Date post: | 20-Dec-2015 |
Category: |
Documents |
View: | 228 times |
Download: | 8 times |
CE 230-Engineering Fluid Mechanics
Lecture # 31-32
Minor losses
Characteristic curve of a pump
Parallel pipes
Components of head loss
Losses due to friction along the length of the pipe call MAJOR LOSS
Losses at localized regions like inlets, outlets, bends.. CALL MINOR LOSS
g
V
D
Lfh f 2
2
g
VKh Lm 2
2
Example 10.9Find the elevation of the left reservoir given:
D=15 cmQ= 0.028 m3/s
ν = 4x10-5 m2/sS=0.9
Characteristic curve of a pump
The head produced by a pump will depend on the discharge rate varying from maximum value when there is no flow and decreasing as Q increases.
The nature of this variation is unique for every pump and is usually supplied by the manufacturer as a curve called the characteristic curve of the pump.
Characteristic curve of a pump
If we place a pump of known c.c. in a pipe line and want to determine the head required from the pump apply the energy equation we could get an equation for hp
hp will be a function of Q (system curve)
Flow in parallel pipes
How much will flow in pipe 1 and 2?
Key concept is the head difference between ant two junctions in the same regardless of the path.