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Scrutinization of Flow in the Immediate Vicinity of a Brink in a Tilting Flume

  • Şahnaz Tiğrek
  • Ş. Yurdagül Kumcu
  • A. Metin Ger
Research Paper
  • 81 Downloads

Abstract

The flow characteristics of the subcritical and supercritical flows over an unconfined free overfall in a rectangular channel are presented with experimental data available in the literature. The experimental observations cover a wide range of flow rate on mild, steep and adverse slopes. The dependence of the ratio of the brink depth to the critical depth according to several flow parameters is examined. The relation between the flow rate and the brink depth ratio is both explicitly and implicitly demonstrated. The location of the critical depth for subcritical flows upstream of the brink is also investigated. It is concluded that the location of the critical depth for subcritical flows depends on the Froude number, the channel bed slope and the Manning roughness coefficient. Furthermore, it is observed that there is a significant similarity of the water surface profiles in the immediate upstream vicinity of the brink of the subcritical and supercritical flows.

Keywords

Brink depth Free overfall Discharge measurement Critical depth Water profile 

List of Symbols

au

Unit conversion factor

b

Width of the channel

Fr

Froude number

g

Acceleration due to gravity

ks

Nikuradse’s sand roughness

lp

Critical depth distance from the brink in subcritical flow condition

L

Length dimension

M

Mass dimension

n

Manning’s roughness coefficient

R

Reynolds’s number

Rh

Hydraulic radius

Sc

Critical bed slope

So

Bed slope

q

Discharge per unit width

r2

Correlation coefficient

RMS

Root mean square error

T

Time dimension

X

Dimensionless horizontal length

x

Coordinate points of water surface in horizontal

Y

Dimensionless vertical length

y

Coordinate points of water surface in vertical

yc

Critical depth

ye

Brink depth

yo

Upstream normal depth

yp

The length of the profile at the immediate vicinity of the brink

ρ

The density of the fluid

Ф

Dimensionless parameter

μ

Viscosity

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Copyright information

© Shiraz University 2017

Authors and Affiliations

  • Şahnaz Tiğrek
    • 1
  • Ş. Yurdagül Kumcu
    • 2
  • A. Metin Ger
    • 3
  1. 1.Faculty of Engineering and Architecture, Civil Engineering Department, Hydraulic DivisionBatman UniversityBatmanTurkey
  2. 2.Civil Engineering Department, Hydraulic DivisionKonya Necmettin Erbakan UniversityKonyaTurkey
  3. 3.Civil Engineering Departmentİstanbul Aydin UniversityIstanbulTurkey

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