2.3
2.3
Baseline
Baseline
2.2
2.2
2.1
2.1
Upstream Spacing
2.0
2.0
(25 m)
Downstream Spacing
(25 m)
1.9
1.9
1.8
1.8
1.7
1.7
0
1000
2000
3000
4000
5000
0
1000
2000
3000
4000
5000
x Location
x Location
a. In the first 1000 m of the system.
b. In the last 1000 m of the system.
Figure 49. Final jam thickness profile for length step reduced to 25 m.
2.3
2.3
Baseline
Baseline
2.2
2.2
2.1
2.1
2.0
2.0
Upstream Spacing
Upstream Spacing
(100 m)
(200 m)
1.9
1.9
1.8
1.8
1.7
1.7
5000
4000
3000
2000
1000
0
5000
4000
3000
2000
1000
0
x Location
x Location
a. Length step increased to 100 m.
b. Length step increased to 200 m.
Figure 50. Final jam thickness profile for length step changes in the first 2000 m of the
system.
taken not to violate any Courant number limitations identified earlier.
The baseline run had uniform length steps of 50 m, which give Cr = 3. The
Courant-number sensitivity findings described earlier indicate that Cr values in
the range of 1 to 12 should provide acceptable results. From eq 151, this finding
translates to acceptable length steps ranging from 16.7 to 200 m. Several runs were
made with a variety of length steps.
The first run involved changing the length step to 25 m for the first 1000 m of the
system. This step length decreased the Cr to 1.5 in the first 1000 m of the system
and increased the total number of cross sections to 121. All the other conditions
were the same as for the baseline run. A similar run decreased the length step to 25
m for the most downstream 1000 m of the system. These two reaches are where the
greatest variations in the final jam thickness profile exist. Figure 49 presents the
final jam thickness profiles for these two runs, compared to that of the baseline run.
The 25-m upstream spacing resulted in a more gradual rise to the maximum thick-
ness, which occurred around 1000 m. The final jam thickness was up to 0.05 m less
than the baseline run, but only for locations upstream of 2000 m. Almost no differ-
ence existed between the baseline and the 25-m downstream spacing runs, espe-
cially in the most downstream 1000 m where the spacing was changed.
The next two runs increased the length step in the most upstream 2000 m of the
system to 100 and 200 m respectively. The values of Cr for the upstream 2000 m
increased to 6 and 12, with the total number of cross sections reduced to 81 and 71
respectively. Figure 50 presents the final jam thickness profiles for these two tests,
66
Previous Page
