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and the stream width at a certain distance from the bed (
T
). Applying the Bucking-
ham theory and eliminating the constant parameters, the dimensionless equation
may be written as follows:
Q
si
Q
su
¼
Q
i
Q
u
;
k
s
D
u
;
f
Fr
;
Re
(1)
where
Fr
is the approaching Froude number at the upstream,
G
r
¼
Q
si
/
Q
su
is the
ratio of entered sediment into the intake,
Q
r
¼
Q
i
/
Q
u
the diversion flow ratio, and
Re
*
is the shear Reynolds number of the particle. Since in all experiments the shear
Reynolds number is greater than the supposed least value, it is abandoned. The ratio
k
s
/
D
u
is the roughness ratio, a parameter which is used in the analysis too.
4 Results and Discussion
Table
1
shows what is done in the laboratory and gives the corresponding explana-
tions. As it is said before, the choice of the diversion flow is based on the free flow
condition. Figure
4
displays the reverse proportion between the Froude number and
the diversion flow ratio. The reason is that in the free state (the end gates are
completely open), at a constant depth, the greater the Froude numbers are, the
higher the flow velocity would be, as a consequence of which, in the intake extent
the momentum force is not sufficient to divert the stream, which leads to the
reduction of the diversion flow. The ratio
k
s
/
D
u
equal to 18.75E-6, 10.50E-6, and
8.73E-6 corresponds to, respectively, 10, 20 and 25 cm.
Because in the experiments the diversion flow ratios (
Q
r
) are different, the dimen-
sionless parameter
G
r
/
Q
r
is taken into use to judge the suspended load ratio (
G
r
).
Table 1
The flow condition
in this study
Side slope
Fr
Q
r
d
u
(m)
1.5
0.25
0.445
0.1
0.3
0.423
0.1
0.35
0.37
0.1
0.4
0.383
0.1
0.45
0.363
0.1
0.25
0.312
0.2
0.3
0.297
0.2
0.35
0.258
0.2
0.4
0.3
0.2
0.45
0.27
0.2
0.25
0.312
0.25
0.3
0.297
0.25
0.35
0.258
0.25
0.4
0.3
0.25
0.45
0.27
0.25
