[engineerm]

Originally Posted by lukasf

In ANSYS R 18.2 for translational cyclic boundary condition I used
the command line of Fluent to create it, following the description of
https://www.researchgate.net/post/Ho...actually_means

/mesh/modify-zones> make-periodic
Periodic zone [()] 25
Shadow zone [()] 26
Rotational periodic? (if no, translational) [yes] no
Create periodic zones? [yes] yes
Auto detect translation vector? [yes] no
x-direction (m) [0] 0
y-direction (m) [0] -0.0273
z-direction (m) [0] 0

translation deltas: 0.000000 -0.027300 0.000000
zone 26 deleted

created periodic zones.

Hint: Fluent tried to compute the delta in y-direction itself but calculated a value of -0.02731. The creation of the periodic zones failed during auto detect. Hence, I just entered the correct offset myself (Auto detect translation vector? [yes] no) and it worked.

I'll try it and hope it'll work! thanks a lot!

[engineerm]

Originally Posted by lukasf

In ANSYS R 18.2 for translational cyclic boundary condition I used
the command line of Fluent to create it, following the description of
https://www.researchgate.net/post/Ho...actually_means

/mesh/modify-zones> make-periodic
Periodic zone [()] 25
Shadow zone [()] 26
Rotational periodic? (if no, translational) [yes] no
Create periodic zones? [yes] yes
Auto detect translation vector? [yes] no
x-direction (m) [0] 0
y-direction (m) [0] -0.0273
z-direction (m) [0] 0

translation deltas: 0.000000 -0.027300 0.000000
zone 26 deleted

created periodic zones.

Hint: Fluent tried to compute the delta in y-direction itself but calculated a value of -0.02731. The creation of the periodic zones failed during auto detect. Hence, I just entered the correct offset myself (Auto detect translation vector? [yes] no) and it worked.

Hi dear lukasf,

Following the link you gave, I only found the solutions with auto detect translation vector as "yes". I just wonder how you set the value as "-0.0273" and why on y direction. My geometry is a little complicated. how can I define the value and the direction? You can see my geometry in the attached files. My problem is 2D, the fluid flows x direction and the peridicity is y direction. Thanks in advance.

[lukasf]

I used the value of -0.0273 m in the y-direction because of my geometry.


I have a rectangular channel. The patches on the left and right side of my channel which are supposed to become cyclic have a distance of -0.0273 m in the y-direction. It is a translational distance. Thus, I am using "Rotational periodic? (if no, translational) [yes]" no


From your images I can see that you are trying to calculate a flow in a turbine. Here you should actually use Rotational periodic YES, in my opinion.

[engineerm]

Originally Posted by lukasf

I used the value of -0.0273 m in the y-direction because of my geometry.


I have a rectangular channel. The patches on the left and right side of my channel which are supposed to become cyclic have a distance of -0.0273 m in the y-direction. It is a translational distance. Thus, I am using "Rotational periodic? (if no, translational) [yes]" no


From your images I can see that you are trying to calculate a flow in a turbine. Here you should actually use Rotational periodic YES, in my opinion.

hi dear friends,

I have solved my problem and overcame the periodicity problem. It was caused due to the creating names for the edges in meshing. I had created the periodic names for the all length of the edges which was incorrect as seen in the photo "incorrect name selection". I have changed the name selections making blade profiles as wall, you can see in the photo " correct name selection". Aften then, I was able to see the velocity vectors in the results.

Thanks your helps

I just demand some literature articles about 2D or 3D turbomachinary axial water or air flow analysis using Fluent. If you have some articles about it, it will be very helpful for me to decide blade chord length, inlet velocity/pressure, turbulent viscosity values selected on Fluent.

best regards

[baeblue]

Originally Posted by engineerm

hi dear friends,

I have solved my problem and overcame the periodicity problem. It was caused due to the creating names for the edges in meshing. I had created the periodic names for the all length of the edges which was incorrect as seen in the photo "incorrect name selection". I have changed the name selections making blade profiles as wall, you can see in the photo " correct name selection". Aften then, I was able to see the velocity vectors in the results.

Thanks your helps

I just demand some literature articles about 2D or 3D turbomachinary axial water or air flow analysis using Fluent. If you have some articles about it, it will be very helpful for me to decide blade chord length, inlet velocity/pressure, turbulent viscosity values selected on Fluent.

best regards

hey, i think i did the same thing like you, if you dont mind. would you like share ur TUI ? cause i just did like what u said, but mine is still cant work

[hassanayaz]

Originally Posted by Chavagnatze

*I know I am late but, you must have the axis of rotation in the global z-direction for rotational periodicity. It may also be true that translational periodicity must be orthogonal across z as well.

Use /mesh/rotate in the interpreter and set your point of origin and axis of mesh rotation so that the global z-axis is parallel with the axis of periodicity

use /mesh/mz/make-periodic in the interpreter and move on as usual. You can also invoke periodicity in your meshing software (* Z-axis and axis of periodicity must be parallel) and Fluent should take care of it from there.

If there is a way to make the stored axis something other than (0 0 1) or any other vector, none of the above would matter.

I am using corrugated wall geometry and wants to apply periodic boundary condition and face the problem that number of elements are not same on both zones.... how to resolve it ??? and also tell how can make periodic before mesh import to fluent using ansys workbench

[hassanayaz]

Hello everyone
i am working with 3d geometry with corrugated wall meshing by patch conforming method and facing a problem with periodic boundary condition that num of elements not same on both zones and also use match tolerance using minimum edge length shown in meshing... tell me is this the tolerance value that i am using?? or something else?
if using non conformal meshing then can anybody guide me how to create interface zones for periodic boundary zones???????

[emreaskin]

Dear friends,

I have also encountered the same problem very often. This problem is not common when you use ICEM for mesh. But when I started using Fluent Meshing, I encountered this problem quite often. Solution:

> mesh
> modify-zones
> mz
> Zone (1) (()) Write your zone ID
> Zone (2) (()) Write your zone ID
> Zone (3) (()] If it is not exist, skip with enter button

merged zones into periodic_wall_right. 1.