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August 30, 2009, 02:45 |
Flow Around a Cylinder
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#1 |
Member
toto
Join Date: Jun 2009
Posts: 71
Rep Power: 17 |
Hi,
I am trying to model a flow around a cylinder 2D using simpleFoam.The Velocity is 3m/s and The turbulence model is k-epsilon Standard. The dimension of the cylinder is 0.1 m diameter. How could i set the Boundary Condition for Wall- Top and Bottom to get no Slip? What about the Cylinder-Wall? Please it ist very important for me and I would greatly appreciate it if you could send me an Answer or a case like that. |
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August 30, 2009, 16:10 |
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#2 |
Senior Member
Steve Hansel
Join Date: Jun 2009
Location: Colorado, USA
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In the boundaryField section of your first U file you would have something like:
minY { type fixedValue; value uniform (0 0 0); } where minY is what ever name you gave your sides and / or the cylinder-wall. See the tutorials for more examples. |
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August 31, 2009, 03:51 |
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#3 |
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toto
Join Date: Jun 2009
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Thanks Hansel!
My Boundary Condition and so on look like: FoamFile { version 2.0; format ascii; class volVectorField; object U; } // // dimensions [0 1 -1 0 0 0 0]; internalField uniform (0 0 0); boundaryField { Rohrwand { type fixedValue; value uniform (0 0 0); } Outlet_Pres { type zeroGradient; } Inlet_Vel { type fixedValue; value uniform (2 0 0); } Sym_Wand { type symmetry; } frontAndBackPlanes { type empty; } } dimensions [0 2 -2 0 0 0 0]; internalField uniform 0; boundaryField { Rohrwand { type zeroGradient; ; } Outlet_Pres { type fixedValue; value uniform 0; } Inlet_Vel { type zeroGradient; } Sym_Wand { type symmetry; } frontAndBackPlanes { type empty; } } // ************************************************** *********************** // \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object k; } // // dimensions [0 2 -2 0 0 0 0]; internalField uniform 0.87; boundaryField { Rohrwand { type zeroGradient; } Outlet_Pres { type zeroGradient; } Inlet_Vel { type fixedValue; value uniform 0.87; } Sym_Wand { type symmetry; } frontAndBackPlanes { type empty; } } // ************************************************** *********************** // FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object epsilon; } // // dimensions [0 2 -3 0 0 0 0]; internalField uniform 8579.621; boundaryField { Rohrwand { type zeroGradient; } Outlet_Pres { type zeroGradient; } Inlet_Vel { type fixedValue; value uniform 8579.621; } Sym_Wand { type symmetry; } frontAndBackPlanes { type empty; } } // ************************************************** *********************** // dimensions [0 2 -1 0 0 0 0]; internalField uniform 0; boundaryField { Rohrwand { type nutWallFunction; Cmu 0.09; kappa 0.41; E 9.8; value uniform 0; } Outlet_Pres { type calculated; value uniform 0; } Inlet_Vel { type calculated; value uniform 0; } Sym_Wand { type calculated; value uniform 0; } frontAndBackPlanes { type empty; } } // ************************************************** *********************** // FoamFile { version 2.0; format ascii; class volSymmTensorField; object R; } // // dimensions [0 2 -2 0 0 0 0]; internalField uniform (0 0 0 0 0 0); boundaryField { Rohrwand { type zeroGradient; } Outlet_Pres { type zeroGradient; } Inlet_Vel { type fixedValue; value uniform (0 0 0 0 0 0 0); } Sym_Wand { type symmetry; } frontAndBackPlanes { type empty; } } // ************************************************** *********************** // FoamFile { version 2.0; format ascii; class polyBoundaryMesh; location "constant/polyMesh"; object boundary; } // // 5( Rohrwand { type wall; physicalType wallFunctions; nFaces 100; startFace 182530; } Outlet_Pres { type patch; physicalType outlet; nFaces 300; startFace 182630; } Inlet_Vel { type patch; physicalType inlet; nFaces 100; startFace 182930; } Sym_Wand { type symmetryPlane; nFaces 700; startFace 183030; } frontAndBackPlanes { type empty; nFaces 183130; startFace 183730; } ) // ************************************************** *********************** // FoamFile { version 2.0; format ascii; class dictionary; location "constant"; object RASProperties; } // // RASModel kEpsilon; turbulence on; printCoeffs on; FoamFile { version 2.0; format ascii; class dictionary; location "constant"; object transportProperties; } // // transportModel Newtonian; nu nu [0 2 -1 0 0 0 0] 1.46e-05; CrossPowerLawCoeffs { nu0 nu0 [0 2 -1 0 0 0 0] 0; nuInf nuInf [0 2 -1 0 0 0 0] 0; m <> [0 0 0 0 0 0 0] 0; n <> [0 0 0 0 0 0 0] 0; } BirdCarreauCoeffs { nu0 nu0 [0 2 -1 0 0 0 0] 0; nuInf nuInf [0 2 -1 0 0 0 0] 0; k <> [0 0 0 0 0 0 0] 0; n <> [0 0 0 0 0 0 0] 0; } FoamFile { version 2.0; format ascii; class volScalarField; object nuTilda; } // * // dimensions [0 2 -1 0 0 0 0]; internalField uniform 0; boundaryField { Rohrwand { type zeroGradient; } Outlet_Pres { type zeroGradient; } Inlet_Vel { type fixedValue; value uniform 0; } Sym_Wand { type symmetry; } frontAndBackPlanes { type empty; } } // ************************************************** *********************** // FoamFile { version 2.0; format ascii; class dictionary; location "system"; object fvSolution; // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // turbulenceModel kEpsilon; turbulence on; laminarCoeffs {} kEpsilonCoeffs { Cmu Cmu [0 0 0 0 0 0 0] 0.09; C1 C1 [0 0 0 0 0 0 0] 1.44; C2 C2 [0 0 0 0 0 0 0] 1.92; alphaEps alphaEps [0 0 0 0 0 0 0] 0.76923; } I get this Error when i start the Simulation: Inconsistent Patch and patchField types for patch type symmetryPlane and patchField type symmety When i change SymmetryPlane to slip or Wall , my solution is absurdity. I need Help please! |
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August 31, 2009, 09:29 |
symmetry should be symmetryPlane
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#4 |
Senior Member
Richard Smith
Join Date: Mar 2009
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Judging by your error message I think you need to replace:
Sym_Wand { type symmetry; } with: Sym_Wand { type symmetryPlane; } within your case/0/* field files.
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September 14, 2009, 11:25 |
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#5 |
Senior Member
Steve Hansel
Join Date: Jun 2009
Location: Colorado, USA
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I think the units on k are supposed to be [0 0 1 0 0 0 0]
and m [0 0 1 0 0 0 0] |
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September 18, 2009, 08:13 |
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#6 |
Member
toto
Join Date: Jun 2009
Posts: 71
Rep Power: 17 |
It is the units on omega! The units on k is [0 2 -2 0 0 0 0 ]
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