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5.2 Fluid Transport
6. The Nanzenji aqueduct water channel of Kyoto,
Japan (Fig. 5.9).
The profile and typical cross-sections of a supply conduit
are shown in Fig. 5.10. Static heads and HGLs are indicated
for pressure conduits.
5.2 FLUID TRANSPORT
The hydraulic design of supply conduits is concerned chiefly
with (a) resistance to flow in relation to available and needed
heads or pressures and (b) required and allowable velocities
of flow relative to cost, scour, and sediment transport. In
long supply lines, frictional or surface resistance offered by
the pipe interior is the dominant element. Form resistance
responsible for losses in transitions and appurtenances is
often negligible. In short transport systems, on the other hand,
form resistance may be of controlling importance.
5.2.1 Rational Equation for Surface Resistance
The most nearly rational relationship between velocity of
flow and head loss in a conduit is also one of the earliest.
Generally referred to as the Darcy–Weisbach formula,itis
actually written in the form suggested by Weisbach, rather
than Darcy, namely,
Figure 5.9 Water channel of the Nanzenji aqueduct, Kyoto, Japan
2
(Source: http://en.wikipedia.org/wiki/Image:Nanzenji_aqueduct_ h = f(L∕d)(v ∕2g) (5.10a)
f
channel.jpg). 2
h = KQ (5.10b)
f
Gate
Dam house Construction
Static pressure line
Gate house shafts Static pressure
1 Hydraulic grade line
Canal Distribution or
2 Hydraulic 3
Pressure grade line 3 3 Gate house service reservoir
aqueduct Grade 4
aqueduct Grade Down Static pressure
Original surface Profile tunnel shaft Up shaft Hydraulic
Original surface
5 grade line
6
Pressure Pipe City
tunnel siphon
1. Lined canal 7
Original Pipe lines
surface
2. Reinforced concrete
pressure aqueduct

Original surface 3. Cut-and-cover
grade aqueduct
4. Grade tunnel
5. Pressure tunnel

6. Steel pipe siphon 7. Pipe line
Figure 5.10 Profile and typical cross-sections of a water supply conduit.