Open Channel Hydraulics

CE 642
HYDRAULICS
Dr. Emre Can
1

HYDRAULICS
Tentative Course Outline
Introduction
Pipe Flow
Open Channel Flows
Uniform Flow
Non-Uniform Flow
Local Changes in Water Levels
Channel Controls
Sedimentation in Open Channels and Rivers
Dimensional Analysis & Theory of Models

EXAM SCHEDULE
31 March 15:00 Midterm exam 1
12 May 15:00 Midterm exam 2
The exams will always be closed book,
(however formula sheets will be provided)
Questions will be in English and there will be no
translation of questions into Turkish,
Answers to all the questions should be in English.

REFERENCES:
HYDRAULICS
Chow, V.T., Open Channel Hydraulics, , Mc Graw Hill,
New York, 1959.
Henderson, F.M., Open Channel Flow, Macmillan Co, 1966.
Vennard, J.K. & Street, R.L., Elementary Fluid Mechanics,
John Wiley & Sons, 1977.
Linsley, R.K. & Franzini, J.B., Water Resources Engineering,
McGraw Hill, Newyork, 1972

HYDRAULICS
REFERENCES:
Sümer, B.M, Ünsal, İ. & Bayazıt M. Hidrolik,
Birsen yayınevi
Yanmaz, A. Melih, Applied Water Resources
Engineering, Metu Press, 3 rd edition, 2006
CE 372 Hydromechanics Lecture Notes, Middle
East Technical University, Civil Engineering Department
UTAH STATE UNIVERSITY Open Courseware
http://ocw.usu.edu/Civil_and_Environmental_Engineering/Fluid_Mechanics

Scope of the Course
In many water systems, transportation of
water from one location to another is the
main concern.
Two main modes of transportation are:
Closed conduits with pressurized flow inside
Open conduits with free surface flow inside
The main objective in this course is to study
the flow in closed conduits (mainly pipes)
and in open channels

Examples include:
Water distribution networks in urban areas
Water transmission line from Çamlıdere Dam to
İvedik Water Treatment Plant
(φ = 3.4 m, L = 15.5 km)
Urfa Tunnels from Atatürk Dam to Harran Plain
(φ = 7.62 m, L = 2 x 26.4 km)
Main irrigation canal in Harran Plain
(L=118 km, Q = 80 m 3 /s)

The View of Atatürk Dam

GAP WATER RESOURCES ROJECTS
Total 22 dams, 19 HPP
1.7 million ha, 7485 MW, 27 billion kWh

Urfa Tunnels from
Atatürk Dam to Harran Plain
φ = 7.62 m,
L = 2 x 26.4 km
Q=80 m 3 /s

Main irrigation canal in Harran Plain
(L=118 km, Q = 80 m3/s)

Before 1995

HARRAN PLAIN

YEŞİ
ŞİLÇAY SYSTEM
BLACKSEA
AĞVA
YEŞİLÇAY REG.
KABAKOZ
DAM
DARLIK
DAM
İSAKÖY
DAM
SUNGURLU
DAM
ÖMERLİ
DAM
EMİRLİ TREATMENT
STORAGE
M A R M A R A SEA

YEŞİLÇAY SYSTEM CHARACTERISTICS
Length of transmission lines: 723 712 m
Length of water Network : 11 738 km
Volume of water reservoir : 914 000 m 3
Water Supplied (2003) : 920 million m 3 /year
Water treatment capacity : 3.5 million m 3 /day

