Up: The KRAKEN Normal Mode
The following test problems have been developed to validate the model by
exercising various components of the code and to illustrate the input
structure required for various kinds of scenarios. In brief, we have:
- PEKERIS: A simple (two-layer) Pekeris waveguide.
- TWERSKY: The Pekeris wave guide with surface roughness.
Demonstrates that the Twersky scatter works properly.
- SCHOLTE: A two-layer waveguide with an elastic bottom which leads to a
Scholte wave. Demonstrates that the elastic half-space condition
- DOUBLE: A double-duct problem demonstrating that gradients are
- FLUSED: A three-layer problem involving ocean, sediment and
half-space. Demonstrates that multiple layers are treated properly.
- ELSED: A three-layer problem with shear properties in the
sediment. Demonstrates that elastic media are handled properly.
- ATTEN: A two-layer problem with volume attenuation. Demonstrates
that attenuation is handled properly.
- NORMAL: A problem with several density changes to check out the
modal normalization in a severe case.
- ICE: A problem with an elastic ice layer to demonstrate that
elastic layers above the water column are handled properly.
For each of these cases, we provide the environmental file along with the
print-out from KRAKEN
. The CPU times printed were obtained on
a 0.5 megaflop workstation.
In all cases, the frequency is chosen as and the transmission
loss is computed for a source/receiver depth combination of and
respectively. The transmission loss plots show an overlay of
(solid line), KRAKENC
(dotted line) and SCOOTER
line) results. These results have also been checked against the NRL
FSTFLD code which agrees to within (usually less).
Michael B. Porter
Tue Oct 28 13:27:38 PST 1997