3 Hydrodynamics
193
Fig. 3.20 Relationship between local head loss coefficient, mechanical energy
utilization efficiency, and area ratio of A 1 /A 2
projects) to supply water for agriculture and urban life and industry. For the
case of single pipe free outlet flow, as shown in Fig. 3.21, one end of the pipe
is connected to the pool and the other end is a free outlet in the atmosphere.
If the horizontal plane passing through the centerline of the pipeline outlet
is taken as the datum plane, the section 1-1 is located at a certain distance
from the inlet in the pool, and the section 2-2 is located at the outlet of the
pipeline, the total flow energy equation between 1-1 and 2-2 is established
H +
α 1 V 2
0
2g
= H 0 =
α 2 V 2
2g
+ h w1−2 =
α 2 V 2
2g
+
λ
L
d
+
ξ
V 2
2g
Fig. 3.21 Free flow from a simple pressure pipe
193
Fig. 3.20 Relationship between local head loss coefficient, mechanical energy
utilization efficiency, and area ratio of A 1 /A 2
projects) to supply water for agriculture and urban life and industry. For the
case of single pipe free outlet flow, as shown in Fig. 3.21, one end of the pipe
is connected to the pool and the other end is a free outlet in the atmosphere.
If the horizontal plane passing through the centerline of the pipeline outlet
is taken as the datum plane, the section 1-1 is located at a certain distance
from the inlet in the pool, and the section 2-2 is located at the outlet of the
pipeline, the total flow energy equation between 1-1 and 2-2 is established
H +
α 1 V 2
0
2g
= H 0 =
α 2 V 2
2g
+ h w1−2 =
α 2 V 2
2g
+
λ
L
d
+
ξ
V 2
2g
Fig. 3.21 Free flow from a simple pressure pipe