Turbulent flow in open channel with different Froude numbers

2015 ◽  
pp. 147-152
Keyword(s):  
Turbulent Flow ◽  
Open Channel

scholarly journals Interactions between Tandem Cylinders in an Open Channel: Impact on Mean and Turbulent Flow Characteristics

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1718
Author(s):  
Hasan Zobeyer ◽  
Abul B. M. Baki ◽  
Saika Nowshin Nowrin
Keyword(s):  
Turbulent Flow ◽  
Open Channel ◽  
Recirculation Zone ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Recirculation ◽  
Tandem Cylinders ◽  
Flow Development ◽  
The Mean ◽  
Recirculation Length

The flow hydrodynamics around a single cylinder differ significantly from the flow fields around two cylinders in a tandem or side-by-side arrangement. In this study, the experimental results on the mean and turbulence characteristics of flow generated by a pair of cylinders placed in tandem in an open-channel flume are presented. An acoustic Doppler velocimeter (ADV) was used to measure the instantaneous three-dimensional velocity components. This study investigated the effect of cylinder spacing at 3D, 6D, and 9D (center to center) distances on the mean and turbulent flow profiles and the distribution of near-bed shear stress behind the tandem cylinders in the plane of symmetry, where D is the cylinder diameter. The results revealed that the downstream cylinder influenced the flow development between cylinders (i.e., midstream) with 3D, 6D, and 9D spacing. However, the downstream cylinder controlled the flow recirculation length midstream for the 3D distance and showed zero interruption in the 6D and 9D distances. The peak of the turbulent metrics generally occurred near the end of the recirculation zone in all scenarios.

scholarly journals Turbulent flow structure at a 90-degree open channel confluence: Accounting for the distortion of the shear layer

2016 ◽  
Vol 12 ◽  
pp. 130-147 ◽  
Author(s):  
Saiyu Yuan ◽  
Hongwu Tang ◽  
Yang Xiao ◽  
Xuehan Qiu ◽  
Huiming Zhang ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Shear Layer ◽  
Flow Structure ◽  
Open Channel ◽  
Turbulent Flow Structure ◽  
Channel Confluence

scholarly journals Entropy-Based Shear Stress Distribution in Open Channel for all types of Flow using Experimental Data

2021 ◽  
Author(s):  
Hae Seong Jeon ◽  
Ji Min Kim ◽  
Yeon Moon Choo
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Turbulent Flow ◽  
Correlation Coefficient ◽  
Open Channel ◽  
Shear Stress Distribution ◽  
Entropy Theory ◽  
Tractive Force ◽  
Design Standards ◽  
Wide Range

Abstract Korea’s river design standards set general design standards for river and river-related projects in Korea, which systematize the technologies and methods involved in river-related projects. This includes measurement methods for parts necessary for river design, but do not include information on shear stress. Shear Stress is to one of the factors necessary for river design and operation. Shear stress is one of the most important hydraulic factors used in the fields of water especially for artificial channel design. Shear stress is calculated from the frictional force caused by viscosity and fluctuating fluid velocity. Current methods are based on past calculations, but factors such as boundary shear stress or energy gradient are difficult to actually measure or estimate. The point velocity throughout the entire cross section is needed to calculate the velocity gradient. In other words, the current Korea’s river design standards use tractive force, critical tractive force instead of shear stress because it is more difficult to calculate the shear stress in the current method. However, it is difficult to calculate the exact value due to the limitations of the formula to obtain the river factor called the tractive force. In addition, tractive force has limitations that use empirically identified base value for use in practice. This paper focuses on the modeling of shear stress distribution in open channel turbulent flow using entropy theory. In addition, this study suggests shear stress distribution formula, which can be easily used in practice after calculating the river-specific factor T. and that the part of the tractive force and critical tractive force in the Korea’s river design standards should be modified by the shear stress obtained by the proposed shear stress distribution method. The present study therefore focuses on the modeling of shear stress distribution in open channel turbulent flow using entropy theory. The shear stress distribution model is tested using a wide range of forty-two experimental runs collected from the literature. Then, an error analysis is performed to further evaluate the accuracy of the proposed model. The results revealed a correlation coefficient of approximately 0.95–0.99, indicating that the proposed method can estimate shear stress distribution accurately. Based on this, the results of the distribution of shear stress after calculating the river-specific factors show a correlation coefficient of about 0.86 to 0.98, which suggests that the equation can be applied in practice.

Open channel turbulent flow over hemispherical ribs

2006 ◽  
Vol 27 (6) ◽  
pp. 1010-1027 ◽  
Author(s):  
M. Agelinchaab ◽  
M.F. Tachie
Keyword(s):  
Turbulent Flow ◽  
Open Channel

Numerical simulation of turbulent flow in open channel with groynes

2014 ◽  
pp. 659-665
Author(s):  
Th Koutrouveli ◽  
N Fourniotis ◽  
A Demetracopoulos ◽  
A Dimas
Keyword(s):  
Numerical Simulation ◽  
Turbulent Flow ◽  
Open Channel

Measurement and simulation of turbulent flow in a steep open‐channel with smooth boundary

2003 ◽  
Vol 26 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Jau‐Yau Lu ◽  
Jian‐Hao Hong ◽  
Chuan‐Yi Wang ◽  
Kun‐Zheng Lee ◽  
Han‐Chung Yang
Keyword(s):  
Turbulent Flow ◽  
Open Channel ◽  
Smooth Boundary

Computation of Normal Depth in Trapezoidal Open Channel Using the Rough Model Method

2014 ◽  
Vol 955-959 ◽  
pp. 3231-3237
Author(s):  
Bachir Achour
Keyword(s):  
Aspect Ratio ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Linear Dimension ◽  
Open Channel ◽  
Discharge Energy ◽  
Flow Discharge ◽  
Model Method ◽  
Rough Model ◽  
Depth Relationship

The recurring problem of calculating the normal depth in a trapezoidal open channel is easily solved by the rough model method. The Darcy-Weisbach relationship is applied to a referential rough model whose friction factor is arbitrarily chosen. This leads to establish the non-dimensional normal depth relationship in the rough model. Through a non-dimensional correction factor of linear dimension, the aspect ratio and therefore normal depth in the studied channel is deduced. Keywords: Rough model method, Trapezoidal channel, Normal depth, Turbulent flow, Discharge, Energy slope.

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