12. J modeling

12.1. Characteristics of modeling

This is a functional test case and computer non-regression of the calculation of the a posteriori error indicator implemented in thermal technology (cf. [R4.10.03]). It excavates a spatial error map on which will be based, in a Python loop, the refinement/deraffination tool HOMARD encapsulated in MACR_ADAP_MAIL (cf. [U7.03.01]).

The calculation of this error indicator map is carried out, via the option “ERTH_ELEM” of the post-processing operator CALC_ERREUR, on a EVOL_THER (provided to the keyword RESULTAT) coming from a previous thermal calculation (linear or not, transient or stationary, isotropic or stationary, isotropic or orthotropic, via THER_LINEAIRE or orthotropic, via or THER_NON_LINE, cf. necessary environment, configuration and scope of use [ R4.10.03] §6.2/4).

This calculation requires first the use of the option “FLUX_ELNO” of CALC_CHAMP which determines the values of the heat flow vector at the nodes (cf. example of use [R4.10.03] §6.5).

The indicator consists of fifteen components per element and for a given moment. In this test case, the fifteen components are calculated but the refinement/deraffination procedure is based only on component ERTABS, which represents the total absolute spatial error (cf. [R4.10.03] §6.3).

In order to be able to post-process via POST_RELEVE or GIBI, we need to extrapolate fields by element to fields at nodes by element. The addition of the “ERTH_ELNO_ELEM” option (after the call to “ERTH_ELEM_TEMP”) allows this purely computer transformation to be carried out. For a given moment and for a given finite element, it only duplicates the fifteen components of the indicator on each node of the element.

This modeling is therefore as much an example of the use, in a PYTHON loop, of possible « indicator calculation »/ »mesh refinement/deraffination » combinations, as well as a test case of non-regression of the options” ERTH_ELEM_TEMP “and” ERTH_ELNO_ELEM “and of their adherence to the remeshing process.

This test case uses the characteristics of modeling I and its associated mesh (TETRA10 + TRIA6).

12.2. Tested values

We test the computer non-regression of the component ERTREL (total relative spatial error) of the error indicator with respect to versions V6.2.1 of the SGI and SUN platforms of Code_Aster and of version V4.3 of the software HOMARD. The relative tolerance is therefore severe: 5.10—6%.

Identification	Aster	Tolerance
Value of ERTRELsur the mesh MA1avant remeshing	4.15918735 10—5	5.10—8
Value of ERTRELsur the NO4avant remeshing node	4.15918735 10—5	5.10—8
Value of ERTRELsur the M1mesh after remeshing	5.48408914 10—6	5.10—7