39
Results
Tabulate your readings and calculations as follows:
Breadth of Weir
b
=…………(m)
Height of weir
h
w
=…………(m)
y
0
y
1
Q
actual
H
0
Q
theoretical
C
d
Plot graphs of Q
actual
against H
0
and C
d
against H
0
.
Conclusion
Does the magnitude of the flowrate affect the discharge coefficient C
d
? Does C
d
increase
or decrease with increasing flowrate?
What is the pattern of the water as it passes over the weir?
Does the height of the weir affect the discharge coefficient?
Would you expect the length of the weir crest to affect the discharge coefficient C
d
?
What is the effect of drowning the weir (increasing the downstream depth)? How does
drowning affect the accuracy of the results?
