CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

cyclic boundary condition

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

Like Tree7Likes

Reply
 
LinkBack Thread Tools Display Modes
Old   June 10, 2013, 09:30
Default
  #21
Member
 
Evangelos
Join Date: Sep 2011
Posts: 82
Rep Power: 6
Danath is on a distinguished road
If you convert your case from Fluent where you define the the cyclic boundary conditions .(Needless blockMeshDic)
Quote:
Originally Posted by huxiaoxia View Post
Dear HuyHoang:

Sorry to reply you late. First of all, in constant/polyMesh/blockMeshDic, you have to define the cyclic boundary, e.g
cyclic back
(
(0 2 3 1)
(6 7 9 8)
)
Then , when you define all the initial or boundary conditions under the folder 0, simply use the type cyclic. e.g
back
{
type cyclic;
}

Is it clear for you?
Danath is offline   Reply With Quote

Old   July 4, 2013, 23:29
Default
  #22
New Member
 
Mohammad
Join Date: Jul 2013
Posts: 10
Rep Power: 5
mohammad81 is on a distinguished road
Hi everyone.
I want to use cyclic (periodic) BC for cavity problem. it sounds simple. I want to use cyclic BC for both P and U (for inlet and outlet). I want to know what I have done is correct or not. Thank you.

This is blockMeshDict:
-------------------------------------------

patches
(
wall topWall
(
(3 7 6 2)
)
wall bottomWall
(
(1 5 4 0)
)
cyclic inout
(
(0 4 7 3)
(2 6 5 1)
)
empty frontAndBack
(
(0 3 2 1)
(4 5 6 7)
)
);

-------------------------------------------
This is my Boundary file:

4
(
topWall
{
type wall;
nFaces 40;
startFace 1540;
}
bottomWall
{
type wall;
nFaces 40;
startFace 1580;
}
inout
{
type cyclic;
nFaces 40;
startFace 1620;
featureCos 0.9;
}
frontAndBack
{
type empty;
nFaces 1600;
startFace 1660;
}
)

--------------------------------------
My 0/U is:
inout
{
type cyclic;
value uniform (0 0 0);
}
---------------------------

Finally 0/P is:
inout
{
type cyclic;
value uniform 0;
}

--------------


Is this correct? I got some result. I get the linear velocity and uniform pressure (Couette Flow). But I am not sure of it.

Is this type of using cyclic correct? what is this "neigbourpathc", "fan" etc..?


Thank you very much.
hua1015 likes this.
mohammad81 is offline   Reply With Quote

Old   July 10, 2013, 04:24
Default
  #23
Member
 
s.rasoul_varedi
Join Date: Feb 2010
Posts: 82
Rep Power: 7
desert_1250 is an unknown quantity at this point
Send a message via Yahoo to desert_1250
Hi Dear mamad (oshtoli)
i think u need fan BC.
In OF the fan BC prescribes a pressure jump.
Note!The fan boundary condition is working on a cyclic patch.

defined in constant/polyMesh/boundary as
{
type cyclic;
}

and then in the pressure file 0/p:

{
type fan;
patchType cyclic;
f List<scalar> 2(10.0 -1.0);
value uniform 0;
}

The f above is a list of polynomial coefficients in the pressure jump definition

delta p = f_1 + f_2 * v + f_3 * v^2 + ...

Above only f_1 and f_2 is assigned, respectively 10.0 and -1.0.

In 0/U and so on, the ad patch is defined as cyclic.

any quastions are wellcome.
--------
Rasoul
desert_1250 is offline   Reply With Quote

Old   October 31, 2014, 16:47
Default cyclic boundry condition
  #24
New Member
 
Join Date: Oct 2014
Posts: 2
Rep Power: 0
vahidshahabi is on a distinguished road
I want to simulate a channel flow in a periodically repeating geometry, the mesh generator is Gambit, I define my boundary conditions in gambit using "wall" not "periodic" or something else, after i converted the mesh with fluentMeshToFoam, in constant/polymesh/boundary i changed wall to cyclic for my periodic boundaries(inlet& outlet). As shown in blow
boundaryField
{
outlet
{
type cyclic;
neighbourPatch inlet;
}
inlet
{
type cyclic;
neighbourPatch outlet;
}
wall-h
{
type fixedValue;
value uniform 300;
}
wall-c
{
type fixedValue;
value uniform 200;
}
frontAndBackPlanes
{
type empty;
}
}


its ok, but after some times, I have following error message
FOAM FATAL ERROR, attemo to cast type patch to type LduInterface
FOAM aborting, foam::error:: print stack
Can you tell me how i solve this issue.

