# Two-phase separator plane coordinate

Hi

In a two-phase problem, I need an approximate coordinate (Normal vector, etc) of the separating plane of two phases per cell. To solve this problem, a multiphase VOF model has been used.

Is there any macro in the UDF environment to get the coordinates of the plane, or should the coordinates of this plane be estimated using the VOF gradient?

Thanks & Regards,

Ehsan

## Comments

if you want coordinate, create isosurface with vof.

then you can export ascii file with file - export - solution data. it will write node and xyz coordinate.

It is bubble rising problem.

I need the coordinates of the planes that separate the bubble from the liquid. There is a method for this purpose, which can be used to determine the coordinates of this plane based on the vof gradient.

Now, my question is, is there a udf that gives the coordinates of these planes without computing?

See this pic plz:

https://upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Vof_scheme.png/220px-Vof_scheme.png

Can you just insert instead of attaching the picture?

Do you mean you have a plane and from that plane you would like to now the coordinates of cells/faces where vof between zero and one? And you want to have that in UDF and not via export as already mentioned by my colleague?

In fact, I need the coordinates of the separator plane for two phases per every cell

And yes,I want to have that in UDF

Edit: Removed Fluent Documentation Pictures

I still do not understand the difference between separator plane and free-surface. The pictures you are inserting are from Fluent documentation that is why I will remove them. If you want to export the coordinates of the cells lying between 0 and 1 for VOF just make a cell loop, make an if statement and do whatever you like.