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June 10, 2013, 09:30 

#21  
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Evangelos
Join Date: Sep 2011
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If you convert your case from Fluent where you define the the cyclic boundary conditions .(Needless blockMeshDic)
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July 4, 2013, 23:29 

#22 
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Mohammad
Join Date: Jul 2013
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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. 

July 10, 2013, 04:24 

#23 
Member

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 

October 31, 2014, 16:47 
cyclic boundry condition

#24 
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Join Date: Oct 2014
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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; } wallh { type fixedValue; value uniform 300; } wallc { 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 
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Nima Samkhaniani
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use AMIcyclic,instead, it may solve your problem
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