Search found 280 matches

by Luciano Garelli
Fri Jan 19, 2024 7:20 pm
Forum: code_saturne usage
Topic: Mixture multiphase model
Replies: 4
Views: 37979

Re: Mixture multiphase model

Ok Yvan,

Thank you for your answer.

I will wait for any recommendations.

Best regards,
Luciano
by Luciano Garelli
Wed Dec 20, 2023 3:42 pm
Forum: code_saturne usage
Topic: Mixture multiphase model
Replies: 4
Views: 37979

Mixture multiphase model

Hello, I have a question regarding utilizing CS to solve multiphase flows using a mixture model. In fact, CS can solve multiphase flows using VOF, an interface-capturing model that combines some highly compressive NVD scheme with a artificial drift flux (cs_vof_deshpande_drift_flux) to compress the ...
by Luciano Garelli
Wed Oct 26, 2022 5:33 pm
Forum: code_saturne usage
Topic: Pressure drop in long pipe
Replies: 8
Views: 6626

Re: Pressure drop in long pipe

Hello,

Did you use the same mesh in CFX and CS?

Regards,

Luciano
by Luciano Garelli
Mon Oct 03, 2022 1:09 pm
Forum: code_saturne usage
Topic: Venturi pipe flow VOF convergence issue
Replies: 6
Views: 7195

Re: Venturi pipe flow VOF convergence issue

Hello Luciano and Yvan, @ Luciano: thank you for the update. I set the upwind scheme for velocity only and the simulation was running without interruptions. My question is: did you use that Scheme in your simulations or it is just a workaround for me? The results of the previous post was with the s...
by Luciano Garelli
Mon Oct 03, 2022 3:48 am
Forum: code_saturne usage
Topic: Tube heat enchange
Replies: 12
Views: 9582

Re: Tube heat enchange

Hello, To have rough wall option, you have to set a turbulence model and also a wall function, for default no wall function is used, soy the rough wall option is in gray. But I have no option rough wall even if I tick turbulence. Attached is the case (The mesh correspond to the first post and should...
by Luciano Garelli
Mon Oct 03, 2022 3:24 am
Forum: code_saturne usage
Topic: Venturi pipe flow VOF convergence issue
Replies: 6
Views: 7195

Re: Venturi pipe flow VOF convergence issue

Hello, 1) if I run the simulation with the Time Step Option = "Constant" (and reference time step = 0.0002 as suggested) the simulation stacks because of an excess of fluid speed. Did you face the same issue? No, but in your setup all the numerical scheme where in automatic, you can try to...
by Luciano Garelli
Wed Sep 28, 2022 7:57 pm
Forum: code_saturne usage
Topic: Tube heat enchange
Replies: 12
Views: 9582

Re: Tube heat enchange

Hello, As Yvan mentioned, you can change the time step factor (cdtvar) for the temperature to have similar characteristics times to reach a steady solution in case it exists. In the following figure, you can see the difference in the temperature field for the same simulation time, while the velocity...
by Luciano Garelli
Tue Sep 27, 2022 3:36 pm
Forum: code_saturne usage
Topic: Venturi pipe flow VOF convergence issue
Replies: 6
Views: 7195

Re: Venturi pipe flow VOF convergence issue

Hello Lorenzo, I checked and ran your case with CS 7.0.4. The time step discretization in your setup was set to steady, but in this situation the regime is transient. The simulation now runs with a time step of 1e-4 s (Co max ~ 2.5) after the change. It is accurate to say that the maximum fluid velo...
by Luciano Garelli
Wed Jul 13, 2022 2:44 pm
Forum: code_saturne usage
Topic: Cell gradient reconstruction
Replies: 5
Views: 5567

Re: Cell gradient reconstruction

Hello Yvan, Attached it is a very simple case (1D) with the comparison of the cell gradient reconstruction for the temperature. The J fields are the thermal fluxes and the Grad fields are the gradients. Additionally, in this case, with different thermal conductivities in the domain, the thermal flux...