Discussion Forum

Hello Idir,

I am quite sure that you need 2 flow interfaces to do this.

Best regards

Julien

Hello Julien,

Thank you very much for your reply, I think that it must be done with two interfaces too, because the turbulent model can't give good results for a laminar flow. I have to couple the two interfaces in some way, perhaps using coupling operators (average or integral) or using weak constraint, do you have any experience on doing this?

Best regards,

Idir

Never try to do this. But I think that it can be possible to express Nusselt number in fonction of turbulent parameters of the gas near the melt (velocity) and to apply heat transfert coefficient depending of the turbulent velocity.
The more simple is to make a first simulation with the gas only and Temperature of the melt imposed. Extract Nusselt numbers at each point of the interface liquid-gas and to apply it on a second casting simulation as heat transfert coefficient on the liquid gas interface.

Best regards

Julien

Sorry if you have the two fluid flow interfaces in the same model (solution 1 in the previous mail), no need to calculate Nuselt numbers. Energy continuity will do the work.

Julien

Hello Julien, thank you for your reply, you are certainly right it can be done using convection heat transfer coefficient, but I still have to make a bidirectional coupling. In my problem the gas is inside a furnace divided in two parts a bigger and a smaller one, in the former it is turbulent, so I have to use two interfaces and to couple the flow between them, my goal is to obtain the temperature at the frontier of the two parts of the furnace since all I know is the temperature on the external frontiers of the furnace.

Thank you Julien.

Best regards,

Idir

Maybe I have not well understood your problem.
If you want to modelize a flow with laminar and turbulent regions in the same model, maybe you can use the low Re number feature.

Best regards

Julien