Discussion Forum » Code_Saturne » ustsns.f90!! qdm and crvexp(iel)

hello, Please i want an answer for these questions: 1- in the subroutine "ustsns" qdm it means?

2- in Results for case Channel Flow (cited as a test case on this site), the source terms is given by: crvexp(iel) = volume(iel)/qdm*propce(iel,ipcrom) while in base reference it is given by: crvexp(iel) = volume(iel)*qdm can you please tell me why this difference in writing

3- how to consider a fluid with an other viscosity compared to test case of Channel Flow?

I thank you

-- NajlaElGharbi - 2011-01-10

I think that I have badly explaine my problem...

I am a new user of code-saturne and I am very interesting by the test case1. I want to use air instead of water, and I want to change the geometry and Re number, but I found some difficulty can someone enlightens me.

1- in the subroutine "ustsns" what qdm it means?

2- in the subroutine "ustsns" for case 1, the source terms is given by:

crvexp(iel) = volume(iel)/qdm*propce(iel,ipcrom)

while in base reference it is given by:

crvexp(iel) = volume(iel)*qdm

can you please tell me why this difference in writing

3- how to consider air in the subroutine "ustsns"?

thank you to answer to my request.

-- NajlaElGharbi - 2011-01-11

Hi,

the units of qdm in the case, crvexp(iel) = volume(iel)*qdm is Pascal/meter

this term permits to drive the flow.

In the ustsns you can download thanks to the following link, I give a mass flow rate and I keep it constant. This subroutine works with RANS models by reading the density and the reference velocity noted down in the GUI.

Sylvain

-- SylvainSerra - 2011-01-12

hello Sylvain, Many thanks for your answer. I will use your subroutine for my 2D case and I will inform you Kind Regards

-- NajlaElGharbi - 2011-01-13

Hi, I have a problem to put periodic BC in saturne GUI. please can you tell me how to put my BC in mesh-->periodic. I thank you

-- NajlaElGharbi - 2011-01-21

Hi, You can do that through the GUI. To introduce the periodic boundary conditions you need to edit the `runcase` file if you are not using the GUI. You need to know the names or "colours" of the periodic boundaries and the translation vector (or rotation matrix). Have a look at the `runcase.help` file where it is explained in detail.

-- JuanUribe - 2011-01-21

thank you Juan for you answer. I can do my simulation for periodic boundary conditions, I have use Sylvain ustsns.f90 subroutine: https://code-saturne.info/products/code-saturne/forums/general-usage/10359587#727725548

but his subroutine is for unsteady flow, I want to simulate steady flow. can you please tell me if it is correct to use the same subroutine and put dt=1! when he calculate dp! thank you very much

-- NajlaElGharbi - 2011-01-28

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Topic revision: r7 - 2011-01-28 - 12:27:42 - NajlaElGharbi
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