code_saturne User's Forum

Posted: **Sat Sep 04, 2021 3:38 pm**

Hello everyone,

So far I've used "cs_user_boundary_condition.f90" to set up the pressure intlet boundary condition;

call getfbr('inlet', nlelt, lstelt)
do ilelt = 1, nlelt
   ifac = lstelt(ilelt)
   itypfb(ifac) = ientre

!Dirichlet B.C for pressure:
   icodcl(ifac,ipr) = 1
   rcodcl(ifac,ipr,1) = 101325.633

!Neumann B.C for velocity:
   icodcl(ifac,iu)= 3
   icodcl(ifac,iv)= 3
   icodcl(ifac,iw)= 3
enddo


call getfbr('outlet', nlelt, lstelt)
do ilelt = 1, nlelt
   ifac = lstelt(ilelt)
   itypfb(ifac) = isolib

!Dirichlet B.C for pressure:
   icodcl(ifac,ipr) = 1
   rcodcl(ifac,ipr,1) = 101325.000

!Neumann B.C for velocity:
   icodcl(ifac,iu)= 3
   icodcl(ifac,iv)= 3
   icodcl(ifac,iw)= 3
enddo

For other subroutines, I am using "C" files such as "cs_user_initialization.c" and "cs_user_parameters.c".
Therefore, I want to rewrite "cs_user_boundary_condition.f90" to "cs_user_boundary_condition.c" to be consiste with C, not Fortran.

It looks like that coding C in "cs_user_boundary_condition.c" is more complicated than that of Fortran ("cs_user_boundary_condition.f90").

Although I checked "cs_user_boundary_condition-notebook.c", I am confused by new words, which I have never seen in CodeSaturn so far.
Is there other samples of conding or guides?

Best regards,
Tsubasa

Posted: **Sun Sep 05, 2021 1:32 pm**

Hello,

Most of our examples for boundary conditions are still in Fortran, because we are working on a new API (shared with the CDO models) which you can see in the following example https://github.com/code-saturne/code_sa ... nditions.c but is not yet complete.

The existing cs_user_boundary_conditions.c examples should remain usable for a while, and may be a good intermediate step, but you may also opt to wait for the new API (which should be in v7.1, and may be backported to future v7.0.z releases).

The notebook aspect is something completely orthogonal to boundary conditions (and so may be composed). It allows defining a value in the GUI (and even on the run command line starting with v7.0.1), and using that value elsewhere in the code. It is specifically oriented to parametric studies, or controlling some values interactively (through the control_file mechanism, also used by the FMI API). It is accessible only from C if I remember correctly.

Best regards,

Yvan

code_saturne User's Forum

Rewrite user defined boundary condition from Fortran to C

Rewrite user defined boundary condition from Fortran to C

Re: Rewrite user defined boundary condition from Fortran to C