Thank you for your help.
vahidshahabi is offline   Reply With Quote

Old   November 3, 2014, 09:59
Default
  #25
Senior Member
 
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,189
Blog Entries: 1
Rep Power: 15
nimasam is on a distinguished road
use AMIcyclic,instead, it may solve your problem
__________________
Telegram channel (https://telegram.me/openfoam4Iranian)
My Weblog (http://openfoam.blogfa.com/)
Training Course on OpenFOAM at (http://www.isme.ir/)
nimasam is offline   Reply With Quote

Old   March 15, 2016, 06:57
Default dsmcFOAM BLOCKMESHDICT
  #26
New Member
 
avinash yadav
Join Date: Mar 2016
Location: Almora
Posts: 1
Rep Power: 0
avinashy34 is on a distinguished road
HI
I AM FACING A PROBLEM TO UNDERSTAND
xPeriodic_half0
{
type cyclic;
faces ((1 2 6 5));
neighbourPatch xPeriodic_half1;
COMMAND WHAT IS THE ACTUAL MEAN OF THIS CAN ANYBODY HELP ME
avinashy34 is offline   Reply With Quote

Old   March 23, 2016, 02:53
Default Cyclic boundary definition
  #27
New Member
 
Maryam
Join Date: Dec 2015
Posts: 6
Rep Power: 2
Persia is on a distinguished road
Quote:
Originally Posted by avinashy34 View Post
HI
I AM FACING A PROBLEM TO UNDERSTAND
xPeriodic_half0
{
type cyclic;
faces ((1 2 6 5));
neighbourPatch xPeriodic_half1;
COMMAND WHAT IS THE ACTUAL MEAN OF THIS CAN ANYBODY HELP ME
It means that "xPeriodic_half0" is a cyclic patch, which is another term for periodic BC. "xPeriodic_half0" consists of the face with corner points 1, 2, 6, and 5, and its neighbour patch is patch "xPeriodic_half1". This means that "xPeriodic_half1" and "xPeriodic_half0" will have the same values for different parameters such as velocity, pressure, or temperature.
Persia is offline   Reply With Quote

Old   August 11, 2016, 17:16
Default cyclic Bc error
  #28
New Member
 
majid
Join Date: Oct 2015
Location: Iran,Tehran
Posts: 10
Rep Power: 2
majid pourdian is on a distinguished road
Hi
I have a simmulation with cyclic boundary condition and I get this error:
"Error in coupled point location"
when I change cyclic Bc to wall Bc error is disapeared.
could anyone help me?
majid pourdian is offline   Reply With Quote

Old   August 15, 2016, 01:46
Default
  #29
New Member
 
Maryam
Join Date: Dec 2015
Posts: 6
Rep Power: 2
Persia is on a distinguished road
Quote:
Originally Posted by majid pourdian View Post
Hi
I have a simmulation with cyclic boundary condition and I get this error:
"Error in coupled point location"
when I change cyclic Bc to wall Bc error is disapeared.
could anyone help me?
Do the cyclic patches fully match geometrically?
Persia is offline   Reply With Quote

Old   August 15, 2016, 16:17
Default
  #30
New Member
 
majid
Join Date: Oct 2015
Location: Iran,Tehran
Posts: 10
Rep Power: 2
majid pourdian is on a distinguished road
Quote:
Originally Posted by Persia View Post
Do the cyclic patches fully match geometrically?
yes,I correct geometrically match error when I run blockMesh.now when I run checkMesh give me second error.
majid pourdian is offline   Reply With Quote

Old   August 16, 2016, 13:23
Default
  #31
New Member
 
majid
Join Date: Oct 2015
Location: Iran,Tehran
Posts: 10
Rep Power: 2
majid pourdian is on a distinguished road
Hi esmaeil
your neighbour patch should have equal area and mesh.
majid pourdian is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Boundary Conditions Thomas P. Abraham Main CFD Forum 20 July 7, 2013 05:05
Mixed/Robin boundary condition aaev OpenFOAM Bugs 2 December 15, 2011 15:03
cyclic boundary condition doesn't work in a tube ?? Cyp OpenFOAM 6 April 16, 2010 15:21
fan cyclic boundary condition leejc OpenFOAM 0 April 15, 2010 16:38
How to set boundary condition in Fluent for the fo Peiyong FLUENT 1 November 10, 2006 12:44


All times are GMT -4. The time now is 15:21.