Etudes et évaluation de processus océaniques par des hiérarchies ...

88 CHAPITRE 4. ETUDES DE PROCESSUS OCÉANOGRAPHIQUES
0.006
A. Wirth / Ocean Modelling 9 (2005) 71–87 85
U (m/s)
0.004
0.002
0
8
16
32
64
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256
256 long
512
-0.002
-0.004
850 900 950 1000
Depth (m)
Fig. 9. Horizontal velocity along x ¼ 250 m near the lower boundary. Symbols correspond to the different spatial
resolution (as given in the figure).
tel-00545911, version 1 - 13 Dec 2010
W (m/s)
0.003
0.002
0.001
0
-0.001
-0.002
850 900 950 1000
Depth (m)
Fig. 10. Vertical velocity along x ¼ 500 m near the lower boundary. Symbols correspond to the different spatial resolution
(as given in the figure).
No spectral convergence is observed in this test-case. This comes at no surprise as the dynamics
even in the interior of the domain is completely slaved to the dynamics at the boundaries and thus
shows the corresponding convergence properties. It is indeed clearly visible from Fig. 7 that no
structures smaller than the basin scale appear in the problem. A problem involving scales smaller
than those imposed by the boundaries would cease to be stationary and the here presented
analysis could not be performed.
With the insight obtained from boundary-layer theory, the velocity components in the buffer
zone can be adjusted so that the real dynamics at the boundary is modeled to higher order. The
convergence properties of the dynamics in the interior fluid would then follow. This is the subject
of future research.
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