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

mediode
Member
Registered: 2009-07-31
Posts: 17

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: 99

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

mediode
Member
Registered: 2009-07-31
Posts: 17

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: 17

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: 103

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

mediode
Member
Registered: 2009-07-31
Posts: 17

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: 103

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#5 2019-12-30 17:20:20

maxmss
Member
Registered: 2019-09-03
Posts: 22

Re: ECHANGE_PAROI in 2D

Hi mediode,

I know it's been a long time since you published this post but I have a problem similar to yours and apparently the problem is due to the generation of the mesh.

What I have to do is apply transfer heat between several solid  with "ECHANGE_PAROI". To do this I need two contact interfaces between two solids, one for each solid where the contact exists.

The problem I get is this: Les deux listes && CAECHP.LLIST1 et && CAECHP.LLIST2 ne sont pas de même longueur. Apparently it is because the groups of meshes of each face have different number of nodes.

First I made the different solids in Salome-Meca and made a partition with "MakePartition" in order to generate contact interfaces between the different solids. Then, make a compound in order to generate an assembly and then create two interfaces for every two solids in contact. But apparently it is not the correct way to generate the mesh.

How did you make it work?

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#6 2020-01-07 11:51:34

mediode
Member
Registered: 2009-07-31
Posts: 17

Re: ECHANGE_PAROI in 2D

Hi maxmss,

as far as I remember:
- creation of the geometry within the geometry module of salome-meca in 2D: 2 Faces with a "sharded" line
- meshing of each face individually with identical hypothesis at the "sharded" line within the mesh module
- creation of a compound mesh without merging of coincident nodes

As you got an error on list length of nodes, you might have been using different resolution for the "shared" line at the two faces (in 2D).

Best regards

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