MIKE 21 BW, User Manual, Page: 99 / 196

1DH Boussinesq Wave Module - Examples
99
As usual the enhanced Boussinesq equations are solved (i.e. deep-water
terms included) in 1DH applications.
Figure 4.67 Model setup
A structured mesh with elements with an edge length of 0.02 m is used. For
the 27.5 m long channel this results in 1375 elements and 1376 nodes. The
time step is 0.005 s and the simulation duration 50 s (10001 time steps).
Model results
Figure 4.68 shows a line series of the simulated surface elevation on top of
the bathymetry. The wave breaking and wave run-up processes are clearly
seen on this figure.
In Figure 4.68 the spatial variation of a number of phase-averaged quantities
are presented. The maximum wave height is 0.121 m at the generation point
and increases towards the break point, see Figure 4.68. Inside the surf zone
the wave height is decreasing. The significant wave height is
times larger
than the regular (linear) wave height. Figure 4.68 also shows the spatial vari-
ation of the crest and trough elevation and of the mean water level. In
Sørensen and Sørensen (2001)
(1)
a comparison is made between measure-
ments and simulated results for the crest and trough elevation.
In Figure 4.68 is also seen that the mean water level increases in the surf
zone in order to balance the decrease in momentum due to the wave height
decay.
1 Paper included in the Scientific Background
2