code_saturne User's Forum

Hello,

This topic should be in "general usage", as it contains questions relative to code usage, and not discussions on development, roadmap, .... exxcept for the question about neptune_cfd.

AS for the question, neptune_cfd is provided to some industrial or academic partners, and this is subject ...

Hello,

In v9.0, ischtp corresponds to 'cs_glob_time_step->time_order' in C (and is still called ischtp in Fortran).

It is set in cs_setup.cpp, near line 1090.

Best regards,

Yvan

Hello,

1) I did not check the exact formulas used (the code is in cs_time_step_compute.cpp, but also has additional layers in cs_matrix_time_step calls), but by default, there is indeed both a Courant and Fourier limitation. In the solid zone, the CFL should be zero, so only the Fourier part is ...

Hello,

Ok thanks, this will be in the next update of Syrthes (probably in a few weeks).

Best regards,

Yvan

Hello,

There is currently no external GitHub of Gitlab mirror for Syrthes, and the support address may not be checked as regularly as that for code_saturne (development resources on Syrthes are currently quite limited, but some members of the code_saturne dev team have write access to the internal ...

Hello,

For polyhedral meshes, our feedback is still limited, but your options seem reasonable.

Independently of the mesh type, small time steps usually lead to faster linear solver convergence, so for such cases, gradients and balances (whose cost is independent of the time step) can become ...

Hello,

The lines in the "configure" are just initializations before the test.

We have had issues with MEDCoupling link on one machine running RHEL 8.8 after a system upgrade due to C++ API achanges, but recompiling both MEDCoupling and code_saturne avoids the problem. An alternative was to add the ...

Hello,

1) We assume that for a pseudo-steady computation, h and temperatures will all stabilize, so the flux expressed as "h(Tw-Tf)" should stabilize. Ideally, in a linear wll law region in a mesh convergence study, the flux should reach a fixed value (assuming wall law computation is also ideal ...

Hello,

Yes, for 1), you should have equilibrium at the steady state. The lower the conductivity h, the higher (Tw-Tf) will need to be to obtain a given flux, the steady solid temperature will be higher if h is lower, lower if h is higher.

For 2), for a steady solution, convergence will often be ...

Hello,

The method used in this coupling (and the coupling with the newer code_saturne external thermal solver based on the CDO numerics) is as follows :

At each time step :
- The solid solver (Syrthes or code_saturne solid domain instance) sends a solid wall temperature.
- The fluid solver (code ...