THE CRITICAL DEPTH OF FLOW IN OPEN CHANNELS. (INCLUDES APPENDICES).

The critical depth and normal depth computation are essential for hydraulic engineers to understanding the characteristics of varied flow in open channels. These depths are fundamental to analyze the flow for irrigation, drainage, and sewer pipes. Several explicit solutions to calculate critical and normal depths in different shape open channels were discovered over time. Regardless of the complexity of using these explicit solutions, these formulas have a significant error percentage compared to the exact solution. Therefore, this research explicitly calculates the normal and critical depth in circular channels and finds simple, fast, and accurate equations. First, the dimensional analysis was used to propose an analytical equation for measuring the circular channels' critical and normal depths. Then, regression analysis has been carried for 2160 sets of discharge versus critical and normal depths data in a circular open channel. The results show that this study's proposed equation for measuring the circular channels' critical and normal depths overcomes the error percentage in previous studies. Furthermore, the proposed equation offers efficiency and precision compared with other previous solutions.

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A novel and exact analytical model for determination of critical depth in trapezoidal open channels

Flow Measurement and Instrumentation ◽

10.1016/j.flowmeasinst.2019.101575 ◽

2019 ◽

Vol 68 ◽

pp. 101575

Author(s):

Seyyed Alireza Varandili ◽

Hadi Arvanaghi ◽

Mohammad Ali Ghorbani ◽

Zaher Mundher Yaseen

Keyword(s):

Analytical Model ◽

Open Channels ◽

Critical Depth

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Investigation of the influence of the flow structure on the accuracy of flow measurement before a hydrometric structure in an open channel

Melioration and Water Management ◽

10.32962/0235-2524-2019-5-41-44 ◽

2020 ◽

pp. 41-44

Author(s):

Anatoly Kusher

Keyword(s):

Velocity Profile ◽

Flow Velocity ◽

Water Flow ◽

Flow Measurement ◽

Water Discharge ◽

Critical Depth ◽

Flow Measurements ◽

Study Results ◽

Flow Velocity Profile ◽

Upstream Flow

The reliability of water flow measurement in irrigational canals depends on the measurement method and design features of the flow-measuring structure and the upstream flow velocity profile. The flow velocity profile is a function of the channel geometry and wall roughness. The article presents the study results of the influence of the upstream flow velocity profile on the discharge measurement accuracy. For this, the physical and numerical modeling of two structures was carried out: a critical depth flume and a hydrometric overfall in a rectangular channel. According to the data of numerical simulation of the critical depth flume with a uniform and parabolic (1/7) velocity profile in the upstream channel, the values of water discharge differ very little from the experimental values in the laboratory model with a similar geometry (δ < 2 %). In contrast to the critical depth flume, a change in the velocity profile only due to an increase in the height of the bottom roughness by 3 mm causes a decrease of the overfall discharge coefficient by 4…5 %. According to the results of the numerical and physical modeling, it was found that an increase of backwater by hydrometric structure reduces the influence of the upstream flow velocity profile and increases the reliability of water flow measurements.

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Uniform Water Flows within Rectangular Open Channels of Composite Roughness

PARIPEX-INDIAN JOURNAL OF RESEARCH ◽

10.15373/22501991/feb2013/46 ◽

2012 ◽

Vol 2 (2) ◽

pp. 137-139

Author(s):

Demetriou J Demetriou J ◽

◽

Retsinis E Retsinis E

Keyword(s):

Open Channels ◽

Water Flows

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Implementation Color-Images Cryptography Using RSA Algorithm

International Journal of Advanced Research in Computer Science and Software Engineering ◽

10.23956/ijarcsse.v7i11.500 ◽

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.

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