192
P. Liu
Total head line
Piezometric
head line
V 1
2
V 1
V 2
2g
V 2
2
2g
p 1
J
p 2
h w
J
Fig. 3.19 Partially separated flow of sudden expansion pipeline
The mechanical energy utilization efficiency of a sudden expansion
pipeline is defined as
η =
V 2
1
2g − h j
V 2
1
2g
= 1 − ξ
Figure 3.20 shows the relationship between the local head loss coefficient
and mechanical energy utilization efficiency of the sudden expansion pipe as
a function of area ratio.
Taken together, for equal-section pipes with several different flow components, the total head loss can be expressed as
h w =
λ
L
d
+
ξ
V 2
1
2g
3.4 Steady Flow Along a Pressure Pipeline
3.4.1 Simple Pipe Flow
Pressure pipe flow refers to the flow without free surface on the cross section
of the pipe. In engineering practice, it is commonly used in water diversion
projects (including water diversion, water supply, water discharge, and other
P. Liu
Total head line
Piezometric
head line
V 1
2
V 1
V 2
2g
V 2
2
2g
p 1
J
p 2
h w
J
Fig. 3.19 Partially separated flow of sudden expansion pipeline
The mechanical energy utilization efficiency of a sudden expansion
pipeline is defined as
η =
V 2
1
2g − h j
V 2
1
2g
= 1 − ξ
Figure 3.20 shows the relationship between the local head loss coefficient
and mechanical energy utilization efficiency of the sudden expansion pipe as
a function of area ratio.
Taken together, for equal-section pipes with several different flow components, the total head loss can be expressed as
h w =
λ
L
d
+
ξ
V 2
1
2g
3.4 Steady Flow Along a Pressure Pipeline
3.4.1 Simple Pipe Flow
Pressure pipe flow refers to the flow without free surface on the cross section
of the pipe. In engineering practice, it is commonly used in water diversion
projects (including water diversion, water supply, water discharge, and other