Download H.W.2 solution

The Islamic University of Gaza
Civil Engineering Department
Fluid Mechanics-Discussion
Autumn Semester (2011-2012)
Instructors:
Dr. Younes Mogheir
Dr. Mazen AbuAltayef
T.A.
Eng: Mohammed Abu Al-hatal
Eng: Amal Qarot
Name: ……………………………………..……..……………
ID: …………………………..……..
Homework (2)b solution
Question
1- Find the pressure at A,B,C and D
Soln. )
PA= (62.4)*(4+2) = 374 Ib/𝑓𝑡 2
PB= -(62.4)*(2) = -125 Ib/𝑓𝑡 2
PB=PC = -125 Ib/𝑓𝑡 2
PD = -125-(62.4)(4+2+2) = -624 Ib/𝑓𝑡 2
Fluid mechanics
Home Work
2- For the open tank , with piezometer on the side containing two different immiscible liquids
find a) the elevation of the liquid surface in piezometer A
b) elevation of the liquid surface in piezometer B
c) total pressure at the bottom of the tank .
a)
‫ ألنه الضغط متساوي على المستوى األفقي‬tank ‫ في‬A ‫ لنفس االرتفاع السائل‬peizometer ‫ ببساطة سيرتفع في‬A ‫السائل‬
‫ م‬2 ‫وهو المنسوب‬
b)
‫ باالضافة الى الضغط الذي‬B ‫ م ناتج عن الضغط الذي يسببه السائل‬0.3 ‫ لمنسوب‬peizometer ‫ سوف يرتفع في‬B ‫السائل‬
‫ المكافئء للضغط‬B‫ لذلك أريد إيجاد االرتفاع من السائل‬B ‫ مختلف عن السائل‬A ‫ ولكن الحظ هنا أن السائل‬A ‫يسببه السائل‬
‫ كما يلي‬A ‫الذي يسببه السائل‬
P = 720*9.81*1.7 =12 KN/𝑚2
Equivalent depth of liquid B to the pressure 12 KN/𝑚2 = 12 /(2.36*9.81) = 0.519 m
The liquid B depth is 0.3+0.519 = 0.819 m
c) 𝑃𝑏𝑜𝑡𝑡𝑜𝑚 = 720*9.81*1.7+2360*9.81*0.3 = 18.9 KPa
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Fluid mechanics
Home Work
3- A monometer is attached to a tank containing three different fluids , what will be the
difference in elevation of the mercury column in monometer (y)
30 + (820*9.81*3)+(1000*9.81*2)+(1000*9.81*1) = 13600*9.81*y
Y= 0.627 m
4- A differential manometer is attached to a pipe , calculate the pressure different between
point A and B
𝑦+4
PA – (9.1*62.4(y/12))-(13.6*62.4*(4/12))+(0.91*62.4( 12 ))=PB
PA-PB = 264 Ib/𝑓𝑡 2
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