D-R-A-F-T
Term in Numerator
Term
Sand
Sand
Clay
Clay Particle
Clay Mass
in
Storage
Advection
Diffusion
Deposition
Erosion
Deposition
Erosion
Erosion
Denominator
Storage
1
Cn
Cn/ Pe
Cv
CvVr
Cv
CvPd
Mr
Advection
1/Cn
1
1/ Pe
Cv /Cn
CvVr/Cn
Cv /Cn
PdCv /Cn
Mr/Cn
Diffusion
Pe /Cn
Pe
1
(Cv /Cn)Pe
PeCvVr/Cn
(Cv /Cn)Pe
(Cv/Cn)PePd
Mr Pe /Cn
Sand
1
-
-
-
-
1/ Cv
Cn /Cv
(Cn
Deposition
/Cv)Pe
Sand
1/
Cn /
Cn /
-
1
-
-
-
Erosion
(CvVr)
(CvVr)
(CvVr Pe)
Clay
-
-
1
-
-
1/ Cv
Cn /Cv
Cn /
Deposition
(Cv Pe)
Clay Particle
Cn /
Cn /
-
-
-
1
-
1/
Erosion
( CvPd)
(PdCv)
(CvPePd)
Clay Mass
1/Mr
Cn / Mr
Cn /
-
-
-
-
1
Erosion
( Mr Pe)
Where
V ∆t / L
Cn
=
Vs ∆t / H
Cv
=
=
V L / Dr
Pe
Pd
=
E0 / (C0 Vs)
Vr
=
V / (Vs Ler)
ρ0 δ0 / (C0 H)
Mr
=
V
=
current velocity, m/sec
∆t
=
time step, sec
=
horizontal size of element, m
L
diffusion coefficient, m2/sec
Dr
=
Vs
=
fall velocity, m/sec
=
horizontal entrainment factor, m
Ler
H
=
water depth, m
particle rate of entrainment for clay, kg/(m2 sec)
E0
=
suspended sediment concentration, kg/m3
C0
=
density of clay bed layer, kg/m3
ρ0
=
δ0
=
thickness of clay bed layer, m
Test problems
The model performance will be tested with a series of test problems designed to
evaluate the response of SED2D to these parameters. These tests will utilize the
following test meshes:
1.
A simple settling column problem. There may be a range of these
meshes with progressively greater resolution, but the simplest is a
single element. The settling column is 1m by 1m and 10m deep. The
hydrodynamics for the test is zero velocity throughout. This test case
eliminates the advective terms in the equation and allows for the
isolation of the storage, diffusion and bed source-sink terms.
52 Advanced Techniques
Users Guide To SED2D-WES
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