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Question about porous term and porosity value in OpenFOAM |
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#1 |
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YongQiang Chi
Join Date: Jun 2010
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Hi:
I'm quite new to OpenFOAM so I still having problem with the porous media setting. 1: I notice that there're some 'porous' solvers like rhoPorousSimpleFoam and set the porosityPorperties in the /constant folder, and some other solvers like rhoSimpleFoam can set the porous media in the fvOption. Are they the same? or rhoPorousSimpleFoam will do better in solving the same problem? 2: I have not idea how to set / use the porosity value in the solver. I read the PorousZone.h and PorousZone.c, it seems in (or before) OF 2.2 the porosity value is not in use. and from OF 2.4 on I can't find the PorousZone.h and PorousZone.c anymore, instead there is porousModel folder included porousModel.h and porousModel .c, also the some other think like DarcyForchheimer.h and DarcyForchheimer.c. I don't seem anything related to porosity value setting. Can anybody tell me where to find the definition of porosity in the solver files? Or how can I set the porosity in the solver and see the velocity changes accordingly? 3: I heard that the porosity is recognized by the time derivative term of some solvers (something like fvm::ddt(U) ?), but I still can't find or proof this. Also if the porosity only use in the time derivative term but not the convection term, that sounds strange too. |
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#2 | |
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Deep
Join Date: Oct 2017
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Quote:
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#3 | |
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Jaydeep
Join Date: Jun 2015
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Quote:
https://github.com/OpenFOAM/OpenFOAM...tant/fvOptions |
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#4 |
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Deep
Join Date: Oct 2017
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Ok. So this is what I found out (which is rather not very complicated but somehow I was stuck for quiet some time) which perhaps will help someone.
When it comes to porosity value,
Thanks |
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#5 | |
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Deep
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Quote:
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#6 |
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Jaydeep
Join Date: Jun 2015
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Hi,
Yes you can do that. Here's how I have done in the past: Add toposet: Code:
actions ( { name face1; type cellSet; action new; source surfaceToCell; sourceInfo { file "constant/triSurface/face.stl"; outsidePoints ((0.7 1.5 0)); // definition of outside includeCut true; // cells cut by surface includeInside false; // cells not on outside of surf includeOutside false; // cells on outside of surf useSurfaceOrientation false; // use closed surface inside/outside // test (ignores includeCut, // outsidePoints) nearDistance -1;//-1 // cells with centre near surf // (set to -1 if not used) //- If > 0 : include cells with distance from cellCentre to surface // less than nearDist. curvature 0.9; // cells within nearDistance } } { name porousSet; type cellZoneSet; action new; source setToCellZone; sourceInfo { set face1; } } ); 1. cellSet face1 from stl file face.stl -- you can use faceZone or any other cellSet with different sources, such as, boxToCell etc. 2. It assigns a new cellZone porousSet to face1 cellSet. 3. Add this cellZone in selection in fvOptions Code:
porosity { type explicitPorositySource; active true; selectionMode cellZone; cellZone porousSet; explicitPorositySourceCoeffs { selectionMode cellZone; cellZone porousSet; type DarcyForchheimer; DarcyForchheimerCoeffs { d d [0 -2 0 0 0 0 0] (5e7 5e7 5e7); f f [0 -1 0 0 0 0 0] (0 0 0); } } } |
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#7 | |
New Member
YongQiang Chi
Join Date: Jun 2010
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Quote:
The solvers in openfoam, at least 3.x and 4.x, will not use any porosity value related to what I want. it only uses Darcy-Forchheimer method which is the pressure-loss rather than a actual porous medium. So, in other words I have to create my own solver with the capability to read the porosity value. I want to have a solver that able to do heat transfer in porous medium, and I think I'm getting there. |
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#8 | |
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YongQiang Chi
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#9 | |
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Ramana
Join Date: Jul 2017
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Quote:
Hi, I am also trying to make custom solver for porous media.Have you got any success in this direction?. Let me know if you can share your source code . Thanks in advance, Regards, S.V.Ramana Last edited by svramana; February 17, 2018 at 01:07. |
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#10 |
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Ramana
Join Date: Jul 2017
Location: India
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Does any one have any idea , how to calculate fixed coefficients inline with Darcy-forchheimer "D&F" coefficients?
Reards, S.V.Ramana |
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#11 |
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Deep
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#12 |
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...
Join Date: May 2018
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hi all
i have same problem...do you solve your problem? how can i add porous media to the solver? Tanks in advance |
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#13 |
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Alejandro
Join Date: Jan 2014
Location: Argentina
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Has anyone solved it?
in particular: a) Why there is a porousSimpleFoam solver if the porous region can be implemented with fvOptions using any solver? b) How I should modify codeAddSup in order to allow D and F variable coefficients? in particular, i do not fully understand the coordinateSystem set with regards to the source term: https://openfoamwiki.net/index.php/DarcyForchheimer thanks in advance |
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