periodic boundary condition
 

hello,

I am trying to simulate laminar flow in microchannel. I want to give periodic boundary condition at inlet and outlet of the channel for a fully developed flow.
The periodic boundary condition will be translational type.

How to do it??

Thanks in advance
Gaurav

You can define inlet and outlet as periodic symmetry (by specifying inlet, outlet and distance between them) while meshing, which will ensure the same number of elements on both inlet and outlet. Later on in fluent, you can use following commands for periodicity

>mesh> mz> mp> periodic zone : inlet > shadow zone: outlet > rotational periodic : No >Auto detect translation vector : Yes

Thanks Sagar,

please let me know how I define inlet and outlet as periodic symmetry in meshing.


Gaurav

In Ansys mechanical right click in Model insert > symmetry look below symmetry tab could have been generated right click on it > insert > Symmetry region > change type to linear periodic in selection panel > specify high and low boundary as inlet and outlet respectively, define the axis of flow and distance between inlet and outlet surface.

Finally, mesh the region.

Thank you,

It was really helpful for my simulation. But for calculating the pressure drop across the channel , the outlet surface is not present. If it is not there then how to calculate the pressure drop ?

Thanks in advance

The idea of periodic bc is the outlet of one part is an inlet of next similar part. Hence when you will define mass flow rate at inlet you can check pressure drop in the same tab after simulation

Thank you,
This will really helpful.
:):)

hello,

I am using periodic boundary condition as described in past discussion.But the solution will not converge on convergence criterion of 1e-05. It oscillates continuously even for large iteration.
How to resolve this?

Please give some suggestion on that .

Thank in advance