code_saturne User's Forum

Hello everyone,

I was wondering if zone porosity adjustments are valid when using the GUI.

I found this in the user manual for 4.0 and 4.0.1


''The management of the porosity is not yet available in the GUI. To define the porosity, the user must
fill in the subroutine usporo and set the keyword iporos to 1 in the cs user parameters file. This
subroutine is called every time step.
When using the subroutine usporo, the user is expected to fill in the array porosi for each cell in
order to give the porosity.''

But actually while initializing a volume and choosing porosity. A new field appears where I can adjust the porosity. see attached pictures. Are those functional, it seems there are results coming out from them .

Choice between isentropic and anistropic are available, when using anistropic. there are additional parameters. I am assuming porosity xx is in the x direction, but how about Porosity xy specifically, what does it mean?

Thanks,

Hello,

The documentation might not be completely up to date in this regard.

For anisotropic porosity, the xy term is one of the terms which appears when the porosity tensor is not alligned with the axes and you apply a rotation to describe it in the reference coordinates.

Regards,

Yvan

So just to confirm I want to make a medium porous in only z direction as 50% porous.

porosity=1.0; (I am not sure what to set this up as)
porosity[XX]=1.;
porosity[YY]=1.;
porosity[ZZ]=0.5;
porosity[XY]=0.; (not sure what values to put here)
porosity[XZ]=0.;
porosity[YZ]=0.;

Thanks in advance.

mhassab wrote:So just to confirm I want to make a medium porous in only z direction as 50% porous.

porosity=1.0; (I am not sure what to set this up as)
porosity[XX]=1.;
porosity[YY]=1.;
porosity[ZZ]=0.5;
porosity[XY]=0.; (not sure what values to put here)
porosity[XZ]=0.;
porosity[YZ]=0.;

Thanks in advance.

I have been trying all kinds of combinations with this but it is not working, what should I do to set up the porosity to be in a certain direction, say x axis for example?

Hello,

I'm not sure about this part, and documentation is "weak" on this aspect...
You may try using 1's instead of 0's for the other directions, but grepping the code, is is also important to set iporos to 2 instead of 1 in cs_user_parameters.f90 (search for iporos in the file, set test to true or remove test).

Regards,

Yvan