code_saturne User's Forum

Hello,

I tried to run the Volker & Prakash's benchmark using the cdo-based solidification modelling introduced in https://www.code-saturne.org/documentat ... ation.html with settings based on the article accessible here https://hal.science/hal-04028238. However, it seems that the GCR algorithm to solve the saddle-point problem leads to a convergence issue and does not lead to physical results in a closed cavity and with the "velocity_divergence" field which however seems to be around 1e-6 (higher velocities in the gravity direction as issued in another discussion in the forum related to solidification).

Moreover by setting the solidus and liquidus temperatures below the initial and the fixed ones at the left / right boundaries, the classical result of the heated cavity benchmark does seem to be retrieved using then the CDO approach instead of the legacy FV one to solve the NS equation for momentum.

Thank you in advance for your attention.

Kind regards,

SS2X.

Hello,

The colleague who could best answer this is on holiday, but I can remind him to check your post when he returns.

In any cases, from conversations withe the colleagues working on solidification, I can confirm robust solvers are needed, and a big part of the work making these studies is related to optimization of solver settings. This is one of the applications where a robust direct solver like MUMPS may be useful, or even required.

Also, as far as I know, the recent work on solidification has been based mostly on the CDO approach, so I would definitely trust that model more than the legacy one, which is more of an early iteration.

Best regards,

Yvan

Hello Yvan,

It works indeed better using the MUMPS solver and with much better convergence of the velocity field.

Thanks !

Kind regards.