# Simulation of Radial Fan with simpleFoam MRF

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 August 13, 2013, 05:34 Simulation of Radial Fan with simpleFoam MRF #1 Member   Join Date: Aug 2013 Posts: 50 Rep Power: 6 Sponsored Links hi, im new here and also in using OpenFoam. I did find good explainations of using mrf in simplefoam within this forum I am now working on the simulation of radial fan with complex geometry including casing for the fan. Im using snappyHexMesh for the meshing and STL file for rotor, casing and MRF Domain are being used here. the MRF Zone are defined within the sHM and the rotors walls are inside the MRFDomain. The rotor walls and also the fluid within the MRF rotate and therefore im using simpleFoam with MRF Code: ```*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.2.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format binary; class polyBoundaryMesh; location "constant/polyMesh"; object boundary; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 21 ( frontAndBack { type patch; nFaces 0; startFace 23495251; } inlet { type patch; nFaces 0; startFace 23495251; } outlet { type patch; nFaces 0; startFace 23495251; } lowerWall { type wall; nFaces 0; startFace 23495251; } upperWall { type patch; nFaces 0; startFace 23495251; } fan_rotor-mrf-02-layersides { type wall; inGroups 1(luefter); nFaces 9195; startFace 23495251; } fan_rotor-mrf-02 { type wall; inGroups 1(luefter); nFaces 194950; startFace 23504446; } fan_casing-03 { type wall; inGroups 1(luefter); nFaces 13678; startFace 23699396; } fan_rotor-mrf-layer-02 { type wall; inGroups 1(luefter); nFaces 55326; startFace 23713074; } fan_rotor-mrf-01 { type wall; inGroups 1(luefter); nFaces 219653; startFace 23768400; } fan_casing { type wall; inGroups 1(luefter); nFaces 120780; startFace 23988053; } fan_plane { type wall; inGroups 1(luefter); nFaces 182812; startFace 24108833; } fan_inlet { type wall; inGroups 1(luefter); nFaces 140059; startFace 24291645; } fan_outlet { type wall; inGroups 1(luefter); nFaces 7870; startFace 24431704; } fan_canal { type wall; inGroups 1(luefter); nFaces 123670; startFace 24439574; } fan_cassing-outter { type wall; inGroups 1(luefter); nFaces 0; startFace 24563244; } fan_casing-mrf { type wall; inGroups 1(luefter); nFaces 16511; startFace 24563244; } fan_casing-02 { type wall; inGroups 1(luefter); nFaces 46960; startFace 24579755; } fan_rotor-mrf-layer-01 { type wall; inGroups 1(luefter); nFaces 621030; startFace 24626715; } mrfDomain_frameBorder-interior { type wall; nFaces 0; startFace 25247745; } mrfDomain_frameBorder-interior_slave { type wall; nFaces 0; startFace 25247745; } )``` Code: ```/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 1.7.1 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volVectorField; location "0"; object U; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 1 -1 0 0 0 0]; internalField uniform ( 0 0 0); boundaryField { frontAndBack { type zeroGradient; value uniform (0 0 0); } inlet { type zeroGradient; value uniform (0 0 0); } outlet { type zeroGradient; value uniform (0 0 0); } lowerWall { type zeroGradient; value uniform (0 0 0); } upperWall { type zeroGradient; value uniform (0 0 0); } "mrfDomain_.*" { type zeroGradient; value uniform (0 0 0); } "fan_rotor.*" { type fixedValue; value uniform (0 0 0); } "fan_casing.*" { type fixedValue; value uniform (0 0 0); } "fan_plane.*" { type fixedValue; value uniform (0 0 0); } "fan_outlet.*" { type zeroGradient; value uniform (0 0 0); } "fan_inlet.*" { type zeroGradient; value uniform (0 0 0); } "fan_canal.*" { type fixedValue; value uniform (0 0 0 ); } }``` Code: ```/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 1.7.1 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; object p; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -2 0 0 0 0]; internalField uniform 0; boundaryField { frontAndBack { type zeroGradient; value uniform 0; } inlet { type zeroGradient; value uniform 0; } outlet { type zeroGradient; value uniform 0; } lowerWall { type zeroGradient; value uniform 0; } upperWall { type zeroGradient; value uniform 0; } "fan_rotor.*" { type zeroGradient; value uniform 0.; } "mrfDomain_.*" { type zeroGradient; value uniform 0; } "fan_gehaeuse.*" { type zeroGradient; value uniform 0.; } "fan_ebene.*" { type zeroGradient; value uniform 0. ; } "fan_outlet.*" { type totalPressure; rho none; psi none; phi phi; gamma 0; p0 uniform 0; value uniform 0.0; } "fan_inlet.*" { type totalPressure; rho none; psi none; phi phi; gamma 0; p0 uniform 0; value uniform 0.; } "fan_canal.*" { type zeroGradient; value uniform 0.; } }``` unfortunately the simulation result seems to differ from the one using Fluent. the velocity is twice as the velocity from the Fluent-Simulation and the pressure as well. are there any improvements so that a good result can be generated? using other solver etc. btw are the configurations of initial conditions okay? thank you in advance geometry of the fan is more likely in this fluent tutorial https://docs.google.com/viewer?url=h...df&chrome=true Last edited by nash; August 13, 2013 at 08:12.

August 15, 2013, 05:44
#2
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Join Date: Aug 2013
Posts: 50
Rep Power: 6
sorry to bother everyone here..
the problem resolved..

the problem is the dimension of the STL file for my cylinder MRFZone in mm.
since sHM always read in meter, so i need to use command surfaceConvert to my STL

Quote:
 Originally Posted by josp Or you can scale the stl files with surfaceConvert when you clean them surfaceConvert in.stl out.stl -clean -scale 0.001
and run sHM again using the new STL generated from surfaceConvert and everything went fine.

check your STL file before running sHM either using surfaceCheck or view STL using Paraview.

 November 5, 2015, 11:12 fvOptions #3 New Member   zakk Join Date: Jun 2009 Posts: 9 Rep Power: 10 Hello Can I see your fvOption or MRFZones files? Which version are you using? I have also results off from Fluent simulations Thank you

 Tags fan, mrf, rotor, simplefoam

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