Ø3 000 mm Prestressed Concrete Cylinder Pipes

BLACKSEA
GREATER MELEN PROJECT
OF ISTANBUL
Cumhuriyet
Pompa
İstasyonu
Hüseyinli Su Su
Arıtma Tesisi
Şile-Alaçalı
Melen
700 000 m³/gün
Tünel
Pompa
3.5 km
İstasyonu
Melen
Regülatörü
8.5 m 33 /s /s
Boğaz
Bekleme
Tüneli
Tüneli
5.5
1.3 km
km
Beykoz
Tüneli
Osmankuyu
Ayazağa
2.6 km
Su Su deposu
Tüneli
2.8 km
Ortaçeşme
Tüneli
0.8 km
MARMARA SEA
Alaçalı
Barajı
Hamidiye
Tüneli 5.2
km
Ömerli Barajı
(mevcut)
Alaçalı-Ömerli
Hattı
Melen-Alaçalı
İsale Hattı
131 km
Boğaz Tüneli
Profili
Melen Barajı
(ileri aşama)
Boğaz
Tüneli
Boğaz Tüneli
Ø=4.0-3.6 m
L=5.5 km

Great Melen Project Technical Specifications
System Length : 185 600 m
Ø 2 500 mm Steel Pipe : 163 950 m
Ø 4 500 mm tunnel length : 8 700 m
Ø 4 000 mm tunnel length : 11 550 m
Ø 3 600 mm tunnel length : 1 400 m

Examples of Fluid Mechanics System

Physical Properties of Fluids
Density
Specific weight
Specific Gravity
Specific Volume
Viscosity
Surface Tension
Vapor Pressure
Compressibility

Density, ρ
Mass per unit volume
ρ = m/∀
[ρ]=ML-3

Specific Weight, γ:
Weight per unit volume
γ = W/∀
[γ]=FL-3
γ = ρg

Specific Gravity, SG
The ratio of the density of the fluid to the
density of water (or air) at standard
conditions
(SG) liquid
=
ρ
ρ
w
(SG) gas
=
ρ
ρ
air

Density and Specific Weights of
some fluids (g=9.81m/s2)
Fluid
Liquids
Gases
G
as
es
Temperature
°
C
Density
kg/m 3
Specific Weight
N/m 3
Water 4.0 1000. 9810.
Mercury 20.0 13600. 133416.
Gasoline 15.6 680. 6671.
Alcohol 20.0 789. 7740.
Air 15.0 1.23 12.0
Oxygen 20.0 1.33 13.0
Hydrogen 20.0 0.0838 0.822
Methane 20.0 0.667 6.54

Deformation of fluid for a short time interval ∆t
U p
∝
hF
A
=
hτ
∆S
B B ’
τ
U p
F
τ ∝
U p
h
h
A
∆θ
y
u(y)
x
τ ∝
dθ
dt
Shear stress is
proportional to the rate
of angular deformation

Newton’s Law of Viscosity
For the linear velocity profile
du U d
=
p =
θ
dy h dt
u(y)
τ
=
U
h
p
y
du
= µ
dy
Newton’s
Law of
viscosity
τ ∝
du
dy
U p =
h
u(y)
y
The proportionality constant µ is known as
dynamic viscosity of the fluid.

Dynamic and Kinematic Viscosity
ν =
µ
ρ
Viscosity can be made independent
of fluid density; kinematic viscosity
is defined as the ratio
µ Dynamic Viscosity : N⋅s/m 2 N (Mass/Length/Time)
ν Kinematic Viscosity :
(m 2 /s) (Length 2 /Time)

Viscosities of air and water
Fluid
Temperature
(°C)
µ
(N⋅s/m 2 )
ν
(m 2 /s)
Water 20 1.00E-03 1.01E-06
Air 20 1.80E-05 1.51E-05

Reynolds Experiment
Dye
pipe
D
Q=VA
Dye streak
Smooth well-rounded entrance

Characteristics of Turbulent Flow

Velocity components in a turbulent pipe flow: (a) x-component
velocity; (b) r-component velocity; (c) θ-component velocity.

Type of Flow
Re…Dimensionless number
f( velocity, diameter, viscosity)
R e
VD
=
ν
4Q
=
πDν
Laminar flow: Re < 2000
Transitional flow: 2000 < Re < 4000
Turbulent flow: Re > 4000