Learning Forum

[soloviev]

Hello,

We are currently working on running an MHD model which incorporates the ocean, atmosphere, and seafloor. We found that when running models with the atmosphere, the magnetic signal between the air and sea does not make sense. We are guessing it may be due to the following (found in the Fluent Theory Guide):

 

For multiphase flows, assuming that the electric surface current at the interface between phases can be ignored, the electric conductivity for the mixture is given by:

(2–28)

where  and  are respectively the electric conductivity and volume fraction of phase .  is used in solving the induction equations.

Is there a way to incorporate a UDF to implement these ignored terms?

Thanks,

Alex

[soloviev]

Hello,

 

Is there any update to this issue?

 

Thanks,
Alex

[Rob]

I think you can do this using a UDF to location the free surface and then do "something" to the electric field, the "how" will be somewhat more difficult, and is beyond what I can do here. 

[soloviev]

We do have a UDF which we implemented, but we didn't see much of a change in the results. Do you know why that might be?

 

Thanks,

Alex

[Rob]

Could be it's a function of the shared velocity field in VOF? If you post process the field does the code put enough "stuff" in the right place?

[soloviev]

 I actually did not write this, but another member of our team did who has since left.  The UDF was written for each component (U, W) of the velocity. Is this what you meant by it being a function of the shared velocity field? Because the way It is written it appears as though its not a function of the shared but rather of the components individually. 

 

Thanks, 

Alex

[Rob]

No, I was wondering how it interacted with the two phases at the boundary.  Unfortunately it's going to be beyond what we can cover on here. 

[soloviev]

Thank you. I will look into the interaction at the two phases at the boundary. 

 

Thanks,
Alex