EASTERN MEDITERRANEAN UNIVERSITY

CIVIL ENGINEERING DEPARTMENT

HYDRO-MECHANICS ‘CIVL332’

INTERM I

Name Surname: 6 November 2013

Student No: 2013-14 Fall

Time: 100 min.

---------------------------------------------------------------------------------------------------------------------------------------

Question 1: (25 points)

General Energy equation for Pressurized, Steady and Incompressible Flow {Bernoulli Equation} is

given below; express the meaning of each symbol the symbol groups separately with proper SI units.

1

2

3

Total

2g

vk

2g

v

D

Lfz

2g

v

γ

pz

2g

v

γ

p2av

2av

2

2av2

2

21

2av1

1

1

Question 2: (40 points)

For the given pipeline system, determine the average discharge ‘Qav

’ passing within the pipe.

Ignore minor losses.

ANSWER: Qav = 82.3 lt/s

Pipe:

• galvinized iron

• 1435 m long

• diameter ϕ = 25 cm

water @ 23 °C

average discharge Q = ?

108.25 m

92.80 m

A

B

Question 3: (35 points)

For the given pipeline system, determine the nominal diameter ‘φ ’ of the pipe based on the

average discharge ‘Q´ you obtained in Question 2. Ignore minor losses.

ANSWER: D = 23 cm

Pipe: • PVC

• 1435 m long

• SAME average discharge Q of Question 2

water @ 23 °C

diameter ϕ = ?

108.25 m

92.80 m

A

B

EASTERN MEDITERRANEAN UNIVERSITY

CIVIL ENGINEERING DEPARTMENT

HYDRO-MECHANICS ‘CIVL332’

INTERM II

Name Surname: 27 November 2013

Student No: 2013-14 Fall

Time: 100 min.

--------------------------------------------------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------------------------------------------------

Question 1: (15 points)

If a discharge of Q = 200 lt/s has to pass within the system, determine the diameter ‘D’ of the

horizontal pipe. Working temperature is 25°C.

ANSWER: D=185 mm

1

2

3

4

Total

A

B

Q = 200 lt/s

Question 2: (15 points)

A 6 mm diameter glass tube of length L= 4.3 m is desigened to carry a liquid between the

cylindrical container B and pressurized tank A. For the given details, if the pressure at the tank A is pA=34.5

kPa gage, determine;

a) the flow rate Q?

b) the direction of the flow?

Note that, at that working temperature the specific weight of the liquid is γ=9.780 N/m3and its the dynamic

viscosity is μ= 0.0008 kg/(m.s).

ANSWER: Qav = 7.3 lt/s (Laminar) from tank A to reservoir B.

1.2 m

80 cm

Tank volume

V =37.70 m3

Φ=4.2 m

25 cm

Φ = 6 mm

L = 4.3 m

Φ=4.0 m

Question 3: (35 points)

The pipeline BCD carries water at 27°C with a discharge of Q=28.5 lt/s from reservoir A to the

main pipe at D. The existing pressure at point D is 138.34 kPa and its topographic elevation is zD=21.815 m.

It is expected to increase the discharge from A to D of the existing pipeline by 25% by adding an extra parallel

pvc pipe from points C to D and also keeping the pressure at D to be 136 kPa. Determine the diameter of this

extra pvc pipe. Ignore minor losses.

ANSWER: Dpvc = 165 mm

Question 4: (35 points)

Find the flow distribution of water at 23°C in the branching system (QA=?, QB=?, QC=? and

QD=?). For simplicity take f=0.02 for all the pipes. The pump manufacturer suggested that Hp=120-0.5Q2.

(Hp (m), Q(m3/s)). Note that water surface elevations at the reservoirs are kept as constant: zA=20 m, zB=52 m,

zC=105 m, zD=40 m. Use at least 3 trials.

ANSWER: From QA = 0.9032 m3/s

To QB = 0.4070 m3/s, QC = 0.1003 m

3/s QC = 0.3963 m3/s.

Pipe Length ‘L’ (m) Diameter ‘ϕ’ (mm) Total Minor Loss ‘Σk’ [-]

1 263.2 500 7.82

2 789.3 320 2.6

3 2106.8 300 3.8

4 1551.8 350 3.6

EASTERN MEDITERRANEAN UNIVERSITY

CIVIL ENGINEERING DEPARTMENT

HYDROMECHANICS ‘CIVL332’

INTERM III

Name Surname: 3 January 2014

Student No: 2013-14 Fall

Time: 100 min.

---------------------------------------------------------------------------------------------------------------------------------------

𝑅𝑒 =𝜌𝑣𝑎𝑣𝐷

𝜇 ; 𝐹𝑟2 =

𝑄2 𝑇

𝑔𝐴3 ; 𝑄 =𝐴

𝑛𝑦

23⁄ √𝑠𝑏 ; 𝑛𝑒𝑞 = [

∑ 𝑃𝑖𝑛𝑖1.5

∑ 𝑃𝑖]

23⁄

;

τo = γ.RH.sb ; 2

2

gA2

QyE ; 𝑦2 =

𝑦1

2(√1 + 8𝐹𝑟1

2 − 1)

---------------------------------------------------------------------------------------------------------------------------------------

Question 1: (35 points)

The single-composite channel cross-section detailed below, carries a uniform water at a depth of

y = 1.65 m. If the longitudinal channel bottom slope is sb = 0.00167 where γw = 9798 N/m3 and νw = 10

-6 m

2/s;

determine the below detailed hydraulic characteristics of this channel section:

i- the flow rate (discharge) ‘Q’

ii- the flow regime,

iii- the available specific energy ‘E’,

iv- the alternate depth,

v- the critical depth ‘ycr’

vi- the minimum energy ‘Emin’

vii- the shear stress along the inner surface of the cross-section ‘τo’,

viii- the Reynolds number ‘Re’,

ix- draw the specific energy ‘E’ versus flow depth ‘y’ curve and show the relevant data related to this flow

for the given cross-section.

1

2

Total

Question 2: (65 points)

Two successive long reaches of rectangular channel cross-section of width B = 3.85 m carries a

uniform discharge Q = 18.540 m3/s. The equivalent Manning’s roughness coefficient of the upper reach is

n1 = 0.018 and for the lower reach is n2 = 0.022. The first reach bottom slope is sb1 = 0.0953 and the second

reach bottom slope is sb2 = 0.00318. Determine:

i- the uniform flow depths y1 and y2 of the reaches,

ii- determine the critical flow depth ycr of the reaches,

iii- classify the reaches,

iv- check the occurrence possibility of the hydraulic jump,

v- establish the hydraulic jump ‘H.J.’ (if occurs),

vi- suggest the possible curve type cooperated with hydraulic jump (if exits),

vii- determine the specific energies at all varying locations,

viii- obtain the minimum specific energy Emin,

ix- calculate the energy loss due H.J. (if exists),

x- calculate the energy loss due non uniform flow portion (if exists),

xi- draw the specific energy curve of this slope break zone,

xii- show the flow variations on the given reaches.