[baeblue]

I want to make a simulation of axial fan and use Periodic Boundary Condition. But i still cant to make my side wall, to be a periodic. i've been used the non-conformal. but it still cant work. Please, i need help.
While in TUI show like this

/grid/modify-zones> make-periodic Periodic zone [()] 5 Shadow zone [()] 7 Rotational periodic? (if no, translational) [yes] yes
Create periodic zones? [yes] yes
Error: Failed to make zones periodic. Error Object: #f

[vinerm]

Creation of periodic boundary requires conformal mesh across both periodic boundaries. For a axial fan, periodic boundary is not a good condition.

[baeblue]

Originally Posted by vinerm

Creation of periodic boundary requires conformal mesh across both periodic boundaries. For a axial fan, periodic boundary is not a good condition.

How about using non-conformal? honestly i've try it too for the conformal. but it still cant work.
so do you have any methode suggestion for me, to simulate axial fan?

[CFD-fellow]

Besides conformal mesh on periodic boundaries, go to cell zone conditions>edit and see if the rotation axis is the same as your fan rotation axis.

[baeblue]

Originally Posted by CFD-fellow

Besides conformal mesh on periodic boundaries, go to cell zone conditions>edit and see if the rotation axis is the same as your fan rotation axis.

thank before, but i just did it. and it's still cant work. i've already change the rotation axial into 0 0 1. unfortunelly still cant work

[vinerm]

If the mesh is same at both boundaries that are supposed to be periodic, then you can use TUI to generate periodic boundary. If that is not the case, then change both of the boundaries to Interface using Boundary Conditions panel. Then, go to Mesh Interface, and create Periodic Boundary using Interface option. This is less accurate and more time-consuming per iteration but the difference won't be significant if meshes on both boundaries have similar scale.

In any case, you need to set up the cell zone origin and its axis correctly before creating periodic boundary.

[baeblue]

Originally Posted by vinerm

If the mesh is same at both boundaries that are supposed to be periodic, then you can use TUI to generate periodic boundary. If that is not the case, then change both of the boundaries to Interface using Boundary Conditions panel. Then, go to Mesh Interface, and create Periodic Boundary using Interface option. This is less accurate and more time-consuming per iteration but the difference won't be significant if meshes on both boundaries have similar scale.

In any case, you need to set up the cell zone origin and its axis correctly before creating periodic boundary.

thanks, but i did it before and still cant work. in case you said to make it by TUI need same mesh. is it relate to make that using Model Mesh and Symetric Geomtry?

[vinerm]

If you use Interface option to generate periodic bc and it still is unable to generate it, then most likely the error is in your cell zone setup (origin and axis) or name selections of the periodic boundaries.

[baeblue]

Originally Posted by vinerm

If you use Interface option to generate periodic bc and it still is unable to generate it, then most likely the error is in your cell zone setup (origin and axis) or name selections of the periodic boundaries.

i still get confuse. cause the warning said about the number cell zone isn't same

[vinerm]

Instead of rephrasing, better to copy the Warning issued by Fluent in the post. That will be more helpful in understanding the issue.

[baeblue]

Originally Posted by vinerm

Instead of rephrasing, better to copy the Warning issued by Fluent in the post. That will be more helpful in understanding the issue.

Warning : Number of elements does not match between zone 5 and 7

[vinerm]

Since there are different number faces on each boundary, you cannot use TUI commands to generate periodic boundary. The alternative is to use Mesh Interface with Periodic Boundary Condition option. Convert both boundaries to Interface under Boundary Conditions. Then, under Mesh Interfaces, create an interface using both boundaries. Do it manually instead of Automatic Generation and select Periodic BC option. There are two periodic option, one is boundary condition and the other one is for periodic repeats. Select periodic boundary condition.

[baeblue]

Originally Posted by vinerm

Since there are different number faces on each boundary, you cannot use TUI commands to generate periodic boundary. The alternative is to use Mesh Interface with Periodic Boundary Condition option. Convert both boundaries to Interface under Boundary Conditions. Then, under Mesh Interfaces, create an interface using both boundaries. Do it manually instead of Automatic Generation and select Periodic BC option. There are two periodic option, one is boundary condition and the other one is for periodic repeats. Select periodic boundary condition.

thanks cause its work. thank u so much

[baeblue]

Originally Posted by vinerm

Since there are different number faces on each boundary, you cannot use TUI commands to generate periodic boundary. The alternative is to use Mesh Interface with Periodic Boundary Condition option. Convert both boundaries to Interface under Boundary Conditions. Then, under Mesh Interfaces, create an interface using both boundaries. Do it manually instead of Automatic Generation and select Periodic BC option. There are two periodic option, one is boundary condition and the other one is for periodic repeats. Select periodic boundary condition.

I have another case. maybe you can help me to solve this problem.

Dot product of flow direction and area normal is zero.
Check the specified flow direction on Mass Flow Inlet boundary
conditions for thread 9.

do you know why this sign show up?

[vinerm]

Check the boundary with zone ID 9 where you have mass flow inlet. You might have chosen direction instead of normal to boundary. Either make it normal to boundary or provide correct direction. If you have many inlet boundaries, then following command could be useful to find out the name of the boundary

(zone-id->name 9)