|
[Sponsors] |
March 16, 2022, 15:12 |
Natural convection on a vertical cylinder
|
#1 |
New Member
Roxana Laspiur
Join Date: Jul 2021
Location: Salta-Argentina
Posts: 5
Rep Power: 5 |
Hi !
I am new to OpenFoam. I am trying to simulate internal natural convection on a vertical cylinder, but I have a problem with the result. I am working with the BuoyantBoussinesqPimpleFoam solver (transient case). A time large (approx 30 min) quasi-steady, I get a full stratified fluid full but streamlines aren't expected (toroidal shape). I also compared the vertical velocity with radius, with a paper by Hess and Miller, did not come up to expectations. I think my problem is in the Dict of fvSolution and fvSchemes. I am working in the laminar regime Ra=10¹⁰. BC:
Attached are the Dict and images of the T-profile and the streamlines. blockMeshDict: Code:
l 0.30; nl -0.30; s 0.35; sn -0.35; //longitud de la curvatura del cuadrado interior // datos del cilindro R 0.5; //radio Rn -0.5; H 1; //altura //arcos del cilindro X 0.353553; //x=R*cos 45º Xn -0.353553; Z 0.353553; //z= R * sen 45º Zn -0.353553; scale 1 ; vertices ( //Cuadrado interior ($l 0 $l) //0 ($nl 0 $l) //1 ($nl 0 $nl)//2 ($l 0 $nl) //3 ($l $H $l) //4 ($nl $H $l) //5 ($nl $H $nl)//6 ($l $H $nl) //7 //cilindro externo ($X 0 $Z) //8 ($X 0 $Zn) //9 ($Xn 0 $Zn) //10 ($Xn 0 $Z) //11 ($X $H $Z) //12 ($X $H $Zn) //13 ($Xn $H $Zn) //14 ($Xn $H $Z) //15 ); blocks ( hex (0 3 2 1 4 7 6 5) (20 20 35) simpleGrading (1 1 1) //block 1 hex (8 9 3 0 12 13 7 4) (20 10 35) simpleGrading (1 4 1) //block 2 hex (9 10 2 3 13 14 6 7) (20 10 35) simpleGrading (1 4 1) //block 3 hex (10 11 1 2 14 15 5 6) (20 10 35) simpleGrading (1 4 1) //block 4 hex (11 8 0 1 15 12 4 5) (20 10 35) simpleGrading (1 4 1) ); edges ( arc 0 1 (0 0 $s) arc 1 2 ($sn 0 0) arc 2 3 (0 0 $sn) arc 3 0 ($s 0 0) arc 4 5 (0 $H $s) arc 5 6 ($sn $H 0) arc 6 7 (0 $H $sn) arc 7 4 ($s $H 0) //cilindro externo arc 8 9 ($R 0 0) arc 9 10 (0 0 $Rn) arc 10 11 ($Rn 0 0) arc 11 8 (0 0 $R) arc 12 13 ($R $H 0) arc 13 14 (0 $H $Rn) arc 14 15 ($Rn $H 0) arc 15 12 (0 $H $R) ); boundary ( wallTop { type wall; faces ( (4 7 6 5) (12 13 7 4) (13 14 6 7) (14 15 5 6) (15 12 4 5) ); } wallDown { type wall; faces ( (0 1 2 3) (8 9 0 3) (10 9 3 2) (10 2 1 11) (1 0 8 11) ); } sides { type wall; faces ( (11 8 12 15) (10 11 15 14) (9 10 14 13) (8 9 13 12) ); } ); ControlDict: Code:
FoamFile { version 2.0; format ascii; class dictionary; location "system"; object controlDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // application buoyantBoussinesqPimpleFoam; startFrom latestTime; startTime 0; stopAt endTime; endTime 2000; deltaT 0.03; writeControl timeStep; writeInterval 1000; purgeWrite 0; writeFormat ascii; writePrecision 6; writeCompression off; timeFormat general; timePrecision 6; runTimeModifiable true; adjustTimeStep no; maxCo 0.5; functions { #includeFunc singleGraph1 #includeFunc singleGraph2 } fvSchemes: Code:
ddtSchemes { default Euler; } gradSchemes { default Gauss linear; } divSchemes { default none; div(phi,U) Gauss QUICK; //upwind div(phi,T) Gauss QUICK; //upwind div(phi,k) Gauss upwind; div(phi,epsilon) Gauss upwind; div(phi,R) Gauss upwind; div(R) Gauss linear; div((nuEff*dev2(T(grad(U))))) Gauss linear; } laplacianSchemes { default Gauss linear uncorrected; } interpolationSchemes { default linear; } snGradSchemes { default uncorrected; } fvSolution: Code:
solvers { p_rgh { solver PCG; preconditioner DIC; tolerance 1e-6; relTol 0.01; } p_rghFinal { $p_rgh; relTol 0; } "(U|T|k|epsilon|R)" { solver PBiCGStab; preconditioner DILU; tolerance 1e-6; relTol 0.1; } "(U|T|k|epsilon|R)Final" { $U; relTol 0; } } PIMPLE { momentumPredictor no; nOuterCorrectors 1; nCorrectors 2; nNonOrthogonalCorrectors 0; pRefCell 0; pRefValue 0; } relaxationFactors { equations { "(U|T|k|epsilon|R)" 1; "(U|T|k|epsilon|R)Final" 1; } } Thanks for your help and sorry for my English. |
|
Tags |
buoyantbousspimplefoam, cylinder, natural convection, water |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Rayleigh Number in Natural Convection along a vertical plate | Mondal131211 | OpenFOAM Pre-Processing | 4 | June 26, 2019 07:55 |
Natural convection from heated rotating cylinder | nived | FLUENT | 0 | November 28, 2018 04:30 |
calculation of mass flow rate from the inner part of a vertical cylinder in natural | manoj kumar dash | FLUENT | 5 | August 24, 2018 11:57 |
Natural convection in an infinite vertical cavity | Zeppo | STAR-CCM+ | 3 | August 31, 2013 03:29 |
natural convection from vertical plate | ghassan77 | FLUENT | 0 | January 3, 2011 02:31 |