Past Year Question Fluid Mechanics 
CONFIDENTIAL
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UNIVERSITI TUN HUSSEIN ONN MALAYSIA
FINAL EXAMINATION
SEMESTER II
SESSION 2012t20t3
COTIRSE NAME
FLUID MECHANICS
COURSE CODE
BNQ 10303
PROGRAMME
I BNN
EXAMINATON DATE
JUNE 20I3
DURATION
3 HOURS
INSTRUCTION
ANSWERALL QUESTIONS
CONFIDENTIAL
BNQIO3O3 FLUID MECHANICS
Ql. (a)
Define pressure head, velocity head, and elevation head for a flurd stream alld express them for a fluid stream whose pressure is p, velocity is V, and elevation is z.
(6 ma*s)
(b)
Outline three (3) major assumptions used in the dedvation of the Bemoulli equation. (6 marks)
(c)
A pressurized tank of water has a 10 cm diameter orifice at the boftom, where water discharges to the atmosphere. The water level is 2.5 m above the outlet.
The rank air pressure above the water level is 250 kpa (absolute) while the atmospheric pressure is 100 kpa. Neglecting frictional effects, determine rhe initial discharge rate ofwater from the tank. Refer to FIGURE
(c).
el
Q2.
(a)
(13 ma*s)
Explain why liquids are usually transported in circular pipes.
(3 marks)
(b)
Briefly describe ihr significance ofReynolds nurnber. Refer to FIGURE e2 (b).
How is it defined for:
(D flow in circular pipe of inner diameter D
(iD flow in a rectangular duct ofcross section a x b
(7 marks)
(c)
Refer to
IGURE Q2 (c), Water at l5"C (p:999.1 kg/m3 and p = 1.138 x l0-3 kg/ms) is flowing steadily in a 30 m long and 5 cm diameter horiiontal pipe made of stainless steel at a rate of 9 L/s. The roughness, e for stainless sdl is 0.002 mm. Calculate:
The pressure drop
The head loss, and
The pumping power requirement to overcome this pressure drop.
(i)
(iD
(iiD
(
Q3.
(a)
l5 marks)
Describe how is friction factor for flow in a pipe related to the pressule loss for a giveo mass flow rate.
(6 marks)
(b)
Consider laminar flow ofair in a circular pipe with perfectly smooth surfaces. Do you think the friction factor for this flow is zero? Explain your answer.
(6 ma*s)
(c)
A
s't
ry ,b
t:.,Wj
UNIVERSITI TUN HUSSEIN ONN MALAYSIA
FINAL EXAMINATION
SEMESTER II
SESSION 2012t20t3
COTIRSE NAME
FLUID MECHANICS
COURSE CODE
BNQ 10303
PROGRAMME
I BNN
EXAMINATON DATE
JUNE 20I3
DURATION
3 HOURS
INSTRUCTION
ANSWERALL QUESTIONS
CONFIDENTIAL
BNQIO3O3 FLUID MECHANICS
Ql. (a)
Define pressure head, velocity head, and elevation head for a flurd stream alld express them for a fluid stream whose pressure is p, velocity is V, and elevation is z.
(6 ma*s)
(b)
Outline three (3) major assumptions used in the dedvation of the Bemoulli equation. (6 marks)
(c)
A pressurized tank of water has a 10 cm diameter orifice at the boftom, where water discharges to the atmosphere. The water level is 2.5 m above the outlet.
The rank air pressure above the water level is 250 kpa (absolute) while the atmospheric pressure is 100 kpa. Neglecting frictional effects, determine rhe initial discharge rate ofwater from the tank. Refer to FIGURE
(c).
el
Q2.
(a)
(13 ma*s)
Explain why liquids are usually transported in circular pipes.
(3 marks)
(b)
Briefly describe ihr significance ofReynolds nurnber. Refer to FIGURE e2 (b).
How is it defined for:
(D flow in circular pipe of inner diameter D
(iD flow in a rectangular duct ofcross section a x b
(7 marks)
(c)
Refer to
IGURE Q2 (c), Water at l5"C (p:999.1 kg/m3 and p = 1.138 x l0-3 kg/ms) is flowing steadily in a 30 m long and 5 cm diameter horiiontal pipe made of stainless steel at a rate of 9 L/s. The roughness, e for stainless sdl is 0.002 mm. Calculate:
The pressure drop
The head loss, and
The pumping power requirement to overcome this pressure drop.
(i)
(iD
(iiD
(
Q3.
(a)
l5 marks)
Describe how is friction factor for flow in a pipe related to the pressule loss for a giveo mass flow rate.
(6 marks)
(b)
Consider laminar flow ofair in a circular pipe with perfectly smooth surfaces. Do you think the friction factor for this flow is zero? Explain your answer.
(6 ma*s)
(c)
A