Three-dimensional Lagrangian Tracer Modelling in Wadden Sea ...

CHAPTER 3. IDEALISED TESTCASES 39
y [m]
y [m]
50
40
30
20
10
0
−10
−20
−30
−40
y [m]
50
40
30
20
10
-10
-20
-30
-40
0
-50
-50 -40 -30 -20 -10 0 10 20 30 40 50
x [m]
= 367 m/s
= 177 m/s
= 33 m/s
Fig. 3.1.1: Velocity field for the two-dimensional advection case.
∆ t = 0.001 s
−50
−50 −40 −30 −20 −10 0 10 20 30 40 50
50
40
30
20
10
0
−10
−20
−30
−40
∆ t = 0.01 s
x [m]
analytical solution
analytical method
−50
−50 −40 −30 −20 −10 0 10 20 30 40 50
x [m]
analytical solution
analytical method
a)
b)
y [m]
y [m]
50
40
30
20
10
0
−10
−20
−30
−40
∆ t = 0.001 s
−50
−50 −40 −30 −20 −10 0 10 20 30 40 50
50
40
30
20
10
0
−10
−20
−30
−40
∆ t = 0.01 s
x [m]
analytical solution
Runge−Kutta method
−50
−50 −40 −30 −20 −10 0 10 20 30 40 50
x [m]
analytical solution
Runge−Kutta method
Fig. 3.1.2: Particle trajectories computed from the analytical and the Runge-
Kutta algorithm for two different time steps ∆t = 0.001 s and ∆t = 0.01 s.
3.2 1D: Vertical sediment transport
In this section results are presented from modelling sediment suspension and
transport with GOTM in a one-dimensional water column (z-direction). To
compute the vertical sediment profile, a Eulerian scheme and the random
walk model are used. The results are compared with the analytical solution
c)
d)