2) ◽  
pp. 137-139
Author(s):  
Demetriou J Demetriou J ◽  
◽  
Retsinis E Retsinis E
Keyword(s):  
Open Channels ◽  
Water Flows

Implementation Color-Images Cryptography Using RSA Algorithm

2017 ◽  
Vol 7 (11) ◽  
pp. 181
Author(s):  
Ali Saleh Al Najjar
Keyword(s):  
Information Security ◽  
Image Encryption ◽  
Color Images ◽  
Public Key ◽  
Open Channels ◽  
Image Security ◽  
Rsa Algorithm ◽  
The Media ◽  
Encrypted Images ◽  
Difficult Issue

Absolute protection is a difficult issue to maintain the confidentiality of images through their transmission over open channels such as internet or networks and is a major concern in the media, so image Cryptography becomes an area of attraction and interest of research in the field of information security. The paper will offer proposed system that provides a special kinds of image Encryption image security, Cryptography using RSA algorithm for encrypted images by HEX function to extract HEX Code and using RSA public key algorithm, to generate cipher image text. This approach provides high security and it will be suitable for secured transmission of images over the networks or Internet.

Improvements to a dual-time-stepping method for computating unsteady flows

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1548-1550 ◽  
Author(s):  
S. DeRango ◽  
D. W. Zingg
Keyword(s):  
Unsteady Flows ◽  
Time Stepping ◽  
Dual Time Stepping
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