8 EXAMPLES
Surface water waves have been modeled using CGWAVE for a number of
idealized testcases and real practical applications. A number of these applications are
presented here to both validate CGWAVE and to demonstrate its ability to model waves.
8.1 Shoal on a Sloping Beach
Surface water waves propagating over the shoal presented by Berkhoff, et al.
(1982) were modeled. This test case demonstrates the ability of CGWAVE to simulate
the effects of complex coastal bathymetric features. The shoal in Figure 7 is oriented such
that the major axis of the shoal is parallel to contours of the water depth. Data is collected
along the eight sections (transects) shown in Figure 7.
Normal incident, plane waves having a period of 1 second are modeled for all runs.
An incident amplitude of 1.0 m is used for model runs using the linear dispersion relation.
Runs that are made using the non-linear dispersion relation use an incident amplitude of
0.0232 m.
Results were compared for model runs made with different grid resolution. This
was accomplished by varying the number of nodes in the computational domain and thus
constructing different finite element grids. Nodes were located such that the number of
nodes per wavelength remains constant throughout the domain. Grid densities from three
to fifteen elements per (local) wavelength were used. The resulting finite element grids
contain between 2500 and 75000 nodes and 5000 and 150000 elements, respectively.
CPU time is not taken into account when comparing the quality of the model results, as
the longest solution run is completed in less than four hours on a desktop (200 MHz
processor) PC.
74
Previous Page
