Single Exponential P-40 = 1 ( cont’d )
FLUMES
Parshall Flume
» sized by throat width
» set on solid foundation
» general free flow equation is Q = K H
x
where: Q = flow rate
K = constant
H = head
x = exponent
» For rated flows under free flow conditions, the head is measured
at 2 / 3 the length of the converging section from the beginning
of the throat section.
» Position the transducer such that it is centered over the flow at a
minimum head.
Khafagi Venturi
» for rated flows under free flow conditions, the head is measured 15 cm
( 6" ) upstream from the beginning of the converging section.
» position the transducer such that it is centered over the flow at a
minimum height of 30 cm ( 12" ) above the maximum head.
C
2
/
3
C
transducer
plan
side
front
0
head
sidefront
transducer
0
head
plan
15 cm ( 6" )
PL-443 6 – 34