cyclic boundary condition

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

June 10, 2013, 09:30
#21
Member

Evangelos
Join Date: Sep 2011
Posts: 70
Rep Power: 6
If you convert your case from Fluent where you define the the cyclic boundary conditions .(Needless blockMeshDic)
Quote:
 Originally Posted by huxiaoxia 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?

 July 4, 2013, 23:29 #22 New Member   Mohammad Join Date: Jul 2013 Posts: 10 Rep Power: 4 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.

 July 10, 2013, 04:24 #23 Member   s.rasoul_varedi Join Date: Feb 2010 Posts: 82 Rep Power: 7 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 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

 October 31, 2014, 16:47 cyclic boundry condition #24 New Member   Join Date: Oct 2014 Posts: 2 Rep Power: 0 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.

 November 3, 2014, 09:59 #25 Senior Member   Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,166 Blog Entries: 1 Rep Power: 15 use AMIcyclic,instead, it may solve your problem __________________ Training Course on OpenFOAM at (http://www.isme.ir/) My Weblog (http://openfoam.blogfa.com/)

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Thomas P. Abraham Main CFD Forum 20 July 7, 2013 05:05 aaev OpenFOAM Bugs 2 December 15, 2011 15:03 Cyp OpenFOAM 6 April 16, 2010 15:21 leejc OpenFOAM 0 April 15, 2010 16:38 Peiyong FLUENT 1 November 10, 2006 12:44

All times are GMT -4. The time now is 15:40.