This directive enables “remeshing”, i.e. changing the topology of a part of the mesh previously defined by directive "GEOM".
Note that this is very different from mesh “rezoning”, i.e. prescribing the motion of a fluid grid in ALE computations. In fact, rezoning operations just move the nodes, without changing the topology (number of nodes and elements, composition of the elements).
For remeshing, two options are possible:
With the option "AUTOMATIQUE", the user has to supply only the boundary points of the zone submitted to remeshing, then EUROPLEXUS builds a new and more regular mesh based on the boundary.
With the option "MANUEL", the user must enumerate all the elements which are to be eliminated and supply the new mesh.
At the present time, only 3-noded triangles ("TRIA") can be taken into account.
"REMAILLAGE" $ "AUTOMATIQUE" . . . $ $ "MANUEL" . . . $
The suppressed elements must belong to the same zone (defined by the instruction "GEOMETRIE").
The new sub-mesh is created by EUROPLEXUS. Therefore, only the boundary points are necessary. As a matter of fact, these points should be common to the old and the new mesh.
"AUTOMATIQUE" "CONTOUR" /LECTURE/ "AJOUTER" npts*( xi , yi ) < "ELEM" ideb ifin > < "ZONE" nzone > < "MAIL" < nmail > > < "STOP" >
If the boundary point is an existing node, it is defined by its number.
If it is an added point, it is defined by a negative number. In this case, at the end to the procedure /LECTURE/, the user must enter the coordinates of these points in the same order as they are mentioned in the procedure, by the means of the instruction "AJOUTER".
The directives "ELEM" and "ZONE" enable the elements submitted for remeshing to be limited.
By means of the directive "MAIL", the user can obtain a data set for "COCO" in order to plot the results of the remeshing.
The key-word "STOP" stops EUROPLEXUS when the mesh is created and enables the user to check his mesh.
This option enables a new partial mesh to be explicitly entered.
"MANUEL" izone nelim nelaj npaj "ANCIEN" /LECTURE/ "NOUVEAU" . . . COCO data set . . . "IDENTIFIER" npts*( numl numg )
The "COCO" data set with its title is composed of the coordinates of the new sub-mesh (in format 6E12.5) and of the numbers of the mesh elements (in format 18I4).
The key-word "IDENTIFIER" enables the integration of the new sub-mesh into the global mesh to be defined.
To edit (verify) the result of a remeshing operation.
< "PERFO" nuperf > < "TRACE" nutrac > < "SAUVE" nusauv >
During a restart the user can save data for another restart.
The user is advised to use these commands, because the numbers of certain elements may have changed after a remeshing. That is why it is necessary to save that time step ( considered by EUROPLEXUS as step zero). Do not forget to check that the new mesh is correct before the computation continues by means of a restart ("REPRISE").