MIKE 21 BW, User Manual, Page: 82 / 196

Examples
82 MIKE 21 BW - © DHI
areas where the surface roller is not properly resolved. The filter is used at
water depths less than approximately 0.7 m, see Figure 4.53.
Figure 4.52 Map of absorbing sponge layers for regular wave simulation (left) and
directional wave simulation (right)
Figure 4.53 Map of low-pass filter coefficients used for both type of waves
A constant Manning number of M= 35 m
1/3
/s is used for the bottom friction
dissipation.
Model parameters
As in the other examples considering wave breaking the deep-water terms
are included.
In this example we use ‘Simple upwinding differencing’ for the space discreti-
sation of the convective terms. The time extrapolation factor is set to a value
of slightly less than one (0.8 in this case). As discussed in the User Guide we
recommend you to use ‘Simple upwinding at steep gradients and near land’
for the space discretisation of the convective terms. However. for numerical