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total head loss discharge coefficient
head
(Munson et al., 2010)
constant2
2
zg
V
g
P (1)
P (Pa)
V (m/s)
z (m)
(kg/m3)
g (m s2)
2
222
1
211
22z
g
V
g
Pz
g
V
g
P (2)
gP pressure head (m) gV 22 velocity head z elevation head
21 zz pressure head velocity head total head (m)
( ,
2556)
total head loss, losstotalh , ,
g
V
g
P
g
V
g
Ph FFAA
losstotal 22
22
, ( )
discharge coefficient, DC ,
21
2
AC
CACD
AA
hhgAQC ( )
Q (m3/s)
h pressure head (m) = gP
A (m2)
CA,
1. valve rotameter L/min
valve L/min , 15
L/min
Flow rate (L/min) hA (mm) hB (mm) hC (mm) hD (mm) hE (mm) hF (mm)
30 510 459 1 301 476 503
25 497 461 143 350 471 491
20 481 457 253 385 462 476
15 475 461 346 419 462 471
10 466 459 407 438 457 463
pressure
head velocity head
pressure head velocity head
pressure head A velocity head
pressure head A B C
A B C
velocity head A B C velocity head pressure
head
0.0
100.0
200.0
300.0
400.0
500.0
600.0
A B C D E F
Hea
d (m
m)
Tube position
h (mm)
v2/2g (mm)
C D, E F velocity head
pressure head
pressure head A F
total head loss
total head loss
total head loss
pressure head
A F total head loss
Darcy-Weisbach equation (Munson et al., 2010)
g
V
D
Lfhloss 2
2
( )
f friction factor
L (m)
D (m)
lossh VAQ head loss
012345678
0 10 20 30 40
Hea
d lo
ss (m
m)
Flow rate (L/min)
discharge coefficient
discharge coefficient
discharge coefficient
0.98 venturi (Munson et al., 2010)
total head loss discharge coefficient
pressure head velocity head
total head loss total head loss - mm discharge
coefficient
0
0.2
0.4
0.6
0.8
1
1.2
0 10 20 30 40
Dis
char
ge c
oeff
icie
nt
Flow rate (L/min)
C_av
C_D
Bruce R. Munson, Donald F. Young, Theodore H. Okiishi, Wade W. Huebsch. 2010. Fundamentals of Fluid Mechanics. 6th
edition.Singapore: John Wiley & Sons.
2. .
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