Geoscience Reference
In-Depth Information
Figure 11.12
Multiple-layer model of bed consolidation.
Discretizing Eq. (11.40) yields
n
dj
j
ρ
n
+
1
n
δ
=
δ
(11.41)
j
n
+
1
ρ
dj
Then, the overall bed change due to consolidation is calculated as
⎛
⎝
ρ
⎞
J
J
n
dj
n
+
1
n
j
n
j
⎠
z
b
,
c
=
1
(δ
−
δ
)
=
1
δ
−
1
(11.42)
j
n
+
1
ρ
j
=
j
=
dj
where
J
is the total number of the divided bed material layers.
Calculation procedure
As described in Section 5.1, the flow and sediment calculations may be coupled or
decoupled, depending on the intensity of sediment transport. If the sediment concen-
tration is low and the bed varies slowly, the effect of sediment transport on the flow
is negligible and thus a decoupled model is applicable; otherwise, a coupled model
should be used. However, in the sediment module (or loop), sediment transport, bed
change, and bed consolidation are correlated, and thus it is usually required to solve
them simultaneously in an iteration form. The following calculation procedure is used
by Wu and Wang (2004c):
(1) Initialize flow, salinity, and sediment fields;
(2) Calculate the flow field using a flow solver;
