code_saturne User's Forum

Hi there,

I am currently using Code Saturne as part of an optimisation study on PWR fuel rod subchannel mixing vanes. This involves running a lot of cases of subtly different meshes (produced by a parametric geometry definition and unstructured batch meshing). Is there any way to restart each case from a converged solution on a different mesh (so as to reduce the number of iterations required for convergence)? I am thinking of a function similar the 'Interpolate Data' function in Fluent. I think the restart option in Code Saturne will only work on the same mesh?

Many thanks
Sam Tabor

Hello,

Yes, restart files are limited to using the same mesh.

The low-level infrastructure required for interpolation does exist in Code_Saturne, but is not directly usable for this yet.

If you need to do this for many calculations, writing a few user subroutines could help: you could use the Code_Saturne/Code_Saturne coupling infrastructure to "restart" a calculation coupling:
- the initial mesh, reading a restart file
- the new mesh, to which cell values can be interpolated, then writing a restart file

I beleive if you define a cell-based coupling, with all support / no coupled cells for the initial mesh, and the reverse for the new mesh, you should be able to do all of this from the cs_user_initialization file, using the varcpl routine (defined in src/base/cs_sat_coupling.c, used in src/base/cscelv.f90).

I am not sure whether you would need to try to run a single iteration for the coupled (receiving) mesh, and let it write its restart files normally (simplest, but might not work), or force output of a restart just after interpolation.

If you feel like trying this, I can help guide you through the basic steps, but I'll let you do most of the setup and testing.

Regards,

Yvan