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#1 2018-02-08 13:25:34

mediode
Member
Registered: 2009-07-31
Posts: 13

ECHANGE_PAROI in 2D

Hello,

I am trying to create a interface heat transfer in 2D (it is based on the example ttlp100c) with ECHANGE_PAROI. Unfortunately I cannot manage to put into effect the heat transfer, getting just constant temperatures of the initial field (but also no error messages).  Please find the files attached/Version 12.6, stable.

The mesh is created with gmsh and has two physical groups at the interface HTC1 & HTC2 (consisting of segments) belonging to different "bodies" BOD1 & BOD2. The location of the interface nodes and the number of segments is identical.

I was wondering if the identical location of the interface poses a problem? There is a hint in viewtopic.php?id=20871 mentioning the necessity of "clearance" between the two sides.  Is this the case (and what for)?. Another post mentions a bug: viewtopic.php?id=20870.

I would appreciate any hint, what I am probably doing wrong.

Best regards
m*


Attachments:
T011.tar, Size: 200 KiB, Downloads: 6

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#2 2018-02-09 10:45:30

mediode
Member
Registered: 2009-07-31
Posts: 13

Re: ECHANGE_PAROI in 2D

Hello,

The problem seems not to rely on a gap between the interfaces. I tried with a "clearance" of 0.1 mm. The result remains identical to the one without gap.
?
Any hints welcome!

Best reagrds m*

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#3 2018-02-13 16:48:10

mediode
Member
Registered: 2009-07-31
Posts: 13

Re: ECHANGE_PAROI in 2D

Hello,

I think there is a tiny flaw in the example ttlp100c.

The temperature boundary conditions and the bodies are not corresponding: tempG is assigned to T-BC GM38 and body GM35, tempD to GM37 and GM36. But with regard to geometry GM36 and GM38 belong together, as does GM35 and GM37.
It does not affect the test, but has been mixed up and can be observed in the fields when using

RESUTHER=THER_NON_LINE(MODELE=MODTHER,
                       CHAM_MATER=CHMATNL,
                       EXCIT=(_F(CHARGE=CHATHER,),
                              _F(CHARGE=CHATIMP,),),
                       INCREMENT=_F(LIST_INST=LINST,
                                    NUME_INST_FIN=2,),
                       ETAT_INIT=_F(CHAM_NO=TEMPINIT,),
                       ARCHIVAGE=_F(PAS_ARCH=1,),);

RESUTHER=THER_NON_LINE(reuse=RESUTHER,
                       MODELE=MODTHER,
                       CHAM_MATER=CHMATNL,
                       EXCIT=(_F(CHARGE=CHATHE2,),
                              _F(CHARGE=CHATIMP,),),
                       INCREMENT=_F(LIST_INST=LINST,
                                    NUME_INST_INIT=2,),
                       ETAT_INIT=_F(EVOL_THER=RESUTHER,
                                    NUME_ORDRE=2,),
                       );


Best regards
m*


Attachments:
TdistributionStep2.png, Size: 10.7 KiB, Downloads: 10

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#4 2018-02-16 14:02:02

mediode
Member
Registered: 2009-07-31
Posts: 13

Re: ECHANGE_PAROI in 2D

Hello,
I eventually succeded. Please find attached the final case.

The difficulty (apart from other minor errors I committed) lies in the mesh generation. One has to create an identical group of nodes/elements on both sides of the heat transfer. First I tried with gmsh, but could not obtain a proper solution (Even with Geometry.AutoCoherence=0; Turning off the merging of coincident points/nodes). Maybe it is possible, at least I failed. Any suggestions welcome.

It worked to create the meshes within salome-meca. One individual mesh for each component of the heat transfer and finally "joining" them together in a compound mesh (turning off merging off coincident nodes). To my understanding no gap is needed in between the components (but of course two nodes at the same location belonging to each components respectively then).

Best regards
m*


Attachments:
T0152D.tar, Size: 1.05 MiB, Downloads: 4

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