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#1 2020-05-23 00:48:48

maxmss
Member
Registered: 2019-09-03
Posts: 25

How to simulate a fictitious thermal contact?

Hello everyone,

I am performing a thermal analysis of heat transfer between the walls of several plates with ECHANGE_PAROI,  but in the real model that I have there is a connection between two nearby plates through millimeter threads, so creating them in my geometric model in salome is complicated and maybe unnecessary.

I would like to know if there is any way to make the connection between two elements that are separate, but in a fictitious way, that is, connect nodes that are not in contact.

Regards,
Max

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#2 2020-05-25 11:36:45

Yvon Goth
Member
Registered: 2007-11-26
Posts: 18

Re: How to simulate a fictitious thermal contact?

Hi Max,

I suggest you use ECHANGE_PAROI in AFFE_CHAR_THER_F, with a heat transfer coefficient function of space coordinates, with local high values to simulate contacts.

Regards

Yvon

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#3 2020-06-02 19:53:22

maxmss
Member
Registered: 2019-09-03
Posts: 25

Re: How to simulate a fictitious thermal contact?

Hi Yvon,

Thanks for your reply. The problem I have is that the connection between the two plates is given by a thinner cable, so creating it in my Salome-Meca geometry model is a bit complicated. So I think maybe I can solve that by making a simulated contact between these plates, but the problem is the small diameter of the wire. I tried to create a node group of specific points in my mesh model, but in Code_Aster I get an error saying that the group node is not part of the mesh, and it happens because Code_Aster doesn't allow to apply boundary conditions on the nodes, instead, I should apply this to elements (mesh group).

Based on your suggestion, I do this before to simulate thermal contacts on plates that are in contact and it works fine because I have two mesh groups (one mesh group for each plate). I think I should create a small mesh group that simulates the circumference of the wire on both plates and then apply the heat transfer coefficient with Echange_Paroi.

Any suggestion to create a circumference mesh group in  in Salome?. Another suggestion about Code_Aster to solve that problem are welcome.

Regards,
Max

Last edited by maxmss (2020-06-02 20:17:34)

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#4 2020-06-02 20:21:43

maxmss
Member
Registered: 2019-09-03
Posts: 25

Re: How to simulate a fictitious thermal contact?

In the attached picture you can see the wire connection that Im talking about. In the real model the plates are more closer and the wires are so small (millimeter threads).


Attachments:
wire conection.jpg, Size: 59.38 KiB, Downloads: 20

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#5 2020-06-06 16:33:38

Yvon Goth
Member
Registered: 2007-11-26
Posts: 18

Re: How to simulate a fictitious thermal contact?

Hi Maxime,

Seeing the picture, I think that the best is to inclure a 3 D mesh of the wires in the model. Taking a square element of same surface as the wire section for base, and extruding along a path   this element using hexahedal mesh should not be too costly (unfortuntely Code_Aster has no 1D thermal elements).
Have in mind also that the heat transfer to ambiant air along the wire may be significative, and a long wire bond cannot be considered as a simple conducting connexion. I suggest that you makes a thermal model of a single wire only, including heat transfer on surface, and considers if it has to be taken into acccount.

Regards

Yvon

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