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10 5
THERMODYNAMICS 1 2 , FLUID MECHANICS 3 4 ,
DYNAMICS 5 6 , STRENGTH OF MATERIAL 7 8
MANUFACTURING 9 10
THERMODYNAMICS
1. 1 V(1800)
PO kPa(0 kPag =100 kPa) P1 kPa( 700 kPag = 800 kPa) t (60) ( PO P1)/ V, PO , P1 t
t (60 )
PO, mO,V P1, m1,V
1 (PO kPa) (20 )
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2. 2-
700 kPa 2- 700 kPa
1 . = hg-hf= hfg =2066.30 kJ/kg
700 kPa 400 kPa 2-
400 kPa
1 . = hg-hf= hfg =2133.81 kJ/kg = (2133.81-2066.30)/2066.30 = 0.032672 = 3.3%
(20
)
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M
1
2
CV
x
y
T
T
T2
mg
2 t
1 1 2 2 0
CS
V dA V A V A = + =vv
12 1 1
2
12A
V V VA
= = = /
x
xS
cs
F u V dA= vv
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2 2 2 1 1 1cos45 ( )x xa CV a CV p A p A T V V A V V A = + o
( ) 21 11 cos 45T V A= o
( ) 3 21 cos45 10 12 0.05= o
2108.83=
(Free Body Diagram)
0M = 0yF = 2T T=
20T mg =
2108.83
214.979.81
Tm
g= = = Ans
4. 40 50 commercial steel 150 90 4 gate valve
2 (20 )
2
400
40
50
50
200
30
P1
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( ),D f f Re e D= 5
6
2.825 0.154.237 10
1 10D
VD VDRe
= = = =
commercial steel 0.046e = .3
4
3
0.046 103.067 10
150 10
e
D
= =
DRe e D f Moody 0.0168f =
2 2
1 2 2 12 2 1 1
2 2 T p p V V
gz gz h
= + + +
l
2 2 2
2 2 21 2 2 1
90
( ) 4 22 2 2
e einlet
gatevalve
L LV V VL p p g z z f f f K
D D D
= + + + + + +
o
3
2 291.9 10p =
= 291.9 190.6 Ans
DYNAMICS
5. 60 A B 450 1.5 m/s2 80
(20 )
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1) 60 A B 450 2m/s2 80
s1 450m:= v1 60km
hr:= t1
s1
v1
:= ; t1 =
vmax
a 1.646 ms2
:=
s1 vmax t1 t2( )1
2a t2
2+ t2 10s:= vmax a t2
Given
s1 a t2 t1 t2( )1
2a t2
2+
t2 Find t2( ):= t2 =
vmax a t2:= vmaxkm
hr=
1.646 m/s2 80 B
6. 10 250 50 /
(20 )
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10:=
Given
10kg g 250mm mm+( )1
250
N
mm mm( )2
Find ( ) =
33.34
STRENGTH OF MATERIAL
7. (20 )1. 1 strength
strength
1.2 (cold working) (mechanical properties) 1.3 (bending equation) 1.4. (torsion equation) 1.5 (modulus of elasticity) (shear modulus)
(Poissons ratio) 1.6 (shear centre) 1.7 I 100 mm x 200 mm 12 mm 1.8 Polar moment of inertia r t 1.9 10. strength of materials
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8. (20 )1.1 (section modulus) 1.2 (simple torsion theory) 1.3 Complementary shear stresses 1.4 Principal plane principal stresses 1.5 (modulus of elasticity) (shear modulus)
(Poissons ratio) 1.6 (strain energy) proof strain energy 1.7 Flexible rigidity 1.8
1.9 1.10 (Euler)
MANUFACTURING
9. (Manufacturing Process)
(4) (20 )
1) (Green Sand Casting)
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, , (Water glass) (Resin)
1%
(Patter)
2) (Gravity Casting)
(Shell core)
(Resin coated sand)
1
0.0025 0.01 ( 0.064 0.25mm) () (outer tube)
3) (Pressure Die Casting)
Aluminum Zinc
7 350 Mpa ()
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1.5 ~ 4.5 . (Die) 2 (Front Platen) (Fix Die) (Moving Platen) (shot chamber) (tip) 50,000 200,000
Die Casting (oilfilter housing, Clutch housing) / , (Crank case) (Cover crank case) 2 (Head cylinder)
4) (Shell Molds)
(1) (Phenolic Resin) (Dump Box)
200 - 500 C (Silicone)
(2)
2-3 ()
(3) 5-7 . 1-3 2
(4) 200 300 C 2-3
(5) (6) 2 (Clamp) (Bonding agent)
( Metal Shot)
(7)
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2 ( , ) (Camshaft) , (Powersteering pump) compressor
10. (20 )
()
()
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