The first step consisted in creating
the bathymetry of the problem. We made a file telling Matisse the position
of the the points we felt were the most important. There are positionned
at the edges of each side of the valley. We first thought it was not necessary
to put some points in the middle of the rivers but the tests we have made
showed that the flow went out of the modelised zone. So, we had to increase
the number of points describing the bathymetry. Here is the bathy.sx we
have used : (the last column deals with the height of the point.)
C Fichier /tmp_mnt/nfs/lhf_a/users3/telcom/INVARIANTS/FORMATION_1997/SINUSX_V2P2/formation.sx
C Version 2.0 - Date Fri Mar 14
08:56:49 1997
C
C
C
B N +0.000000E+00 +0.000000E+00 +0.000000E+00 +3.000000E+02 +3.000000E+02
+1.000000E+00 1
CN C1
CP 0 1
CP +2.600000E+02
CP 0
C contour
C
-0.500000E+03 +0.000000E+00 +0.500000E+00
+0.000000E+00 +0.000000E+00 +0.000000E+00
+0.500000E+03 +0.000000E+00 +0.500000E+00
+0.500000E+03 +5.000000E+03 +5.500000E+00
+8.370000E+03 +1.837000E+04 +2.050000E+01
+6.630000E+03 +1.937000E+04 +2.050000E+01
+0.000000E+00 +6.950000E+03 +5.500000E+00
-1.413000E+04 +3.237000E+04 +3.550000E+01
-1.587000E+04 +3.137000E+04 +3.550000E+01
-0.500000E+03 +5.000000E+03 +5.500000E+00
+0.000000E+00 +5.870000E+03 +4.500000E+00
+7.500000E+03 +1.887000E+04 +1.950000E+01
-1.500000E+04 +3.187000E+04 +3.450000E+01
Then, we used Matisse to generate the mesh. The geometry we have visualised was :
We enlarged the bottom of the
modelised area to avoid the problem of a too important confluence of the
floods. The result on the bathymetry (visualised with Rubens) is quite
good :
This picture shows that to be at the same level for the side of the
valley requires to be further in the denivellation.
Then, we generated the mesh with Matisse. The mesh is composed of about
3500 nodes. We decided to place nodes along the deepest points of the aera
to modelise the phenomenon very precisely.
Here is the mesh we obtained for the top of the aera :
And for the bottom of the aera :
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