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-   -   2D or Axisymmetric PROBLEM (http://www.cfd-online.com/Forums/fluent/92835-2d-axisymmetric-problem.html)

 macatuk September 26, 2011 19:32

2D or Axisymmetric PROBLEM

I am studying the stratified flow in pipe, but I am not clear some points such this kind of flow, in which water lying on bottom and compressed Air flow on the top in pipe, and void fraction is 0.5.

To save time consuming, how can I choose to set up my model correctly in Fluent (Using Re-construct VOF), "Between using 2D model or Axisymmetric model"?

As I just found only that 2D model is used for studying the flow in channel, and Axisymmetric will be introduced when the geometry and flow condition are symmetry around axis.

Big Thanks!!!

Regards
Mac

 m.beh September 29, 2011 13:41

hi
as I understand you have a horizontal pipe with 2 flow in it, liquid at the bottom and gas at teh top.
As I know, your case is not axisymetric.

your case is just symetry but you can not model your case with the boundary of symmetry too because you have a pipe and you can not model it with a 2D symetry boundary.

so I think in your case you must use a 3D case.

you can use a symmetry boundary for a half of pipe in a 3D case.

that is all I know

hope you can find your solution soon

 m2montazari September 29, 2011 16:28

hi,
exactly m.beh is right. only thing you can do is to use symmetry plane that has normal vector in Z direction(if axis of pipe is in X direction and gravity is in Y direction)