CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Periodic boundary condition error

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 11, 2020, 03:26
Unhappy Periodic boundary condition error
  #1
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
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
baeblue is offline   Reply With Quote

Old   May 11, 2020, 03:47
Default Periodic BC
  #2
Senior Member
 
vinerm's Avatar
 
Vinerm
Join Date: Jun 2009
Location: Nederland
Posts: 2,946
Blog Entries: 1
Rep Power: 33
vinerm will become famous soon enough
Creation of periodic boundary requires conformal mesh across both periodic boundaries. For a axial fan, periodic boundary is not a good condition.
__________________
Regards,
Vinerm

PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.
vinerm is offline   Reply With Quote

Old   May 11, 2020, 06:22
Default
  #3
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
Quote:
Originally Posted by vinerm View Post
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?
baeblue is offline   Reply With Quote

Old   May 11, 2020, 06:34
Default
  #4
Senior Member
 
Behrooz Jamshidi
Join Date: Apr 2013
Posts: 110
Rep Power: 10
CFD-fellow is on a distinguished road
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.
CFD-fellow is offline   Reply With Quote

Old   May 11, 2020, 07:27
Default
  #5
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
Quote:
Originally Posted by CFD-fellow View Post
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
baeblue is offline   Reply With Quote

Old   May 11, 2020, 11:17
Default Periodic Conditions
  #6
Senior Member
 
vinerm's Avatar
 
Vinerm
Join Date: Jun 2009
Location: Nederland
Posts: 2,946
Blog Entries: 1
Rep Power: 33
vinerm will become famous soon enough
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.
__________________
Regards,
Vinerm

PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.
vinerm is offline   Reply With Quote

Old   May 12, 2020, 13:00
Default
  #7
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
Quote:
Originally Posted by vinerm View Post
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?
baeblue is offline   Reply With Quote

Old   May 12, 2020, 13:30
Default Periodic BC
  #8
Senior Member
 
vinerm's Avatar
 
Vinerm
Join Date: Jun 2009
Location: Nederland
Posts: 2,946
Blog Entries: 1
Rep Power: 33
vinerm will become famous soon enough
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.
__________________
Regards,
Vinerm

PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.
vinerm is offline   Reply With Quote

Old   May 14, 2020, 12:29
Default
  #9
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
Quote:
Originally Posted by vinerm View Post
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
baeblue is offline   Reply With Quote

Old   May 14, 2020, 15:00
Default Warning
  #10
Senior Member
 
vinerm's Avatar
 
Vinerm
Join Date: Jun 2009
Location: Nederland
Posts: 2,946
Blog Entries: 1
Rep Power: 33
vinerm will become famous soon enough
Instead of rephrasing, better to copy the Warning issued by Fluent in the post. That will be more helpful in understanding the issue.
__________________
Regards,
Vinerm

PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.
vinerm is offline   Reply With Quote

Old   May 15, 2020, 13:54
Default
  #11
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
Quote:
Originally Posted by vinerm View Post
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
baeblue is offline   Reply With Quote

Old   May 15, 2020, 14:32
Default Different number of faces
  #12
Senior Member
 
vinerm's Avatar
 
Vinerm
Join Date: Jun 2009
Location: Nederland
Posts: 2,946
Blog Entries: 1
Rep Power: 33
vinerm will become famous soon enough
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.
__________________
Regards,
Vinerm

PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.
vinerm is offline   Reply With Quote

Old   May 15, 2020, 16:32
Default
  #13
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
Quote:
Originally Posted by vinerm View Post
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 is offline   Reply With Quote

Old   May 15, 2020, 16:45
Default
  #14
New Member
 
Join Date: May 2020
Posts: 20
Rep Power: 3
baeblue is on a distinguished road
Quote:
Originally Posted by vinerm View Post
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?
baeblue is offline   Reply With Quote

Old   May 15, 2020, 16:47
Default Mass Flow Inlet
  #15
Senior Member
 
vinerm's Avatar
 
Vinerm
Join Date: Jun 2009
Location: Nederland
Posts: 2,946
Blog Entries: 1
Rep Power: 33
vinerm will become famous soon enough
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)
__________________
Regards,
Vinerm

PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.
vinerm is offline   Reply With Quote

Reply

Tags
airfoil 3d, axial fan design, fluent 14 to fluent 15., periodic boundary fluent

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[swak4Foam] swak4foam openfoam 7 installation problem Andrea23 OpenFOAM Community Contributions 1 February 17, 2020 18:11
[blockMesh] blockMesh with double grading. spwater OpenFOAM Meshing & Mesh Conversion 92 January 12, 2019 09:00
error compiling modified applications yvyan OpenFOAM Programming & Development 21 March 1, 2016 04:53
An error has occurred in cfx5solve: volo87 CFX 5 June 14, 2013 17:44
DecomposePar links against liblamso0 with OpenMPI jens_klostermann OpenFOAM Bugs 11 June 28, 2007 17:51


All times are GMT -4. The time now is 16:01.