Modeling A ============== Characteristics of modeling ----------------------------------- The aim of this modeling is to obtain the solution to the thermal problem from the calculation carried out on 1/8th of the structure. The test case is carried out as follows: • reading the mesh, 1/8th structure, from the file in "MED" format, command LIRE_MAILLAGE. • reading the temperature field from the file in "MED" format, command LIRE_CHAMP. • creating a result from the field previously read, command CREA_RESU. • creating a model from the mesh previously read, command AFFE_MODELE. • creation of a model for the groups of cells that belong to the symmetry plane, command AFFE_MODELE (see note 1). • reading the mesh, 1/8th structure, from the file in "MED" format and modifying the mesh by symmetry with respect to the plane (:math:`{\pi }_{\mathrm{sym}}`) defined by: • AXE_1 = :math:`(\mathrm{1.0,}1.0,0.0)`, AXE_2 = :math:`(0.0,0.0,-1.0)`, POINT = :math:`(0.0,0.0,0.0)` commands LIRE_MAILLAGE and MODI_MAILLAGE. • reading the temperature field from the file in "MED" format, command LIRE_CHAMP. • creating a result from the field previously read, command CREA_RESU. • creating a model from the symmetric mesh, command AFFE_MODELE. • reading the mesh representing 1/4 of the structure, command LIRE_MAILLAGE. • creating a model from the mesh previously read, command AFFE_MODELE. • projection of the 3 results created from the solution calculated on 1/8th of the structure, command PROJ_CHAMP with the keyword DISTANCE_MAX. • extraction of the temperature fields of the 3 results from the projection, command CREA_CHAMP. • creation of a null field on the model built on 1/4 of the structure, command CREA_CHAMP (see note no. 2). • combination of all fields, command CREA_CHAMP/OPERATION =' ASSE ' • creating a result from the combination of fields, CREA_RESU. **Note 1:** In this test case, nodes in the mesh, [Figure *], belong to the symmetry plane* :math:`{\pi }_{\mathrm{sym}}`\ *. For these nodes, the projection of the temperature field will therefore be counted twice. To avoid accumulating the temperature field one too many times, one solution is to create a model containing only these nodes and to perform the projection on the complete mesh. This projected field will then be subtracted using the command* *CREA_CHAMP/OPERATION =' ASSE ' .* **Note #2:** *Projecting fields using the command* *PROJ_CHAMP and the keyword* *DISTANCE_MAXpermet not to create a field on nodes that are not contained in one of the elements of the initial mesh and that are at a distance greater than* *DISTANCE_MAXde the closest element. When combining fields using the* *CREA_CHAMP/OPERATION =' ASSE 'command*, the first field at the nodes is taken as a reference. If the field is incomplete, as in our case, the combination will not give the expected result. The solution is therefore to create a null field on the whole model and to use it as a reference field. * Characteristics of the mesh ---------------------------- The projection of the temperature field calculated on 1/8th of the structure (mesh of the [:ref:`Figure1.1-a `]) is projected onto the model constructed from the mesh of 1/4 of the structure [:ref:`Figure3.2-a `]). +-------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------+ | | | + .. image:: images/10001CCE000069D50000B7DDA82026376C67EA37.svg + .. image:: images/1000158C000069D5000069D513B881C59921B39B.svg + | :width: 255 | :width: 3.4744in | + :height: 447 + :height: 3.4744in + | | | + + + | | | +-------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------+ Figure 3.2-a: 1/4 mesh size of the structure. Tested sizes and results ------------------------------ The test is carried out on the temperature field. From the result obtained by projection and combination on 1/4 of the structure, the temperature field TEMP1 is extracted. From the result calculated on 1/4 of the structure, the 2nd temperature field TEMP2 is extracted. These 2 fields are subtracted using the command CREA_CHAMP/OPERATION =' ASSE ', and the test is performed on the maximum and minimum value of the resulting field. At all points of the structure, we must have TEMP1 = TEMP2, so the field resulting from the command CREA_CHAMP/OPERATION =' ASSE 'must be zero at all points. .. csv-table:: "**Values tested**", "**Reference**", "**Code_Aster**", "**Precision**" "Maximum", "0.0", "2.694E-05", "1.0E-4" "Minimum", "0.0", "-1.808E-05", "1.0E-4" The [Figure] shows the map of the differences between the two temperature fields obtained during this test case. .. image:: images/10000200000001F7000001FB405DB26B1E15A1E3.png :width: 5.7634in :height: 5.8091in .. _RefImage_10000200000001F7000001FB405DB26B1E15A1E3.png: Figure 3.3-a: Temperature difference map.