[hyugakojiro999]

Didn't help....

Some pictures would be fine. Some steps are hidden.

[Antanas]

Originally Posted by hyugakojiro999

Didn't help....

Some pictures would be fine. Some steps are hidden.

What do you mean?

[amir_hiwa]

there is no problem with specifying more than one periodic boundary condition. but i'm confused in this: when i specify the flow direction for one set of periodic boundaries , the flow direction for other boundary changed automatically, which is not desired. do u have any suggestion for me??
thanks

[amir_hiwa]

Originally Posted by Antanas

What do you mean?

there is no problem with specifying more than one periodic boundary condition. but i'm confused in this: when i specify the flow direction for one set of periodic boundaries , the flow direction for other boundary changed automatically, which is not desired. do u have any suggestion for me??
thanks

[amir_hiwa]

Originally Posted by 1994bm

Yes. Just create different faces. There shouldn't be overlap.

Hi i wish u could help me,
there is no problem with specifying more than one periodic boundary condition. but i'm confused in this: when i specify the flow direction for one set of periodic boundaries , the flow direction for other boundary changed automatically, which is not desired. do u have any suggestion for me??
thanks

[Costas]

Hi guys, Im having some trouble making the rotational periodic boundary conditions. So im trying to model a blade rotating while the rest of the domains are stationary. Ive tried using the method described at the beginning of this thread but my mesh wont work after i apply the changes. So i have three domains: the big one along with the medium one are both stationary while the smaller one will be rotating, but i have to apply the rotational periodic boundary condition on all three of them i guess. My middle domain is so that i can have a finer mesh around the blade. Could anyone help me?

[amir_hiwa]

Originally Posted by Costas

Hi guys, Im having some trouble making the rotational periodic boundary conditions. So im trying to model a blade rotating while the rest of the doma"ins are stationary. Ive tried using the method described at the beginning of this thread but my mesh wont work after i apply the changes. So i have three domains: the big one along with the medium one are both stationary while the smaller one will be rotating, but i have to apply the rotational periodic boundary condition on all three of them i guess. My middle domain is so that i can have a finer mesh around the blade. Could anyone help me?

Hi
If u are using ansys meshing try ""mesh match"" for specifying periodic boundaries and then u could have a better control on the other boundaries.like aplying "refinment" . Hope can help u

[Costas]

Originally Posted by amir_hiwa

Hi
If u are using ansys meshing try ""mesh match"" for specifying periodic boundaries and then u could have a better control on the other boundaries.like aplying "refinment" . Hope can help u

Hi there, thanks for the reply. I have tried mesh match but only after I have already tried face meshing on the separate domains. Do you suggest applying mesh match before starting to mesh?

Sent from my A0001 using CFD Online Forum mobile app

[amir_hiwa]

Originally Posted by Costas

Hi there, thanks for the reply. I have tried mesh match but only after I have already tried face meshing on the separate domains. Do you suggest applying mesh match before starting to mesh?

Sent from my A0001 using CFD Online Forum mobile app

Hi
Mesh matching will chang some of your previous settings, automatically.
Perhaps its better to try different methods

[Costas]

Hi again, it was suggested that i would apply periodic b.c separately for each of the domains, however that didnt work. Is there something im missing? Do you need any special conditions to be able to apply periodic b.c?

[Costas]

So i figured that the mesh on the periodic boundaries should match and so i applied match control. I have applied them on two of my faces but it does not work on the faces that are going to be rotating and i get an error that they dont have the same geometry or topology although all 3 domains have the same boundaries. Could anyone help me?

[hyugakojiro999]

Originally Posted by Antanas

What do you mean?

I tried to do the steps written above in the 1st post. But some steps are hidden. I couldnt figure it

[Shamoon Jamshed]

Originally Posted by michel2008

Dear Peter023

Thanks for your consideration and respond.

I think maybe it is better to explain more about my problem.

Actually, I am trying to simulate micro-cylinders embedded in a rectangular microchannel so I simplified the model with a unit cell which is a square microchannel including a micro-cylinder with an inlet and outlet by apply periodic boundary condition in the inlet and outlet (I used mass-flow rate for inlet boundary condition).
The point is when I applied periodic boundary condition in Fluent, an error just appeared before the first iteration calculating solution "divergence detected in AMG solver-pressure correction" . Although I tried to overcome this problem by reducing under relaxation factor and change some parameters in solution control, unfortunately I could not be able to solve it. In the other hand when I want to make periodic region in inlet and outlet in mesh utility, as I wrote the coordinate system light yellow prevent to well define it.

I hope you can help me with your experience to solve this problem.

I would appreciate if you give me some advices.

Thanks again,
Michel

In Mesher, goto models>symmtery>and right click on it to apply symmetry Region from (symmetry Region, periodic or cycllic)
Then in the symmetry first menu under definition, set Type to Linear periodic,
MEsher will automatically ask in the top of the menu to selct higher and lower surface. Then you will get this region as linear periodic and Fluent will apply translational boundary.

[teguhtf]

Dear All,

I have the same case. I am trying to solve simulation of plain pipe by using periodic boundary condition with Internal Diameter 15.88 mm, Length 22.5 mm. The inlet temperature of water flow is 27 C and the mass flow is 0.0166 kg/s. The wall is constant temperature at 17 C.

However, when I try to simulate the there are several errors. How to solve these errors?

Thank you so much
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



Error: Non-conformal periodic interface with empty intersection. This is likely due to incorrect specification of periodic
offset values. Please check the offset values specified
and recreate the interface.


Error: Couldn't intersect threads 5 and 6.




Error: Couldn't intersect threads 5 and 6.\n
Error Object: #f

[AlexLi_HIT_KHAI]

Do I understant it correctly, to relized periodic b.c, rebuilding two faces in Fluent using TUI is the only approach?

[hassanayaz]

Hello
I am doing transient simulation for the fluidized bed with 3D geometry... the problem is that solution is converged for some second's simulation and after that it does not converge .... what should be the possible solutions???? i have change controls and convergence criteria and methods but issue is still there