CEDRE Interface

Solver CEDRE
Type of mesh unstructured mesh
Dimension 2D and 3D

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The translator creates a grid and boundary conditions file in the Cedre file format.

Creating the Cedre Input File

The Cedre output interface can be invoked from the AI-Environment.  First select the solver (format) Cedre.  Then the Cedre boundary conditions can be defined.  The next section explains in detail how to set the boundary conditions for Cedre.  Once the mesh and boundary conditions are set, the translator can be launched.    A window opens to allow the specification of the files to be translated into the Cedre format.  First, an unstructured mesh file must be selected.     In addition, the output interface requires the boundary conditions file, and offers the option to define the prefix of the Cedre input file(s).  The interface generates the Cedre input file(s) in the current project directory.  At the minimum, the file "maillage.dat" is written.  If a prefix is defined, this file is named "prefix_maillage.dat".  The file "maillage.dat" contains all the information about the mesh nodes, elements and face marks.  When periodic boundary conditions are found, two additional files are created: "multi.dat" ("prefix_multi.dat") and "psl.dat" (prefix_psl.dat).

Defining boundary conditions and properties for Cedre

After generating the mesh, and prior to running the translator, boundary conditions and properties for Cedre can be defined using the Cedre  Graphical User Interface.   The boundary condition menu for the Cedre translator must first be selected.    The "Family Boundary Conditions" window opens allowing to set the boundary conditions and properties on the mesh families. The program supports the definition of face marking, axisymmetry and periodicity.

Face marking

The face marking is supported on boundary faces or internal faces.  In the Cedre Boundary Condition menu,  a "face family" must first be selected.   Note that a face family is defined as a family composed solely of 2D elements for a 3D mesh, or a family composed solely of 1D elements for a 2D mesh.  Then the boundary conditions  "Boundary Mark" can be added to this family.  The default name (mark) is set to the family name.  This can be changed to any character string.

Axisymmetry

The translator supports 3 types of meshes.  In Cedre, these are refered to with the names 2D_AXI, 2D_PLAN and 3D.  For a mesh type 2D_PLAN, the translator computes automatically the normal to the plane.  For a mesh type 2D_AXI, the translator needs to inquire information about the axis of symmetry.  The user must define the axis of symmetry using the option "Mesh parameters: 2D Axisymmetry parameters".  When selecting this option, the user is prompted to enter the coordinates (x, y, z) of a point on the axis of symmetry, as well as a vector (UX, UY, UZ) along this axis.  Note that the axisymmetry parameters can only be defined on a surface family (2D elements) and should be defined only once.
 

Periodicity

The periodicity is supported on boundary faces only.  The periodicity must have been first defined in the mesh generator.  In addition, the periodic face families must be tagged as such in the boundary conditions file.  In order to do so, a "face family" must first be selected, then the boundary condition "Periodic Face" must be selected.  This should be done for each family that are part of the periodicity.
 

Limitations

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