## Explanation of variables in periodicity for radiation

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Laurent Bertrand
Posts: 26
Joined: Tue May 08, 2018 9:24 am

### Explanation of variables in periodicity for radiation

Dear Yvan,

I am simulating a 2D radiation problem in Syrthes by extruding my geometry with a small thickness. The simulation converging by this way. I have defined one side with symetry condition but, according to the documentation, I couldn't defined two parallel faces with symetry to close the system. So, I am trying use periodicity definition on the other side.

Unfortunately, i couldn't find in the documentation the actual meaning of the variables: lx, ly, lz, Vx, Vy, Vz, o.

V are related to transation vector such as for conduction but what are the meaning of lx, ly, lz?
Is it the cordinate of one point of the plane?
For translation, should I define a angle of 0°C or 360°C or just nothing?

Could you please give me more details about the way to perfectly use this definition?

Best regards
Yvan Fournier
Posts: 3284
Joined: Mon Feb 20, 2012 3:25 pm

### Re: Explanation of variables in periodicity for radiation

Hello,

If anybody else knows the answer, they are welcome, so please do not specify that I should be the one to answer (as other readers may assume this is an ongoing exchange and their chances of helping are even lower).

I have not set up a Syrthes computation in probably 10 years (though I regularly check coupled test cases), so I have absolutely no idea of the answer.

In your place, If I do not find something in the documentation and absolutely need it, I would use "grep" to navigate my way through the source code and find the answer (in any case, that's how I work almost every day when I answer questions or search for issues in parts of code_saturne I am not expert with, and even in parts I wrote myself when I am not sure of an answer).

Best regards,

Yvan