Armfield C4-MKII, Инструкция по эксплуатации

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6.3 Nomenclature for Free Surface Flow
Name Symbol Units Definition
Velocity of gravity wave in still
shallow water c ms
-1
(sometimes called
celerity)
Coefficient of contraction C
c
-
Coefficient of discharge C
d
-
Coefficient of velocity C
v
- 0.95<C
v
<1.0
Specific energy head (total energy
head measured relative to channel
bed) E m E = y + V
2
/2g Note : If
the datum is the channel
bed then E = H (z = 0)
Force of a stream F N
F = ρ gby
2
/2 + ρ Q
2
/by
Height of water surface above a
weir crest y
c
m
Total energy head or total head
(height of energy line (e) above a
datum) H m H = y + V
2
/2g + z
Loss of total head between
specified sections
∆ H
m
Pressure at height y above channel
bed p Nm
2
Measured
Height of weir crest above
channel bed h m Measured
Height of water surface above the
bed at position x y
x
m Measured
Critical depth y
crit
m Depth at which specific
energy of flow is at a
minimum.
Height of sluice gate opening y
g
m Measured
Height of siphon throat y
t
m Measured
Slope of energy line (for uniform
flow assumed to be the same slope
as the channel bed and the surface
of the water) S °
Sin θ