code_saturne User's Forum

Hello,
I need help for a 3D simulation with Code_Saturne 3.2. I have to simulate diffusion and mass transfer around a vertical rotating cylinder in confined space, so I have to assign a tangential velocity on the cylinder surface. From the GUI interface it's possible to assign a sliding wall with x, y, z velocity components but I'm not sure this can be useful for my case. How can I assign a tangential velocity for a cylinder in CS 3.2?
Thanks
Best regards
Valeria

Hello,

For this, you'll probably need to use the cs_user_boundary_conditions.f90 user subroutine (but as definitions with user subroutines override those of the GUI, you can define everything with the GUI, and handle just the rotating wall with the user subroutine).

Best regards,

Yvan

Yvan Fournier wrote:Hello,

For this, you'll probably need to use the cs_user_boundary_conditions.f90 user subroutine (but as definitions with user subroutines override those of the GUI, you can define everything with the GUI, and handle just the rotating wall with the user subroutine).

Best regards,

Yvan

Hello,
thanks for the previous suggestion! I have another question about this simulation, I need to calculate averaged mass flow through the outlet section. In particular I want to calculate the mass flow of a tracer (passive scalar) in this way: vz*rho*concentration.
I don't think this is possible to do with the GUI, I need a subroutine, isn't it?
Best regards
Valeria

Hello,

Yes, you will need a user subroutine (cs_user_extra_operations) to do this. Check the examples in src/user_example/cs_user_extra-operations-energy_balance.f90 for a good starting point.

A less precise but simpler selection is also to do the computation using the field calculator function (with EnSight or ParaView).

Regards,

Yvan